MIC4451/4452 Micrel MIC4451/4452 12A-Peak Low-Side MOSFET Driver Bipolar/CMOS/DMOS Process General Description Features MIC4451 and MIC4452 CMOS MOSFET drivers are tough, efficient, and easy to use. The MIC4451 is an inverting driver, while the MIC4452 is a non-inverting driver. • BiCMOS/DMOS Construction • Latch-Up Proof: Fully Isolated Process is Inherently Immune to Any Latch-up. • Input Will Withstand Negative Swing of Up to 5V • Matched Rise and Fall Times ............................... 25ns • High Peak Output Current ............................ 12A Peak • Wide Operating Range .............................. 4.5V to 18V • High Capacitive Load Drive ........................... 62,000pF • Low Delay Time ........................................... 30ns Typ. • Logic High Input for Any Voltage from 2.4V to VS • Low Supply Current .............. 450µA With Logic 1 Input • Low Output Impedance ........................................ 1.0Ω • Output Voltage Swing to Within 25mV of GND or VS • Low Equivalent Input Capacitance (typ) ................. 7pF Both versions are capable of 12A (peak) output and can drive the largest MOSFETs with an improved safe operating margin. The MIC4451/4452 accepts any logic input from 2.4V to VS without external speed-up capacitors or resistor networks. Proprietary circuits allow the input to swing negative by as much as 5V without damaging the part. Additional circuits protect against damage from electrostatic discharge. MIC4451/4452 drivers can replace three or more discrete components, reducing PCB area requirements, simplifying product design, and reducing assembly cost. Modern Bipolar/CMOS/DMOS construction guarantees freedom from latch-up. The rail-to-rail swing capability of CMOS/ DMOS insures adequate gate voltage to the MOSFET during power up/down sequencing. Since these devices are fabricated on a self-aligned process, they have very low crossover current, run cool, use little power, and are easy to drive. Applications • • • • • • • • Switch Mode Power Supplies Motor Controls Pulse Transformer Driver Class-D Switching Amplifiers Line Drivers Driving MOSFET or IGBT Parallel Chip Modules Local Power ON/OFF Switch Pulse Generators Functional Diagram VS 0.3mA MIC4451 INVERTING 0.1mA OUT IN 2kΩ MIC4452 NONINVERTING GND 5-70 April 1998 MIC4451/4452 Micrel Ordering Information Part No. MIC4451BN Temperature Range –40°C to +85°C Package 8-Pin PDIP Configuration Inverting MIC4451BM MIC4451CT MIC4452BN –40°C to +85°C 0°C to +70°C –40°C to +85°C 8-Pin SOIC 5-Pin TO-220 8-Pin PDIP Inverting Inverting Non-Inverting MIC4452BM MIC4452CT –40°C to +85°C 0°C to +70°C 8-Pin SOIC 5-Pin TO-220 Non-Inverting Non-Inverting Pin Configurations VS 1 8 VS IN 2 7 OUT NC 3 6 OUT GND 4 5 GND 5 Plastic DIP (N) SOIC (M) TAB 5 4 3 2 1 OUT GND VS GND IN TO-220-5 (T) Pin Description Pin Number TO-220-5 Pin Number DIP, SOIC Pin Name Pin Function 1 2 IN Control Input 2, 4 4, 5 GND 3, TAB 1, 8 VS 5 6, 7 OUT 3 NC April 1998 Ground: Duplicate pins must be externally connected together. Supply Input: Duplicate pins must be externally connected together. Output: Duplicate pins must be externally connected together. Not connected. 5-71 MIC4451/4452 Absolute Maximum Ratings Micrel Operating Ratings (Notes 1, 2 and 3) Supply Voltage .............................................................. 20V Input Voltage .................................. VS + 0.3V to GND – 5V Input Current (VIN > VS) ............................................ 50 mA Power Dissipation, TAMBIENT ≤ 25°C PDIP .................................................................... 960mW SOIC ................................................................. 1040mW 5-Pin TO-220 .............................................................. 2W Power Dissipation, TCASE ≤ 25°C 5-Pin TO-220 ......................................................... 12.5W Derating Factors (to Ambient) PDIP ................................................................ 7.7mW/°C SOIC .............................................................. 8.3 mW/°C 5-Pin TO-220 .................................................... 17mW/°C Storage Temperature ............................... –65°C to +150°C Lead Temperature (10 sec) ....................................... 300°C Operating Temperature (Chip) .................................. 150°C Operating Temperature (Ambient) C Version ................................................... 0°C to +70°C B Version ................................................ –40°C to +85°C Thermal Impedances (To Case) 5-Pin TO-220 (θJC) .............................................. 10°C/W Electrical Characteristics: (TA = 25°C with 4.5 V ≤ VS ≤ 18 V unless otherwise specified.) Symbol Parameter Conditions Min Typ 2.4 1.3 Max Units INPUT VIH Logic 1 Input Voltage VIL Logic 0 Input Voltage VIN Input Voltage Range IIN Input Current 0 V ≤ VIN ≤ VS VOH High Output Voltage See Figure 1 VOL Low Output Voltage See Figure 1 RO Output Resistance, Output High IOUT = 10 mA, VS = 18V RO Output Resistance, Output Low IPK Peak Output Current IDC Continuous Output Current IR Latch-Up Protection Withstand Reverse Current 1.1 V 0.8 V –5 VS+.3 V –10 10 µA OUTPUT VS–.025 V .025 V 0.6 1.5 Ω IOUT = 10 mA, VS = 18V 0.8 1.5 Ω VS = 18 V (See Figure 6) 12 Duty Cycle ≤ 2% t ≤ 300 µs A 2 A >1500 mA SWITCHING TIME (Note 3) tR Rise Time Test Figure 1, CL = 15,000 pF 20 40 ns tF Fall Time Test Figure 1, CL = 15,000 pF 24 50 ns tD1 Delay Time Test Figure 1 15 30 ns tD2 Delay Time Test Figure 1 35 60 ns VIN = 3 V VIN = 0 V 0.4 80 1.5 150 mA µA 18 V Power Supply IS Power Supply Current VS Operating Input Voltage 4.5 5-72 April 1998 MIC4451/4452 Micrel Electrical Characteristics: (Over operating temperature range with 4.5V < VS < 18V unless otherwise specified.) Symbol Parameter Conditions Min Typ 2.4 1.4 Max Units INPUT VIH Logic 1 Input Voltage VIL Logic 0 Input Voltage VIN Input Voltage Range IIN Input Current 0V ≤ VIN ≤ VS VOH High Output Voltage Figure 1 VOL Low Output Voltage Figure 1 RO Output Resistance, Output High IOUT = 10mA, VS = 18V RO Output Resistance, Output Low V 1.0 0.8 V –5 VS+.3 V –10 10 µA OUTPUT VS–.025 V 0.025 V 0.8 2.2 Ω IOUT = 10mA, VS = 18V 1.3 2.2 Ω SWITCHING TIME (Note 3) tR Rise Time Figure 1, CL = 15,000pF 23 50 ns tF Fall Time Figure 1, CL = 15,000pF 30 60 ns tD1 Delay Time Figure 1 20 40 ns tD2 Delay Time Figure 1 40 80 ns VIN = 3V VIN = 0V 0.6 0.1 3 0.4 mA 18 V POWER SUPPLY IS Power Supply Current VS Operating Input Voltage NOTE 1: NOTE 2: NOTE 3: 4.5 Functional operation above the absolute maximum stress ratings is not implied. Static-sensitive device. Store only in conductive containers. Handling personnel and equipment should be grounded to prevent damage from static discharge. Switching times guaranteed by design. Test Circuits VS = 18V VS = 18V 0.1µF 0.1µF IN 1.0µF 0.1µF 0.1µF OUT IN OUT 15000pF 15000pF MIC4451 INPUT MIC4452 5V 90% tPW ≥ 0.5µs 10% 0V VS 90% tD1 tPW tF tD2 INPUT 5V 90% tPW ≥ 0.5µs 10% 0V tR VS 90% tD1 tPW tR tD2 tF OUTPUT OUTPUT 10% 0V 10% 0V Figure 2. Noninverting Driver Switching Time Figure 1. Inverting Driver Switching Time April 1998 1.0µF 5-73 5 MIC4451/4452 Micrel TIME (ns) 6 8 10 12 14 16 SUPPLY VOLTAGE (V) Fall Time vs. Capacitive Load 150 10V 100 200 5V 150 10V 100 18V 18V 50 4 6 kH z 1000 10k CAPACITIVE LOAD (pF) 45 30 Hz 100k 1M FREQUENCY (Hz) 10M 20 10k 100 1000 10k CAPACITIVE LOAD (pF) 100k Supply Current vs. Frequency 100k 1M FREQUENCY (Hz) 5-74 10M µF 0.01 50 40 pF 30 1000 pF µF 1000 0.01 F 40 0 1M 15 VS = 5V SUPPLY CURRENT (mA) 20 0.1µ pF 1000 µF 60 18 Supply Current vs. Capacitive Load 60 100 60 16 60 0 100k Supply Current vs. Frequency 80 8 10 12 14 VOLTAGE (V) F 100 50 1 30 z MH z 60 H 50 90 120 40 10k 75 VS = 12V 0.01 80 10-8 VS = 5V 120 0 100k VS = 18V 120 PER TRANSITION 10-9 100k Supply Current vs. Capacitive Load 0k z kH z H 0k 1000 10k CAPACITIVE LOAD (pF) Supply Current vs. Frequency 100 1000 10k CAPACITIVE LOAD (pF) 20 z H 1M 100 100 120 Crossover Energy vs. Supply Voltage 10-7 VS = 12V SUPPLY CURRENT (mA) VS = 18V 140 0 150 SUPPLY CURRENT (mA) 160 0 100k Supply Current vs. Capacitive Load F SUPPLY CURRENT (mA) 180 1000 10k CAPACITIVE LOAD (pF) 20 220 200 180 160 140 120 100 80 60 40 20 0 100 0.1µ SUPPLY CURRENT (mA) 0 50 -40 0 40 80 TEMPERATURE (°C) z 5V 200 0 18 250 FALL TIME (ns) RISE TIME (ns) 250 4 10 kH 300 10,000pF tRISE 50 Rise Time vs. Capacitive Load 20 22,000pF z 18 30 H 6 8 10 12 14 16 SUPPLY VOLTAGE (V) tFALL 40 0.1µ 4 47,000pF 0k 10,000pF CL = 10,000pF VS = 18V 50 20 22,000pF Rise and Fall Times vs. Temperature 60 CROSSOVER ENERGY (A•s) 300 47,000pF 220 200 180 160 140 120 100 80 60 40 20 0 Fall Time vs. Supply Voltage SUPPLY CURRENT (mA) 220 200 180 160 140 120 100 80 60 40 20 0 Rise Time vs. Supply Voltage FALL TIME (ns) RISE TIME (ns) Typical Characteristic Curves 20 10 0 10k 100k 1M FREQUENCY (Hz) 10M April 1998 MIC4451/4452 Micrel Typical Characteristic Curves (Cont.) 20 tD1 10 QUIESCENT SUPPLY CURRENT (µA) 0 4 6 8 10 12 14 16 SUPPLY VOLTAGE (V) 18 Quiescent Supply Current vs. Temperature 1000 VS = 18V INPUT = 1 100 INPUT = 0 10 April 1998 -40 0 40 80 TEMPERATURE (°C) 120 Propagation Delay vs. Input Amplitude 50 Propagation Delay vs. Temperature VS = 10V 40 TIME (ns) tD2 30 TIME (ns) TIME (ns) 40 HIGH-STATE OUTPUT RESISTANCE (Ω) 50 120 110 100 90 80 70 60 50 40 30 20 10 0 30 tD2 20 tD2 tD1 10 0 2 4 6 INPUT (V) tD1 8 0 10 High-State Output Resist. vs. Supply Voltage 2.4 2.2 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 TJ = 150°C TJ = 25°C 4 6 8 10 12 14 16 SUPPLY VOLTAGE (V) 5-75 18 LOW-STATE OUTPUT RESISTANCE (Ω) Propagation Delay vs. Supply Voltage -40 0 40 80 TEMPERATURE (°C) 120 Low-State Output Resist. vs. Supply Voltage 2.4 2.2 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 TJ = 150°C TJ = 25°C 4 6 8 10 12 14 16 SUPPLY VOLTAGE (V) 18 5 MIC4451/4452 Micrel Applications Information Supply Bypassing Charging and discharging large capacitive loads quickly requires large currents. For example, changing a 10,000pF load to 18V in 50ns requires 3.6A. The MIC4451/4452 has double bonding on the supply pins, the ground pins and output pins. This reduces parasitic lead inductance. Low inductance enables large currents to be switched rapidly. It also reduces internal ringing that can cause voltage breakdown when the driver is operated at or near the maximum rated voltage. Internal ringing can also cause output oscillation due to feedback. This feedback is added to the input signal since it is referenced to the same ground. V DD 1µF V DD MIC4451 φ 2 φ1 DRIVE SIGNAL φ DRIVE LOGIC CONDUCTION ANGLE CONTROL 0° TO 180° CONDUCTION ANGLE CONTROL 180° TO 360° 1 M φ 3 V DD V DD 1µF MIC4452 PHASE 1 OF 3 PHASE MOTOR DRIVER USING MIC4451/4452 To guarantee low supply impedance over a wide frequency range, a parallel capacitor combination is recommended for supply bypassing. Low inductance ceramic disk capacitors with short lead lengths (< 0.5 inch) should be used. A 1µF low ESR film capacitor in parallel with two 0.1µF low ESR ceramic capacitors, (such as AVX RAM GUARD®), provides adequate bypassing. Connect one ceramic capacitor directly between pins 1 and 4. Connect the second ceramic capacitor directly between pins 8 and 5. Grounding The high current capability of the MIC4451/4452 demands careful PC board layout for best performance. Since the MIC4451 is an inverting driver, any ground lead impedance will appear as negative feedback which can degrade switching speed. Feedback is especially noticeable with slow-rise time inputs. The MIC4451 input structure includes 200mV of hysteresis to ensure clean transitions and freedom from oscillation, but attention to layout is still recommended. Figure 5 shows the feedback effect in detail. As the MIC4451 input begins to go positive, the output goes negative and several amperes of current flow in the ground lead. As little as 0.05Ω of PC trace resistance can produce hundreds of millivolts at the MIC4451 ground pins. If the driving logic is referenced to power ground, the effective logic input level is reduced and oscillation may result. To insure optimum performance, separate ground traces should be provided for the logic and power connections. Connecting the logic ground directly to the MIC4451 GND pins will ensure full logic drive to the input and ensure fast output switching. Both of the MIC4451 GND pins should, however, still be connected to power ground. Figure 3. Direct Motor Drive +15 (x2) 1N4448 5.6 kΩ OUTPUT VOLTAGE vs LOAD CURRENT 560 Ω 30 0.1µF 50V + 1 8 2 0.1µF WIMA MKS 2 1µF 50V MKS 2 6, 7 VOLTS 29 BYV 10 (x 2) + 4 12 Ω LINE 27 26 MIC4451 5 28 + 560µF 50V 100µF 50V UNITED CHEMCON SXE 25 0 50 100 150 200 250 300 350 mA Figure 4. Self Contained Voltage Doubler 5-76 April 1998 MIC4451/4452 Micrel Input Stage The input voltage level of the MIC4451 changes the quiescent supply current. The N channel MOSFET input stage transistor drives a 320µA current source load. With a logic “1” input, the maximum quiescent supply current is 400µA. Logic “0” input level signals reduce quiescent current to 80µA typical. The MIC4451/4452 input is designed to provide 200mV of hysteresis. This provides clean transitions, reduces noise sensitivity, and minimizes output stage current spiking when changing states. Input voltage threshold level is approximately 1.5V, making the device TTL compatible over the full temperature and operating supply voltage ranges. Input current is less than ±10µA. The MIC4451 can be directly driven by the TL494, SG1526/ 1527, SG1524, TSC170, MIC38C42, and similar switch mode power supply integrated circuits. By offloading the power-driving duties to the MIC4451/4452, the power supply controller can operate at lower dissipation. This can improve performance and reliability. The input can be greater than the VS supply, however, current will flow into the input lead. The input currents can be as high as 30mA p-p (6.4mARMS) with the input. No damage will occur to MIC4451/4452 however, and it will not latch. The input appears as a 7pF capacitance and does not change even if the input is driven from an AC source. While the device will operate and no damage will occur up to 25V below the negative rail, input current will increase up to 1mA/V due to the clamping action of the input, ESD diode, and 1kΩ resistor. dissipation limit can easily be exceeded. Therefore, some attention should be given to power dissipation when driving low impedance loads and/or operating at high frequency. The supply current vs. frequency and supply current vs capacitive load characteristic curves aid in determining power dissipation calculations. Table 1 lists the maximum safe operating frequency for several power supply voltages when driving a 10,000pF load. More accurate power dissipation figures can be obtained by summing the three dissipation sources. Given the power dissipation in the device, and the thermal resistance of the package, junction operating temperature for any ambient is easy to calculate. For example, the thermal resistance of the 8-pin plastic DIP package, from the data sheet, is 130°C/W. In a 25°C ambient, then, using a maximum junction temperature of 125°C, this package will dissipate 960mW. Accurate power dissipation numbers can be obtained by summing the three sources of power dissipation in the device: • Load Power Dissipation (PL) • Quiescent power dissipation (PQ) • Transition power dissipation (PT) Calculation of load power dissipation differs depending on whether the load is capacitive, resistive or inductive. Resistive Load Power Dissipation Dissipation caused by a resistive load can be calculated as: PL = I2 RO D Power Dissipation where: CMOS circuits usually permit the user to ignore power dissipation. Logic families such as 4000 and 74C have outputs which can only supply a few milliamperes of current, and even shorting outputs to ground will not force enough current to destroy the device. The MIC4451/4452 on the other hand, can source or sink several amperes and drive large capacitive loads at high frequency. The package power I = the current drawn by the load RO = the output resistance of the driver when the output is high, at the power supply voltage used. (See data sheet) D = fraction of time the load is conducting (duty cycle) Capacitive Load Power Dissipation Dissipation caused by a capacitive load is simply the energy placed in, or removed from, the load capacitance by the +18 WIMA MKS-2 1 µF 5.0V 1 8 6, 7 TEK CURRENT PROBE 6302 Table 1: MIC4451 Maximum Operating Frequency VS Max Frequency 18 V MIC4451 0V 0V 5 0.1µF 0.1µF 4 LOGIC GROUND 2,500 pF POLYCARBONATE 12 AMPS 300 mV PC TRACE RESISTANCE = 0.05Ω POWER GROUND 220kHz 300kHz 10V 5V 640kHz 2MHz Conditions: 1. θJA = 150°C/W 2. TA = 25°C 3. CL = 10,000pF Figure 5. Switching Time Degradation Due to Negative Feedback April 1998 18V 15V 5-77 5 MIC4451/4452 Micrel driver. The energy stored in a capacitor is described by the equation: E = 1/2 C V2 As this energy is lost in the driver each time the load is charged or discharged, for power dissipation calculations the 1/2 is removed. This equation also shows that it is good practice not to place more voltage on the capacitor than is necessary, as dissipation increases as the square of the voltage applied to the capacitor. For a driver with a capacitive load: VS = power supply voltage Transition Power Dissipation Transition power is dissipated in the driver each time its output changes state, because during the transition, for a very brief interval, both the N- and P-channel MOSFETs in the output totem-pole are ON simultaneously, and a current is conducted through them from VS to ground. The transition power dissipation is approximately: PT = 2 f VS (A•s) where (A•s) is a time-current factor derived from the typical characteristic curve “Crossover Energy vs. Supply Voltage.” PL = f C (VS)2 where: Total power (PD) then, as previously described is: f = Operating Frequency C = Load Capacitance VS = Driver Supply Voltage PD = PL + PQ + PT Definitions Inductive Load Power Dissipation CL = Load Capacitance in Farads. For inductive loads the situation is more complicated. For the part of the cycle in which the driver is actively forcing current into the inductor, the situation is the same as it is in the resistive case: D = Duty Cycle expressed as the fraction of time the input to the driver is high. f = Operating Frequency of the driver in Hertz IH = Power supply current drawn by a driver when both inputs are high and neither output is loaded. PL1 = I2 RO D However, in this instance the RO required may be either the on resistance of the driver when its output is in the high state, or its on resistance when the driver is in the low state, depending on how the inductor is connected, and this is still only half the story. For the part of the cycle when the inductor is forcing current through the driver, dissipation is best described as PL2 = I VD (1 – D) where VD is the forward drop of the clamp diode in the driver (generally around 0.7V). The two parts of the load dissipation must be summed in to produce PL PL = PL1 + PL2 Quiescent Power Dissipation Quiescent power dissipation (PQ, as described in the input section) depends on whether the input is high or low. A low input will result in a maximum current drain (per driver) of ≤ 0.2mA; a logic high will result in a current drain of ≤ 3.0mA. Quiescent power can therefore be found from: IL = Power supply current drawn by a driver when both inputs are low and neither output is loaded. ID = Output current from a driver in Amps. PD = Total power dissipated in a driver in Watts. PL = Power dissipated in the driver due to the driver’s load in Watts. PQ = Power dissipated in a quiescent driver in Watts. PT = Power dissipated in a driver when the output changes states (“shoot-through current”) in Watts. NOTE: The “shoot-through” current from a dual transition (once up, once down) for both drivers is stated in Figure 7 in ampere-nanoseconds. This figure must be multiplied by the number of repetitions per second (frequency) to find Watts. RO = Output resistance of a driver in Ohms. VS = Power supply voltage to the IC in Volts. PQ = VS [D IH + (1 – D) IL] where: IH = quiescent current with input high IL = quiescent current with input low D = fraction of time input is high (duty cycle) 5-78 April 1998 MIC4451/4452 Micrel +18 V WIMA MK22 1 µF 5.0V 1 8 2 6, 7 TEK CURRENT PROBE 6302 18 V MIC4452 0V 0V 5 0.1µF 0.1µF 4 15,000 pF POLYCARBONATE Figure 6. Peak Output Current Test Circuit 5 April 1998 5-79