Datasheet MIC4452, MIC4451 Datasheet (MICREL)

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Page 1

MIC4451/4452 Micrel

MIC4451/4452

12A-Peak Low-Side MOSFET Driver

Bipolar/CMOS/DMOS Process

General Description

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.

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.

Features

• 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 V

• Low Supply Current..............450µA With Logic 1 Input

• Low Output Impedance ........................................ 1.0Ω

• Output Voltage Swing to Within 25mV of GND or V

• Low Equivalent Input Capacitance (typ).................7pF

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

2kΩ

0.1mA

0.3mA

MIC4451

INVERTING

MIC4452

NONINVERTING

GND

OUT

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MIC4451/4452 Micrel

Ordering Information

Part No. Temperature Range Package Configuration

MIC4451BN –40°C to +85°C 8-Pin PDIP Inverting MIC4451BM –40°C to +85°C 8-Pin SOIC Inverting MIC4451CT 0°C to +70°C 5-Pin TO-220 Inverting MIC4452BN –40°C to +85°C 8-Pin PDIP Non-Inverting MIC4452BM –40°C to +85°C 8-Pin SOIC Non-Inverting MIC4452CT 0°C to +70°C 5-Pin TO-220 Non-Inverting

Pin Configurations

TAB

GND

1 2 3 4

Plastic DIP (N)

SOIC (M)

TO-220-5 (T)

8 7

OUT

GND

5 OUT 4 GND 3VS 2 GND 1IN

Pin Description

Pin Number Pin Number Pin Name Pin Function

TO-220-5 DIP, SOIC

1 2 IN Control Input

2, 4 4, 5 GND Ground: Duplicate pins must be externally connected together.

3, TAB 1, 8 V

5 6, 7 OUT Output: Duplicate pins must be externally connected together.

3 NC Not connected.

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Supply Input: Duplicate pins must be externally connected together.

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MIC4451/4452 Micrel

Absolute Maximum 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, T

AMBIENT

PDIP....................................................................960mW

SOIC .................................................................1040mW

≤ 25°C

Operating Ratings

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

5-Pin TO-220..............................................................2W

Power Dissipation, T

CASE

≤ 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

Electrical Characteristics:

(TA = 25°C with 4.5 V ≤ V

Symbol Parameter Conditions Min Typ Max Units INPUT

OUTPUT

SWITCHING TIME (Note 3) t

Power Supply

Logic 1 Input Voltage 2.4 1.3 V Logic 0 Input Voltage 1.1 0.8 V Input Voltage Range –5 VS+.3 V Input Current 0 V ≤ VIN ≤ V

High Output Voltage See Figure 1 VS–.025 V Low Output Voltage See Figure 1 .025 V Output Resistance, I

Output High Output Resistance, I

Output Low Peak Output Current VS = 18 V (See Figure 6) 12 A Continuous Output Current 2 A Latch-Up Protection Duty Cycle ≤ 2% >1500 mA

Withstand Reverse Current t ≤ 300 µs

Rise Time Test Figure 1, CL = 15,000 pF 20 40 ns Fall Time Test Figure 1, CL = 15,000 pF 24 50 ns Delay Time Test Figure 1 15 30 ns Delay Time Test Figure 1 35 60 ns

Power Supply Current VIN = 3 V 0.4 1.5 mA

Operating Input Voltage 4.5 18 V

≤ 18 V unless otherwise specified.)

OUT

VIN = 0 V 80 150 µA

= 10 mA, VS = 18V 0.6 1.5 Ω

= 10 mA, VS = 18V 0.8 1.5 Ω

–10 10 µA

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MIC4451/4452 Micrel

Electrical Characteristics:

(Over operating temperature range with 4.5V < V

Symbol Parameter Conditions Min Typ Max Units INPUT

Logic 1 Input Voltage 2.4 1.4 V Logic 0 Input Voltage 1.0 0.8 V Input Voltage Range –5 VS+.3 V Input Current 0V ≤ VIN ≤ V

OUTPUT

High Output Voltage Figure 1 VS–.025 V Low Output Voltage Figure 1 0.025 V Output Resistance, I

Output High

Output Resistance, I

Output Low SWITCHING TIME (Note 3) t

Rise Time Figure 1, CL = 15,000pF 23 50 ns

Fall Time Figure 1, CL = 15,000pF 30 60 ns

Delay Time Figure 1 20 40 ns

Delay Time Figure 1 40 80 ns

POWER SUPPLY

Power Supply Current VIN = 3V 0.6 3 mA

Operating Input Voltage 4.5 18 V

NOTE 1: Functional operation above the absolute maximum stress ratings is not implied. NOTE 2: Static-sensitive device. Store only in conductive containers. Handling personnel and equipment should be grounded to

prevent damage from static discharge.

NOTE 3: Switching times guaranteed by design.

< 18V unless otherwise specified.)

= 10mA, VS = 18V 0.8 2.2 Ω

OUT

= 10mA, VS = 18V 1.3 2.2 Ω

OUT

–10 10 µA

VIN = 0V 0.1 0.4

Test Circuits

0.1µF

90%

INPUT

10%

90%

OUTPUT

10%

Figure 1. Inverting Driver Switching Time

VS = 18V

MIC4451

VS = 18V

0.1µF 1.0µF

OUT

15000pF

0.1µF

0.1µF 1.0µF

OUT

15000pF

MIC4452

≥ 0.5µs

INPUT

OUTPUT

90% 10%

90%

10%

≥ 0.5µs

Figure 2. Noninverting Driver Switching Time

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MIC4451/4452 Micrel

Typical Characteristic Curves

Rise Time

vs. Supply Voltage

220 200 180 160 140 120 100

RISE TIME (ns)

60 40 20

4 6 8 1012141618

SUPPLY VOLTAGE (V)

47,000pF

22,000pF 10,000pF

Rise Time

vs. Capacitive Load

300

250

200

150

100

RISE TIME (ns)

100 1000 10k 100k

CAPACITIVE LOAD (pF)

10V

Fall Time

vs. Supply Voltage

220 200 180 160 140 120 100

FALL TIME (ns)

60 40 20

4 6 8 1012141618

SUPPLY VOLTAGE (V)

47,000pF

22,000pF 10,000pF

Fall Time

vs. Capacitive Load

300

18V

250

200

150

100

FALL TIME (ns)

100 1000 10k 100k

CAPACITIVE LOAD (pF)

10V

18V

Rise and Fall Times

vs. Temperature

CL = 10,000pF

= 18V

TIME (ns)

-40 0 40 80 120 TEMPERATURE (°C)

FALL

Crossover Energy

vs. Supply Voltage

-7

PER TRANSITION

-8

CROSSOVER ENERGY (A•s)

-9

4 6 8 1012141618

VOLTAGE (V)

RISE

Supply Current

vs. Capacitive Load

220

VS = 18V

200 180 160 140 120 100

80 60 40

SUPPLY CURRENT (mA)

1 MHz

200kHz

100 1000 10k 100k

CAPACITIVE LOAD (pF)

Supply Current

vs. Frequency

180

VS = 18V

160 140 120 100

SUPPLY CURRENT (mA)

0.1µF

80 60 40 20

10k 100k 1M 10M

0.01µF

FREQUENCY (Hz)

1000pF

50kHz

Supply Current

vs. Capacitive Load

150

VS = 12V

120

1 MHz

SUPPLY CURRENT (mA)

100 1000 10k 100k

CAPACITIVE LOAD (pF)

200kHz

Supply Current

vs. Frequency

120

VS = 12V

100

0.1µF

SUPPLY CURRENT (mA)

10k 100k 1M 10M

0.01µF

1000pF

FREQUENCY (Hz)

50kHz

Supply Current

vs. Capacitive Load

VS = 5V

1 MHz

SUPPLY CURRENT (mA)

100 1000 10k 100k

CAPACITIVE LOAD (pF)

200kHz

Supply Current

vs. Frequency

VS = 5V

0.1µF

SUPPLY CURRENT (mA)

10k 100k 1M 10M

FREQUENCY (Hz)

0.01µF

50kHz

1000pF

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MIC4451/4452 Micrel

4 6 8 1012141618

2.4

2.2

2.0

1.4

1.2

1.0

0.8

0.6

0.4

0.2 0

SUPPLY VOLTAGE (V)

LOW-STATE OUTPUT RESISTANCE (Ω)

Low-State Output Resist.

vs. Supply Voltage

1.6

1.8

TJ = 25°C

TJ = 150°C

Typical Characteristic Curves (Cont.)

Propagation Delay vs. Supply Voltage

TIME (ns)

4 6 8 1012141618

SUPPLY VOLTAGE (V)

Quiescent Supply Current

vs. Temperature

1000

VS = 18V

INPUT = 1

100

INPUT = 0

QUIESCENT SUPPLY CURRENT (µA)

-40 0 40 80 120 TEMPERATURE (°C)

Propagation Delay

vs. Input Amplitude

120 110

VS = 10V

100

90 80 70 60 50

TIME (ns)

40 30 20 10

0246810

INPUT (V)

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

4 6 8 1012141618

HIGH-STATE OUTPUT RESISTANCE (Ω)

SUPPLY VOLTAGE (V)

TJ = 150°C

TJ = 25°C

Propagation Delay

vs. Temperature

TIME (ns)

-40 0 40 80 120 TEMPERATURE (°C)

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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.

1µF

M φ

DRIVE SIGNAL

CONDUCTION ANGLE

CONTROL 0° TO 180°

CONDUCTION ANGLE

CONTROL 180° TO 360°

DRIVE LOGIC

MIC4451

MIC4452

1µF

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.

0.1µF 50V

0.1µF WIMA MKS 2

Figure 3. Direct Motor Drive

+15

MIC4451

(x2) 1N4448

1µF 50V MKS 2

6, 7

UNITED CHEMCON SXE

5.6 kΩ

560 Ω

BYV 10 (x 2)

560µF 50V

100µF 50V

Figure 4. Self Contained Voltage Doubler

OUTPUT VOLTAGE vs LOAD CURREN

VOLTS

0 50 100 150 200 250 300 350

12 Ω LIN

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MIC4451/4452 Micrel

Ω

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 (6.4mA

) with the input. No damage will

RMS

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

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

+18

WIMA MKS-2 1 µF

0 V

LOGIC

GROUND

POWE

GROUND

5.0V

0.1µF

300 mV

MIC4451

12 AMP

TEK CURRENT

PROBE 6302

6, 7

0.1µF

PC TRACE RESISTANCE = 0.05

18 V

0 V

2,500 pF POLYCARBONATE

where:

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

Table 1: MIC4451 Maximum Operating Frequency

Max Frequency

18V 220kHz 15V 300kHz 10V 640kHz

5V 2MHz

Conditions: 1. θJA = 150°C/W

2. TA = 25°C

3. CL = 10,000pF

Figure 5. Switching Time Degradation Due to

Negative Feedback

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MIC4451/4452 Micrel

driver. The energy stored in a capacitor is described by the equation:

E = 1/2 C V

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:

PL = f C (VS)

where:

f = Operating Frequency

C = Load Capacitance

VS = Driver Supply Voltage

Inductive Load Power Dissipation

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:

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)

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.”

Total power (PD) then, as previously described is:

PD = PL + PQ + P

Definitions

CL = Load Capacitance in Farads.

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.

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.

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 P

PL = PL1 + P

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:

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)

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.

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MIC4451/4452 Micrel

+18

WIMA MK22 1 µF

5.0V

0 V

0.1µF

MIC4452

TEK CURRENT

6, 7

PROBE 6302

0.1µF

Figure 6. Peak Output Current Test Circuit

18 V

0 V

15,000 pF POLYCARBONATE

April 1998 5-79