HIGH VOLTAGE POWER OPERATIONAL AMPLIFIER PA95 HTTP://WWW.APEXMICROTECH.COM M I C R O T E C H N O L O G Y (800) 546-APEX (800) 546-2739 FEATURES • • • • HIGH VOLTAGE — 900V (±450V) LOW QUIESCENT CURRENT — 1.6mA HIGH OUTPUT CURRENT — 100mA PROGRAMMABLE CURRENT LIMIT APPLICATIONS • • • • HIGH VOLTAGE INSTRUMENTATION PROGRAMMABLE POWER SUPPLIES UP TO ±430V MASS SPECTROMETERS SEMICONDUCTOR MEASUREMENT EQUIPMENT PATENT PENDING DESCRIPTION The PA95 is a high voltage, MOSFET operational amplifier designed as a low cost solution for driving continuous output currents up to 100mA and pulse currents up to 200mA into capacitive loads. The safe operating area (SOA) has no second breakdown limitations and can be observed for all load types by choosing an appropriate current limiting resistor. The MOSFET output stage is biased AB for linear operation. External compensation provides flexibility in choosing bandwidth and slew rate for the application. APEX’s Power SIP04 package uses a minimum of board space allowing for high density circuit boards. TYPICAL APPLICATION 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 PA95 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. RF EQUIVALENT SCHEMATIC 12 +VS R1 R2 C1 +VS R IN R3 1 12 PIEZO DRIVE 7 PA95 Q1 Q3 Q2 R4 Q4 Q6 4 CC1 Q5 V OUT 2 6 CC2 ILIM 8 Q8 8 COMPUTER FOCUS COMMAND VOLTAGE 10 R CL –V S R7 Q11 1 –IN 7 OUT R6 R5 R8 R9 Q12 Q13 EXTERNAL CONNECTIONS –IN +IN CC1 1 2 4 PACKAGE SIP04 CC2 OUT Ilim 6 7 8 Q14 2 R10 +IN Cc Q16 RLIM –Vs +Vs 10 12 * * Q15 R11 –VS 10 R12 * .01µF or greater ceramic power supply bypassing required. PHASE COMPENSATION GAIN CC ≥10 4.7pF R LIM = .7 ILIM APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL [email protected] ABSOLUTE MAXIMUM RATINGS SPECIFICATIONS PA95 SUPPLY VOLTAGE, +VS to –VS OUTPUT CURRENT, source, sink POWER DISSIPATION, continuous @ TC = 25°C INPUT VOLTAGE, differential INPUT VOLTAGE, common mode3 TEMPERATURE, pin solder - 10s max TEMPERATURE, junction2 TEMPERATURE, storage OPERATING TEMPERATURE RANGE, case ABSOLUTE MAXIMUM RATINGS 900V 200mA, within SOA 30W ±20V ±VS 220°C 150°C –65 to +150°C –55 to +125°C SPECIFICATIONS TEST CONDITIONS 1 PARAMETER MIN TYP MAX UNITS .5 15 10 75 200 4 50 1011 4 5 50 25 98 2 mV µV/°C µV/V µV/√kh pA pA/V pA Ω pF V dB µVrms 94 118 10 20 60 dB MHz kHz ° ±VS 24 100 ±VS 20 V mA V/µs µs Ω INPUT Full temperature range Vs=±250V SEE NOTE 3 VCM = ±90V 10KHz BW, RS = 1KΩ ±VS 30 80 ± OFFSET VOLTAGE, initial OFFSET VOLTAGE, vs. temperature OFFSET VOLTAGE, vs. supply OFFSET VOLTAGE, vs. time BIAS CURRENT, initial BIAS CURRENT, vs. supply OFFSET CURRENT, initial INPUT IMPEDANCE, DC INPUT CAPACITANCE COMMON MODE VOLTAGE RANGE3 COMMON MODE REJECTION, DC NOISE 2000 500 GAIN OPEN LOOP, @ 15Hz GAIN BANDWIDTH PRODUCT at 1MHz POWER BANDWIDTH PHASE MARGIN,Av=10 RL = 5KΩ RL = 5KΩ RL = 5KΩ Full temperature range OUTPUT ± IO = 100mA CC =4.7pF 2V step no load ± VOLTAGE SWING CURRENT, continuous SLEW RATE, AV = 100 SETTLING TIME to .1% RESISTANCE 30 1 100 POWER SUPPLY VOLTAGE 5 CURRENT, quiescent See note 5 ±50 ±300 1.6 ±450 2.2 V mA 2.5 4.2 °C/W °C/W °C/W °C THERMAL RESISTANCE, AC, junction to case 4 RESISTANCE, DC, junction to case RESISTANCE, junction to air TEMPERATURE RANGE, case NOTES: 1. 2. 3. 4. 5. CAUTION Full temperature range, F > 60Hz Full temperature range, F < 60Hz Full temperature range 30 –25 +85 Unless otherwise noted: TC = 25°C, DC input specifications are ± value given. Power supply voltage is typical rating. Cc= 4.7pF. Long term operation at the maximum junction temperature will result in reduced product life. Derate internal power dissipation to achieve high MTTF. Although supply voltages can range up to ± 450V the input pins cannot swing over this range. The input pins must be at least 30V from either supply rail but not more than 500V from either supply rail. See text for a more complete description of the common mode voltage range. Rating applies if the output current alternates between both output transistors at a rate faster than 60Hz. Derate max supply rating .625 V/°C below 25°C case. No derating needed above 25°C case. The PA95 is constructed from MOSFET transistors. ESD handling procedures must be observed. APEX MICROTECHNOLOGY CORPORATION • 5980 NORTH SHANNON ROAD • TUCSON, ARIZONA 85741 • USA • APPLICATIONS HOTLINE: 1 (800) 546-2739 PA95 POWER DERATING 30 PHASE RESPONSE QUIESCENT CURRENT, I(X) T = TC 10 T = TA 80 C C = 4.7pF 60 40 20 100 1K 10K 100K 1M 10M FREQUENCY, F (Hz) CURRENT LIMIT 200 120 100 70 50 30 20 10 50 100 150 3 5 10 20 CURRENT LIMIT RESISTOR, RCL (Ω ) -360 1M 1.00 .96 .92 .88 0 2M 3M 4M 5M FREQUENCY, F (Hz) POWER RESPONSE 12 5° C 1K = 20 = °C 85 TC 16 25° C T C= 12 TC = –55°C 8 500 C C= 4.7pF 200 100 4 0 250 SAFE OPERATING AREA 10 0m S 0m S 20 100 DC 50 DC ,T C ,T C DC 15 50 10K 100 20 40 80 60 OUTPUT CURRENT, I O (mA) 150 25 200 800 1000 400 600 TOTAL SUPPLY VOLTAGE, VS (V) OUTPUT VOLTAGE SWING 24 C 150 T 25 50 75 100 125 TEMPERATURE, T (°C) 100 0 10 -270 -315 0 0 -225 VOLTAGE DROP FROM SUPPLY, V S – VO (V) 5 C = 4.7pF OUTPUT VOLTAGE, VO (VP-P) 15 -180 1.04 ,T C = = = 85 25 ° °C C 12 5° C 10 PULSE CURVES @ 10% DUTY CYCLE MAX INPUT NOISE VOLTAGE, VN (nV/√Hz) PHASE, φ(°) 20 SMALL SIGNAL RESPONSE OPEN LOOP GAIN, A (dB) 1.08 -135 25 120 CURRENT LIMIT, I LIM (mA) QUIESCENT CURRENT -90 OUTPUT CURRENT FROM +VS OR –VS, (mA) INTERNAL POWER DISSIPATION, P(W) TYPICAL PERFORMANCE GRAPHS 20 100K FREQUENCY, F (Hz) 300K INPUT NOISE 15 10 7 5 3 5 2 100 50 200 500 1K 10 SUPPLY TO OUTPUT DIFFERENTIAL, VS –VO (V) 100 1K 10K FREQUENCY, F (Hz) 1M APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL [email protected] OPERATING CONSIDERATIONS PA95 GENERAL Please read the “General Operating Considerations” section, which covers stability, supplies, heatsinking, mounting, current limit, SOA interpretation, and specification interpretation. Additional information can be found in the application notes. For information on the package outline, heatsinks, and mounting hardware, consult the “Accessory and Package Mechanical Data” section of the handbook. CURRENT LIMIT For proper operation, the current limit resistor (RLIM) 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 RLIM = ILIM COMMON MODE INPUT RANGE Operational amplifiers are usually designed to have a common mode input voltage range that approximates the power supply voltage range. However, to keep the cost as low as possible and still meet the requirements of most applications the common mode input voltage range of the PA95 is restricted. The input pins must always be a least 30V from either supply voltage but never more than 500V. This means that the PA95 cannot be used in applications where the supply voltages are extremely unbalanced. For example, supply voltages of +800V and –100V would not be allowed in an application where the non-inverting pin is grounded because in normal operation both input pins would be at 0V and the difference voltage between the positive supply and the input pins would be 800V. In this kind of application, however, supply voltages +500V and -100V does meet the input common mode voltage range requirements since the maximum difference voltage between the inputs pins and the supply voltage is 500V (the maximum allowed). The output has no such restrictions on its voltage swing. The output can swing within 24V of either supply voltage regardless of value so long as the total supply voltage does not exceed 900V. INPUT PROTECTION Although the PA95 can withstand differential input voltages up to ±20V, additional external protection is recommended. In most applications 1N4148 or 1N914 signal diodes are sufficient (D1, D2 in Figure 1a). 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 1b). In either case the input differential voltage will be clamped to ±.7V. This is sufficient overdrive to produce maximum power bandwidth. Note that this protection does not automatically protect the amplifier from excessive common mode input voltages. POWER SUPPLY PROTECTION Unidirectional zener diode transient suppressors are recommended 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 amplifier as possible. STABILITY The PA95 is stable at gains of 10 or more with a NPO (COG) compensation capacitor of 4.7pF. The compensation capacitor, Cc, in the external connections diagram must be rated at 1000V working voltage and mounted closely to pins 4 and 6 to prevent spurious oscillation. A compensation capacitor less than 4.7pF is not recommended. EXTERNAL COMPONENTS The compensation capacitor Cc must be rated for the total supply voltage. An NPO (COG)capacitor rated a 1kV is recommended. Of equal importance are the voltage rating and voltage coefficient of the gain setting feedback resistor. Typical voltage ratings of low wattage resistors are 150 to 250V. Up to 500 V can appear across the feedback resistor. High voltage rated resistors can be obtained. However a 1 megohm feedback resistor composed of five 200k resistors in series will produce the proper voltage rating. CAUTIONS The operating voltages of the PA95 are potentially lethal. During circuit design develop a functioning circuit at the lowest possible voltages. Clip test leads should be used for "hands off" measurements while troubleshooting. A. +VS Z1 –IN D1 +IN 1 12 D2 PA95 2 10 +VS Z2 Z1 –VS B. –IN Q1 +IN 1 12 Q2 PA95 2 10 Z2 FIGURE 1. OVERVOLTAGE PROTECTION –VS This data sheet has been carefully checked and is believed to be reliable, however, no responsibility is assumed for possible inaccuracies or omissions. All specifications are subject to change without notice. PA95U REV. B DECEMBER 1999 © 1999 Apex Microtechnology Corp.