PA340CC

PA340 PA340 PA340 High Voltage Power Operational Amplifier DESCRIPTION FEATURES The PA340 is a high voltage monolithic MOSFET operational amplifier achieving 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 limitations. External compensation provides the user flexibility in choosing optimum gain and bandwidth for the application. ♦ RoHS COMPLIANT ♦ MONOLITHIC MOS TECHNOLOGY ♦ LOW COST ♦ HIGH VOLTAGE OPERATION – 350V ♦ LOW QUIESCENT CURRENT TYP. – 2.2mA ♦ NO SECOND BREAKDOWN ♦ HIGH OUTPUT CURRENT – 120 mA PEAK APPLICATIONS The surface mount package of the PA340CC is an industry standard non-hermetic plastic 7-pin DDPAK. ♦ TELEPHONE RING GENERATOR ♦ PIEZO ELECTRIC POSITIONING ♦ ELECTROSTATIC TRANSDUCER & DEFLECTION ♦ DEFORMABLE MIRROR FOCUSING ♦ PACKAGING OPTIONS 7-pin DDPAK Surface Mount Package (PA340CC) FIGURE 1: Equivalent Schematic 3 +VS D1 Q1 Q2 Q3 Q4 6 COMP –IN D2 D3 D4 Q6 D5 COMP Q8 Q12 Q13 2 +IN 5 Q5 1 I OUT 7 Q11 Q10 Q14 –VS 4 SUB Copyright © Apex Microtechnology, Inc. 2012 www.apexanalog.com PA340U (All Rights Reserved) OCT 2013 PA340U REVC1 PA340 High voltage considerations should be taken when designing board layouts for the PA340. The PA340 may require a derate in supply voltage depending on the spacing used for board layout. The 14-mil minimum spacing of the 7-pin DDPAK is adequate to standoff the 350V rating of the PA340. However, a supply voltage derate to 250V is required if the spacing of circuit board artwork is less than 11 mils. The metal tab of the PA340CC package is directly tied to -Vs. PA340CX TYPICAL APPLICATION PA340CC A A 1 1 -IN +IN +Vs -Vs OUT COMP (Cc) COMP (Cc) DDPAK PKG. STYLE CC FIGURE 2. External Connections. -IN +IN +Vs -Vs OUT COMP (Cc) COMP (Cc) For CC values, see graph on page 4. Note: CC must be rated for full supply voltage. Ref: APPLICATION NOTE 20: "Bridge Mode Operation of Power Amplifiers" Two PA340 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. VIN 20R 20R R 20R +175 +175 CC 10pF CC 10pF A1 PA340 A2 PA340 PIEZO TRANSDUCER –175 LOW COST 660V p-p PIEZO DRIVER RN CN –175 FIGURE 3. Low Cost 660VP-P Piezo Driver 2 PA340U PA340 1. CHARACTERISTICS AND SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS Parameter Symbol Min Max Units 350 V OUTPUT CURRENT, continuous within SOA 60 mA OUTPUT CURRENT, peak (Note 3) 120 mA POWER DISSIPATION, continuous @ TC = 25°C 14 W SUPPLY VOLTAGE, +VS to -VS INPUT VOLTAGE, differential -16 +16 V INPUT VOLTAGE, common mode -VS +VS V 220 °C TEMPERATURE, pin solder - 10 sec TEMPERATURE, junction 150 °C TEMPERATURE, storage (Note 2) -65 150 °C TEMPERATURE RANGE, powered (case) -40 125 °C SPECIFICATIONS (PER AMPLIFIER) Parameter Test Conditions (Note 1) Min Typ Max Units OFFSET VOLTAGE, initial 12 40 mV OFFSET VOLTAGE, vs. temperature 25°C to 85°C (Note 3) 17 250 µV/°C OFFSET VOLTAGE, vs. temperature -25°C to 25°C (Note 3) 18 500 µV/°C OFFSET VOLTAGE, vs. supply 4.5 OFFSET VOLTAGE, vs. time 80 BIAS CURRENT, initial 50 BIAS CURRENT, vs. supply 2 INPUT OFFSET CURRENT, initial 50 INPUT IMPEDANCE, DC INPUT CAPACITANCE µV/V µV/kh 200 pA pA/V 200 pA 1011 Ω 3 pF COMMON MODE, voltage range +VS - 12 V COMMON MODE, voltage range -VS + 12 V COMMON MODE REJECTION, DC VCM = ± ­ 90VDC NOISE, broad band 10kHz BW, RS = 1KΩ 84 115 dB 337 µV RMS GAIN OPEN LOOP at 15Hz RL = 5KΩ 103 dB GAIN BANDWIDTH PRODUCT @1MHz 10 MHz POWER BANDWIDTH 280V p-p 35 kHz PA340U 90 3 PA340 Parameter Test Conditions (Note 1) Min Typ Max Units OUTPUT VOLTAGE SWING CURRENT, peak IO = 40mA (Note 3) CURRENT, continuous SETTLING TIME to 0.1% SLEW RATE ±VS 12 ±VS 10 V 120 mA 60 mA 10V step, A V = -10 2 µs CC = 4.7pF 32 V/µS RESISTANCE, 10mA (Note 4) RCL = 0Ω 91 Ω RESISTANCE, 40mA (Note 4) RCL = 0Ω 65 Ω POWER SUPPLY VOLTAGE ±10 CURRENT, quiescent ±150 ±175 V 2.2 2.5 mA THERMAL RESISTANCE, AC junction to case F > 60Hz 5.9 6.85 °C/W RESISTANCE, DC junction to case F < 60Hz 7.7 8.9 °C/W RESISTANCE, junction to air Full temperature range (Note 5) TEMPERATURE RANGE, case Meets full range specifications 27 -25 25 °C/W +85 °C NOTES: 1. Unless otherwise noted TC = 25°C, 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. Guaranteed but not tested. 4. Since the PA340 has no current limit, load impedance must be large enough to limit output current to 120mA. 5. Heat tab attached to 3/32" FR-4 board with 2oz. copper. Topside copper area (heat tab directly attached) = 1000 sq. mm, backside copper area = 2500 sq. mm, board area = 2500 sq. mm. CAUTION The PA340 is constructed from MOSFET transistors. ESD handling procedures must be observed. 4 PA340U PA340 8 6 4 VDROP-@85°C 15 VDROP-@27°C 10 5 2 0 25 50 75 100 TEMPERATURE, T (°C) 0 125 -80 -90 100 PHASE, Φ (°) 60 2.2pF 40 0.75pF -110 2.2pF 6.8pF -140 -150 68pF 15pF -160 0 -170 -20 10 10 68pF -130 15pF 20 PHASE RESPONSE -120 6.8pF 100 1K 10K 100K 1M 10M FREQUENCY, F (Hz) -180 10K 100K 1M FREQUENCY, F (Hz) HARMONIC DISTORTION 10M SLEW RATE 0.01 A V = 20 C C = 15pF R L = 2K 1K 10K FREQUENCY, F (Hz) SLEW RATE, (V/µs) 0.1 180V P-P 0.001 100 COMMON MODE REJECTION, CMR (dB) 30VP-P 60VP-P 100 80 60 40 20 0 10 100 1K 10K FREQUENCY, F (Hz) 100K 10 RISE 5 15 25 35 45 55 65 75 85 COMPENSATION CAPACITANCE, CC (pF) 10 25°C 55°C 1 1000 1 GAIN 10 POWER RESPONSE 2.2pF 6.8pF 15pF 100 33pF 68pF 10 10K 100K FREQUENCY, F (Hz) 1M QUIESCENT CURRENT 102 100 5°C 12 C 25° 98 °C -40 96 20 60 100 140 180 220 260 300 340 TOTAL SUPPLY VOLTAGE, (V) POWER SUPPLY REJECTION COMMON MODE REJECTION 120 FALL 20 0 100K POWER SUPPLY REJECTION, PSR (dB) DISTORTION, (%) 30 1 125°C 85°C 0.1 0.1 20 40 60 80 100 120 OUTPUT CURRENT, IO (mA) -100 0.75pF 80 VDROP+@27°C 0 SMALL SIGNAL RESPONSE OPEN LOOP GAIN, A (dB) 20 COMPENSATION, pF 10 GAIN AND COMPENSATION VDROP+@85°C 25 12 100 OUTPUT VOLTAGE, (VOUT) (p-p) 14 0 OUTPUT VOLTAGE SWING 30 NORMALIZED QUIESCENT CURRENT, IQ (%) POWER DERATING 16 VDROP FROM VS, (V) INTERNAL POWER DISSIPATION, P(W) 2. TYPICAL PERFORMANCE GRAPHS 100 POSITIVE 90 80 70 NEGATIVE 60 50 40 10 100 1K 10K FREQUENCY, F (Hz) PA340U 100K 5 PA340 3. APPLICATION 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, β (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 β constant over a wide frequency range. Paragraph 6 of Application Note 19 details suitable stability tests for the finished circuit. SAFE OPERATING AREA The MOSFET output stage of the PA340 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 metallization. 3. Temperature of the output MOSFETS. SOA 1.0 OUTPUT CURRENT FROM +VS OR –VS, (A) 3.3 0.5 0.3 0.2 200mS 300mS 0.1 0.05 0.03 0.02 DC, TC = 25°C These limitations can be seen in the SOA (see Safe Operating Area DC, TC = 85°C graphs). Note that each pulse capability line shows a constant power 0.01 level (unlike second breakdown limitations where power varies with 0.005 voltage stress). These lines are shown for a case temperature of 0.003 25°C. Pulse stress levels for other case temperatures can be calcu0.002 lated in the same manner as DC power levels at different tempera0.001 tures. The output stage is protected against transient flyback by the 10 20 30 50 100 200 300 500 1K parasitic diodes of the output stage MOSFET structure. However, SUPPLY TO OUTPUT DIFFERENTIAL, VS - VO, (V) for protection against sustained high energy flyback external fastFIGURE 4. Safe Operating Area recovery diodes must be used. 6 PA340U PA340 3.4 HEATSINKING The PA340CC 7-pin DDPAK surface mountable package has a large exposed integrated copper heatslug to which the monolithic amplifier is directly attached. The PA340CC requires surface mount techniques of heatsinking. A solder connection to a copper foil area as defined in Note 5 of Page 3 is recommended for circuit board layouts. This may be adequate heatsinking but the large number of variables suggests temperature measurements to be made on the top of the package. Do not allow the temperature to exceed 85°C. 3.5 OVERVOLTAGE PROTECTION Although the PA340 can withstand differential input voltages up to 16V, in 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 above 16V, adding series resistance limiting input current to 1mA will prevent damage. Alternatively, 1N4148 signal diodes connected anti-parallel across the input pins is usually sufficient. In more demanding applications where bias current is important, diode connected JFETs such as 2N4416 will be required. See Q1 and Q2 in Figure 5. In either case the differential input voltage will be clamped to 0.7V. This is sufficient overdrive to produce the maximum power bandwidth. +Vs +Vs -IN Q1 +IN Z1 OUT Q2 -Vs -Vs Z2 In the case of inverting circuits where the +IN pin is grounded, the diodes FIGURE 5. Overvoltage Protection 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 5. 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. Copyright © Apex Microtechnology, Inc. 2012 www.apexanalog.com PA340U (All Rights Reserved) OCT 2013 7 PA340U REVC