MIC5013YM

MIC5013 Micrel, Inc. MIC5013 Protected High- or Low-Side MOSFET Driver General Description Features The MIC5013 is an 8-pin MOSFET driver with over-current shutdown and a fault flag. It is designed to drive the gate of an N-channel power MOSFET above the supply rail high-side power switch applications. The MIC5013 is compatible with standard or current-sensing power MOSFETs in both highand low-side driver topologies. The MIC5013 charges a 1nF load in 60µs typical and protects the MOSFET from over-current conditions. The current sense trip point is fully programmable and a dynamic threshold allows high in-rush current loads to be started. A fault pin indicates when the MIC5013 has turned off the FET due to excessive current. Other members of the Micrel driver family include the MIC5011 minimum parts count driver and MIC5012 dual driver. • • • • Typical Application Ordering Information • • • • • • 7V to 32V operation Less than 1µA standby current in the “OFF” state Available in small outline SOIC packages Internal charge pump to drive the gate of an N-channel power FET above supply Internal zener clamp for gate protection 60µs typical turn-on time to 50% gate overdrive Programmable over-current sensing Dynamic current threshold for high in-rush loads Fault output pin indicates current faults Implements high- or low-side switches Applications • • • • • Lamp drivers Relay and solenoid drivers Heater switching Power bus switching Motion control Part Number + V =24V MIC5013 Control Input 10µF Standard Pb-Free MIC5013BN MIC5013YN Package –40ºC to +85ºC 8-pin Plastic DIP MIC5013BM MIC5013YM –40ºC to +85ºC 8-pin SOIC + Fault 8 2 Thresh V+ 7 20kΩ 3 Sense Gate 6 RTH Temperature Range 1 Input R = S 4 Source Gnd 5 SR(V TR I P +100mV) R I L – (V TR I P IRCZ44 (S=2590, R=11mΩ) SENSE R SOURCE S 43Ω KEL VIN R1= +100mV) V+S R RS 100mV (SR+ R S) R TH = 2200 V –1000 TR I P LOAD For this example: I =30A (trip current) R1 4.3kΩ L V TR I P =100mV Figure 1. High-Side Driver with Current-Sensing MOSFET Protected under one or more of the following Micrel patents: patent #4,951,101; patent #4,914,546 Note: The MIC5013 is ESD sensitive. Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com July 2005 1 MIC5013 MIC5013 Micrel, Inc. Absolute Maximum Ratings (Note 1, 2) Input Voltage, Pin 1 Threshold Voltage, Pin 2 Sense Voltage, Pin 3 Source Voltage, Pin 4 Current into Pin 4 Gate Voltage, Pin 6 Supply Voltage (V+), Pin 7 Fault Output Current, Pin 8 Junction Temperature Operating Ratings (Notes 1, 2) V+ –10 to –0.5 to +5V –10V to V+ –10V to V+ 50mA –1V to 50V –0.5V to 36V –1mA to +1mA 150°C Power Dissipation θJA (Plastic DIP) θJA (SOIC) Ambient Temperature: B version Storage Temperature Lead Temperature (Soldering, 10 seconds) Supply Voltage (V+), Pin 7 1.25W 100°C/W 170°C/W –40°C to +85°C –65°C to +150°C 260°C 7V to 32V high side 7V to 15V low side Pin Description (Refer to Figures 1 and 2) Pin Number Pin Name 1 Input 2 Threshold Pin Function Resets current sense latch and turns on power MOSFET when taken above threshold (3.5V typical). Pin 1 requires 25ms), the bootstrap capacitor will discharge and the MIC5013 supply pin will fall to V+ = VDD –1.4. Under this condition pins 3 and 4 will be held above V+ and may false trigger the over-current circuit. A larger capacitor will lengthen the maximum “on” time; 1000µF will hold the circuit up for 2.5 seconds, but requires more charge time when the circuit is turned off. The optional Schottky barrier diode improves turn-on time on supplies of less than 10V. 100kΩ 1kΩ Figure 8. Improved Opto-Isolator Performance 24V 24V 100kΩ CR2943-NA102A ( GE ) ON OFF MIC5013 20kΩ 10µF 1 Input Fault 8 2 Thresh V+ 7 3 Sense Gate 6 + 4 Source Gnd 5 IRFP044 (2) 100Ω 5mΩ 330kΩ LVF-15 (RCD) 15kΩ LOAD Figure 9. 50-Ampere Industrial Switch MIC5013 10 July 2005 MIC5013 Micrel, Inc. Applications Information (Continued) Since the supply current in the “OFF” state is only a small leakage, the 100nF bypass capacitor tends to remain charged for several seconds after the MIC5013 is turned off. In a PWM application the chip supply is actually much higher than the system supply, which improves switching time. Electronic Circuit Breaker (Figure 7). The MIC5013 forms the basis of a high-performance, fast-acting circuit breaker. By adding feedback from FAULT to INPUT the breaker can be made to automatically reset. If an over-current condition occurs, the circuit breaker shuts off. The breaker tests the load every 18ms until the short is removed, at which time the circuit latches ON. No reset button is necessary. Opto-Isolated Interface (Figure 8). Although the MIC5013 has no special input slew rate requirement, the lethargic transitions provided by an opto-isolator may cause oscillations on the rise and fall of the output. The circuit shown accelerates the input transitions from a 4N35 opto-isolator by adding hysteresis. Opto-isolators are used where the control circuitry cannot share a common ground with the MIC5013 and high-current power supply, or where the control circuitry is located remotely. This implementation is intrinsically safe; if the control line is severed the MIC5013 will turn OFF. Fault-Protected Industrial Switch (Figure 9). The most common manual control for industrial loads is a push button on/off switch. The “on” button is physically arranged in a recess so that in a panic situation the “off” button, which extends out from the control box, is more easily pressed. This circuit is compatible with control boxes such as the CR2943 series (GE). The circuit is configured so that if both switches close simultaneously, the “off” button has precedence. If there is a fault condition the circuit will latch off, and it can be reset by pushing the “ON” button. This application also illustrates how two (or more) MOSFETs can be paralleled. This reduces the switch drop, and distributes the switch dissipation into multiple packages. High-Voltage Bootstrap (Figure 10). Although the MIC5013 is limited to operation on 7 to 32V supplies, a floating bootstrap arrangement can be used to build a high-side switch that operates on much higher voltages. The MIC5013 and MOSFET are configured as a low-side driver, but the load is connected in series with ground. The high speed normally associated with low-side drivers is retained in this circuit. Power for the MIC5013 is supplied by a charge pump. A 20kHz square wave (15Vp-p) drives the pump capacitor and delivers current to a 100µF storage capacitor. A zener diode limits the supply to 18V. When the MIC5013 is off, power is supplied by a diode connected to a 15V supply. The circuit of Figure 8 is put to good use as a barrier between low voltage control circuitry and the 90V motor supply. Half-Bridge Motor Driver (Figure 11). Closed loop control of motor speed requires a half-bridge driver. This topology presents an extra challenge since the two output devices should not cross conduct (shoot-through) when switching. Cross conduction increases output device power dissipation and, in the case of the MIC5013, could trip the over-current comparator. Speed is also important, since PWM control requires the outputs to switch in the 2 to 20kHz range. The circuit of Figure 11 utilizes fast configurations for both the top- and bottom-side drivers. Delay networks at each input provide a 2 to 3µs dead time effectively eliminating cross conduction. Both the top- and bottom-side drivers are protected, so the output can be shorted to either rail without damage. 15V + 1N4003 (2) 33kΩ 33pF 100kΩ 10mA Control Input MPSA05 4N35 1N4003 MIC5013 1 Input Fault 8 2 Thresh V+ 7 3 Sense Gate 6 6.2kΩ 100µF 90V 1N4746 IRFP250 4 Source Gnd 5 100kΩ 10mΩ KC1000-4T (Kelvin) 1kΩ 1/4 HP, 90V 5BPB56HAA100 M ( GE ) 100nF 200V 15Vp-p, 20kHz Squarewave Figure 10. High-Voltage Bootstrapped Driver July 2005 11 MIC5013 MIC5013 Micrel, Inc. Applications Information (Continued) The top-side driver is based on the bootstrapped circuit of Figure 6, and cannot be switched on indefinitely. The bootstrap capacitor (1µF) relies on being pulled to ground by the bottom-side output to recharge. This limits the maximum duty cycle to slightly less than 100%. Two of these circuits can be connected together to form an H-bridge. If the H-bridge is used for locked antiphase control, no special considerations are necessary. In the case of sign/magnitude control, the “sign” leg of the H-bridge should be held low (PWM input held low) while the other leg is driven by the magnitude signal. If current feedback is required for torque control, it is available in chopped form at the bottom-side driver's 22 mΩ current-sensing resistor. Time-Delay Relay (Figure 12). The MIC5013 forms the basis of a simple time-delay relay. As shown, the delay commences when power is applied, but the 100 kΩ/1N4148 could be independently driven from an external source such as a switch or another high-side driver to give a delay relative to some other event in the system. Hysteresis has been added to guarantee clean switching at turn-on. Note that an over-current condition latches the relay in a safe, OFF condition. Operation is restored by either cycling power or by momentarily shorting pin 1 to ground. Motor Driver with Stall Shutdown (Figure 13). Tachometer feedback can be used to shut down a motor driver circuit when a stall condition occurs. The control switch is a 3-way type; the “START” position is momentary and forces the driver ON. When released, the switch returns to the “RUN” position, and the tachometer’s output is used to hold the MIC5013 input ON. If the motor slows down, the tach output is reduced, and the MIC5013 switches OFF. Resistor “R” sets the shutdown threshold. If the output current exceeds 30A, the MIC5013 shuts down and remains in that condition until the momentary “RESET” button is pushed. Control is then returned to the START/RUN/STOP switch. 15V 1N5817 100nF 1N4148 22kΩ 1N4001 (2) MIC5013 1 Input Fault 8 2 Thresh V+ 7 3 Sense Gate 6 220pF 20kΩ + 1µF 4 Source Gnd 5 IRF541 100Ω 22mΩ CP S L - 3 (Dale) 15kΩ PWM INPUT 12V, M 10A Stalled 15V MIC5013 10kΩ 22kΩ 1nF 10kΩ 2N3904 1 Input Fault 8 2 Thresh V+ 7 3 Sense Gate 6 + 10µF 4 Source Gnd 5 IRF541 22mΩ CP S L - 3 (Dale) Figure 11. Half-Bridge Motor Driver MIC5013 12 July 2005 MIC5013 Micrel, Inc. Applications Information (Continued) 12V 100kΩ 1N4148 20kΩ MIC5013 + 10µF Fault 8 2 Thresh V+ 7 3 Sense Gate 6 1 Input 4 Source Gnd 5 100µF IRCZ44 SOURCE + SENSE 10kΩ KEL VIN 43Ω 100Ω OUT P UT (Delay=5s) 4.3kΩ Figure 12. Time-Delay Relay with 30A Over-Current Protection 1N4148 330kΩ 12V RESET 10µF + MIC5013 330kΩ R 330kΩ 20kΩ 1 Input Fault 8 2 Thresh V+ 7 3 Sense Gate 6 4 Source Gnd 5 IRCZ44 SOURCE SENSE 43Ω 1N4148 KEL VIN 4.3kΩ 100nF T ST A R T M 12V RUN STOP Figure 13. Motor Stall Shutdown July 2005 13 MIC5013 MIC5013 Micrel, Inc. Applications Information (Continued) Q5. For the second phase Q4 turns off and Q3 turns on, pushing pin C2 above supply (charge is dumped into the gate). Q3 also charges C1. On the third phase Q2 turns off and Q1 turns on, pushing the common point of the two capacitors above supply. Some of the charge in C1 makes its way to the gate. The sequence is repeated by turning Q2 and Q4 back on, and Q1 and Q3 off. In a low-side application operating on a 12 to 15V supply, the MOSFET is fully enhanced by the action of Q5 alone. On supplies of more than approximately 14V, current flows directly from Q5 through the zener diode to ground. To prevent excessive current flow, the MIC5010 supply should be limited to 15V in low-side applications. The action of Q5 makes the MIC5013 operate quickly in low-side applications. In high-side applications Q5 precharges the MOSFET gate to supply, leaving the charge pump to carry the gate up to full enhancement 10V above supply. Bootstrapped high-side drivers are as fast as lowside drivers since the chip supply is boosted well above the drain at turn-on. Gate Control Circuit When applying the MIC5010, it is helpful to understand the operation of the gate control circuitry (see Figure 14). The gate circuitry can be divided into two sections: 1) charge pump (oscillator, Q1-Q5, and the capacitors) and 2) gate turn-off switch (Q6). When the MIC5010 is in the OFF state, the oscillator is turned off, thereby disabling the charge pump. Q5 is also turned off, and Q6 is turned on. Q6 holds the gate pin (G) at ground potential which effectively turns the external MOSFET off. Q6 is turned off when the MIC5013 is commanded on. Q5 pulls the gate up to supply (through 2 diodes). Next, the charge pump begins supplying current to the gate. The gate accepts charge until the gate-source voltage reaches 12.5V and is clamped by the zener diode. A 2-output, three-phase clock switches Q1-Q4, providing a quasi-tripling action. During the initial phase Q4 and Q2 are ON. C1 is discharged, and C2 is charged to supply through + V Q3 Q5 Q1 125pF 125pF COM C1 C1 100 kHz OSCILLATOR C2 C2 Q2 G Q4 500Ω Q6 OFF GATE CLAMP ZENER 12.5V S ON Figure 14. Gate Control Circuit Detail MIC5013 14 July 2005 MIC5013 Micrel, Inc. Package Information PIN 1 DIMENSIONS: INCH (MM) 0.380 (9.65) 0.370 (9.40) 0.255 (6.48) 0.245 (6.22) 0.135 (3.43) 0.125 (3.18) 0.300 (7.62) 0.013 (0.330) 0.010 (0.254) 0.018 (0.57) 0.130 (3.30) 0.100 (2.54) 0.0375 (0.952) 0.380 (9.65) 0.320 (8.13) 8-Pin Plastic DIP (N) 0.026 (0.65) MAX) PIN 1 0.157 (3.99) 0.150 (3.81) DIMENSIONS: INCHES (MM) 0.050 (1.27) TYP 0.064 (1.63) 0.045 (1.14) 0.197 (5.0) 0.189 (4.8) 0.020 (0.51) 0.013 (0.33) 45° 0.0098 (0.249) 0.0040 (0.102) 0°–8° 0.010 (0.25) 0.007 (0.18) 0.050 (1.27) 0.016 (0.40) SEATING PLANE 0.244 (6.20) 0.228 (5.79) 8-Pin SOIC (M) MICREL INC. TEL 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA + 1 (408) 944-0800 FAX + 1 (408) 474-1000 WEB http://www.micrel.com This information furnished by Micrel in this data sheet is believed to be accurate and reliable. However no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser's use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser's own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 1998 Micrel, Inc. July 2005 15 MIC5013