PA88A

PA88 • PA88A High Voltage Power Operational Amplifiers RoHS COMPLIANT FEATURES • • • • • High Voltage— 450V (±225V) Low Quiescent Current — 2mA 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 MOSFET operational amplifier designed for output cur‐ rents up to 100mA. Output voltages can swing up to ±215V with a dual supply and up to +440 volts with a sin‐ gle 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 configuration. 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 flexibility. This hybrid circuit utilizes beryllia (BeO) substrates, thick film resistors, ceramic capacitors and semicon‐ ductor chips to maximize reliability, minimize size and give top performance. Ultrasonically bonded alumi‐ num wires provide reliable interconnections 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 Application Note 1, “General Operating Considerations.” www.apexanalog.com © Apex Microtechnology Inc. All rights reserved Aug 2017 PA88U Rev S PA88 • PA88A TYPICAL CONNECTION Figure 1: Typical Connection 2 PA88U Rev S PA88 • PA88A PINOUT AND DESCRIPTION TABLE Figure 2: External Connections Pin Number Name Description 1 OUT The output. Connect this pin to load and to the feedback resistors. 2 CL Connect to the current limit resistor. Output Current flows into/out of these pins through RCL. The output pin and the load are connected to the other side of RCL. 3 +Vs The positive supply rail. 4 +IN The non‐inverting input. 5 ‐IN The inverting input. 6 ‐Vs The negative supply rail. 7 RC Compensation resistor connection. Select value based on Phase Compensation. See applicable section. 8 CC Compensation capacitor connection. Select value based on Phase Compensation. See applicable section. PA88U Rev S 3 PA88 • PA88A SPECIFICATIONS Unless otherwise noted: TC = 25°C, compensation = CC = 68pF, RC = 100 Ω. DC input specifications are ± value given. Power supply voltage is typical rating. ABSOLUTE MAXIMUM RATINGS Parameter Symbol Max Units +Vs to ‐Vs 450 V Output Current IO See SOA Power Dissipation, continuous @ Tc = 25°C PD 15 W VIN (Diff) ±25 V Vcm ±VS V 350 °C 150 °C ‐65 +150 °C ‐55 +125 °C Supply Voltage, +Vs To ‐Vs Input Voltage, differential Input Voltage, common mode Min Temperature, pin solder ‐ 10s max. Temperature, junction 1 TJ Temperature, storage TC Operating Temperature Range, case 1. Long term operation at the maximum junction temperature will result in reduced product life. Derate internal power dis‐ sipation to achieve high MTTF. INPUT Test Conditions Parameter PA88 Min Offset Voltage, initial Offset Voltage vs. Temperature Full temp range PA88A Typ Max 0.5 2 Min Units Typ Max 0.25 0.5 mV 10 30 5 10 µV/°C Offset Voltage vs. Supply 1 5 * * µV/V Offset Voltage vs. Time 75 Bias Current, initial 1 5 * 50 3 µV/√kh 10 Bias Current vs. Supply 0.01 Offset Current, initial 1 2.5 Input Impedance, DC 1011 * Ω 4 * pF Input Capacitance Common Mode Voltage Range 2 * pA 100 ±VS–15 Common Mode Rejection, DC VCM = ±90V Noise 100 kHz BW, RS=1 kΩ, CC=15pf 90 3 * 110 2 * pA/V 20 pA V * dB * µVrms 1. Doubles for every 10°C of temperature increase. 2. +VS and –VS denote the positive and negative power supply rail respectively. 4 PA88U Rev S PA88 • PA88A GAIN Parameter Test Conditions PA88 Min Typ 96 111 PA88A Max Max Units Min Typ * * dB Open Loop, @ 15 Hz RL= 2 kΩ, CC= OPEN Gain Bandwidth Product @ 1 MHz RL = 2 kΩ, CC = 15pf, RC = 100 Ω 2.1 * MHz Power Bandwidth RL = 2 kΩ, CC = 15pf, RC = 100 Ω 6 * kHz Phase Margin Full temp range 60 * ° Test Conditions PA88 PA88A OUTPUT Parameter Min Typ Max Min Typ Max Units Voltage Swing 1 Full temp range, ±VS–16 ±VS–14 IO = ±75mA * * V Voltage Swing 1 Full temp range, ±VS–10 ±VS–5.2 IO = ±20mA * * V Current, continuous TC = 85°C * mA Slew Rate, AV = 20 CC = 15pf, RC = 100 Ω 8 * V/µs Slew Rate, AV = 100 CC = OPEN 30 * V/µs Capacitive Load, AV = +1 Full temp range Settling Time to 0.1% CC = 15pf, RC = 100 Ω, 2V step 10 * µs Resistance, no load RCL = 0 100 * Ω ±100 470 * pF 1. +VS and –VS denote the positive and negative power supply rail respectively. POWER SUPPLY Parameter Voltage1 Current, quiescent, Test Conditions PA88 PA88A Units Min Typ Max Min Typ Max ±15 ±200 ±225 * * * V 1.7 2 * * mA 1. Derate max supply rating 0.625 V/°C below 25°C case. No derating needed above 25°C case. PA88U Rev S 5 PA88 • PA88A THERMAL Parameter Test Conditions PA88 Min Typ PA88A Max Min Typ Max Units Resistance, AC, junction to case1 Full temp range, F > 60 Hz 5 * °C/W Resistance, DC, junction to case Full temp range, F < 60 Hz 8.3 * °C/W Resistance, junction to air Full temp range Temperature Range, case Meets full range specifications 30 ‐25 * +85 * °C/W * °C 1. Rating applies if the output current alternates between both output transistors at a rate faster than 60 Hz. CAUTION 6 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 850°C to avoid generating toxic fumes. PA88U Rev S PA88 • PA88A TYPICAL PERFORMANCE GRAPHS Figure 4: Quiescent Current 15 2.5 12.5 2.25 Quiescent Current, IQ (mA) /ŶƚĞƌŶĂůƉŽǁĞƌŝƐƐŝƉĂƟŽŶ͕W;t) Figure 3: Power Derating T = TC 10 7.5 T = TA 5 2.5 0 5°C T C = 12 2.0 5°C TC = 2 °C T = -55 1.75 C 1.0 1.25 1.0 0 25 50 75 100 125 0 150 120 0 100 -30 CC = 3.3pF CC = 33pF CC = 68pF 20 450 CC = 3.3pF -60 80 40 300 Figure 6: Phase Response Phase ˇ;Σ) Open Loop Gain, A (dB) Figure 5: Small Signal Response CC = 15pF 200 Total Supply Voltage, VS (V) Temperature (°C) 60 100 CC = 33pF CC = 68pF -90 CC = 68pF -120 -150 0 -180 -20 -210 CC = 33pF CC = 3.3pF 1 10 100 1k 10k .1M 1M 10M Frequency, F (Hz) PA88U Rev S 1 10 100 1k 10k .1M 1M 10M Frequency, F (Hz) 7 PA88 • PA88A Figure 7: Output Voltage Swing Figure 8: Power Response 500 Output Voltage, VO (VPP) 50 TC=-55°C 40 60 80 25 1k 100 2k 3k 5k 10k 20k 50k 100k Frequency, F (Hz) Output Current, Io (mA) Figure 9: Slew Rate Figure 10: Harmonic Distortion 10 50 30 1 ŝƐƚŽƌƟŽŶ;йͿ 20 ^ůĞǁZĂƚĞ;sͬʅƐ) f 5p =1 f 75 TC=25°C 4 2 20 10 5 RLсϮŬɏ PO = 2.5W AV = 30 0.1 .01 3 .001 2 1 .0001 0 10 20 30 40 50 60 ŽŵƉĞŶƐĂƟŽŶĂƉĂĐŝƚŽƌ͕C;Ɖ&) 8 3p f 6 125 100 8p 8 =3 10 =6 TC=85°C 12 CC 14 250 CC TC=125°C f .3p =3 16 CC WŽƐŝƟǀĞ 18 EĞŐĂƟǀĞ CC Voltage Drop From Supply, Vs-Vo (V) 20 70 3 30 300 3k 30k Frequency, F (Hz) PA88U Rev S PA88 • PA88A Figure 11: Input Noise Figure 12: Common Mode Rejection 120 ŽŵŵŽŶDŽĚĞZĞũĞĐƟŽŶ͕DZ;ĚͿ Input Noise Voltage, VN;Ŷsͬя,njͿ 20 15 10 7 5 3 2 10 100 1k 10k 100 80 60 40 20 1 100k 10 1k 10k .1M 1M Frequency, F (Hz) Frequency, F (Hz) Figure 13: Power Supply Rejection Figure 14: Current Limit 140 200 120 120 100 Current Limit, ILIM (mA) WŽǁĞƌ^ƵƉƉůLJZĞũĞĐƟŽŶ͕W^Z;ĚͿ 100 100 80 60 70 50 30 20 40 20 1 10 10 100 1k 10k Frequency, F (Hz) PA88U Rev S .1M 1M 3 5 10 20 50 100 150 Current Limit Resistor, RCL;ɏ) 9 PA88 • PA88A SAFE OPERATING AREA (SOA) The MOSFET output stage of this power operational amplifier 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 flyback. However, for protection against sustained, high energy flyback, external fast‐recovery diodes should be used. KƵƚƉƵƚƵƌƌĞŶƚ&ƌŽŵ+VSŽƌʹsS͕;ŵͿ Figure 15: SOA 250 ϭϬ 150 Ϭŵ ϮϬ ^ Ϭŵ 100  ^ ͕d C= 25 ͕d °C C= 85 °C  50  ͕d C= 12 5° C 25 15 10 5 25 50 75 100 125 250 500 ^ƵƉƉůLJƚŽKƵƚƉƵƚŝīĞƌĞŶƟĂů͕VS –VO (V) 10 PA88U Rev S PA88 • PA88A GENERAL Please read Application Note 1 “General Operating Considerations” which covers stability, supplies, heat sinking, mounting, current limit, SOA interpretation, and specification interpretation. Visit www.apexana‐ log.com for Apex Microtechnology’s complete Application Notes library, Technical Seminar Workbook, and Evaluation Kits. 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 com‐ plex systems the PA88’s 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 posi‐ tioners. Figure 16: Typical Application RF CC +V S RC RIN PIEZO DRIVE V OUT PA88 COMPUTER FOCUSED COMMAND VOLTAGE RCL -V S PHASE COMPENSATION Gain CC* RC 1 68pf 100Ω 10 33pf 100Ω 20 15pf 100Ω 100 15pf ‐‐‐ *CC Rate for full supply voltage PA88U Rev S 11 PA88 • PA88A STABILITY The PA88 has sufficient phase margin to be stable with most capacitive loads at a gain of 4 or more, using the recommended phase compensation. The PA88 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 amplifier pins 7 and 8 to avoid spurious oscillation. CURRENT LIMIT For proper operation, the current limit resistor (RCL) must be connected as shown in the typical connec‐ tion diagram. The minimum value is 3.5 Ω, 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 Ω. 0.7V R CL    = ------------------I LIM  A  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 sufficient (D1, D2 in Figure 17a). 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 17b). In either case the input differential voltage will be clamped to ± 0.7V. This is sufficient overdrive to produce maximum power bandwidth. 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 per‐ formance 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. 12 PA88U Rev S PA88 • PA88A Figure 17: Overvoltage Protection PA88U Rev S 13 PA88 • PA88A PACKAGE OPTIONS PACKAGE STYLE CE NEED TECHNICAL HELP? CONTACT APEX SUPPORT! For all Apex Microtechnology product questions and inquiries, call toll free 800-546-2739 in North America. For inquiries via email, please contact apex.support@apexanalog.com. International customers can also request support by contacting their local Apex Microtechnology Sales Representative. To find the one nearest to you, go to www.apexanalog.com IMPORTANT NOTICE Apex Microtechnology, Inc. has made every effort to insure the accuracy of the content contained in this document. However, the information is subject to change without notice and is provided "AS IS" without warranty of any kind (expressed or implied). 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APEX MICROTECHNOLOGY PRODUCTS ARE NOT DESIGNED, AUTHORIZED OR WARRANTED TO BE SUITABLE FOR USE IN PRODUCTS USED FOR LIFE SUPPORT, AUTOMOTIVE SAFETY, SECURITY DEVICES, OR OTHER CRITICAL APPLICATIONS. PRODUCTS IN SUCH APPLICATIONS ARE UNDERSTOOD TO BE FULLY AT THE CUSTOMER OR THE CUSTOMER’S RISK. Apex Microtechnology, Apex and Apex Precision Power are trademarks of Apex Microtechnology, Inc. All other corporate names noted herein may be trademarks of their respective holders. 14 PA88U Rev S