pa91 pa91u 1 features ? high voltage 450v (225v) ? low quiescent current 10ma ? high output current 20 0ma ? programmable current limit ? high slew rate 300v/s applications ? piezoelectric positioning ? high voltage instrumentation ? electrostatic transducers ? programmable power supplies up to 440v q1 q2 r1 r2 c1 r3 q3 cc1 12 11 1 4 5 9 6 10 2 7 8 cc2 3 q6 q5 r5 r8 r9 q15 r11 r12 q16 q12 q8 r4 r7 q4 ilim out q17 r10 q13 q11 +v s Cin +in Cv s i q r6 q14b q14a high voltage power operational amplifiers pa91 p r o d u c t i n n o v a t i o n f r o m description the pa91 is a high voltage, low quiescent current mosfet operational amplifer designed as a low cost solution for driving continuous output currents up to 200ma and pulse currents up to 350ma. the safe oper- ating area (soa) has no second breakdown limitations and can be observed for all type loads by choosing an appropriate current limiting resistor. the mosfet output stage is biased ab for linear operation. exter- nal compensation provides fexibility in choosing band - width and slew rate for the application. apex precision powers power sip package uses a minimum of board space allowing for high density circuit boards. the 12- pin powersip package is electrically isolated. equivalent schematic copyright ? cirrus logic, inc. 2009 (all rights reserved) http://www.cirrus.com jun 2009 apex ? pa91urevh p r o d u c t i n n o v a t i o n f r o m
pa91 2 pa91u caution the pa91 is constructed from mosfet transistors. esd handling procedures must be observed. the exposed substrate contains beryllia (beo). do not crush, machine, or subject to temperatures in excess of 850c to avoid generating toxic fumes. parameter symbol min max units supply voltage, +v s to -v s 450 v output current, source, sink, peak, within soa 350 ma power dissipation, continuous @ t c = 25c 30 w input voltage, differential -20 20 v input voltage, common mode -v s v s v temperature, pin solder, 10s max. 260 c temperature, junction (note 2) 150 c temperature range, storage ?40 85 c operating temperature, case ?25 85 c 1. characteristics and s pecifications absolute maximum r atings parameter test conditions 1 min typ max units input offset voltage, initial 0.5 2 mv offset voltage vs. temperature full temperature range 15 50 v/c offset voltage vs. supply 10 25 v/v offset voltage vs. time 75 v/khz bias current, initial 200 2000 pa bias current vs. supply 4 pa/v offset current, initial 50 500 pa input impedance, dc 10 11 ? input capacitance 4 pf common mode voltage range (note 3) v s ? 15 v common mode rejection, dc v cm = 90v 80 98 db noise 100khz bandwidth, r s = 1k?, c c = open 1 v rms s pecifications 1 2 3 4 5 6 7 8 9 10 Cin +in r cl +v s Cv s to load and feedback 11 12 r c c c * * (see text.) * bypassing required. i q 12-pin sip packa ge style dp formed leads available see package style ee ex ternal connections p r o d u c t i n n o v a t i o n f r o m
pa91 pa91u 3 notes: 1. (all min/max characteristics and specifcations are guaranteed over the specifed operating condi - tions. typical performance characteristics and specifcations are derived from measurements taken at typical supply voltages and t c = 25c). 2. long term operation at the maximum junction temperature will result in reduced product life. derate power dissipation to achieve high mttf. 3. +v s and Cv s denote the positive and negative power supply rail respectively. 4. rating applies if the output current alternates between both output transistors at a rate faster than 60hz. 5. derate max supply rating 0.625 v/c below 25c case. no derating needed above 25c case. parameter test conditions 1 min typ max units gain open loop @ 15hz r l = 2k?, c c = open 94 111 db gain bandwidth product @ 1mhz r l = 2k?, c c = open 100 mhz power bandwidth r l = 2k?, c c = open 470 khz phase margin full temperature range 60 output voltage swing (note 3) i o = 200ma v s ? 12 v s ? 10 v current, continuous 200 ma slew rate, a v = 100 c c = open 240 300 v/s capacitive load, a v = +1 full temperature range 470 pf settling time to 0.1% c c = open, 2v step 1 s resistance, no load 50 ? power supply voltage (note 5) 40 150 225 v current, quiescent 10 14 ma thermal resistance, ac, junction to case (note 4) full temp range, f > 60hz 2.5 c/w resistance, dc, junction to case full temp range, f < 60hz 4.2 c/w resistance, junction to air full temp range 30 c/w temperature range, case meets full range specifcations -25 +85 c p r o d u c t i n n o v a t i o n f r o m
pa91 4 pa91u internal power dissipation, p(w) 10 harmonic distortion 100k 100 1k 10k 100k frequency f (hz) 135 90 phase response phase, () 10 100 10k 100k frequency, f (hz) input noise voltage, v (nvhz) 100k frequency, f (hz) C10 0 30 small signal response open loop gain, a (db) 10 20 40 50 0 0.15 0.2 output current, i o (a) 5 6 output voltage swing 4.5 4 5.5 0 8 12 20 24 resistor value, r cl () 0 .05 .2 current limit current limit, i lim (a) .1 .15 0.1 ext. compensation capacitor, c c (pf) 10 slew rate slew rate, (v/s) 50 40 30 20 1k 10 100 frequency, f (hz) distortion, (%) 1 25 50 100 case temperature, t c (c) 1.1 normalized quies. current normalized quiescent current, i q (x) 1.0 4 16 input noise voltage 1k 2 7 10 20 5 3 15 .05 voltage drop from supply, v s C v o (v) 225 75 .001 1m 10m 270 180 125 1.2 1.3 0.1 3.5 700 300 200 100 70 500 1 .01 .1 1m 10m c c = 68 pf c c = 10 pf c c = 4.7 pf c c = open c c = 68 pf c c = 10 pf c c = 4.7 pf c c = open 0 25 50 75 100 125 150 case temperature, t c (c) 0 8 24 32 power derating 16 40 r l = 1k v s = 200v a v = 63 p o = 5w p o = 1w p o = 17.6w output stage power response frequency, f (hz) output voltage, v o (v p-p ) 10k 100k 1m 50 60 70 80 90 100 200 300 500 400 c c = open c c = 4.7pf c c = 10pf c c = 68pf p r o d u c t i n n o v a t i o n f r o m
pa91 pa91u 5 general please read application note 1 "general operating considerations" which covers stability, supplies, heat sinking, mounting, current limit, soa interpretation, and specifcation interpretation. visit www.cirrus.com for design tools that help automate tasks such as calculations for stability, internal power dissipation, current limit; heat sink selec- tion; apex precision powers 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 dia- gram. 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 32 ohms. .65 r cl = i lim safe operatin g area (soa) the mosfet output stage of this power operational amplifer has two distinct limitations: 1. the current handling capability of the mosfet ge- ometry and the wire bonds. 2. the junction temperature of the output mosfets. note: the output stage is protected against transient fyback. however, for protection against sustained, high energy fyback, external fast-recovery diodes should be used. safe operatin g curves the safe operating area curves defne the maximum additional internal power dissipation the amplifer can tolerate when it produces the necessary output to drive an external load. soa supply to output differential, v s - v o (v) output current from +v s or -v s (ma) 25 50 75 100 125 250 500 500 300 200 100 50 30 20 10 pulse curves @ 10% duty cycle max. 100ms 200ms dc, t c = 25c dc, t c = 125c dc, t c = 85c typical application low power, piezoelectric positioning piezo positioning may be applied to the focusing of seg- mented mirror systems. the composite mirror may be composed of hundreds of elements, each requiring focus- ing under computer control. in such complex systems the pa91 reduces the costs of power supplies and cooling with its advantages of low cost and low quiescent power consumption while increasing circuit density with the sip package. phase compensation gain c c * r c 1 68pf 100 5 10pf 100 10 4.7pf 0 30 none 0 *c c to be rated for the full supply voltage +v s to Cv s . use npo ceramic (cog) type. f r pa91 in r 1 2 6 7,8 9,10 11,12 piezo drive s Cv s +v out v computer focus command voltage cl r p r o d u c t i n n o v a t i o n f r o m
pa91 6 pa91u input protection although the pa91 can withstand differential voltages up to 20v, additional external protection is recommended. low leakage, low capacitance jfets connected as diodes are recommended (e.g. 2n4416, q1-q4 in figure 2). the differential input voltage will be clamped to 1.4v. this is suffcient overdrive to produce maximum power bandwidth. power supply protection unidirectional zener diode transient suppressors are recommended as protection on the supply pins. see figure 2. 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 per- formance including power-on overshoot and power-off polarity reversals as well as line regulation. conditions which can cause open circuits or polarity reversals on either power supply rail should be avoided or pro- tected 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 amplifer as possible. sta bility the pa91 is externally 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 cc must be rated at 500v working voltage. an npo capacitor is recommended. the compensation network ccrc must be mounted closely to the amplifer pins 4 and 5 to avoid spurious oscillation. quiescent current reduction when pin 3 (iq) is shorted to pin 5 (cc2) the ab biasing of the output stage is disabled. this raises distortion since the output stage is then class c biased, but reduces the quiescent current by 1ma for a power dissipation savings of 0.4w. pin 3 may be left open if not used. +v s Cin +in z1 z2 11, 12 7, 8 1 2 6 pa91 q1 q2 Cv s q3 q4 figure 2. overvoltage protection c ontacting cirrus logic support for all apex precision power product questions and inquiries, call toll free 800-546-2739 in north america. for inquiries via email, please contact tucson.support@cirrus.com. international customers can also request support by contacting their local cirrus logic sales representative. to fnd the one nearest to you, go to www.cirrus.com important notice cirrus logic, inc. and its subsidiaries ("cirrus") believe that the information contained in this document is accurate and reliable. however, the information is subject to change without notice and is provided "as is" without warranty of any kind (express or implied). customers are advised to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. all products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgment, including those pertaining to warranty, indemnifcation, and limitation of liability. no 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designs, apex precision power, apex and the apex precision power logo designs are trademarks of cirrus logic, inc. all other brand and product names in this document may be trademarks or service marks of their respective owners. p r o d u c t i n n o v a t i o n f r o m
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