apex microtechnology corporation ? telephone (520) 690-8600 ? fax (520) 888-3329 ? orders (520) 690-8601 ? email prodlit@apexmicrotech.com 1 features ? high voltage 450v (225v) ? low quiescent current 2ma ? high output current 100ma ? programmable current limit ? low bias current fet input applications ? piezoelectric positioning ? high voltage instrumentation ? electrostatic transducers ? programmable power supplies up to 440v description the PA88 is a high voltage, low quiescent current mos - fet operational ampli?er designed for output currents up to 100ma. output voltages can swing up to 215v with a dual supply and up to +440 volts with a single supply. the safe operating area (soa) has no second breakdown limitations and can be observed with all types of loads by choosing an appropriate current limiting resistor. high accuracy is achieved with a cascode input circuit con?guration. all internal biasing is referenced to a bootstrapped zener-mosfet current source. as a result, the PA88 features an unprecedented supply range and excellent supply rejection. the mosfet output stage is biased on for linear operation. external compensation provides user ?exibility. this hybrid circuit utilizes beryllia (beo) substrates, thick ?lm resistors, ceramic capacitors and semiconductor chips to maximize reliability, minimize size and give top performance. ultrasonically bonded aluminum wires provide reliable inter - connections at all operating temperatures. the 8-pin to-3 package is hermetically sealed and electrically isolated. the use of compressible thermal isolation washers and/or improper mounting torque will void the product warranty. please see general operating considerations. equivalent schematic typical application low power, piezoelectric positioning piezo positioning may be applied to the focusing of segmented mirror systems. the composite mirror may be composed of hundreds of elements, each requiring focusing under computer control. in such complex systems the PA88s advantage of low quiescent power consumption reduces the costs of power supplies and cooling, while providing the interface between the computer and the high voltage drive to the piezo positioners. external connections ? ? ???? ?? ? ??????????? ? ?? ? ?? ??? ? ? ? ???????? ????? ??????? ??????? ? ? ? ? ? ? ? ? ???????? ?? ??? ??? ??? ???? ??? ? ?? ??? ? ? ?????????????????? ???? ??? ? ? ?? ?? ??? ???? ???? ???? ????? ???? ? ? ???? ???? ???? ? ? ? ? ? ? ? ?? ?? ?? ? ??? ? ? ???????????????? ?????????????? patented ? ? ? ? ? ? ? ? ???? ???? ?? ??? ?? ? ?? ? ?? ?? ?? ?? ?? ?? ?? ??? ???? ???? ??? ??? ??? ??? ??? ?? ??? ?? ???? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ????????????????????????????????????????? ???????????? 8-pin to-3 package style ce
apex microtechnology corporation ? 5980 north shannon road ? tucson, arizona 85741 ? usa ? applications hotline: 1 (800) 546-2739 2 absolute maximum ratings specifications absolute maximum ratings supply voltage, +v s to Cv s 450v output current, source, sink see soa power dissipation, continuous @ t c = 25c 15w input voltage, differential 25v input voltage, common mode v s temperature, pin solder - 10s max 300c temperature, junction 2 150c temperature, storage C65 to +150c operating temperature range, case C55 to +125c PA88 ? PA88a specifications PA88 PA88a parameter test conditions 1 min typ max min typ max units input offset voltage, initial .5 2 .25 .5 mv offset voltage, vs. temperature full temperature range 10 30 5 10 v/c offset voltage, vs. supply 1 5 * * v/v offset voltage, vs. time 75 * v/kh bias current, initial 3 5 50 3 10 pa bias current, vs. supply .01 * pa/v offset current, initial 3 2.5 100 3 20 pa input impedance, dc 10 11 * input capacitance 4 * pf common mode voltage range 4 v s C15 * v common mode rejection, dc v cm = 90v 90 110 * * db noise 100khz bw, r s = 1k, c c = 15pf 2 * vrms gain open loop, @ 15hz r l = 2k, c c = open 96 111 * * db gain bandwidth product at 1mhz r l = 2k, c c = 15pf, r c = 100 2.1 * mhz power bandwidth r l = 2k, c c = 15pf, r c = 100 6 * khz phase margin full temperature range 60 * output voltage swing 4 full temp. range, i o = 75ma v s C16 v s C14 * * v voltage swing 4 full temp. range, i o = 20ma v s C10 v s C5.2 * * v current, continuous t c = 85c 100 * ma slew rate, a v = 20 c c = 15pf, r c = 100 8 * v/s slew rate, a v = 100 c c = open 30 * v/s capacitive load, a v = +1 full temperature range 470 * pf settling time to .1% c c = 15pf, r c = 100, 2v step 10 * s resistance, no load r cl = 0 100 * power supply voltage 6 see note 6 15 200 225 * * * v current, quiescent, 1.7 2 * * ma thermal resistance, ac, junction to case 5 full temperature range, f > 60hz 5.0 * c/w resistance, dc, junction to case full temperature range, f < 60hz 8.3 * c/w resistance, junction to air full temperature range 30 * c/w temperature range, case meets full range speci?cations C25 +85 * * c notes: * the speci?cation of PA88a is identical to the speci? cation for PA88 in applicable column to the left. 1. unless otherwise noted: t c = 25c, compensation = c c = 68pf, r c = 100. dc input speci?cations are value given. power supply voltage is typical rating. 2. long term operation at the maximum junction temperature will result in reduced product life. derate internal power dissipation to achieve high mttf. 3. doubles for every 10c of temperature increase. 4. +v s and Cv s denote the positive and negative power supply rail respectively. 5. rating applies if the output current alternates between both output transistors at a rate faster than 60hz. 6. derate max supply rating .625 v/c below 25c case. no derating needed above 25c case. the PA88 is constructed from mosfet transistors. esd handling procedures must be observed. the internal substrate contains beryllia (beo). do not break the seal. if accidentally broken, do not crush, machine, or subject to temperatures in excess of 850c to avoid generating toxic fumes. caution
apex microtechnology corporation ? telephone (520) 690-8600 ? fax (520) 888-3329 ? orders (520) 690-8601 ? email prodlit@apexmicrotech.com 3 typical performance graphs PA88 ? PA88a ? ?? ?? ?? ??? ??? ??? ??????????????????? ? ??? ??? ?? ?????????????? ????????????????????????????????? ? ??? ?? ?? ????????????????? ???? ???? ??? ? ?????????????? ???????????? ?? ??? ??? ?? ????????????????? ?????????????????????? ? ????????? ? ??? ????????????????? ??? ? ?? ??? ????????????????????? ?????????????????????? ?? ?? ?? ??? ?? ?? ???? ????????????????? ?? ??? ??? ????????????????? ? ??? ?? ? ?? ??? ? ?? ?? ????????????????? ?? ?? ????????????????????? ??????????????????????????????? ?? ?? ??? ? ?? ????????????????? ?? ?? ??? ?????????????????????? ???????????????????????????????? ?? ??? ? ?? ?? ??? ????????????????????????? ?? ???? ?? ?? ??? ????????????? ???????????????? ??? ????? ?? ?? ? ?? ????????????????????????? ? ?????? ? ????????? ????????????????? ? ?? ?? ?? ?? ? ????????????????? ???? ??????????????????? ??????????????? ? ?? ??? ?? ??? ?? ? ??? ??? ??????????????????????? ? ???? ??? ??? ????????????????? ???????????????????? ? ????? ???? ?? ??? ? ?? ?? ??????????? ?? ? ? ?? ?? ? ? ?? ?? ??? ??? ???? ? ?? ?????????????? ?? ?? ??? ?? ??? ??? ?? ??? ???? ??? ????? ??? ?? ??? ??? ?? ???? ??? ??? ???? ??? ?? ?? ?? ?? ??? ?? ??? ??? ???? ? ? ???????? ? ? ??????? ? ? ???????? ?? ??? ??? ??? ??? ? ? ??????? ? ? ??????? ? ? ????? ??? ??? ? ? ??????? ? ? ??????? ? ? ??????? ? ? ???????? ??? ? ? ??????? ? ? ???????? ? ? ??????? ? ? ???????? ? ? ??????? ? ? ??????? ??? ??? ??? ? ? ???????? ? ? ??????? ? ? ??????? ? ? ??????? ?? ??? ?? ? ? ?? ?? ????? ? ????? ? ???????????????????? ? ? ? ? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ??? ????????????????? ? ????? ???????????????????????????????????? ? ? ?????? ? ? ?????? ? ? ????? ???????? ???????? ? ? ?????
apex microtechnology corporation ? 5980 north shannon road ? tucson, arizona 85741 ? usa ? applications hotline: 1 (800) 546-2739 4 operating considerations PA88 ? PA88a general please read application note 1 "general operating con - siderations" which covers stability, supplies, heat sinking, mounting, current limit, soa interpretation, and speci?cation interpretation. visit www.apexmicrotech.com for design tools that help automate tasks such as calculations for stability, internal power dissipation, current limit; heat sink selection; apexs complete application notes library; technical seminar workbook; and evaluation kits. current limit for proper operation, the current limit resistor (r cl ) must be connected as shown in the external connection diagram. the minimum value is 3.5 ohm, however for optimum reliability the resistor value should be set as high as possible. the value is calculated as follows; with the maximum practical value of 150 ohms. .7 r cl = i lim safe operating area (soa) the mosfet output stage of this power operational ampli - ?er has two distinct limitations: 1. the current handling capability of the mosfet geometry and the wire bonds. 2. the junction temperature of the output mosfets. note: the output stage is protected against transient ?yback. however, for protection against sustained, high energy ?yback, external fast-recovery diodes should be used. ??? ???????????????????????????????? ? ??? ? ???? ?? ?? ?? ??? ??? ??? ?????????????????????? ? ?????? ? ?????? ? ?? ?? ?? ?? ??? ??? ??? ????? ? ???????? ????? ? ??????? ????? ????????????????????????????????? ????? ? ??????? ????? ??? input protection although the PA88 can withstand differential input voltages up to 25v, additional external protection is recommended, and required at total supply voltages above 300 volts. in most applications 1n4148 or 1n914 signal diodes are suf?cient (d1, d2 in figure 2a). in more demanding applications where low leakage or low capacitance are of concern 2n4416 or 2n5457- 2n5459 jfets connected as diodes will be required (q1, q2 in figure 2b). in either case the input differential voltage will be clamped to .7v. this is suf?cient overdrive to produce maximum power bandwidth. power supply protection unidirectional zener diode transient suppressors are recom - mended as protection on the supply pins. the zeners clamp transients to voltages within the power supply rating and also clamp power supply reversals to ground. whether the zeners are used or not, the system power supply should be evaluated for transient performance including power-on overshoot and power-off polarity reversal as well as line regulation. conditions which can cause open circuits or polarity reversals on either power supply rail should be avoided or protected against. reversals or opens on the negative supply rail is known to induce input stage failure. unidirectional transzorbs prevent this, and it is desirable that they be both electrically and physically as close to the ampli?er as possible. stability the PA88 has suf?cient phase margin to be stable with most capacitive loads at a gain of 4 or more, using the rec - ommended phase compensation. the PA88 is exter - nally compensated and performance can be tailored to the application. use the graphs of small signal response and power response as a guide. the compensation capacitor c c must be rated at 500v working voltage. an npo capacitor is recommended. the compensation net - work c c r c must be mounted closely to the ampli?er pins 7 and 8 to avoid spuri - ous oscillation. figure 2. overvoltage protection ???? ?? ? ??? ??? ?? ?? ?? ?? ? ? ? ? ?? ? ??? ??? ?? ?? ? ? ? ? ???? ?? ?? ?? ?? ?? ? ?? ? this data sheet has been carefully checked and is believed to be reliable, however, no responsibility is assumed for possible inaccuracies or omissions. all speci?cations are subject to change without notic PA88u rev l february 2005 ? 2005 apex microtechnology corp.
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