apex microtechnology corporation ? telephone (520) 690-8600 ? fax (520) 888-3329 ? orders (520) 690-8601 ? email prodlit@apexmicrotech.com 1 features ? very fast slew rate 900 v/s ? power mos technology 4a peak rating ? low internal losses 2v at 2a ? protected output stage thermal shutoff ? wide supply range 15v to 40v applications ? video distribution and amplification ? high speed deflection circuits ? power transducers up to 5 mhz ? modulation of rf power stages ? power led or laser diode excitation description the PA19 is a high voltage, high current operational ampli - ?er optimized to drive a variety of loads from dc through the video frequency range. excellent input accuracy is achieved with a dual monolithic fet input transistor which is cascoded by two high voltage transistors to provide outstanding common mode characteristics. all internal current and voltage levels are referenced to a zener diode biased on by a current source. as a result, the PA19 exhibits superior dc and ac stability over a wide supply and temperature range. high speed and freedom from second breakdown is assured by a complementary power mos output stage. for optimum linearity, especially at low levels, the power mos transistors are biased in a class a/b mode. thermal shutoff provides full protection against overheating and limits the heatsink requirements to dissipate the internal power losses under normal operating conditions. a built-in current limit of 0.5a can be increased with the addition of two external resistors. transient inductive load kickback protection is provided by two internal clamping diodes. external phase compensation allows the user maximum ?exibility in obtaining the optimum slew rate and gain bandwidth product at all gain settings. a heatsink of proper rating is recommended. this hybrid circuit utilizes thick ?lm (cermet) resistors, ceramic capacitors, and silicon semiconductor chips to maximize reli - ability, minimize size, and give top performance. ultrasonically bonded aluminum wires provide reliable interconnections at all operating temperatures. the 8-pin to-3 package is hermeti - cally sealed and electrically isolated. the use of compressible thermal washers and/or improper mounting torque will void the product warranty. please see general operating con - siderations. ??? ???? ? ? ? ? ? ? ? ? ?? ??? ??? ??? ? ? ? ??? ?????????????????? ? ? ????? ???? ????? ???? ???? ? ?? ??? ???? ?? ? ??? typical application this fast power driver utilizes the 900v/s slew rate of the PA19 and provides a unique interface with a current output dac. by using the dacs internal 1k feedback resistor, temperature drift errors are minimized, since the temperature drift coef?cients of the internal current source and the internal feedback resistor of the dac are closely matched. gain of v out to i in is C6.5/ma. the dacs internal 1k resistor together with the external 500 and 110 form a tee network in the feedback path around the PA19. this effective resistance equals 6.5k . therefore the entire circuit can be modeled as 6.5k feedback resistor from output to inverting input and a 5ma current source into the inverting input of the PA19. now we see the familiar current to voltage conversion for a dac where v out = Ci in x r feedback . equivalent schematic external connections ? ? ? ? ? ? ?? ?? ?? ?? ?? ??? ??? ??? ?? ?? ??? ???? ??? ??? ? ? ??? ??? ??? ??? ??? ??? ?? ?? ?? ???? ??? ???? ???? ?????? ? ??? ???? ?????????????????????????? ? ??? ????? ???????? ???? ???? ???? ?? ??? typical application ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?????????????????????????????????? ???????????? 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 specifications absolute maximum ratings supply voltage, +v s to Cv s 80v output current, within soa 5a power dissipation, internal 78w input voltage, differential 40v input voltage, common mode v s temperature, pin solder 10 sec 300c temperature, junction 1 150c temperature, storage C65 to 155c operating temperature range, case C55 to 125c PA19 PA19a parameter test conditions 2 min typ max min typ max units input offset voltage, initial t c = 25c .5 3 .25 .5 mv offset voltage, vs. temperature t c = 25c to +85c 10 30 5 10 v/c offset voltage, vs. supply t c = 25c 10 * v/v offset voltage, vs. power t c = 25c to +85c 20 * v/w bias current, initial t c = 25c 10 200 5 50 pa bias current, vs. supply t c = 25c .01 * pa/v offset current, initial t c = 25c 5 100 3 25 pa input impedance, dc t c = 25c 10 11 * m input capacitance t c = 25c 6 * pf common mode voltage range 3 t c = 25c to +85c v s C15 v s C12 * * v common mode rejection, dc t c = 25c to +85c, v cm = 20v 70 104 * * db gain open loop gain at 10hz t c = 25c, r l = 1k? 111 * db open loop gain at 10hz t c = 25c, r l = 15? 74 78 * * db gain bandwidth product at 1mhz t c = 25c, c c = 2.2pf 100 * mhz power bandwidth, a v = 100 t c = 25c, c c = 2.2pf 3.5 * mhz power bandwidth, a v = 1 t c = 25c, c c = 330pf 250 * khz output voltage swing 3 t c = 25c, i o = 4a v s C5 v s C4 * * v voltage swing 3 t c = 25c to +85c, i o = 2a v s C3 v s C2 * * v voltage swing 3 t c = 25c to +85c, i o = 78ma v s C1 v s C.5 * * v settling time to .1% t c = 25c, 2v step .3 * s settling time to .01% t c = 25c, 2v step 1.2 * s slew rate, a v = 100 t c = 25c, c c = 2.2pf 600 900 800 * v/s slew rate, a v = 10 t c = 25c, c c = 22pf 650 * v/s power supply voltage t c = 25c to +85c 15 35 40 * * * v current, quiescent t c = 25c 100 120 * * ma thermal resistance, ac, junction to case 4 t c = 25c to +85c, f > 60hz 1.2 1.3 * * c/w resistance, dc, junction to case t c = 25c to +85c, f < 60hz 1.6 1.8 * * c/w resistance, junction to air t c = 25c to +85c 30 * c/w temperature range, case meets full range speci?cations C25 +85 * * c PA19 ? PA19a notes: * the speci?cation of PA19a is identical to the speci? cation for PA19 in applicable column to the left. 1. long term operation at the maximum junction temperature will result in reduced product life. derate internal power dissipation to achieve high mttf. 2. the power supply voltage for all speci? cations is the typ rating unless noted as a test condition. 3. +v s and Cv s denote the positive and negative supply rail respectively. total v s is measured from +v s to Cv s . 4. rating applies if the output current alternates between both output transistors at a rate faster than 60hz. 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 PA19 ? PA19a ? ?? ?? ?? ??? ??? ??????????????????? ? ????? ?? ?? ?? ?? ?????????????? ???????????????????????????????? ??? ??? ??? ??? ??? ????????????? ??? ?? ?? ??? ??? ?? ????????????????? ?????????????????????? ? ????????? ??? ???? ????????????????? ??? ? ?? ????????????????????? ????????????????? ?? ????? ?? ?? ?? ??? ? ?? ???????????????????? ?? ????????????????? ????????????????? ? ??? ??? ? ????????????????????????? ? ????? ??????????????????? ???????????????? ??? ???????????? ??? ??? ?? ?????????????? ????????????????? ? ???? ??? ?? ?? ???????????????????? ??????????????????????? ?? ??? ??? ? ?? ??? ????????????????? ????????????????????? ??????????????????????????????? ?? ?? ??? ??? ???? ?? ????????????????? ?????????????????????? ???????????????????????????????? ?? ?? ?? ??????????????????????? ? ???? ??? ????????????????? ???????????????? ??? ???? ??? ?? ??????????? ?? ?? ?? ?? ??? ?? ?? ?? ??? ?? ?????????????? ??? ? ?? ??? ??? ?? ?? ?? ?? ?? ?? ?? ???? ??? ?? ????????????????? ? ???? ???????????????????????????? ??????????????????????????????? ? ???? ??? ?? ?? ?? ??? ??? ???? ?? ???? ? ?? ?? ?? ?? ??? ? ??? ??? ??????????????????? ? ????? ?? ?? ?? ??? ?? ??? ???? ?? ?? ?? ?? ?? ?? ? ???? ? ??? ? ? ? ? ??? ? ? ? ???? ?? ??? ??? ?? ?? ? ??? ?? ??? ? ??? ?? ??? ??? ? ? ?? ?? ??? ?? ??? ??? ??? ??? ???? ??? ? ?? ?? ?? ?? ?? ?? ?? ?? ??? ???? ???? ?? ?? ?? ???? ?? ?? ? ? ? ???????? ? ? ??????? ? ? ???????? ???? ? ????????? ? ???????? ? ? ?????? ?? ?? ????? ???? ????? ? ? ?????? ? ?? ????? ? ? ????? ? ? ??????? ? ? ?????? ? ?? ???????? ? ?? ??????? ? ?? ??? ? ?????????????????
apex microtechnology corporation ? 5980 north shannon road ? tucson, arizona 85741 ? usa ? applications hotline: 1 (800) 546-2739 4 operating considerations PA19 ? PA19a simple for resistive loads but more complex for reactive and emf generating loads. the following guidelines may save extensive analytical efforts: 1. capacitive and inductive loads up to the following maximums are safe: v s capacitive load inductive load 40v .1f 11mh 30v 500f 24mh 20v 2500f 75mh 15v 100mh 2. safe short circuit combinations of voltage and current are limited to a power level of 100w. 3. the output stage is protected against transient ?yback. however, for protection against sustained, high energy ?yback, external fast-recovery diodes should be used. supply current the PA19 features a class a/b driver stage to charge and discharge gate capacitance of q7 and q19. as these currents approach 0.5a, the savings of quiescent current over that of a class a driver stage is considerable. however, supply current drawn by the PA19, even with no load, varies with slew rate of the output signal as shown below. output leads keep the output leads as short as possible. in the video frequency range, even a few inches of wire have signi?cant inductances, raising the interconnection impedance and limit - ing the output current slew rate. furthermore, the skin effect increases the resistance of heavy wires at high frequencies. multistrand litz wire is recommended to carry large video currents with low losses. thermal shutdown the thermal protection circuit shuts off the ampli?er when the substrate temperature exceeds approximately 150c. this allows the heatsink selection to be based on normal operating conditions while protecting the ampli?er against excessive junction temperature during temporary fault conditions. thermal protection is a fairly slow-acting circuit and therefore does not protect the ampli?er against transient soa violations (areas outside of the steady state boundary). it is designed to 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 q2 (and q25) limit output current by turning on and remov - ing gate drive when voltage on pin 2 (pin 7) exceeds .65v dif - ferential from the positive (negative) supply rail. with internal resistors equal to 1.2, current limits are approximately 0.5a with no external current limit resistors. with the addition of external resistors current limit will be: .65v i lim = +.54a r cl to determine values of external current limit resistors: .65v r cl = i cl - .54a phase compensation at low gain settings, an external compensation capacitor is required to insure stability. in addition to the resistive feedback network, roll off or integrating capacitors must also be consid - ered when determining gain settings. the capacitance values listed in the external connection diagram, along with good high frequency layout practice, will insure stability. interpolate values for intermediate gain settings. 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. the soa curves combine the effect of these limits and allow for internal thermal delays. for a given application, the direc - tion and magnitude of the output current should be calculated or measured and checked against the soa curves. this is ??? ??? ??? ??? ??? ??? ??? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?????????????????????? ? ??????? ? ???? ???????????????????????????????????????? ? ???? ? ???? ???????????? ????????? ????????? ? ? ??????? ??? ?????????????? ??? ??? ??? ??? ? ??? ???? ???? ?? ?? ??? ????????????????? ????????????????? ? ????? ? ??? ?????? ??? ????? ? ? ???????
apex microtechnology corporation ? telephone (520) 690-8600 ? fax (520) 888-3329 ? orders (520) 690-8601 ? email prodlit@apexmicrotech.com 5 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 notice. PA19u rev h february 1998 ? 1998 apex microtechnology corp. protect against short-term fault conditions that result in high power dissipation within the ampli?er. if the conditions that cause thermal shutdown are not removed, the ampli?er will oscillate in and out of shutdown. this will result in high peak power stresses, destroy signal integrity, and reduce the reli - ability of the device. stability due to its large bandwidth, the PA19 is more likely to oscil - late than lower bandwidth power operational ampli?ers. to prevent oscillations a reasonable phrase margin must be maintained by: 1. selection of the proper phase compensation capacitor. use the values given in the table under external connec - tions and interpolate if necessary. the phase margin can be increased by using a larger capacitor at the expense of slew rate. total physical length (pins of the PA19, capaci - tor leads plus printed circuit traces) should be limited to a maximum of 3.5 inches. 2. keep the external sumpoint stray capacitance to ground at a minimum and the sumpoint load resistance (input and feedback resistors in parallel) below 500. larger sumpoint load resistances can be used with increased phase com - pensation and/or by bypassing the feedback resistor. 3. connect the case to any ac ground potential. operating considerations PA19 ? PA19a
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