POWER BOOSTER AMPLIFIERS PB58 • PB58A 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 • WIDE SUPPLY RANGE — ±15V to ±150V • HIGH OUTPUT CURRENT — 1.5A Continuous (PB58) 2.0A Continuous (PB58A) • VOLTAGE AND CURRENT GAIN • HIGH SLEW — 50V/µs Minimum (PB58) 75V/µs Minimum (PB58A) • PROGRAMMABLE OUTPUT CURRENT LIMIT • HIGH POWER BANDWIDTH — 320 kHz Minimum • LOW QUIESCENT CURRENT — 12mA Typical • EVALUATION KIT — See EK50 EQUIVALENT SCHEMATIC 3 +Vs APPLICATIONS Q2 Q1 • HIGH VOLTAGE INSTRUMENTATION • Electrostatic TRANSDUCERS & DEFLECTION • Programmable Power Supplies Up to 280V p-p Q3 IN 4 DESCRIPTION The PB58 is a high voltage, high current amplifier designed to provide voltage and current gain for a small signal, general purpose op amp. Including the power booster within the feedback loop of the driver amplifier results in a composite amplifier with the accuracy of the driver and the extended output voltage range and current capability of the booster. The PB58 can also be used without a driver in some applications, requiring only an external current limit resistor to function properly. The output stage utilizes complementary MOSFETs, providing symmetrical output impedance and eliminating second breakdown limitations imposed by Bipolar Transistors. Internal feedback and gainset resistors are provided for a pin-strapable gain of 3. Additional gain can be achieved with a single external resistor. Compensation is not required for most driver/gain configurations, but can be accomplished with a single external capacitor. Enormous flexibility is provided through the choice of driver amplifier, current limit, supply voltage, voltage gain, and compensation. This hybrid circuit utilizes a beryllia (BeO) substrate, thick film resistors, ceramic capacitors and semiconductor chips to maximize reliability, minimize size and give top performance. Ultrasonically bonded aluminum wires provide reliable interconnections at all operating temperatures. The 8-pin TO-3 package is electrically isolated and hermetically sealed using one-shot resistance welding. The use of compressible isolation washers voids the warranty. Figure 1. Inverting TYPICAL APPLICATION composite amplifier. C Q4 OUT 1 50K 3.1K Q11 COMP 8 Q8 Q9 RI +15V +Vs EXTERNAL CONNECTIONS R CL +Vs CL 3 1 4 TOP VIEW COMP 5 8 PB58 –Vs CC R CL 7 IN COM –15V 2 OUT IN –Vs 6 OP AMP Q10 –Vs 6 COM VIN 2 CL Q7 COM 5 F RF Q5 Q6 GAIN 6.2K 7 OUT CC RG GAIN RL RG APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL [email protected] ABSOLUTE MAXIMUM RATINGS SPECIFICATIONS PB58 • PB58A ABSOLUTE MAXIMUM RATINGS SUPPLY VOLTAGE, +VS to –VS OUTPUT CURRENT, within SOA POWER DISSIPATION, internal at TC = 25°C1 INPUT VOLTAGE, referred to COM TEMPERATURE, pin solder—10 sec max TEMPERATURE, junction1 TEMPERATURE, storage OPERATING TEMPERATURE RANGE, case SPECIFICATIONS PB58 TEST CONDITIONS2 PARAMETER 300V 2.0A 83W ±15V 300°C 175°C –65 to +150°C –55 to +125°C MIN PB58A TYP MAX ±.75 –4.5 50 3 10 ±10 ±15 10 60 ±1.75 –7 MIN TYP MAX UNITS ±1.0 * V mV/°C kΩ pF V/V % % ° ° INPUT OFFSET VOLTAGE, initial OFFSET VOLTAGE, vs. temperature INPUT IMPEDANCE, DC INPUT CAPACITANCE CLOSED LOOP GAIN RANGE GAIN ACCURACY, internal Rg, Rf GAIN ACCURACY, external Rf PHASE SHIFT Full temperature range3 25 3 AV = 3 AV = 10 f = 10kHz, AVCL = 10, CC = 22pF f = 200kHz, AVCL = 10, CC = 22pF * 25 ±15 ±25 * * * * * * * * * * * * * OUTPUT VOLTAGE SWING VOLTAGE SWING VOLTAGE SWING CURRENT, continuous SLEW RATE CAPACITIVE LOAD SETTLING TIME to .1% POWER BANDWIDTH SMALL SIGNAL BANDWIDTH SMALL SIGNAL BANDWIDTH Io = 1.5A (PB58), 2A (PB58A) Io = 1A Io = .1A Full temperature range Full temperature range RL = 100Ω, 2V step VC = 100 Vpp CC = 22pF, AV = 25, Vcc = ±100 CC = 22pF, AV = 3, Vcc = ±30 VS–11 VS–10 VS–8 1.5 50 160 VS –8 VS –7 VS –5 VS–15 * * 2.0 75 100 2200 2 320 100 1 240 VS–11 * * V V V A V/µs pF µs kHz kHz MHz * * * * * * POWER SUPPLY VOLTAGE, ±VS4 CURRENT, quiescent Full temperature range VS = ±15 VS = ±60 VS = ±150 ±156 ±60 11 12 14 ±150 1.2 1.6 30 25 1.3 1.8 * 18 * * * * * V mA mA mA * THERMAL RESISTANCE, AC junction to case5 RESISTANCE, DC junction to case RESISTANCE, junction to air TEMPERATURE RANGE, case NOTES: * 1. 2. 3. 4. 5. 6. CAUTION Full temp. range, f > 60Hz Full temp. range, f < 60Hz Full temperature range Meets full range specifications –25 85 * * * * * * * * °C/W °C/W °C/W °C The specification of PB58A is identical to the specification for PB58 in applicable column to the left. Long term operation at the maximum junction temperature will result in reduced product life. Derate internal power dissipation to achieve high MTTF (Mean Time to Failure). The power supply voltage specified under typical (TYP) applies, TC = 25°C unless otherwise noted. Guaranteed by design but not tested. +VS and –VS denote the positive and negative supply rail respectively. Rating applies if the output current alternates between both output transistors at a rate faster than 60Hz. +VS/–VS must be at least 15V above/below COM. The PB58 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. APEX MICROTECHNOLOGY CORPORATION • 5980 NORTH SHANNON ROAD • TUCSON, ARIZONA 85741 • USA • APPLICATIONS HOTLINE: 1 (800) 546-2739 POWER DERATING CURRENT LIMIT –45 –90 0 100 1K 10K 100K 1M FREQUENCY, F (Hz) –180 10M 20 AV CL = 10 10 AV CL = 3 0 10 50V V 00 Vs = ±1 Vs = ±3 0V 5 0 0 25 50 –25 75 100 125 CASE TEMPERATURE, T C (°C) C C = 22pF 10K 100K 1M FREQUENCY, F (Hz) -1 AV CL = 25 C C = 22pF –180 1K 60 100 50 40 30 20 10M 10M SLEW RATE VS. TEMP. +S LE W 200 100 -SLEW 0 –25 0 25 50 75 100 125 CASE TEMPERATURE, T C (°C) 0 25 50 75 100 125 CASE TEMPERATURE, TC (°C) HARMONIC DISTORTION .1 DISTORTION, THD (%) 200 10K 100K 1M FREQUENCY, F (Hz) 300 PULSE RESPONSE 80 AV CL = 10 –90 400 -.5 -1.5 –25 OUTPUT VOLTAGE, VQ (V) OUTPUT VOLTAGE, VQ (VPP ) 10M 0 POWER RESPONSE 1M 300K 3M FREQUENCY, F (Hz) –45 .5 300 10 100K AV CL = 3 INPUT OFFSET VOLTAGE Vs = ±1 2 –135 –10 1K INPUT OFFSET VOLTAGE, VOS (V) QUIESCENT CURRENT, I Q (mA) 15 .05 1 1.5 OUTPUT CURRENT, I O (A) 0 AV CL = 25 QUIESCENT CURRENT 20 4 .01 SMALL SIGNAL RESPONSE 30 –135 VO + 6 40 20 0 -20 -40 .03 DRIVER = TL070 VS = ±60V V O = 95VPP Ω 20 VO - 8 .01 R 40 10 R 60 25 0 50 75 100 125 CASE TEMPERATURE, TC (°C) 12 SMALL SIGNAL RESPONSE 0 OPEN LOOP PHASE, ϕ (°) OPEN LOOP GAIN, A (dB) 0 –25 CLOSED LOOP PHASE, ϕ (°) SMALL SIGNAL RESPONSE 80 R CL = 1.5 Ω .5 0 25 50 75 100 125 CASE TEMPERATURE, TC (°C) 7Ω RC = L .68 Ω 1 CLOSED LOOP GAIN, A (dB) 0 –25 = .4 1K 20 CL = 40 R L 60 1.5 5Ω 80 OUTPUT VOLTAGE SWING 14 =3 CURRENT LIMIT, I LIM (A) 2 L 100 VOLTAGE DROP FROM SUPPLY, VS — VO (V) PB58 • PB58A SLEW RATE, SR (V/µ s) INTERNAL POWER DISSIPATION, P(W) TYPICAL PERFORMANCE GRAPHS .003 -60 -80 1 2 3 4 5 6 TIME, t (µs) 7 8 .001 300 10K 1K 3K FREQUENCY, F (Hz) 30K APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL [email protected] OPERATING CONSIDERATIONS PB58 • PB58A GENERAL STABILITY 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. Stability can be maximized by observing the following guidelines: 1. Operate the booster in the lowest practical gain. 2. Operate the driver amplifier in the highest practical effective gain. 3. Keep gain-bandwidth product of the driver lower than the closed loop bandwidth of the booster. 4. Minimize phase shift within the loop. CURRENT LIMIT For proper operation, the current limit resistor (RCL) must be connected as shown in the external connection diagram. The minimum value is 0.33Ω with a maximum practical value of 47Ω. For optimum reliability the resistor value should be set as high as possible. The value is calculated as follows: +IL= .65/ RCL + .010, -IL = .65/RCL. SAFE OPERATING AREA (SOA) OUTPUT CURRENT FROM +Vs or –Vs (A) 3 2 t= 1 ste ad ys te ys Tc 0m ta te 12 s ys ta = 10 ad ad ta .5 .4 .3 ste ste Tc A good compromise for (1) and (2) is to set booster gain from 3 to 10 with total (composite) gain at least a factor of 3 times booster gain. Guideline (3) implies compensating the driver as required in low composite gain configurations. Phase shift within the loop (4) is minimized through use of booster and loop compensation capacitors Cc and Cf when required. Typical values are 5pF to 33pF. Stability is the most difficult to achieve in a configuration where driver effective gain is unity (ie; total gain = booster gain). For this situation, Table 1 gives compensation values for optimum square wave response with the op amp drivers listed. = 5° C 85 te °C Tc = 25 °C .2 .1 10 20 30 40 50 100 200 300 SUPPLY TO OUTPUT DIFFERENTIAL VOLTAGE, Vs –Vo (V) NOTE: The output stage is protected against transient flyback. However, for protection against sustained, high energy flyback, external fast-recovery diodes should be used. COMPOSITE AMPLIFIER CONSIDERATIONS Cascading two amplifiers within a feedback loop has many advantages, but also requires careful consideration of several amplifier and system parameters. The most important of these are gain, stability, slew rate, and output swing of the driver. Operating the booster amplifier in higher gains results in a higher slew rate and lower output swing requirement for the driver, but makes stability more difficult to achieve. GAIN SET DRIVER OP07 741 LF155 LF156 TL070 CF 22p 18p 4.7p 4.7p 15p CCH 22p CC 22p 10p 10p 10p 10p FPBW 4kHz 20kHz 60kHz 80kHz 80kHz SR 1.5 7 >60 >60 >60 For: RF = 33K, RI = 3.3K, RG = 22K Table 1: Typical values for case where op amp effective gain = 1. CF +15V RI RF CCH OP AMP VIN R CL +Vs IN COM PB58 –15V OUT COMP CC –Vs RL GAIN R G Figure 2. Non-inverting composite amplifier. RG = [ (Av-1) * 3.1K] – 6.2K Av = RG + 6.2K SLEW RATE +1 3.1K The booster’s closed-loop gain is given by the equation above. The composite amplifier’s closed loop gain is determined by the feedback network, that is: –Rf/Ri (inverting) or 1+Rf/Ri (non-inverting). The driver amplifier’s “effective gain” is equal to the composite gain divided by the booster gain. Example: Inverting configuration (figure 1) with R i = 2K, R f = 60K, R g = 0 : Av (booster) = (6.2K/3.1K) + 1 = 3 Av (composite) = 60K/2K = – 30 Av (driver) = – 30/3 = –10 The slew rate of the composite amplifier is equal to the slew rate of the driver times the booster gain, with a maximum value equal to the booster slew rate. OUTPUT SWING The maximum output voltage swing required from the driver op amp is equal to the maximum output swing from the booster divided by the booster gain. The Vos of the booster must also be supplied by the driver, and should be subtracted from the available swing range of the driver. Note also that effects of Vos drift and booster gain accuracy should be considered when calculating maximum available driver swing. This data sheet has been carefully checked and is believed be reliable, however, no responsibility assumed forARIZONA possible inaccuracies All specifications are subject to change without notice. APEX MICROTECHNOLOGY CORPORATION • to 5980 NORTH SHANNON ROAD •is TUCSON, 85741 or • omissions. USA • APPLICATIONS HOTLINE: 1 (800) 546-2739 PB58U REV. H JANUARY 1998 © 1998 Apex Microtechnology Corp.