POWER OPERATIONAL AMPLIFIER PA17 M I C R O T E C H N O L O G Y HTTP://WWW.APEXMICROTECH.COM FEATURES (800) 546-APEX (800) 546-2739 PRELIMINARY • HIGH INTERNAL DISSIPATION — 850 WATTS • HIGH VOLTAGE, HIGH CURRENT — 200V 50A CONTINUOUS, 100A PULSE • HIGH SLEW RATE — 50V/µS • 4 WIRE CURRENT LIMIT SENSING • EXTERNAL SHUT DOWN CONTROL • OPTIONAL BOOST VOLTAGE INPUTS APPLICATIONS EXTERNAL CONNECTIONS Rc Cc +Vs +Vs – Vs – Vs 12 – OUT 11 – OUT GND 10 – OUT +Vb 9 -Vb1 CC2 8 -Vb2 7 +IN 6 -IN 5 IS2 4 SHT DN 3 +5V 2 STATUS 1 CC1 * IS1 * RESET The PA17 is a high voltage MOSFET power operational amplifier that extends the performance limits of power amplifiers in slew rate and power bandwidth, while maintaining high current and power dissipation ratings. The PA17 is a highly flexible amplifier. The shutdown feature allows ultra-low quiescent current for standby operation or load protection by disabling the entire amplifier. Boost voltage inputs allow the small signal portion of the amplifier to operate at a higher voltage than the high current output stage. The amplifier is then biased to achieve close linear swings to the supply rails at high currents for extra efficient operation. External compensation tailors performance to user needs. A four wire sense technique allows current limiting without the need to consider internal or external milliohm parasitic resistance in the output line. +OUT DESCRIPTION +OUT SEMI CONDUCTOR TESTING SONAR TRANSDUCER DRIVER LINEAR AND ROTARY MOTOR DRIVES YOKE/MAGNETIC FIELD EXCITATION +OUT • • • • 24 23 22 21 20 19 18 17 16 15 14 13 * PHASE COMPENSATION GAIN Rc 1 100 >3 SHORT >10 SHORT 100 SHORT LOAD Rcl** * Cc 470pF 220pF 100pF 10pF * * PIN SIDE VIEW * BYPASSING OF SUPPLIES IS REQUIRED ** SEE TEXT FOR OTHER CURRENT LIMIT CONNECTIONS EQUIVALENT SCHEMATIC APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL [email protected] ABSOLUTE MAXIMUM RATINGS SPECIFICATIONS PA17 SUPPLY VOLTAGE, +VS to –VS BOOST VOLTAGE OUTPUT CURRENT, within SOA POWER DISSIPATION, internal INPUT VOLTAGE, differential INPUT VOLTAGE, common mode TEMPERATURE, pin solder - 10s TEMPERATURE, junction2 TEMPERATURE, storage OPERATING TEMPERATURE RANGE, case ABSOLUTE MAXIMUM RATINGS 200V ±VS±20V 100A 850W ±20V ±VB 300°C 150°C –65 to +150°C –25 to +85°C SPECIFICATIONS MIN TYP MAX UNITS 5 30 15 10 .01 10 1011 4 10 50 98 10 mV µV/°C µV/V pA pA/V pA Ω pF V dB µVrms 102 2 90 dB MHz kHz 60 ° ± ± TEST CONDITIONS 1 PARAMETER V V A µs V/µs nF INPUT Full temperature range Full temperature range Full temp. range, VCM = ±20V 100kHz BW, RS = 1KΩ ±VB 10 86 ± OFFSET VOLTAGE, initial OFFSET VOLTAGE, vs. temperature OFFSET VOLTAGE, vs. supply BIAS CURRENT, initial BIAS CURRENT, vs. supply OFFSET CURRENT, initial INPUT IMPEDANCE, DC INPUT CAPACITANCE COMMON MODE VOLTAGE RANGE COMMON MODE REJECTION, DC INPUT NOISE 50 50 GAIN OPEN LOOP, @ 15Hz GAIN BANDWIDTH PRODUCT POWER BANDWIDTH Full temperature range, CC = 100pF IO = 10A RL = 4.5Ω, VO = 180V p-p PHASE MARGIN Full temperature range 94 OUTPUT IO = 50A ±VB=±Vs ± 10V, IO = 50A Cc= 100pF AV = +1 ±VS 8.8 ±VS 6.8 100 ± ± VOLTAGE SWING5 VOLTAGE SWING5 CURRENT, peak5 SETTLING TIME to .1% SLEW RATE CAPACITIVE LOAD 40 10 ±VS 7.5 ±VS 5.5 2.5 50 POWER SUPPLY VOLTAGE CURRENT, quiescent, boost supply CURRENT, quiescent, total CURRENT, quiescent, total, shutdown Full temperature range ±15 ±75 Full temperature range ±100 30 120 22 V mA mA mA .1 .15 °C/W °C/W °C/W °C THERMAL RESISTANCE, AC, junction to case3 RESISTANCE, DC, junction to case RESISTANCE4, 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 Meets full range specification 10 –25 85 Unless otherwise noted: TC = 25°C. DC input specifications are ± value given. Power supply voltage is typical rating. ±VB= ±VS, Cc = 470pF, Rc=100Ω. 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 the heatsink data sheet. Rating applies if the output current alternates between both output transistors at a rate faster than 60 Hz. The PA17 must be used with a heatsink or the quiescent power may drive the unit to junction temperatures higher than 150°C. Parameter guaranteed but not tested. The PA17 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 PA17 OPERATING CONSIDERATIONS 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.apexmicrotech.com for design tools that help automate tasks such as calculations for stability, internal power dissipation, current limit; heat sink selection; Apex’s complete Application Notes library; Technical Seminar Workbook; and Evaluation Kits. CURRENT LIMIT The positive and negative outputs of the PA17 must be connected together by the user. However, the fact that multiple pins share the output current allows for some unusual current limit schemes not found in amplifiers with a single output pin. Three pins each in the positive and negative outputs share the output current of the PA17. Pins 8 and 10 of the positive output and pins 15 and 17 of the negative output each carry approximately 25% of the output current. Pin 9 of the positive output and pin 16 of the negative output carry the remaining 50% of the output current . For the current limit to operate correctly pin 3 (IS1) must be connected to the amplifier output side and pin 2 (IS2) connected to the load side of the current limit resistor Rcl, as shown in Figure 1. But Rcl may be connected to sample only a fraction of the output current. With this method the current limit resistor consumes less power and only slightly lowers the overall accuracy of the current limit set point. Figure 1, shows a circuit that samples only 25% of the output current. Only those pins necessary to illustrate the current limit function are shown in Figure 1. FIGURE 1. In addition, the current limit of the PA17 operates differently than other Apex linear power amplifiers in that the output current is not clamped at the current limit set point. Instead, when an over-current condition is detected the PA17 sets STATUS (pin 23) high. This flag can alert external circuitry to do a variety of things to deal with this fault condition. For example, when STATUS is connected directly to SD (pin 22) the output stage of the PA17 is disabled until RESET (pin 24) is toggled high (Figure 1). Another possibility would be to connect STATUS to the SD pin via a RC circuit to delay the shutdown of the output stage (Figure 2). This technique would be useful if a short-term overload is normally expected that does not exceed the safe operating area of the PA17. In still another variation STATUS could trigger an external timer that would periodically reset the PA17 until the fault is cleared. STATUS, SHUTDOWN AND RESET FUNCTIONS The 5V logic section of the PA17 provides control and monitoring functions. The PA17 is protected from thermal overloads by directly measuring the temperature of the output transistors. When a thermal overload is detected the output stage is latched off and the STATUS output goes high, indicating an alarm condition. A high on the RESET pin resets the output stage. A high on the SHUTDOWN pin will also latch the output stage off and forces the STATUS pin high. The SHUTDOWN pin can be used to put the PA17 in a standby mode to lower the quiescent current and standby power dissipation. A thermal overload immediately latches off the output stage and cannot be delayed by external circuitry. BOOST OPERATION With the VBOOST feature the small signal stages of the amplifier are operated at higher supply voltages than the amplifier’s high current output stage. +VBOOST (pin 6) and –VBOOST (pins 18, 19) are connected to the small signal circuitry of the amplifier. +VS (pins 11,12) and –VS (pins 13, 14) are connected to the high current output stage. An additional 10V on the VBOOST pins is sufficient to allow the small signal stages to drive the output transistors into saturation and improve the output voltage swing for extra efficient operation when required. When close swings to the supply rails is not required the +VBOOST and +VS pins must be strapped together as well as the –VBOOST and –VS pins. The boost voltage pins must not be at a voltage lower than the VS pins. COMPENSATION The external compensation components CC and RC are connected to pins 4 and 5. Unity gain stability can be achieved at any compensation capacitance greater than 330 pF with at least 60 degrees of phase margin. At higher gains more phase shift can be tolerated in most designs and the compensation capacitance can accordingly be reduced, resulting in higher bandwidth and slew rate. Use the typical operating curves as a guide to select CC and RC for the application. FIGURE 2. APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL [email protected] PA17U REV 3 JUNE 2000 © 2000 Apex Microtechnology Corp.