PA341 PA341 PA341 High Voltage Power Operational Amplifier FEATURES RoHS COMPLIANT MONOLITHIC MOS TECHNOLOGY LOW COST HIGH VOLTAGE OPERATION-350V LOW QUIESCENT CURRENT TYP.-2.2mA NO SECOND BREAKDOWN HIGH OUTPUT CURRENT-120mA PEAK AVAILABLE IN DIE FORM-CPA341 APPLICATIONS PIEZO ELECTRIC POSITIONING ELECTROSTATIC TRANSDUCER AND DEFLECTION DEFORMABLE MIRROR FOCUSING BIOCHEMISTRY STIMULATORS COMPUTER TO VACUUM TUBE INTERFACE DESCRIPTION The PA341 is a high voltage monolithic MOSFET operational amplifier which achieves performance features previously found only in hybrid designs while increasing reliability. Inputs are protected from excessive common mode and differential mode voltages. The safe operating area (SOA) has no second breakdown limitation and can be observed with all type loads by choosing an appropriate current limiting resistor. External compensation provides the user flexibility in choosing optimum gain and bandwidth for the application. The PA341CE is packaged in a hermetically sealed 8-pin TO-3 package. The metal case of the PA341CE is isolated in excess of full supply voltage. The PA341DF is packaged in a 24 pin PSOP (JEDEC MO-166) package. The metal heat slug of the PA341DF is isolated in excess of full supply voltage. The PA341DW is packaged in Apex Microtechnology's hermetic ceramic SIP package. The alumina ceramic isolates the die in excess of full supply voltage. FIGURE 1. Equivalent Schematic +VS C C1 CC2 ILIM +IN -IN OUT -VS www.apexanalog.com PA341U Copyright (c) Apex Microtechnology, Inc. 2012 (All Rights Reserved) OCT 2012 1 PA341U REVC PA341 FIGURE 2. Package Styles 8-PIN TO-3 24-PIN PSOP 10-PIN SIP PACKAGE STYLE CE PACKAGE STYLE DF PACKAGE STYLE DW FIGURE 3. External Connections. 8 NC 5 TOP VIEW ILIM 1 CC 2 3 2 CC NC -IN 4 OUT 1 NC NC NC NC NC OUT -IN NC NC +IN NC C C1 24 1 2 NC COMP NC NC NC ILIM NC NC -VS +VS 3 4 5 6 NC NC -VS +VS COMP + +IN 6 7 - -VS +VS CC 7 8 9 10 ILIM CC2 CC1 OUT RCL CC -IN +IN RCL RCL PA341CE PA341DF PA341DW For CC values, see graph on page 7. Note: CC must be rated for full supply voltage. NOTE: PA341CE Recommended mounting torque is 4-7 in*lbs (.45 -.79 N*m) CAUTION: The use of compressible, thermally conductive insulators may void warranty. TYPICAL APPLICATION Ref: APPLICATION NOTE 20: "Bridge Mode Operation of Power Amplifiers" Two PA341 amplifiers operated as a bridge driver for a piezo transducer provides a low cost 660 volt total drive capability. The RN CN network serves to raise the apparent gain of A2 at high frequencies. If RN is set equal to R the amplifiers can be compensated identically and will have matching bandwidths. R V IN +175 20R 20R +175 10pF A1 PA341 R CL 47 -175 20R 10pF R CL A2 PA341 PIEZO TRANSDUCER 47 Rn Cn -175 FIGURE 4. Low Cost 660VP-P Piezo Driver 2 PA341U PA341 1. CHARACTERISTICS AND SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS PA341CE Parameter Min SUPPLY VOLTAGE, +VS to -VS PA341DF Max Min PA341DW Max 350 Min 350 Max Units 350 V OUTPUT CURRENT, continuous within SOA 60 60 60 mA OUTPUT CURRENT, peak 120 120 120 mA POWER DISSIPATION, continuous @ TC = 25C 12 12 9 W INPUT VOLTAGE, differential -16 +16 -16 +16 -16 +16 V INPUT VOLTAGE, common mode -VS +VS -VS +VS -VS +VS V TEMPERATURE, pin solder - 10 sec 350 220 220 C TEMPERATURE, junction (Note 2) 150 150 150 C TEMPERATURE, storage -65 150 -65 150 -65 150 C TEMPERATURE RANGE, powered (case) -40 125 -40 125 -40 125 C SPECIFICATIONS Parameter Test Conditions (Note 1) PA341CE, PA341DF Min Typ Max 12 PA341DW Min Typ Max Units 40 12 40 mV INPUT OFFSET VOLTAGE, initial OFFSET VOLTAGE, vs. temperature (Note 3) 25 to 85C 17 250 17 250 V/C OFFSET VOLTAGE, vs. temperature (Note 3) -25 to 25C 18 500 18 500 V/C OFFSET VOLTAGE, vs. supply 4.5 OFFSET VOLTAGE, vs. time 4.5 80 BIAS CURRENT, initial (Note 6) 5/50 BIAS CURRENT, vs. supply 0.2/2 OFFSET CURRENT, initial (Note 6) 2.5/50 INPUT IMPEDANCE, DC 10 INPUT CAPACITANCE V/V 80 50/200 100 50/200 pA 15 50 pA/V 100 400 pA 10 11 3 V/kh 2000 11 3 pF COMMON MODE, voltage range +VS - 12 +VS - 12 V COMMON MODE, voltage range -VS + 12 -VS + 12 V COMMON MODE REJECTION, DC VCM = 90V DC NOISE, broad band 84 10kHz BW, RS = 1K 115 84 337 115 dB 337 V RMS 103 dB GAIN OPEN LOOP at 15Hz RL = 5K BANDWIDTH, gain bandwidth product @ 1MHz 10 10 MHz POWER BANDWIDTH 280V p-p 35 35 kHz PA341U 90 103 90 3 PA341 Parameter Test Conditions (Note 1) PA341CE, PA341DF Min Typ Max PA341DW Min Typ Max Units OUTPUT VOLTAGE SWING IO = 40mA CURRENT, peak (Note 4) CURRENT, continuous VS - 12 VS - 10 VS - 12 VS - 10 V 120 120 mA 60 60 mA SETTLING TIME to .1% 10V step, A V = -10 2 2 S SLEW RATE CC = 4.7pF 32 32 V/S RESISTANCE, 10mA (Note 5) RCL = 0 91 91 RESISTANCE, 40mA (Note 5) RCL = 0 65 65 POWER SUPPLY VOLTAGE 10 CURRENT, quiescent 150 175 2.2 2.5 10 150 175 V 2.2 2.5 mA THERMAL PA341CE RESISTANCE, AC junction to case F > 60Hz 5.4 6.5 C/W PA341DF RESISTANCE, AC junction to case F > 60Hz 6 7 C/W PA341DW RESISTANCE, AC junction to case F > 60Hz PA341CE RESISTANCE, DC junction to case F < 60Hz 9 10.4 C/W PA341DF RESISTANCE, DC junction to case F < 60Hz 9 11 C/W PA341DW RESISTANCE, DC junction to case F < 60Hz PA341CE RESISTANCE, junction to air Full Temperature Range 30 C/W PA341DF RESISTANCE, Full Temperajunction to air (Note 7) ture Range 25 C/W PA341DW RESISTANCE, junction to air Full Temperature Range TEMPERATURE RANGE, case Meets full range spec's 7 12 10 14 30 -25 +85 -25 C/W C/W C/W +85 C NOTES: 1. Unless otherwise noted TC = 25C, CC = 6.8pF. DC input specifications are value given. Power supply voltage is typical rating. 2. Long term operation at the maximum junction temperature will result in reduced product life. Derate internal power dissipation to achieve high MTTF. For guidance, refer to heatsink data sheet. 3. Sample tested by wafer to 95%. 4. Guaranteed but not tested. 5. The selected value of RCL must be added to the values given for total output resistance. 6. Specifications separated by / indicate values for the PA341CE and PA341DF respectively. 7. Rating applies with solder connection of heatslug to a minimum 1 square inch foil area of the printed circuit board. CAUTION 4 The PA341 is constructed from MOSFET transistors. ESD handling procedures must be observed. PA341U PA341 TYPICAL PERFORMANCE GRAPHS POWER DERATING PA341CE PA341DF 12 9 0.80 0.75 PA341DW T = TC T = TA 0.60 3 0 25 50 75 100 TEMPERATURE, T (C) 0.50 -40 -20 125 -80 -90 100 PHASE, () 60 2.2pF 2.2pF 6.8pF -140 -150 68pF 15pF -160 0 10 0.75pF -110 -130 15pF -170 -20 10 100 1K 10K 100K 1M 10M FREQUENCY, F (Hz) -180 10K 100K 1M FREQUENCY, F (Hz) 1K 10K FREQUENCY, F (Hz) 80 60 40 20 0 10 PA341U 100 1K 10K FREQUENCY, F (Hz) 100K 10 RISE POWER SUPPLY REJECTION COMMON MODE REJECTION 100 20 0 5 15 25 35 45 55 65 75 85 COMPENSATION CAPACITANCE, CC (pF) 100K 120 FALL 80 70 NEGATIVE 60 15pF 100 33pF 100K FREQUENCY, F (Hz) 1M 102 125C 100 25C -40C 98 96 20 60 100 140 180 220 260 300 340 TOTAL SUPPLY VOLTAGE, (V) OUTPUT VOLTAGE SWING VDROP+@85C 20 VDROP-@85C 15 VDROP-@27C 10 5 40 10 0 100K 68pF QUIESCENT CURRENT 50 100 1K 10K FREQUENCY, F (Hz) 10 2.2pF 6.8pF 25 POSITIVE 90 1 GAIN POWER RESPONSE 30 100 VDROP FROM VS, (V) A V = 20 C C = 15pF R L = 2K SLEW RATE, (V/s) 0.1 180V P-P 0.001 100 COMMON MODE REJECTION, CMR (dB) 30VP-P 60VP-P POWER SUPPLY REJECTION, PSR (dB) DISTORTION, (%) 30 0.01 1 10 10K 10M SLEW RATE HARMONIC DISTORTION 1 25C 55C 1000 68pF -120 6.8pF 20 PHASE RESPONSE -100 0.75pF 80 40 10 0.1 0.1 0 20 40 60 80 100 120 TEMPERATURE (C) OUTPUT VOLTAGE, VOUT (P-P) 0 VBE- 125C 85C 0.55 T = TA SMALL SIGNAL RESPONSE OPEN LOOP GAIN, A (dB) VBE+ 0.70 0.65 6 GAIN AND COMPENSATION 100 COMPENSATION, pF T = TC VBE for ILIMIT 0.85 NORMALIZED QUIESCENT CURRENT (%) 15 VBE (V) INTERNAL POWER DISSIPATION, P (W) 2. VDROP+@27C 0 20 40 60 80 100 120 OUTPUT CURRENT, IO, (mA) 5 PA341 3. APPLICATIONS INFORMATION 3.1 PHASE COMPENSATION 3.2 OTHER STABILITY CONCERNS Please read Application Note 1 "General Operating Considerations" which covers stability, power supplies, heat sinking, mounting, current limit, SOA interpretation, and specification interpretation. Visit www.apexanalog.com for design tools that help automate tasks such as calculations for stability, internal power dissipation, current limit, heat sink selection, Apex Microtechnology's complete Application Notes library, Technical Seminar Workbook and Evaluation Kits. Open loop gain and phase shift both increase with increasing temperature. The PHASE COMPENSATION typical graph shows closed loop gain and phase compensation capacitor value relationships for four case temperatures. The curves are based on achieving a phase margin of 50. Calculate the highest case temperature for the application (maximum ambient temperature and highest internal power dissipation) before choosing the compensation. Keep in mind that when working with small values of compensation, parasitics may play a large role in performance of the finished circuit. The compensation capacitor must be rated for at least the total voltage applied to the amplifier and should be a temperature stable type such as NPO or COG. There are two important concepts about closed loop gain when choosing compensation. They stem from the fact that while "gain" is the most commonly used term, (the feedback factor) is really what counts when designing for stability. 1. Gain must be calculated as a non-inverting circuit (equal input and feedback resistors can provide a signal gain of -1, but for calculating offset errors, noise, and stability, this is a gain of 2). 2. Including a feedback capacitor changes the feedback factor or gain of the circuit. Consider RIN=4.7k, RF=47k for a gain of 11. Compensation of 4.7 to 6.8pF would be reasonable. Adding 33pF parallel to the 47K rolls off the circuit at 103kHz, and at 2MHz has reduced gain from 11 to roughly 1.5 and the circuit is likely to oscillate. As a general rule the DC summing junction impedance (parallel combination of the feedback resistor and all input resistors) should be limited to 5k ohms or less. The amplifier input capacitance of about 6pF, plus capacitance of connecting traces or wires and (if used) a socket will cause undesirable circuit performance and even oscillation if these resistances are too high. In circuits requiring high resistances, measure or estimate the total sum point capacitance, multiply by RIN/RF, and parallel RF with this value. Capacitors included for this purpose are usually in the single digit pF range. This technique results in equal feedback factor calculations for AC and DC cases. It does not produce a roll off, but merely keeps constant over a wide frequency range. Paragraph 6 of Application Note 19 details suitable stability tests for the finished circuit. 3.3 CURRENT LIMIT For proper operation, the current limiting resistor, RCL, must be connected as shown in Figure 3, "External Connections". The current limit can be predicted as follows: ILIMIT = VBE RCL The "VBE for ILIMIT" performance graph is used to find VBE. On this graph, the VBE+ and VBE- curves show the voltages across the current limiting resistor at which current limiting is turned on. The VBE+ curve shows these turn-on voltages when the amplifier is sourcing current, and the VBE- curve shows these voltages when the amplifier is sinking current. The current limit can be thought of as a ceiling or limit for safe operation. For continuous operation it is any value between the desired load current and 60 mA (as long as the curves on the SOA graph are not exceeded, please 6 PA341U PA341 refer to section 3.4 for information on the SOA graph). As an example, suppose the desired load current for the application is 20 mA. In this case we may set a current limit of 30 mA. Starting with the smaller VBE- of 0.6 we have: RCL = 0.6 = 20 1.03 For the larger VBE+ this RCL resistor will allow for a maximum current of: ILIMIT = 0.7 = 35mA 20 This value is still acceptable because it is less than 60 mA. For the case of continuous load currents, check that the current limit does not exceed 60 mA. FIGURE 5. Safe Operating Area 3.4 SAFE OPERATING AREA The MOSFET output stage of the PA341 is not limited by second breakdown considerations as in bipolar output stages. However there are still three distinct limitations: 1. Voltage withstand capability of the transistors. 2. Current handling capability of the die metalization. 3. Temperature of the output MOSFETS. These limitations can be seen in the SOA (see Safe Operating Area graphs). Note that each pulse capability line shows a constant power level (unlike second breakdown limitations where power varies with voltage stress). These lines are shown for a case temperature of 25C and correspond to thermal resistances of 5.2C/W for the PA341CE and DF and 10.4C/W for the PA341DW respectively. Pulse stress levels for other case temperatures can be calculated in the same manner as DC power levels at different temperatures. The output stage is protected against transient flyback by the parasitic diodes of the output stage MOSFET structure. However, for protection against sustained high energy flyback external fast-recovery diodes must be used. 20 0m 100 50 40 ,T = C 20 85 C DC ,T C 10 S DC DC 30 = 12 5 C 5 4 3 2 10 200 PULSE CURVES @ 10% DUTY CYCLE MAX 20 30 50 100 200 300 500 SUPPLY TO OUTPUT DIFFERENTIAL, VS -VO (V) PA341DW SOA 120 100 20 0m 50 40 20 ,T DC ,T C 10 C = S DC DC 30 12 = 85 C 5 C 5 4 3 2 10 PA341U PA341CE and DF SOA 120 OUTPUT CURRENT FROM +VS OR -VS, (mA) The absolute minimum value of the current limiting resistor is bounded by the largest current and the largest VBE in the application. The largest VBE is determined by the coldest temperature in the application. In general the largest VBE is VBE+ = 0.78, which occurs at T = - 40C. The largest allowed current occurs in pulsed applications where, from the SOA graph, we can see current pulses of 120 mA. This gives us an absolute minimum RCL value of 0.78/0.12 = 6.5. 200 OUTPUT CURRENT FROM +VS OR -VS, (mA) The VBE values used above are approximate and can vary with process. To allow for this possibility the user can reduce the VBE = 0.6 value by 20%. This results in a RCL value of 16 . Using this same RCL value and allowing for a 20% increase in the other VBE , the current limit maximum is 52 mA. PULSE CURVES @ 10% DUTY CYCLE MAX 20 30 50 100 200 300 500 SUPPLY TO OUTPUT DIFFERENTIAL, VS -VO (V) 7 PA341 3.5 HEATSINKING 3.6 OVERVOLTAGE PROTECTION The PA341DF package has a large exposed integrated copper heatslug to which the monolithic amplifier is directly attached. The solder connection of the heatslug to a minimum of 1 square inch foil area on the printed circuit board will result in thermal performance of 25C/W junction to air rating of the PA341DF. Solder connection to an area of 1 to 2 square inches is recommended. This may be adequate heatsinking but the large number of variables involved suggest temperature measurements be made on the top of the package. Do not allow the temperature to exceed 85C. Although the PA341 can withstand differential input voltages up to 16V, in FIGURE 6. Overvoltage Protection +Vs Z1 some applications additional external protection may be needed. Differential inputs exceeding 16V will be clipped by the protection circuitry. However, if more than a few milliamps of current is available from the overload source, the protection circuitry could be destroyed. For differential sources +Vs -IN above 16V, adding series resistance limiting input current to 1mA will prevent damage. Alternatively, 1N4148 signal diodes connected anti-parallel OUT Q1 Q2 across the input pins is usually sufficient. In more demanding applications where bias current is important, diode connected JFETs such as 2N4416 +IN -Vs will be required. See Q1 and Q2 in Figure 6. In either case the differential input voltage will be clamped to 0.7V. This is sufficient overdrive to produce the maximum power bandwidth. In the case of inverting circuits where the +IN pin is grounded, the diodes Z2 -Vs mentioned above will also afford protection from excessive common mode voltage. In the case of non-inverting circuits, clamp diodes from each input to each supply will provide protection. Note that these diodes will have substantial reverse bias voltage under normal operation and diode leakage will produce errors. Some applications will also need over-voltage protection devices connected to the power supply rails. Unidirectional zener diode transient suppressors are recommended. 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 reversals as well as line regulation. See Z1 and Z2 in Figure 6. 8 PA341U PA341 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). Apex Microtechnology reserves the right to make changes without further notice to any specifications or products mentioned herein to improve reliability. This document is the property of Apex Microtechnology and by furnishing this information, Apex Microtechnology grants no license, expressed or implied under any patents, mask work rights, copyrights, trademarks, trade secrets or other intellectual property rights. Apex Microtechnology owns the copyrights associated with the information contained herein and gives consent for copies to be made of the information only for use within your organization with respect to Apex Microtechnology integrated circuits or other products of Apex Microtechnology. This consent does not extend to other copying such as copying for general distribution, advertising or promotional purposes, or for creating any work for resale. 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 Microtechnolgy, Inc. All other corporate names noted herein may be trademarks of their respective holders. www.apexanalog.com PA341U Copyright (c) Apex Microtechnology, Inc. 2012 (All Rights Reserved) OCT 2012 9 PA341U REVC