POWER DUAL OPERATIONAL AMPLIFIERS PA28/29 • PA28A/29A M I C R O T E C H N O L O G Y HTTP://WWW.APEXMICROTECH.COM (800) 546-APEX (800) 546-2739 FEATURES • LOW COST • WIDE COMMON MODE RANGE — Includes negative supply • WIDE SUPPLY VOLTAGE RANGE Single supply: 5V to 40V–to 44V,A Grade Split supplies: ±2.5V to ±20V–to ± 22V,A Grade • HIGH EFFICIENCY — |Vs–2.2V| at 2.5A typ • HIGH OUTPUT CURRENT — 2.5A min, 3.5A min for A grade • LOW DISTORTION M + 1/2 PA28 R5 10K R6 10K COMMAND INPUT 0/10V FIGURE 1: BIDIRECTIONAL SPEED CONTROL FROM A SINGLE SUPPLY The amplifiers are especially well-suited for this application. The extended common mode range allows command inputs as low as 0V. Its superior output swing abilities let it drive within 2V of supply at an output current of 2A. This means that a command input that ranges from 0V to 10V will drive a 24V motor from full scale CCW to full scale CW at up to ±2A. A single power op amp with an output swing capability of Vs –6 would require ±30V supplies and would be required to swing 48V p-p at twice the speed to deliver an equivalent drive. EXTERNAL CONNECTIONS PA29 – PA28 7 8 9 10 VBOOST/+VS 11 12 –IN B 6 OUT B 5 OUT, B 1 B + TOP VIEW –VS 6 4 + A 5 OUT, A 3 + – ISENSE/–VS 2 B SUB –VS 1 +VS 2 +IN, A 3 –IN, A 4 + A – +IN B Connect pins 3 and 10 to pin 7 and connect pins 4 and 9 to pin 6 unless special functions are required. +VS R1 and R2 set up amplifier A in a non-inverting gain of 2.8. Amp B is set up as a unity gain inverter driven from the output of amp A. Note that amp B inverts signals about the reference node, which is set at mid-supply (14V) by R5 and R6. When the command input is 5V, the output of amp A is 14V. Since this is equal to the reference node voltage, the output of amp B is also 14V, resulting in 0V across the motor. Inputs more positive than 5V result in motor current flow from left to right (see Figure 1). Inputs less positive than 5V drive the motor in the opposite direction. A OUT A TYPICAL APPLICATION 10K – B + 1/2 PA28 – 5K +28V 10K ISENSE/–VS The amplifiers consist of a monolithic dual power op amp in a 8-pin hermetic TO-3 package (PA28) and a 12-pin SIP package (PA29). Putting two power op amps in one package and on one die results in an extremely cost effective solution for applications requiring multiple amplifiers per board or bridge mode configurations. The wide common mode input range includes the negative rail, facilitating single supply applications. It is possible to have a “ground based” input driving a single supply amplifier with ground acting as the “second” or “bottom” supply of the amplifier. This hybrid integrated circuit utilizes semiconductor chips to maximize reliability, minimize size and give top performance. Ultrasonically bonded aluminum wires provide reliable interconnections at all operating temperatures. The 8pin TO-3 package is hermetically sealed and electrically isolated. The use of compressible isolation washers voids the warranty. The tab of the SIP12 plastic package is tied to –VS. R4 –IN A DESCRIPTION 9K +28V VBOOST/+VS • HALF & FULL BRIDGE MOTOR DRIVERS • AUDIO POWER AMPLIFIER STEREO — 18W RMS per channel BRIDGE — 36W RMS per package • IDEAL FOR SINGLE SUPPLY SYSTEMS 5V — Peripherals 12V — Automotive 28V — Avionic R1 R3 +IN A APPLICATIONS R2 7 +IN, B – 8 –IN, B APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL [email protected] ABSOLUTE MAXIMUM RATINGS SPECIFICATIONS PA28/29 • PA28A/29A ABSOLUTE MAXIMUM RATINGS SUPPLY VOLTAGE, total OUTPUT CURRENT POWER DISSIPATION, internal (per amplifier) POWER DISSIPATION, internal (both amplifiers) INPUT VOLTAGE, differential INPUT VOLTAGE, common mode JUNCTION TEMPERATURE, max1 TEMPERATURE, pin solder—10 sec max TEMPERATURE RANGE, storage OPERATING TEMPERATURE RANGE, case SPECIFICATIONS PA28/29 TEST CONDITIONS 2 PARAMETER 5V to 44V SOA 54W 60W ±VS +VS, -VS–.5V 150°C 300°C –65°C to 150°C –55°C to 125°C MIN PA28A/29A TYP MAX 5 15 35 12 MIN TYP MAX UNITS 1.5 * * 10 * * * mV µV/°C nA V dB dB dB * * * * * dB kHz ° kHz 3.5 * * * 4.0 * * * A V/µs V V V V uf INPUT OFFSET VOLTAGE, initial OFFSET VOLTAGE, vs. temperature BIAS CURRENT, initial COMMON MODE RANGE COMMON MODE REJECTION, DC POWER SUPPLY REJECTION CHANNEL SEPARATION Full temperature range Full temperature range Full temperature range Full temperature range IOUT = 1A, F = 1kHz –VS–.3 60 60 50 Full temperature range AV = 40dB Full temperature range VO(P-P) = 28V 80 1000 +VS–2 85 80 68 * * * * * * GAIN OPEN LOOP GAIN GAIN BANDWIDTH PRODUCT PHASE MARGIN POWER BANDWIDTH 100 600 65 15 OUTPUT CURRENT, peak SLEW RATE VOLTAGE SWING VOLTAGE SWING VOLTAGE SWING VOLTAGE SWING CAPACITIVE LOAD DRIVE Full temp. range, IO = 95mA Full temp. range, IO = 1A IO = 2.5A IO = 3.5A Av = 1 2.5 .5 1.5 |VS| –1.0 |VS| –0.8 |VS| –1.8 |VS| –1.0 |VS| –3.0 |VS| –2.0 10 22nf 54 30 30 |VS| –3.5 |VS| –2.5 * POWER SUPPLY VOLTAGE, VSS3 CURRENT, quiescent, total 40 90 * * * 44 * V mA 85 °C/W °C/W °C/W °C/W °C/W °C THERMAL RESISTANCE, junction to case DC, single amplifier DC, both amplifiers4 AC, single amplifier AC, both amplifiers4 RESISTANCE, junction to air TEMPERATURE RANGE, case NOTES: * 1. 2. 3. 4. CAUTION 2.3 2.1 1.7 1.6 30 Meets full range specifications –25 * * * 85 –25 The specification of PA28A or PA29A is identical to the specification for PA28 or PA29 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. Unless otherwise noted, the following conditions apply: ±VS = ±15V, TC = 25°C. +VS and –VS denote the positive and negative supply rail respectively. VSS denotes the total rail-to-rail supply voltage. Rating applies when power dissipation is equal in the two amplifiers. 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 PA28/29 • PA28A/29A POWER DERATING BIAS CURRENT 70 60 BOTH AMPLIFIERS 40 30 SINGLE AMPLIFIER 20 10 0 0 25 50 75 100 125 150 TEMPERATURE, T (°C) 80 1.5 75 1.25 1.0 .75 .5 SMALL SIGNAL RESPONSE 0 1 O –120 –150 10 100 1K 10K 100K 1M FREQUENCY, F (Hz) –210 0 POWER SUPPLY REJECTION 10 100 1K 10K .1M FREQUENCY, F (Hz) 40 30 25 20 15 10 |+VS | + |–VS | = 40V 5 1K 1M 10K FREQUENCY, F (Hz) 100K AV = 1 R L =10 Ω 10 86 83 80 77 74 71 5 0 –5 69 66 63 –10 0 10 100 1K 10K 100K 1M FREQUENCY, F (Hz) 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 10 100 1K FREQUENCY, F(Hz) 10K 30K 200 400 600 TIME, t (µs) 800 1K QUIESCENT CURRENT 45 125 40 100 35 75 30 50 25 20 25 15 0 10 -25 5 0.5 0.7 0.9 1.1 1.3 1.5 NORMALIZED QUIESCENT CURRENT -50 1.7 CASE TEMPERATURE, Tc(°C) TOTAL SUPPLY VOLTAGE, Vss(V) HARMONIC DISTORTION 0 VOLTAGE DROP FROM SUPPLY,(V) 60 10K 20K PULSE RESPONSE 89 OUTPUT VOLTAGE, V O(V) POWER SUPPLY REJECTION, PSR (dB) –90 –180 –20 TOTAL HARMONIC DISTORTION, THD(%) OUTPUT VOLTAGE, V PHASE, ϕ (°) OPEN LOOP GAIN, A (dB) 20 1K 100 FREQUENCY, F (Hz) POWER RESPONSE –60 40 AMP 2 I OUT = 0 AV = –100 60 50 –30 60 65 PHASE RESPONSE 0 80 70 50 10 .25 –50 –25 0 25 50 75 100 125 CASE TEMPERATURE, T C(°C) 100 AMP 1 I OUT = 1A AV = –100 55 (V PP) 50 CROSSTALK 1.75 CROSSTALK (dB) 40 NORMALIZED BIAS CURRENT, I B (X) INTERNAL POWER DISSIPATION, P(W) TYPICAL PERFORMANCE GRAPHS OUTPUT VOLTAGE SWING 1.5 1.25 1 .75 .5 0 0.5 1 1.5 2 2.5 3 3.5 OUTPUT CURRENT, Io (A) APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL [email protected] OPERATING CONSIDERATIONS PA28/29 • PA28A/29A GENERAL THERMAL CONSIDERATIONS 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 and heat sink selection. The "Application Notes" and "Technical Seminar" sections contain a wealth of information on specific types of applications. Package outlines, heat sinks, mounting hardware and other accessories are located in the "Packages and Accessories" section. Evaluation Kits are available for most Apex product models, consult the "Evaluation Kit" section for details. For the most current version of all Apex product data sheets, visit www.apexmicrotech.com. Although R θJC is the same for PA28/29 there are differences in the thermal interface between case and heatsink which will limit power dissipation capability. Thermal grease or an Apex TW03 thermal washer, R θCS = .1-.2°C/W, is the only recommended interface for the PA28. The PA29 may require a thermal washer which is electrically insulating since the tab is tied to –VS. This can result in thermal impedances for R θCS of up to 1°C/W or greater. ADDITIONAL PA29 PIN FUNCTIONS VBOOST +VS 5 4 s 1m ED AD ED LO AD NE LO H ,O OT CH ,B EA CH EA OUTPUT CURRENT, Io(A) SOA 3 2 – IN +IN OUT ISENSE RS 1 1 2 3 4 5 10 20 – VS 30 40 SUPPLY TO OUTPUT DIFFERENTIAL VOLTAGE, Vs – Vo(V) FIGURE 2. PA29 EQUIVALENT SCHEMATIC (ONE CHANNEL) VBOOST SAFE OPERATING AREA (SOA) The SOA curves combine the effect of all limits for this power op amp. For a given application, the direction and magnitude of the output current should be calculated or measured and checked against the SOA curves. This is simple for resistive loads but more complex for reactive and EMF generating loads. NOTE: For protection against sustained, high energy flyback, external fast-recovery diodes should be used. The VBOOST pin is the positive terminal for the load of the second stage of the amplifier. When that terminal is connected to a voltage greater than +VS it will provide more drive to the upper output transistor, which is a darlington connected emitter follower. This will better saturate the output transistor. When VBOOST is about 5 Volts greater than +VS the positive output can swing 0.5 Volts closer to the rail. This is as much improvement as is possible. VBOOST pin requires approximately 4-6mA of current. Dynamically it represents 1K Ω impedance. The maximum voltage that can be applied to VBOOST is 40 volts with respect to – VS . There is no limit to the difference between +VS and VBOOST. MONOLITHIC AMPLIFIER STABILITY CONSIDERATIONS All monolithic power op amps use output stage topologies that present special stability problems. This is primarily due to non-complementary (both devices are NPN) output stages with a mismatch in gain and phase response for different polarities of output current. It is difficult for the op amp manufacturer to optimize compensation for all operating conditions. The recommended R-C network of 1 ohm in series with 0.1µF from output to AC common (ground or a supply rail, with adequate bypass capacitors) will prevent local output stage oscillations. APEX MICROTECHNOLOGY CORPORATION • 5980 NORTH SHANNON ROAD • TUCSON, ARIZONA 85741 • USA • APPLICATIONS HOTLINE: 1 (800) 546-2739 PA28/29 • PA28A/29A OPERATING CONSIDERATIONS +VS ≤ 20V DB1 +VS DB2 PA29 7 3 10 CB1 PA29A 5 VREF CB2 PA29B SPEAKER B R RL VIN IL R A RFB 8 RIN FIGURE 3. SIMPLE BOOTSTRAPPING IMPROVES POSITIVE OUTPUT SWING. CONNECT PINS 3 AND 10 TO VS IF NOT USED. TYPICAL CURRENTS ARE 12mA EACH. Figure 3 shows a bootstrap which dynamically couples the output waveform onto the VBOOST pin. This causes VBOOST to swing positive from it's initial value, which is equal to +VS -0.7 V (one diode drop), an amount equal to the output. In other words, if VBOOST was initially 19.3, and the output swings positive 18 Volts, the voltage on the VBOOST pin will swing to 19.3 -0.7 + 18 or 36.6. The capacitor needs to be sized based on a 1K Ω impedance and the lowest frequency required by the circuit. For example, 20Hz will require > 8uF. ISENSE The ISENSE pin is in series with the negative half of the output stage only. Current will flow through this pin only when negative current is being outputted. The current that flows in this pin is the same current that flows in the output (if –1A flows in the output, the ISENSE pin will have 1A of current flow, if +1A flows in the output the ISENSE pin will have 0 current flow). The resistor choice is arbitrary and is selected to provide whatever voltage drop the engineer desires, up to a maximum of 1.0 volt. However, any voltage dropped across the resistor will subract from the swing to rail. For instance, assume a +/– 12 volt power supply and a load that requires +/–1A. With no current sense resistor the output could swing +/–10.2 volts. If a 1 Ω resistor is used for current sense (which will drop 1 Volt at 1 Amp) then the output could swing +10.2, –9.2 Volts. RS RS RIN –VS OR GND RS VREF FIGURE 4. ISENSE TRANSCONDUCTANCE BRIDGING AMPLIFIER Figure 4 shows the PA29 ISENSE feature being used to obtain a Transconductance function. In this example, amplifier "A" is the master and amplifier "B" is the slave. Feedback from sensing resistors RS is applied to the summing network and scaled to the inverting input of amplifier "A" where it is compared to the input voltage. The current sensing feedback imparts a Transconductance feature to the amplifiers transfer function. In other words, the voltage developed across the sensing resistors is directly proportional to the output current. Using this voltage as a feedback source allows expressing the gain of the circuit in amperes vs input voltage. The transfer funcion is approximately: IL + (VIN – VREF) = RIN RFB * RS In the illustration, resistors RIN, RFB and RS determine gain. MOUNTING PRECAUTIONS 1. Always use a heat sink. Even unloaded, the PA29 can dissipate up to 3.6 watts. A thermal washer or thermal grease should always be used. 2. Avoid bending the leads. Such action can lead to internal damage. 3. Always fasten the tab to the heat sink before the leads are soldered to fixed terminals. 4. Strain relief must be provided if there is any probability of axial stress to the leads. This data sheet has been carefully checked and is believed to be reliable, however, no responsibility is assumed for possible inaccuracies or omissions. All specifications are subject to change without notice. PA28/29U REV. A MARCH 2000 © 2000 Apex Microtechnology Corp.