View R1280D002A_180706.PDF datasheet online --- IC-ON-LINE

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2001.6.16
2CH PWM DC/DC Controller
R1280D002X Series
s OUTLINE
The R1280D002X Series are 2-channel PWM Step-up (as Channel 1)/Inverting (as Channel 2) DC/DC converter controllers with CMOS process. Each of the R1280D002X Series consists of an oscillator, a PWM control circuit, a reference voltage unit, an error amplifier, a reference current unit, a protection circuit, and an under voltage lockout (UVLO) circuit. A high efficiency Step-up/Inverting DC/DC converter can be composed of this IC with inductors, diodes, power MOSFETs, resisters, and capacitors. Each Output Voltage can be adjustable with external resistors, while soft-start time can be adjustable with external capacitors.. Maximum Duty Cycle of R1280D002A and C series can be also adjustable with external resistors. Maximum Duty Cycle of R1280D002B is built-in as 90%(TYP.). When CE pin of R1280D002B is set at GND level, this IC turns off external power MOSFETs of Step-up/Inverting as Standby-mode. Standby current is typically 0A. As for a protection circuit, if Maximum duty cycle of either Step-up DC/DC converter side or Inverting DC/DC converter side is continued for a certain time, the R1280D Series latch both external drivers with their off state by its Latch-type protection circuit. Delay time for protection is internally fixed typically at 100ms. To release the protection circuit, restart with power-on (Voltage supplier is equal or less than UVLO detector threshold level), or as for R1280D002B, once after making the circuit be stand-by with chip enable pin and enable the circuit again.
s FEATURES
q Input Voltage Range * * * * * * * * * * * * * 2.5V to 5.5V q Built-in Latch-type Protection Function by monitoring duty cycle (Fixed Delay Time TYP. 100ms) q Oscillator Frequency * * * * * * * * * * * * * 700kHz(R1280D002A,B)/200kHz(r1280D002C) q Maximum Duty Cycle * * * * * * * * * * * * * TYP. 90%(Only applied to R1280D002B Series) q High Reference Voltage Accuracy * * * * * * 1.5% q U.V.L.O. Threshold * * * * * * * * * * * TYP. 2.2V (Hysteresis: TYP. 0.1V) q Small Package * * * * * * * * * * * * * * * * thin SON-10 (package thickness MAX. 0.9mm)
s APPLICATIONS
q Constant Voltage Power Source for portable equipment. q Constant Voltage Power Source for LCD and CCD.
Rev. 1.10
-1-
s BLOCK DIAGRAM
q R1280D002A/C
DTC1 VFB1
O SC
EXT1
CH AM POUT1 V re f1 V IN V re fo u t V re fo u t
U VLO
GND VFB2
La tc h
EXT2
D elay C irc u it
CH
DTC2
q
R1280D002B
DTC1 VFB1
OSC CE CH1
EXT1
CHIP ENABLE
Vref1 VIN Vrefout Vrefout
UVLO
GND VFB2
Latch
EXT2
Delay Circuit
CH DTC2
Rev.1.10
-2-
s SELECTION GUIDE
The mask option for the ICs can be selected at the user's request. The selection can be made with designating the part number as shown below; Part Number R1280D002X-TR ab Code a Contents Designation of Mask Option : A version: fosc=700kHz, with External Phase Compensation for Channel 1. B version: fosc=700kHz, with Internal Phase Compensation and standby mode. C version: fosc=200kHz, with External Phase Compensation for Channel 1 Designation of Taping Type : (Refer to Taping Specifications.)
b
s PIN CONFIGURATION
q SON10
10
6
(mark side)
1
5
s PIN DESCRIPTION
q R1280D002A/C Pin No. 1 2 3 4 5 6 7 8 9 10 Symbol EXT1 GND AMPOUT1 DTC1 VFB1 VFB2 DTC2 Vrefout VIN EXT2 Ground Pin Amplifier Output Pin of Channel 1 Maximum Duty Cycle of Channel 1 Setting Pin Feedback pin of Channel 1 Feedback pin of Channel 2 Maximum Duty Cycle of Channel 2 Setting Pin Reference Output Pin Voltage Supply Pin of the IC External Transistor of Channel 2 Drive Pin (CMOS Output) Description External Transistor of Channel 1 Drive Pin (CMOS Output)
Rev. 1.10
-3-
q
R1280D002B Pin No. 1 2 3 4 5 6 7 8 9 10
Symbol EXT1 GND CE DTC1 VFB1 VFB2 DTC2 Vrefout VIN EXT2 Ground Pin Chip Enable Pin
Description External Transistor of Channel 1 Drive Pin (CMOS Output)
Maximum Duty Cycle of Channel 1 Setting Pin Feedback pin of Channel 1 Feedback pin of Channel 2 Maximum Duty Cycle of Channel 2 Setting Pin Reference Output Pin Voltage Supply Pin of the IC External Transistor of Channel 2 Drive Pin (CMOS Output)
s ABSOLUTE MAXIMUM RATINGS
q R1280D002A/C Symbol VIN VEXT1,2 VAMPOUT1 VDTC1,2 Vrefout VFB1,2 IEXT1,2 PD Topt Tstg R1280D002B Symbol VIN VEXT1,2 VCE VDTC1,2 Vrefout VFB1,2 IEXT1,2 PD Topt Tstg Item VIN Pin Voltage VEXT1,2 Pin Output Voltage AMPOUT1 Pin Voltage DTC1,2 Pin Voltage VREFOUT Pin Voltage VFB1,VFB2 Pin Voltage EXT1,2 Pin Output Current Power Dissipation Operating Temperature Range Storage Temperature Range Rating 6.5 -0.3VIN+0.3 -0.3VIN+0.3 -0.3VIN+0.3 -0.3VIN+0.3 -0.3VIN+0.3 50 250 -40 to +85 -55 to +125 Unit V V V V V V mA mW C C
q
Item VIN Pin Voltage VEXT1,2 Pin Output Voltage CE Pin Voltage DTC1,2 Pin Voltage VREFOUT Pin Voltage VFB1,VFB2 Pin Voltage EXT1,2 Pin Output Current Power Dissipation Operating Temperature Range Storage Temperature Range
Rating 6.5 -0.3VIN+0.3 -0.3VIN+0.3 -0.3VIN+0.3 -0.3VIN+0.3 -0.3VIN+0.3 50 250 -40 to +85 -55 to +125
Unit V V V V V V mA mW C C
Rev.1.10
-4-
s ELECTRICAL CHARACTERISTICS
q R1280D002A Conditions VIN=3.3V, IOUT=1mA VIN=3.3V 2.5V VIN 5.5V MIN. 2.5 1.478 20 TYP. 1.500 2 6 25 150 0.985 1.000 150 1.015 (Topt=25C) MAX. Unit 5.5 V 1.522 V mA 6 mV 12 mV mA ppm/C V ppm/C A kHz mA ms V V V
Symbol Item VIN Operating Input Voltage VREFOUT VREFOUT Voltage Tolerance IROUT VREFOUT Output Current VREFOUT VREFOUT Line Regulation
/VIN
VREFOUT
1mA IROUT 10mA VIN=3.3V ILIM VREFOUT Short Current Limit VIN=3.3V, VREFOUT=0V VREFOUT VREFOUT Voltage -40C Topt 85C /T Temperature Coefficient VFB1 VFB1 Voltage VIN=3.3V -40C Topt 85C VFB1/T VFB1 Voltage Temperature Coefficient IFB1,2 IFB1,2 Input Current VIN=5.5V,VFB1 or VFB2=0V or 5.5V fOSC Oscillator Frequency EXT1,2 Pins at no load, VIN=3.3V IDD1 Supply Current VIN=5.5V, EXT1,2 pins at no load REXTH1 EXT1 "H" ON Resistance VIN=3.3V, IEXT=-20mA VREFOUT Load Regulation
/IOUT
-0.1 595
700 1.4 4.0 2.7 4.0 3.7
0.1 805 3.0 8.0 5.0 8.0 8.0 140 2.35 2.45 0.3 1.3 0.3 1.3
REXTL1 EXT1 "L" ON Resistance REXTH2 EXT2 "H" ON Resistance REXTL2 EXT2 "L" ON Resistance TDLY Delay Time for Protection
VIN=3.3V, IEXT=20mA VIN=3.3V, IEXT=-20mA VIN=3.3V, IEXT=20mA VIN=3.3V, VFB1=1.1V0V 60 2.10
100 2.20 VUVLOD +0.10 0.2 1.2 0.2 1.2 110 1.9 0.7 to VIN 115 -1.4 60 3 -0.2 to VIN-1.3
VUVLOD UVLO Detector Threshold VUVLO UVLO Released Voltage VDTC10 VDTC1100 VDTC20 VDTC2100 AV1 FT1 VICR1 IAMPL IAMPH AV2 FT1 VICR1 VFB2 CH1 Duty=0% VIN=3.3V CH1 Duty=100% VIN=3.3V CH2 Duty=0% VIN=3.3V CH2 Duty=100% VIN=3.3V CH1 Open Loop Gain VIN=3.3V CH1 Single Gai n Frequency VIN=3.3V, AV1=0dB Band CH1 Input Voltage Range VIN=3.3V VIN=3.3V, VAMPOUT1=1.0V, VFB1=VFB1+ 0.1V CH1 Source Current VIN=3.3V, VAMPOUT1=1.0V, VFB1=VFB1- 0.1V CH2 Open Loop Gain VIN=3.3V CH2 Single Gain Frequency VIN=3.3V, AV2=0dB Band CH2 Input Voltage Range VIN=3.3V, CH2 Input Offset Voltage VIN=3.3V, CH1 Sink Current
0.1 1.1 0.1 1.1
V
V V dB MHz V A
70
-0.7
mA dB MHz V
-12
12
mV
Rev. 1.10
-5-
q
R1280D002B Conditions VIN=3.3V, IOUT=1mA VIN=3.3V 2.5V VIN 5.5V MIN. 2.5 1.478 20 TYP. 1.500 2 6 25 150 0.985 1.000 150 1.015 (Topt=25C) MAX. Unit 5.5 V 1.522 V mA 6 mV 12 mV mA ppm/C V ppm/C A kHz mA % ms ms ms V 0.3 2.10 2.20 VUVLOD +0.10 2.35 2.45 0.1 0.1 2 12 V V V A A A mV
Symbol Item VIN Operating Input Voltage VREFOUT VREFOUT Voltage Tolerance IROUT VREFOUT Output Current VREFOUT VREFOUT Line Regulation
/VIN
VREFOUT
/IOUT
ILIM
VREFOUT
/T
VFB1
VFB1/T
IFB1,2 fOSC IDD1 Maxdty REXTH1
1mA IROUT 10mA VIN=3.3V VREFOUT Short Current Limit VIN=3.3V, VREFOUT=0V VREFOUT Voltage -40C Topt 85C Temperature Coefficient VFB1 Voltage VIN=3.3V VFB1 Voltage -40C Topt 85C Temperature Coefficient IFB1,2 Input Current VIN=5.5V,VFB1 or VFB2=0V or 5.5V Oscillator Frequency EXT1,2 Pins at no load, VIN=3.3V Supply Current VIN=5.5V, EXT1,2 pins at no load Maximum Duty Cycle VIN=3.3V, CDTC1,2=1000pF EXT1 "H" ON Resistance VIN=3.3V, IEXT=-20mA VREFOUT Load Regulation VIN=3.3V, IEXT=20mA VIN=3.3V, IEXT=-20mA VIN=3.3V, IEXT=20mA VIN=3.3V, VFB1=1.1V0V VIN=3.3V, CDTC1=0.33F VIN=3.3V, CDTC2=0.33F VIN=5.5V VIN=2.5V
-0.1 595 84
700 1.4 90 4.0 2.7 4.0 3.7
0.1 805 3.0 95 8.0 5.0 8.0 8.0 140
REXTL1 EXT1 "L" ON Resistance REXTH2 EXT2 "H" ON Resistance REXTL2 EXT2 "L" ON Resistance TDLY Tss1 Tss2 VCEH VCEL Delay Time for Protection Soft Start Time1 for Ch1 Soft Start Time2 for Ch2
CE "H" Input Voltage CE "L" Input Voltage
60
100 10 15
1.5
VUVLOD UVLO Detector Threshold VUVLO UVLO Released Voltage ICEH ICEL ISTB VOFF2 CE "H" Input Current CE "L" Input Current Standby Current Input Offset Voltage of Ch2. VIN= VCE =5.5V VIN=5.5V, VCE=0.0V VIN=5.5V, VCE=0.0V VIN=3.3V
-0.1 -0.1 0 -12
Rev.1.10
-6-
q
R1280D002C Conditions VIN=3.3V, IOUT=1mA VIN=3.3V 2.5V VIN 5.5V MIN. 2.5 1.478 20 TYP. 1.500 2 6 25 150 0.985 1.000 150 1.015 (Topt=25C) MAX. Unit 5.5 V 1.522 V mA 6 mV 12 mV mA ppm/C V ppm/C A kHz mA ms V V V
Symbol Item VIN Operating Input Voltage VREFOUT VREFOUT Voltage Tolerance IROUT VREFOUT Output Current VREFOUT VREFOUT Line Regulation
/VIN
VREFOUT
1mA IROUT 10mA VIN=3.3V ILIM VREFOUT Short Current Limit VIN=3.3V, VREFOUT=0V VREFOUT VREFOUT Voltage -40C Topt 85C /T Temperature Coefficient VFB1 VFB1 Voltage VIN=3.3V -40C Topt 85C VFB1/T VFB1 Voltage Temperature Coefficient IFB1,2 IFB1,2 Input Current VIN=5.5V,VFB1 or VFB2=0V or 5.5V fOSC Oscillator Frequency EXT1,2 Pins at no load, VIN=3.3V IDD1 Supply Current VIN=5.5V, EXT1,2 pins at no load REXTH1 EXT1 "H" ON Resistance VIN=3.3V, IEXT=-20mA VREFOUT Load Regulation
/IOUT
-0.1 160
200 0.7 4.0 2.7 4.0 3.7
0.1 240 1.2 8.0 5.0 8.0 8.0 150 2.35 2.45 0.35 1.3 0.35 1.3
REXTL1 EXT1 "L" ON Resistance REXTH2 EXT2 "H" ON Resistance REXTL2 EXT2 "L" ON Resistance TDLY Delay Time for Protection
VIN=3.3V, IEXT=20mA VIN=3.3V, IEXT=-20mA VIN=3.3V, IEXT=20mA VIN=3.3V, VFB1=1.1V0V 50 2.10
100 2.20 VUVLOD +0.10 0.25 1.2 0.25 1.2 110 1.9 0.7 to VIN 115 -1.4 60 3 -0.2 to VIN-1.3
VUVLOD UVLO Detector Threshold VUVLO UVLO Released Voltage VDTC10 VDTC1100 VDTC20 VDTC2100 AV1 FT1 VICR1 IAMPL IAMPH AV2 FT1 VICR1 VFB2 CH1 Duty=0% VIN=3.3V CH1 Duty=100% VIN=3.3V CH2 Duty=0% VIN=3.3V CH2 Duty=100% VIN=3.3V CH1 Open Loop Gain VIN=3.3V CH1 Single Gain Frequency VIN=3.3V, AV1=0dB Band CH1 Input Voltage Range VIN=3.3V CH1 Sink Current VIN=3.3V, VAMPOUT1=1.0V, VFB1=VFB1+ 0.1V CH1 Source Current VIN=3.3V, VAMPOUT1=1.0V, VFB1=VFB1- 0.1V CH2 Open Loop Gain VIN=3.3V CH2 Single Gain Frequency VIN=3.3V, AV2=0dB Band CH2 Input Voltage Range VIN=3.3V, CH2 Input Offset Voltage VIN=3.3V,
0.15 1.1 0.15 1.1
V
V V dB MHz V A
70
-0.7
mA dB MHz V
-12
12
mV
Rev. 1.10
-7-
s Operation of Step-up DC/DC Converter and Output Current
Step-up DC/DC Converter makes higher output voltage than input voltage by releasing the energy accumulated during on time of Lx Transistor on input voltage.
i2
Inductor Diode
IOUT VOUT
VIN i1
Lx Tr
CL
GND
Discontinuous Mode
IL ILxmax IL
Continuous Mode
ILxmax
ILxmin ILxmin Tf Iconst t Ton T=1/fosc Toff Ton T=1/fosc Toff t
Step 1. Lx Tr. is on, then the current IL=i1 flows, and the energy is charged in L. In proportion to the on time of Lx Tr. (Ton), IL=i1 increases from IL=ILxmin=0 and reaches ILxmax. Step 2. When the Lx Tr. is off, L turns on Schottky Diode (SD), and IL=i2 flows to maintain IL=ILxmax. Step 3. IL=i2 gradually decreases, and after Tf passes, IL=ILxmin=0 is true, then SD turns off. Note that in the case of the continuous mode, before IL=ILxmin=0 is true, Toff passes, and the next cycle starts, then Lx Tr. turns on again. In this case, ILxmin>0, therefore IL=ILxmin>0 is another starting point and ILx max increases. With the PWM controller, switching times during the time unit are fixed. By controlling Ton, output voltage is maintained.
s Output Current and Selection of External Components
Output Current of Step-up Circuit and External Components There are two modes, or discontinuous mode and continuous mode for the PWM step-up switching regulator depending on the continuous characteristic of inductor current. During on time of the transistor, when the voltage added on to the inductor is described as VIN, the current is VIN xt/L. Therefore, the electric power, PON, which is supplied with input side, can be described as in next formula. PON=VIN xt/L dt
0 TON 2
Formula 1
With the step-up circuit, electric power is supplied from power source also during off time. In this case, input current is described as (VOUT-VIN)xt/L, therefore electric power, POFF is described as in next formula.
Rev.1.10
-8-
Tf
POFF=VINx(VOUT-VIN)xt/L dt
0
Formula 2
In this formula, Tf means the time of which the energy saved in the inductance is being emitted. Thus average electric power, PAV is described as in the next formula. PAV=1/(Ton+Toff)x{VIN xt/L dt + VINx(VOUT-VIN)xt/L dt} Formula 3
0 0 TON 2 Tf
In PWM control, when Tf=Toff is true, the inductor current becomes continuos, then the operation of switching regulator becomes continuous mode. In the continuous mode, the deviation of the current is equal between on time and off time. Formula 4 VINxTon/L=(VOUT-VIN)xToff/L Further, the electric power, PAV is equal to output electric power, VOUTxIOUT, thus, 2 2 2 Formula 5 IOUT = fOSC x VIN xTON /{2xL x(VOUT-VIN)}=VIN xTON/(2xLxVOUT) When IOUT becomes more than formula 5, the current flows through the inductor, then the mode becomes continuous. The continuous current through the inductor is described as Iconst, then, 2 2 Formula 6 IOUT = fOSC xVIN xtON /(2xLx(VOUT-VIN))+VINxIconst/VOUT In this moment, the peak current, ILxmax flowing through the inductor and the driver Tr. is described as follows: Formula 7 ILxmax = Iconst +VINxTon/L With the formula 4,6, and ILxmax is, Formula 8 ILxmax = VOUT/VINxIOUT+VINxTon/(2xL) Therefore, peak current is more than IOUT. Considering the value of ILxmax, the condition of input and output, and external components should be selected. In the formula 7, peak current ILxmax at discontinuous mode can be calculated. Put Iconst=0 in the formula. The explanation above is based on the ideal calculation, and the loss caused by Lx switch and external components is not included. The actual maximum output current is between 50% and 80% of the calculation. Especially, when the ILx is large, or VIN is low, the loss of VIN is generated with the on resistance of the switch. As for VOUT, Vf (as much as 0.3V) of the diode should be considered.
s Operation of Inverting DC/DC converter and Output Current
Inverting DC/DC converter saves energy during on time of Lx transistor, and supplies the energy to output during off time, output voltage opposed to input voltage is obtained.
Lx Tr Diode
IOUT VOUT
VIN i1
Inductor
i2
CL
GND
Rev. 1.10
-9-
Discontinuous Mode IL
ILxmax ILxmin ILxmin Tf Iconst
Continuous Mode
ILxmax
IL
t
Ton T=1/fosc Toff Ton T=1/fosc Toff
t
Step 1. Lx Tr. turns on, current, IL=i1 flows, energy is charged in L. In proportion to the on time, Ton, of Lx Tr. IL=i1 increases from IL=ILxmin=0 and reaches ILxmax. Step 2. When the Lx Tr. turns off, L turns on Shottky diode (SD) and flow IL=i2 to maintain IL = ILxmax. Step 3. IL=i2 decreases gradually, after Tf passes, IL=ILxmin=0 is true, then SD turns off. Note that in the case of continuous mode, before IL=ILxmin=0 is true, Toff passes and next cycle starts, then Lx Tr. turns on. In this case, ILxmin>0, therefore IL increases from IL=ILxmin>0. With the PWM controller, switching time (fosc) in the time unit is fixed, and by controlling Ton, output voltage is maintained.
s Output Current and Selection of External Components
There are also two modes, or discontinuous mode and continuous mode for the PWM inverting switching regulator depending on the continuous characteristic of inductor current. During on time of the transistor, when the voltage added on to the inductor is described as VIN, the current is VIN xt/L. Therefore, the electric power, P, which is supplied with input side, can be described as in next formula. P=VIN xt/L dt
0 TON 2
Formula 9
Thus average electric power in one cycle, PAV is described as in the next formula. PAV=1/(Ton +Toff)xVIN xt/L dt =VIN2xTon /(2xLx(Ton + Toff))
0 TON 2 2
Formula 10
This electric power PAV equals to output electric power VOUTxIOUT, thus, 2 2 Formula 11 IOUT = fOSC x VIN xTON /(2xL xVOUT) When IOUT becomes more than formula 11, the current flows through the inductor continuously, then the mode becomes continuous. In the continuous mode, the deviation of the current equals between Ton and Toff, therefore, Formula 12 VINxTon/L=VOUTxToff/L In this moment, the current flowing continuously through L, is assumed as Iconst, IOUT is described as in the next formula: 2 2 Formula 13 IOUT = fOSC xVIN xTON /(2xLxVOUT)+Ton/(Ton + Toff)xVINx Iconst /VOUT In this moment, the peak current, ILxmax flowing through the inductor and the driver Tr. is described as follows: Formula 14 ILxmax = Iconst +VINxTon/L With the formula 12,13, ILxmax is, Formula 15 ILxmax = (Ton+Toff)/ToffxIOUT+VINxTon/(2xL) Therefore, peak current is more than IOUT. Considering the value of ILxmax, the condition of input and output, and external components should be selected. In the formula 14, peak current ILxmax at discontinuous mode can be calculated. Put Iconst=0 in the formula. The explanation above is based on the ideal calculation, and the loss caused by Lx switch and external components is not included. The actual maximum output current is between 50% and 80% of the calculation. Especially, when the ILx is large, or VIN is low, the loss of VIN is generated with the on resistance of the switch. As for VOUT, Vf (as much as 0.3V) of the diode should be considered.
Rev.1.10
- 10 -
s TEST CIRCUITS
q Test Circuit 1 q Test Circuit 2
EXT1 EXT 2
OSCILLOSCOPE
C1
GND VIN AMPOUT Vrefout DTC1 DTC2 VFB1 VFB2
C2
C1
EXT1 EXT 2 V IN GND AMPOUT Vrefout DTC1 DTC2 VFB1 VFB2
OSCILLOSC OPE
C2
q
Test Circuit 3
q
Test Circuit 4
EXT1 EXT2
OSCILLOSCOPE
EXT1 EXT 2
C1
V IN GND C2 AMPOUT Vrefout DTC1 DTC2 VFB1 VFB2
C1
GND V IN AMPOUT Vrefout DTC1 DTC2 V
FB1
OSCILLOSCOPE
C2
V
FB2
q
Test Circuit 5
EXT1 EXT 2 GND V IN
q
Test Circuit 6
EXT1 EXT 2
C1
AMPOUT Vrefout DTC1 DTC2 VFB1 VFB2
C2
C1
GND
VIN
AMPOUT Vrefout
C2 A
V
q Test Circuit 8
DTC1 DTC2 VFB1 VFB2
V
q
Test Circuit 7
OSCILLOSC OPE
EXT1 EXT 2
OSCILLOSCOPE
2 EXT1 EXT
C1
GND VIN AMPOUT Vrefout DTC1 DTC2 VFB1 VFB2
C1 C2
V IN GND AMPOUT Vrefout DTC1 DTC2 V
FB1
V
FB2
Rev. 1.10
- 11 -
q
Test Circuit 9
q
Test Circuit 10
EXT1 EXT 2
C1 A
GND V
IN
EXT1 EXT 2
OSCILLOSCOPE
C1
GND VIN
AMPOUT Vrefout DTC1 DTC2 VFB1 VFB2
C2
CE Vrefout
C2
C3
DTC1 DTC2 VFB1 VFB2
q
Test Circuit 11
q
Test Circuit 12
EXT1 EXT 2
C1
OSCILLOSCOPE
EXT1 EXT 2
OSCILLOSCOPE
GND
VIN
C2
C1
GND
VIN
CE Vrefout DTC1 DTC2
CE Vrefout DTC1 DTC2 V FB1 VFB2
C2
C4
VFB1 VFB2
q
Test Circuit 13
q
Test Circuit 14
EXT1
EXT1 EXT 2 EXT 2 V
IN
OSCILLOSCOPE
GND
VIN
C1
GND CE
C1 C2
Vrefout
CE Vrefout DTC1 DTC2 VFB1 VFB2
C2
DTC1 DTC2 V
FB1
V
V
FB2
q
Test Circuit 15
q
Test Circuit 16
EXT1 EXT 2
EXT1 EXT 2
C1
GND
VIN
C1 C2
OSCILLOSCOPE
GND
V
IN
CE Vrefout DTC1 DTC2 V FB1 VFB2
A V
CE Vrefout DTC1 DTC2 VFB1 VFB2
C2
Rev.1.10
- 12 -
q
Test Circuit 17
q
Test Circuit 18
C1
EXT1 EXT 2 GND
OSCILLOSCOPE
C1
EXT1 EXT2 GND VIN CE Vrefout
VIN
C2
CE Vrefout DTC1 DTC2 V
FB1
C2
C3
DTC1 DTC2 VFB1 VFB2
OSCILLOSCOPE
C4
VFB2
OSCILLOSCOPE
Typical Characteristics shown in the following pages are obtained with test circuits shown above. q R1280D002A/C Test Circuit 1,2: Typical Characteristic 4) Test Circuit 3: Typical Characteristic 6) Test Circuit 4: Typical Characteristic 7) Test Circuit 5: Typical Characteristic 8) Test Circuit 6: Typical Characteristics 9) 10) Test Circuit 7: Typical Characteristic 11) Test Circuit 8: Typical Characteristic 12) Test Circuit 9: Typical Characteristics 13) 14) q R1280D002B Test Circuit 10,11: Typical Characteristics 4) 5) Test Circuit 12: Typical Characteristic 6) Test Circuit 13: Typical Characteristic 7) Test Circuit 14: Typical Characteristic 8) Test Circuit 15: Typical Characteristics 9) 10) Test Circuit 16: Typical Characteristic 11) Test Circuit 17: Typical Characteristics 15) 16) Test Circuit 18: Typical Characteristics 17) 18) Standard Circuit Example: Typical Characteristics 1) 2) 3) 19) 20) Note) Capacitors' values of test circuits Capacitors: Ceramic Type: C1=4.7F, C2=1.0F, C3=C4=1000pF Efficiency (%) can be calculated with the next formula: =(VOUT1xIOUT1+VOUT2xIOUT2)/(VINxIIN)x100
Rev. 1.10
- 13 -
s TYPICAL CHARACTERISTICS
1) Output Voltage vs. Output Current
L1=6.8uH,C1=10uF, VOUT2=-10V,IOUT2=0mA R1280D002A VIN=2.5V VIN=3.3V VIN=5.5V Output Voltage VOUT2(V) Topt=25C L2=6.8uH,C2=10uF, VOUT1=10V,IOUT1=0mA R1280D002A
10.10
-9.90
Output Voltage VOUT1(V)
10.05
-9.95
10.00
-10.00
VIN=2.5V VIN=3.3V VIN=5.5V
9.95
-10.05
9.90 0 50 100 150 200
Output Current IOUT1(mA) L1=6.8uH,C1=10uF, VOUT2=-10V,IOUT2=0mA R1280D002B
-10.10 0 -50 -100 -150 Output Current IOUT2(mA) -200
L2=6.8uH,C2=10uF, VOUT1=10V,IOUT1=0mA R1280D002B -9.90
10.10
Output Voltage VOUT1(V)
10.05
Output Voltage VOUT2(V)
-9.95
10.00
VIN=2.5V
-10.00
9.95
VIN=3.3V VIN=5.5V
-10.05
VIN=2.5V VIN=3.3V VIN=5.5V
9.90 0 50 100 150 Output Current IOUT1(mA) 200
-10.10 0 -50
Output Current IOUT2(mA)
-100
-150
-200
L1=22uH,C1=10uF, VOUT2=-10V,IOUT2=0mA R1280D002C
L2=22uH,C2=10uF, VOUT1=10V,IOUT1=0mA R1280D002C -9.90 VIN=2.5V VIN=3.3V -9.95 VIN=5.5V
10.10
Output Voltage VOUT1(V)
10.05
10.00
VIN=2.5V
9.95
VIN=3.3V VIN=5.5V
9.90 0 50 100 150 200
Output Voltage VOUT2(V)
-10.00
-10.05
-10.10
Output Current IOUT1(mA)
0
-50
-100
-150
Output Current IOUT2(mA)
Rev.1.10
- 14 -
2) Efficiency vs. Output Current
L1=6.8uH,C1=10uF, VOUT2=-VOUT1,IOUT2=0mA R1280D002A
VIN=3.3V, Topt=25C L2=6.8uH,C2=10uF, VOUT1=-VOUT2,IOUT1=0mA R1280D002A 90 80 70 Efficiency (%)
90 80 70 Efficiency (%) 60 50 40 30 20 10 0 0 50 100 150 Output Current IOUT1(mA) 200
Vout1=5V Vout1=10V Vout1=15V
60 50 40 30 20 10 0 0 -50 -100 -150 Output Current IOUT2(mA) -200 Vout2=-5V Vout2=-10V Vout2=-15V
L1=6.8uH,C1=10uF, VOUT2=-VOUT1,IOUT2=0mA R1280D002B
L2=6.8uH,C2=10uF, VOUT1=-VOUT2,IOUT1=0mA R1280D002B 90 80 70 Efficiency (%) 60 50 40 30 20 10 0 0 -50 -100 -150 Output Current IOUT2 (mA) -200 Vout2=-5V Vout2=-10V Vout2=-15V
90 80 70 Efficiency (%) 60 50 40 30 20 10 0 0
Vout1=5V Vout1=10V Vout1=15V
50 100 150 Output Current IOUT1 (mA)
200
L1=22uH,C1=10uF, VOUT2=-VOUT1,IOUT2=0mA R1280D002C
L2=22uH,C2=10uF, VOUT1=-VOUT2,IOUT1=0mA R1280D002C 90 80 70 Efficiency (%) 60 50 40 30 20 10 0 Vout2=-5V Vout2=-10V Vout2=-15V
90 80 70 Efficiency (%) 60 50 40 30 20 10 0 0 50 100 150 Output Current IOUT1 (mA) 200
Vout1=5V Vout1=10V Vout1=15V
0
-25
-50 -75 -100 Output Current IOUT2 (mA)
-125
-150
Rev. 1.10
- 15 -
3) Output Voltage vs. Temperature
L1=6.8uH,C1=10uF R1280D002A
VIN=3.3V L2=6.8uH,C2=10uF R1280D002A
11.0
IOUT=10mA
-9.0 Output Voltage VOUT2 (V)
Output Voltage VOUT1 (V)
10.5
IOUT=100mA
-9.5
10.0
-10.0
IOUT=-10mA
9.5
-10.5
9.0 -60 -40 -20 0 20 40 60 Temperature Topt(C) 80 100
-11.0 -60 -40 -20 0 20 40 60 Temperature Topt(C) 80 100
L1=6.8uH,C1=10uF R1280D002B R1280D002B -9.0 Output Voltage VOUT2 (V)
L2=6.8uH,C2=10uF
11.0 Output Voltage VOUT1 (V)
10.5
-9.5
10.0
IOUT=10mA IOUT=100mA
-10.0 IOUT=-10mA -10.5
9.5
9.0 -60 -40 -20 0 20 40 60 (C) Temperature Topt 80 100
-11.0 -60 -40 -20 0 20 40 60 Temperature Topt (C) 80 100
L1=22uH,C1=10uF R1280D002C R1280D002C
L2=22uH,C2=10uF
11.0 Output Voltage VOUT2 (V) Output Voltage VOUT1(V)
IOUT=10mA
-9.0
10.5
IOUT=100mA
-9.5
10.0
-10.0
9.5
-10.5
IOUT=-10mA
9.0 -60 -40 -20 0 20 40 60 Temperature Topt (C) 80 100
-11.0 -60 -40 -20 0 20 40 60 Temperature Topt(C) 80 100
Rev.1.10
- 16 -
4) Frequency vs. Temperature
R1280D002A R1280D002B
800 750 700 650 600 550 -60 -40 -20 0 20 40 60 Temperature Topt (C)
R1280D002C VIN=2.5V VIN=3.3V VIN=5.5V
800 Frequency fosc (kHz) 750 700 650 600 550
80 100
VIN=2.5V VIN=3.3V VIN=5.5V
Frequency fosc (kHz)
-60
-40
-20
0 20 40 60 Temperature Topt (C)
80
100
230 Frequency fosc (kHz) 210 190
VIN=2.5V
170 150 -60 -40 -20
VIN=3.3V VIN=5.5V
0 20 40 60 Temperature Topt (C)
80
100
VIN=3.3V R1280D002B
5) Maximum Duty Cycle vs. Temperature
R1280D002B
94
Maximum Duty Cycle maxduty2 (%)
94
Maximum Duty Cycle maxduty1(%)
92
92
90
90
88
88
86 -60 -40 -20 0 20 40 60 (C) Temperature Topt 80 100
86 -60 -40 -20 0 20 40 60 Temperature Topt (C) 80 100
Rev. 1.10
- 17 -
6) Feedback Voltage vs. Temperature
VIN=3.3V R1280D002A/B/C
7) Input Offset Voltage vs. Temperature
R1280D002A/B/C
1.02 Feedback Voltage VFB1(V) 1.01 1.00 0.99 0.98 0.97 -60 -40 -20 0 20 40 60 Temperature Topt (C) 80 100
10.0 Input Offset Voltage VFB2 (mV)
VIN=3.3V R1280D002A/B/C R1280D002A/B/C
5.0 0.0 -5.0
-10.0 -60 -40 -20 0 20 40 60 80 100 Temperature Topt (C)
8) Vrefout Output Voltage vs. Temperature
9) Vrefout Output Voltage vs. Output Current
1.55 Vrefout Voltage(V)
Vrefout Voltage(V)
1.8 1.5 1.2 0.9 0.6 0.3 0
1.53 1.51 1.49 1.47 1.45 -60 -40 -20 0 20 40 60 Temperature Topt (C) 80 100
0
10
20
30 40 IROUT (mA)
50
60
10) Vrefout Output Voltage vs. Output Current
R1280D002A/B/C
11) Protection Circuit Delay Time vs. Temperature
VIN=3.3V R1280D002A/B/C
1.508 1.506 1.504 1.502 1.500 1.498 0 5 10 IROUT(mA) 15 20
140 Protection Circuit Delay Time TDLY (ms)
Vrefout Voltage(V)
120
100
80
60 -60 -40 -20 0 20 40 60 Temperature Topt(C) 80 100
Rev.1.10
- 18 -
12) Duty Cycle vs. DTC Voltage
VIN=3.3V, EXT=1000pF R1280D002A R1280D002C VIN=3.3V, EXT=1000pF
100 80 60 40 20 0 0 0.2 0.4 0.6 0.8 VDTC(V) 1 1.2 1.4
100 Duty Cycle Duty(%) 80 60 40 20 0 0 0.2 0.4 0.6 0.8 VDTC(V) 1 1.2 1.4
13) Output Sink Current vs. Temperature
VIN=3.3V R1280D002A/C
Duty Cycle Duty(%)
14) Output Source Current vs. Temperature
VIN=3.3V R1280D002A/C
130
Output Sink Current IAMPH(mA)
0.0 -0.5 -1.0 -1.5 -2.0 -2.5 -3.0
Output Sink Current IAMPL(uA)
120 110 100 90 -60 -40 -20 0 20 40 60 80 Temperature Topt (C) 100
-60
-40
-20
0 20 40 60 Temperature Topt(C)
80
100
15) CE "H" Input Voltage vs. Temperature
VIN=5.5V R1280D002B
16) CE "L" Input Voltage vs. Temperature
VIN=2.5V R1280D002B
1.25 CE"H" Input Voltage VCEH(V)
1.25 CE"L" Input Voltage VCEL(V)
-50 0 50 Temperature Topt (C) 100
1.00
1
0.75
0.75
0.50
0.5
0.25
0.25 -50 0 50 (C) Temperature Topt 100
Rev. 1.10
- 19 -
17) Soft Starting Time vs. Capacitance value
40 R1280D002B 50 R1280D002B
VIN=3.3V
Soft Starting Time TSS1(ms)
30
Soft Starting Time TSS2(ms)
0 0.2 0.4 0.6 0.8 1 Capacitance value for Soft Start(uF) 1.2
40
30
20
20
10
10
0
0 0 0.2 0.4 0.6 0.8 1 Capacitance value for Soft Start(uF) 1.2
18) Soft Starting Time vs. Temperature
CDTC1=0.33F R1280D002B R1280D002B
VIN=3.3V CDTC2=0.33F
20 Soft Starting Time TSS1(ms)
Soft Starting Time TSS2(ms)
30 25 20 15 10 5 0 -50 0 50 Temperature Topt(C) 100
VIN=3.3V L1=6.8H R1280D002A
15
10
5
0 -50 0 50 Temperature Topt(C) 100
19) Load Transient Response(Step-up Side)
L1=6.8H R1280D002A
10.5 Output Current IOUT(mA) 10 Output Voltage VOUT1(V) 9.5 9 8.5 8 7.5 0 0.0005 0.001 0.0015 Time (sec)
0.1 100
11.5 11
Output Voltage VOUT1(V)
10.5 10 9.5 9 8.5 0 0.01 0.02 0.03 Time (sec) 0.04
0.1 100
0.002
0.05
Rev.1.10
- 20 -
Output Current IOUT(mA)
L1=6.8H R1280D002B R1280D002B
L1=6.8H
10.5 10 9.5 9 8.5 8 7.5 0 0.0005 0.001 Time (sec) 0.0015
0.1 100
11.5 Output Current IOUT(mA) Output Current IOUT(mA) Output Current IOUT(mA) 11 10.5 10 9.5 9 8.5 0 0.01 0.02 0.03 Time (sec) 0.04
0.1 100
Output Voltage VOUT1(V)
Output Current IOUT(mA)
0.002
L1=22H
Output Voltage VOUT1(V)
0.05
L1=22H
R1280D002C 10.5 10 9.5 9 8.5 8 7.5 0 0.0005 0.001 Time (s) 0.0015 0.1 0.002 100
R1280D002C
11.5 11 10.5 10 9.5 9 8.5 0 0.01 0.02 0.03 Time (sec) 0.04
0.1 100
Output Voltage VOUT1(V)
Output Voltage VOUT1(V)
Output Curren IOUT(mA)
0.05
VIN=3.3V L2=6.8H
20) Load Transient Response (Inverting Side)
L2=6.8H R1280D002A R1280D002A
-9 Output Voltage VOUT2(V) -9.5 -10 -10.5 -11
-50 -0.1
-9.5 Output Current IOUT(mA) -10 -10.5 -11 -11.5 -12 0.000
-50
Output Voltage VOUT2(V)
-0.1
-11.5 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0 1 2 Time (sec) 4 3 5 6
0.005
0.010 Time (sec)
0.015
0.020
Rev. 1.10
- 21 -
L2=6.8H R1280D002B
L2=6.8H
R1280D002B -9.5
Output Current IOUT(mA)
-9
Output Voltage VOUT2(V)
Output Voltage VOUT2(V)
-10
-10
-50 -0.1
-10.5 -11 -50 -0.1
-10.5 -11
-11.5 -12 0.000
-11.5 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0 1 2 Time (sec) 4 3 5 6
L2=22H R1280D002C -9
0.005
0.010 0.015 Time (sec)
0.020
L2=22H
R1280D002C
-9.5 Output Voltage VOUT2(V) Output Current IOUT(mA) -10 -10.5 -11 -11.5 -12 0.000
-50 -0.1
-9.5 -10 -50 -0.1
-10.5 -11
-11.5 0.0000 0.0001 0.0002 0.0003 0.0004 0.0005 0.0006 Time(s)
0.005
0.010 Time(s)
0.015
0.020
Rev.1.10
- 22 -
Output Current IOUT(mA)
Output Voltage VOUT2 (V)
Output Current IOUT(mA)
-9.5
s TYPICAL APPLICATION AND TECHNICAL NOTES
q R1280D002A/C
VOUT1 C1
L1 C3
EXT1 EXT2
PMOS C8 R9 R3 L2
R1
C6
NMOS
GND VIN
AMPOUT1
R2
C9 R5 R11 C4
R7 R8
Vrefout C5
DTC1 DTC2
R10
VFB1 V FB2 C7 R6 R4 C2
Diode VOUT2
External Components Inductor L1,2: 6.8H, LDR655312T(TDK) for A type, 22H for C type Diode: FS1J3 (Origin Electronics) NMOS: IR7601 (International Rectifier) PMOS: Si3443 (Siliconix) Resistors: R1, R2, R3, R4 for Setting Output Voltage. Recommendation values are R1+R2100k or R3+R4100k R5=43k, R6=10k, R7=R9=22k, R8=R10=43k, R11=220k Capacitors: Ceramic Capacitor (Example) R1280D002A: C1=C2=10F, C3=4.7F, C4=0.22F, C5=0.47F, C6=120pF, C7=50pF, C8=1F, C9=1000pF R1280D002C: C1=C2=10F, C3=4.7F, C4=0.22F, C5=0.47F, C6=220pF, C7=330pF, C8=1F, C9=1000pF Note: Maximum voltage tolerance of each component should be considered. With the transistor shown above is appropriate to set up to 15V as output voltage. q R1280D002B
VOUT1 C1
L1 C3
EXT2 EXT1
PMOS C8 C5 R3 L2
R1
C6
NMOS
GND VIN CE
R2
R5
DTC1DTC2
C4 VFB1 VFB2
C7 R6
R4
Diode
Rev. 1.10
- 23 -
External Components Inductor L1,2: 6.8H, LDR655312T(TDK) Diode: FS1J3 (Origin Electronics) NMOS: IR7601 (International Rectifier) PMOS: Si3443 (Siliconix) Resistors: R1, R2, R3, R4 for Setting Output Voltage. Recommendation values are R1+R2100k or R3+R4100k R5=43k, R6=10k Capacitors: Ceramic Capacitor (Example) C1=C2=10F, C3=4.7F, C4=0.33F, C5=0.33F, C6=120pF, C7=50pF, C8=1F Note: Maximum voltage tolerance of each component should be considered. With the transistor shown above is appropriate to set up to 15V as output voltage.
s APPLICATION EXAMPLE
q R1280D002A/C
VOUT3 C10 VOUT1 C1 NMOS C11 L1 C3 R1 C6 EXT1EXT2 GND VIN R7 C4 R8 VFB1 VFB2 C7 R6 R4
AMPOUT1 Vrefout
DTC1 DTC2
PMOS C8 R9 R10 R3 L2
R2
C9 R5 R11
C5
Diode VOUT2
C2
External Components Inductor L1,2: 6.8H, LDR655312T(TDK) for A version, 22H for R1280D002C Diode: FS1J3 (Origin Electronics) NMOS: IR7601 (International Rectifier) PMOS: Si3443 (Siliconix) Resistors: R1, R2, R3, R4 for Setting Output Voltage. Recommendation values are R1+R2100k or R3+R4100k R5=43k, R6=10k, R7=R9=22k, R8=R10=43k, R11=220k Capacitors: Ceramic Capacitor (Example) R1280D002A: C1=C2=10F, C3=4.7F, C4=0.22F, 5=0.47F,C6=120pF,C7=50pF,C8=C10=C11=1F,C9=1000pF R1280D002C:C1=C2=10F,C3=4.7F, C4=0.22F,C5=0.47F,C6=220pF,C7=330pF,C8=C10=C11=1F,C9=1000pF This IC can be used 3 Output TFT Bias Circuit as shown above. VOUT3=2xVOUT1-Vf Note: Maximum voltage tolerance of each component should be considered. With the transistor shown above is appropriate to set up to +15V as VOUT1, -15V as VOUT2, 30V as VOUT3.
Rev.1.10
- 24 -
q
R1280D002B
VOUT3 C10 VOUT1 C1 NMOS C11 L1
C3 R1 C6
EXT1 EXT2
PMOS C8 R3 L2
GND CE
VIN
Vrefout C5
R2
R5
C4
DTC1DTC2
VFB1 VFB2 C7 R4
Diode VOUT2
R6
External Components Inductor L1,2: 6.8H, LDR655312T(TDK) Diode: FS1J3 (Origin Electronics) NMOS: IR7601 (International Rectifier) PMOS: Si3443 (Siliconix) Resistors: R1, R2, R3, R4 for Setting Output Voltage. Recommendation values are R1+R2100k or R3+R4100k R5=43k, R6=10k Capacitors: Ceramic Capacitor (Example) R1280D002B: C1=C2=10F, C3=4.7F, C4=0.33F, 5=0.33F, C6=120pF,C7=50pF,C8=C10=C11=1F This IC can be used 3 Output TFT Bias Circuit as shown above. VOUT3=2xVOUT1-Vf Note: Maximum voltage tolerance of each component should be considered. With the transistor shown above is appropriate to set up to +15V as VOUT1, -15V as VOUT2, 30V as VOUT3
s EXTERNAL COMPONENTS
1. How to set the output voltages As for step-up side, feedback (VFB1) pin voltage is controlled to maintain 1V, therefore, VOUT1: R1+R2=VFB1: R2 Thus, VOUT1=VFB1x(R1+R2)/R2 Output Voltage is adjustable with R1 and R2. As for inverting side, Feedback (VFB2) pin voltage is controlled to maintain 0V, therefore, Vrefout : R3=|-VOUT2|:R4 Thus, |-VOUT2|=VrefoutxR4/R3 Output Voltage is adjustable with R3 and R4. 2. How to set Soft Starting Time As for R1280D002B, soft start time is adjustable with connecting a capacitor to DTC pin. Soft starting time, TSS1 and TSS2 are adjustable. Soft starting time can be set with the time constant of RC. Soft starting time can be described as in next formula. (Topt=25C) TSS1RS1xC4, TSS2RS2xC5 In the above formulas, RS1 value is TYP. 32k, while RS2 value is TYP. 45k. Tolerance of these values is 25% caused by dispersion of wafer process parameters. On the other hand, as for R1280D002A/C, each soft start time is set with the time constant of each external resistor Rev. 1.10 - 25 -
and capacitor.
s TECHNICAL NOTES on EXTERNAL COMPONENTS
q q q q External components should be set as close to this IC as possible. Especially, wiring of the capacitor connected to VIN pin should be shortest. Enforce the ground wire. Large current caused by switching operation flows through GND pin. If the impedance of ground wire is high, internal voltage level of this IC might fluctuate and operation could be unstable. Recommended capacitance value of C3 is equal or more than 4.7F. Recommended maximum voltage tolerance of C3 is three times as large as set output voltage or more, because the external transistor might generate hi voltage with a shape of spike because of an effect from inductor. If the spike noise of VOUT is too large, the noise is feedback from VFB1 pin and operation might be unstable. In that case, use the resistor ranging from 10k to 50k as R5 and try to reduce the noise level. In the case of VOUT2, use the resistor as much as 10k as R6. Select an inductor with low D.C. current, large permissible current, and uneasy to cause magnetic saturation. If the inductance value is too small, ILX might be beyond the absolute maximum rating at the maximum load. Select a Schottky diode with fast switching speed and large enough permissible current. Recommended capacitance value of C1 and C2 is as much as Ceramic 10F. In case that the operation with the system of DC/DC converter would be unstable, use tantalum capacitors with higher ESR than ceramic capacitor. Use a capacitor with three times as large as voltage tolerance of the capacitor. In this IC, for the test efficiency, Latch release function is included. By forcing (VIN-0.3) V or more voltage to DTC1 pin or DTC2 pin, Latch release function works. Consider the threshold voltage of Power MOSFET transistor. Select an appropriate MOSFET transistor, depending on the input voltage in order to make the MOSFET turn on completely. Performance of the power controller with using this IC depends on external components. Each component, layout should not be beyond each absolute maximum rating such as voltage, current, and power dissipation.
q q q q q q
Rev.1.10
- 26 -

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