MIC5021 MIC5020 MIC5022 MIC5021AJB MIC5021BM MIC5021BN IRF540 IRCZ34 MIC5014 - Datasheet Archive

 

Micrel MIC5021 High-Speed High-Side MOSFET Driver General Description Features The MIC5021 high-side MOSFET driver is designed to

 

MIC5021 MIC5021 Micrel MIC5021 MIC5021 High-Speed High-Side MOSFET Driver General Description Features The MIC5021 MIC5021 high-side MOSFET driver is designed to operate at frequencies up to 100kHz (5kHz PWM for 2% to 100% duty cycle) and is an ideal choice for high speed applications such as motor control, SMPS (switch mode power supplies), and applications using IGBTs. The MIC5021 MIC5021 can also operate as a circuit breaker with or without automatic retry. A rising or falling edge on the input results in a current source pulse or sink pulse on the gate output. This output current pulse can turn on a 2000pF MOSFET in approximately 550ns. The MIC5021 MIC5021 then supplies a limited current (< 2mA), if necessary, to maintain the output state. An overcurrent comparator with a trip voltage of 50mV makes the MIC5021 MIC5021 ideal for use with a current sensing MOSFET. An external low value resistor may be used instead of a sensing MOSFET for more precise overcurrent control. An optional external capacitor placed from the CT pin to ground may be used to control the current shutdown duty cycle (dead time) from 20% to < 1%. A duty cycle from 20% to about 75% is possible with an optional pull-up resistor from CT to VDD. The MIC5021 MIC5021 is available in 8-pin SOIC, plastic DIP and ceramic DIP packages. Other members of the MIC502x family include the MIC5020 MIC5020 low-side driver and the MIC5022 MIC5022 half-bridge driver with a cross-conduction interlock. · · · · · · · 12V to 36V operation 550ns rise/fall time driving 2000pF TTL compatible input with internal pull-down resistor Overcurrent limit Gate to source protection Internal charge pump 100kHz operation guaranteed over full temperature and operating voltage range · Compatible with current sensing MOSFETs · Current source drive reduces EMI Applications · · · · · · Lamp control Heater control Motor control Solenoid switching Switch-mode power supplies Circuit breaker Ordering Information 5 Part Number Temperature Range Package MIC5021AJB MIC5021AJB* ­55°C to +125°C 8-pin CerDIP MIC5021BM MIC5021BM ­40°C to +85°C 8-pin SOIC MIC5021BN MIC5021BN ­40°C to +85°C 8-pin Plastic DIP * AJB indicates units screened to MIL-STD 883, Method 5004, condition B, and burned-in for 1-week. Typical Application +12V to +36V MIC5021 MIC5021 10µF TTL Input 1 2 3 optional* 4 VDD Input VBOOST Gate CT Sense Gnd Sense 8 7 N-Channel Power MOSFET 6 5 2.7 nF Load RSENSE RSENSE = 50mV ITRIP * increases time before retry High-Side Driver with Overcurrent Trip and Retry 1997 5-169 MIC5021 MIC5021 Micrel Pin Configuration VBOOST 8 1 VDD Gate 7 2 Input 3 CT Sense- 6 3 CT 4 Gnd Sense+ 5 4 Gnd Sense+ 5 1 VDD 2 Input DIP Packages (N, J) Block Diagram VBOOST 8 Gate 7 Sense- 6 SOIC Package (M) 6V Internal Regulator I1 Fault CT CINT 2I1 VDD Normal CHARGE PUMP Q1 Sense + VBOOST 15V Sense ­ ON 50mV OFF ONE SHOT Input 10I2 I2 6V Gate Transistor: 106 Pin Description Pin Number Pin Name Pin Function 1 VDD Supply: +12V to +36V. Decouple with 10µF capacitor. 2 Input TTL Compatible Input: Logic high turns the external MOSFET on. An internal pull-down returns an open pin to logic low. 3 CT 4 Gnd 5 Sense + Current Sense Comparator (+) Input: Connect to high side of sense resistor or current sensing MOSFET sense lead. A built-in offset in conjunction with RSENSE sets the load overcurrent trip point. 6 Sense ­ Current Sense Comparator (­) Input: Connect to the low side of the sense resistor (usually the high side of the load). 7 Gate Gate Drive: Drives the gate of an external power MOSFET. Also limits VGS to 15V max. to prevent Gate-to-Source damage. Will sink and source current. 8 VBOOST Charge Pump Boost Capacitor: A bootstrap capacitor from VBOOST to the FET source pin supplies charge to quickly enhance the Gate output during turn-on. Retry Timing Capacitor: Controls the off time (tG(OFF) of the overcurrent retry cycle. (Duty cycle adjustment.) · Open = approx. 20% duty cycle. · Capacitor to Ground = approx. 20% to < 1% duty cycle. · Pull-up resistor = approx. 20% to approx. 75% duty cycle. · Ground = maintained shutdown upon overcurrent condition. Circuit Ground 5-170 1997 MIC5021 MIC5021 Micrel Absolute Maximum Ratings Operating Ratings Supply Voltage (VDD) . +40V Input Voltage . ­0.5V to +15V Sense Differential Voltage . ±6.5V Sense + or Sense ­ to Gnd . ­0.5V to +36V Timer Voltage (CT) . +5.5V VBOOST Capacitor . 0.01µF Supply Voltage (VDD) . +12V to +36V Temperature Range CerDIP . ­55°C to +125°C PDIP . ­40°C to +85°C SOIC . ­40°C to +85°C Electrical Characteristics TA = 25°C, Gnd = 0V, VDD = 12V, CT = Open, Gate CL = 1500pF (IRF540 IRF540 MOSFET) unless otherwise specified Symbol Parameter Condition D.C. Supply Current Min Typ Max Units VDD = 12V, Input = 0V 1.8 4 mA VDD = 36V, Input = 0V 2.5 6 mA VDD = 12V, Input = 5V 1.7 4 mA VDD = 36V, Input = 5V 2.5 6 mA 1.4 2.0 V Input Threshold 0.8 Input Hysteresis 0.1 V Input Pull-Down Current Input = 5V 10 20 40 µA Current Limit Threshold Note 1 30 50 70 mV Gate On Voltage VDD = 12V Note 2 16 18 21 V VDD = 36V Note 2 46 50 52 V tG(ON) Gate On Time, Fixed Sense Differential > 70mV 2 6 10 µs tG(OFF) Gate Off Time, Adjustable Sense Differential > 70mV, CT = 0pF 10 20 50 µs tDLH Gate Turn-On Delay Note 3 500 1000 ns tR Gate Rise Time Note 4 400 500 ns tDLH Gate Turn-Off Delay Note 5 800 1500 ns tF Gate Fall Time Note 6 400 500 ns fmax Maximum Operating Frequency Note 7 100 150 kHz Note 1 When using sense MOSFETs, it is recommended that RSENSE < 50. Higher values may affect the sense MOSFET's current transfer ratio. Note 2 DC measurement. Note 3 Input switched from 0.8V (TTL low) to 2.0V (TTL high), time for Gate transition from 0V to 2V. Note 4 Input switched from 0.8V (TTL low) to 2.0V (TTL high), time for Gate transition from 2V to 17V. Note 5 Input switched from 2.0V (TTL high) to 0.8V (TTL low), time for Gate transition from 20V (Gate on voltage) to 17V. Note 6 Input switched from 2.0V (TTL high) to 0.8V (TTL low), time for Gate transition from 17V to 2V. Note 7 Frequency where gate on voltage reduces to 17V with 50% input duty cycle. 1997 5-171 5 MIC5021 MIC5021 Micrel Typical Characteristics Gate Voltage Change vs. Supply Voltage Supply Current vs. Supply Voltage 2.5 Gate Turn-On Delay vs. Supply Voltage 900 25 VGATE = VSUPPLY + 4V CL = 1500pF (IRCZ34 IRCZ34) CBOOST = 0.01µF VGATE = VGATE ­ VSUPPLY VIN = 0V VIN = 5V 1.0 tON 4V (ns) 1.5 850 20 VGATE (V) ISUPPLY (mA) 2.0 15 10 800 750 INCLUDES PROPAGATION DELAY 5 0.5 0.0 5 10 15 20 25 30 VSUPPLY (V) 35 0 40 700 5 VGATE = VSUPPLY + 10V CL = 1500pF (IRCZ34 IRCZ34) CBOOST = 0.01µF 35 650 40 2000 1750 1.5 tON (µs) 850 0.5 15 20 25 30 VSUPPLY (V) 35 Overcurrent Retry Duty Cycle vs. Timing Capacitance 5 0 0.1 NOTE: tON, tOFF TIME INDEPENDENT OF VSUPPLY 1 60 40 20 10 100 CT (pF) 0 1000 10000 Input Gate Sense +, ­ Differential 10 15 20 25 30 VSUPPLY (V) 35 40 70 80 IIN (µA) 10 CGATE = 1500pF (IRCZ34 IRCZ34) 80 VSUPPLY = 12V 15 RL = 400 Sense Threshold vs. Temperature VOLTAGE (mV) 20 750 5 Input Current vs. Input Voltage 100 tON = 5µs VSUPPLY = 12V 40 INCLUDES PROPAGATION DELAY 0.0 1x100 1x101 1x102 1x103 1x104 1x105 CGATE (pF) 25 35 1000 INCLUDES PROPAGATION DELAY 40 20 25 30 VSUPPLY (V) VGATE = VSUPPLY + 4V 1250 INCLUDES PROPAGATION DELAY 10 15 1500 1.0 800 10 Gate Turn-Off Delay vs. Supply Voltage VGATE = VSUPPLY + 4V VSUPPLY = 12V 2.0 900 5 5 tOFF 4V (ns) 950 tON 10V (ns) 20 25 30 VSUPPLY (V) 2.5 1000 RETRY DUTY CYCLE (%) 15 Gate Turn-On Delay vs. Gate Capacitance Gate Turn-On Delay vs. Supply Voltage 750 10 60 50 40 30 0 5 10 15 VIN (V) 20 20 -60 -30 0 30 60 90 120 150 TEMPERATURE (°C) 25 TTL (H) 0V 15V (max.) Source 50mV 0V Timing Diagram 1. Normal Operation 6µs Input Gate Sense +, ­ Differential 20µs 6µs TTL (H) Input 0V 15V (max.) Gate Source Sense +, ­ Differential 50mV 0V Timing Diagram 2. Fault Condition, CT = Open TTL (H) 0V 15V (max.) Source 50mV 0V Timing Diagram 3. Fault Condition, CT = Grounded 5-172 1997 MIC5021 MIC5021 Micrel Functional Description Refer to the MIC5021 MIC5021 block diagram. Input A signal greater than 1.4V (nominal) applied to the MIC5021 MIC5021 INPUT causes gate enhancement on an external MOSFET turning the MOSFET on. An internal pull-down resistor insures that an open INPUT remains low, keeping the external MOSFET turned off. Gate Output Rapid rise and fall times on the GATE output are possible because each input state change triggers a one-shot which activates a high-value current sink (10I2) for a short time. This draws a high current though a current mirror circuit causing the output transistors to quickly charge or discharge the external MOSFET's gate. A second current sink continuously draws the lower value of current used to maintain the gate voltage for the selected state. An internal charge pump utilizes an external "boost" capacitor connected between VBOOST and the source of the external MOSFET. (Refer to typical application.) The boost capacitor stores charge when the MOSFET is off. As the MOSFET turns on, its source to ground voltage increases and is added to the voltage across the capacitor, raising the VBOOST pin voltage. The boost capacitor charge is directed through the GATE pin to quickly charge the MOSFET's gate to 16V maximum above VDD. The internal charge pump maintains the gate voltage. Applications Information The MIC5021 MIC5021 MOSFET driver is intended for high-side switching applications where overcurrent limiting and high speed are required. The MIC5021 MIC5021 can control MOSFETs that switch voltages up to 36V. High-Side Switch Circuit Advantages High-side switching allows more of the load related components and wiring to remain near ground potential when compared to low-side switching. This reduces the chances of short-to-ground accidents or failures. Speed Advantage The MIC5021 MIC5021 is about two orders of magnitude faster than the low cost MIC5014 MIC5014 making it suitable for high-frequency high-efficiency circuit operation in PWM (pulse width modulation) designs used for motor control, SMPS (switch mode power supply) and heating element control. Switched loads (on/off) benefit from the MIC5021 MIC5021's fast switching times by allowing use of MOSFETs with smaller safe operating areas. (Larger MOSFETs are often required when using slower drivers.) 1997 An internal zener diode protects the external MOSFET by limiting the gate to source voltage. Sense Inputs The MIC5021 MIC5021's 50mV (nominal) trip voltage is created by internal current sources that force approximately 5µA out of SENSE + and approximately 15µA (at trip) out of SENSE ­. When SENSE ­ is 50mV or more below SENSE +, SENSE ­ steals base current from an internal drive transistor shutting off the external MOSFET. Overcurrent Limiting Current source I1 charges CINT upon power up. An optional external capacitor connected to CT is kept discharged through a MOSFET Q1. A fault condition (> 50mV from SENSE + to SENSE ­) causes the overcurrent comparator to enable current sink 2I1 which overcomes current source I1 to discharge CINT in a short time. When CINT is discharged, the INPUT is disabled, which turns off the gate output, and CINT and CT are ready to be charged. When the gate output turns the MOSFET off, the overcurrent signal is removed from the sense inputs which deactivates current sink 2I1. This allows CINT and the optional capacitor connected to CT to recharge. A Schmitt trigger delays the retry while the capacitor(s) recharge. Retry delay is increased by connecting a capacitor to CT (optional). The retry cycle will continue until the fault is removed or the input is changed to TTL low. If CT is connected to ground, the circuit will not retry upon a fault condition. Supply Voltage The MIC5021 MIC5021's supply input (VDD) is rated up to 36V. The supply voltage must be equal to or greater than the voltage applied to the drain of the external N-channel MOSFET. A 16V minimum supply is recommended to produce continuous on-state, gate drive voltage for standard MOSFETs (10V nominal gate enhancement). When the driver is powered from a 12V to 16V supply, a logiclevel MOSFET is recommended (5V nominal gate enhancement). PWM operation may produce satisfactory gate enhancement at lower supply voltages. This occurs when fast switching repetition makes the boost capacitor a more significant voltage supply than the internal charge pump. 5-173 5 MIC5021 MIC5021 Micrel A 0.01µF boost capacitor is recommended for best performance in the 12V to 20V range. Refer to figure 1. Larger capacitors may damage the MIC5021 MIC5021. +12V to +36V MIC5021 MIC5021 10µF TTL Input 1 2 3 4 VDD Input CT VBOOST Gate Sense Gnd Sense 8 7 6 5 2.7 µF Load Logic-Level MOSFET Precautions Logic-level MOSFETs have lower maximum gate-to-source voltage ratings (typically ±10V) than standard MOSFETs (typically ±20V). When an external MOSFET is turned on, the doubling effect of the boost capacitor can cause the gate-tosource voltage to momentarily exceed 10V. Internal zener diodes clamp this voltage to 16V maximum which is too high for logic-level MOSFETs. To protect logic-level MOSFETs, connect a zener diode (5VVZener