MICREL MIC4422BM

MIC4421/4422
Micrel
MIC4421/4422
9A-Peak Low-Side MOSFET Driver
Bipolar/CMOS/DMOS Process
General Description
Features
MIC4421 and MIC4422 MOSFET drivers are rugged, efficient, and easy to use. The MIC4421 is an inverting driver,
while the MIC4422 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 .............................. 9A Peak
• Wide Operating Range .............................. 4.5V to 18V
• High Capacitive Load Drive ........................... 47,000pF
• Low Delay Time ........................................... 30ns Typ.
• Logic High Input for Any Voltage from 2.4V to VS
• Low Equivalent Input Capacitance (typ) ................. 7pF
• Low Supply Current .............. 450µA With Logic 1 Input
• Low Output Impedance ........................................ 1.5Ω
• Output Voltage Swing to Within 25mV of GND or VS
Both versions are capable of 9A (peak) output and can drive
the largest MOSFETs with an improved safe operating margin. The MIC4421/4422 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.
MIC4421/4422 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
MIC4421
INVERTING
0.1mA
OUT
IN
2kΩ
MIC4422
NON-INVERTING
GND
5-42
April 1998
MIC4421/4422
Micrel
Ordering Information
Part No.
MIC4421CN
MIC4421BN
MIC4421CM
MIC4421BM
MIC4421CT
MIC4422CN
MIC4422BN
MIC4422CM
MIC4422BM
MIC4422CT
Temperature Range
0°C to +70°C
–40°C to +85°C
0°C to +70°C
–40°C to +85°C
0°C to +70°C
0°C to +70°C
–40°C to +85°C
0°C to +70°C
–40°C to +85°C
0°C to +70°C
Package
8-Pin PDIP
8-Pin PDIP
8-Pin SOIC
8-Pin SOIC
5-Pin TO-220
8-Pin PDIP
8-Pin PDIP
8-Pin SOIC
8-Pin SOIC
5-Pin TO-220
Configuration
Inverting
Inverting
Inverting
Inverting
Inverting
Non-Inverting
Non-Inverting
Non-Inverting
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.
5-43
MIC4421/4422
Micrel
Absolute Maximum Ratings
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, TA ≤ 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 ............................................................... 8.3mW/°C
5-Pin TO-220 .................................................... 17mW/°C
Storage Temperature ............................... –65°C to +150°C
Lead Temperature (10 sec) ....................................... 300°C
Electrical Characteristics:
Symbol
Junction Temperature ............................................... 150°C
Ambient Temperature
C Version ................................................... 0°C to +70°C
B Version ................................................ –40°C to +85°C
Thermal Resistance
5-Pin TO-220 (θJC) .............................................. 10°C/W
(TA = 25°C with 4.5 V ≤ VS ≤ 18 V unless otherwise specified.)
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 = 18 V
0.6
RO
Output Resistance,
Output Low
IOUT = 10 mA, VS = 18 V
0.8
IPK
Peak Output Current
VS = 18 V (See Figure 5)
9
IDC
Continuous Output Current
IR
Latch-Up Protection
Withstand Reverse Current
1.1
V
0.8
V
–5
VS+0.3
V
–10
10
µA
OUTPUT
Duty Cycle ≤ 2%
t ≤ 300 µs
VS–.025
V
0.025
V
Ω
1.7
Ω
A
2
A
>1500
mA
SWITCHING TIME (Note 3)
tR
Rise Time
Test Figure 1, CL = 10,000 pF
20
75
ns
tF
Fall Time
Test Figure 1, CL = 10,000 pF
24
75
ns
tD1
Delay Time
Test Figure 1
15
60
ns
tD2
Delay Time
Test Figure 1
35
60
ns
IS
Power Supply Current
VIN = 3 V
VIN = 0 V
0.4
80
1.5
150
mA
µA
VS
Operating Input Voltage
18
V
Power Supply
4.5
5-44
April 1998
MIC4421/4422
Micrel
Electrical Characteristics:
Symbol
(Over operating temperature range with 4.5V ≤ VS ≤ 18V unless otherwise specified.)
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+0.3
V
–10
10
µA
OUTPUT
VS–.025
V
0.025
V
0.8
3.6
Ω
IOUT = 10mA, VS = 18V
1.3
2.7
Ω
SWITCHING TIME (Note 3)
tR
Rise Time
Figure 1, CL = 10,000pF
23
120
ns
tF
Fall Time
Figure 1, CL = 10,000pF
30
120
ns
tD1
Delay Time
Figure 1
20
80
ns
tD2
Delay Time
Figure 1
40
80
ns
VIN = 3V
VIN = 0V
0.6
0.1
3
0.2
mA
18
V
POWER SUPPLY
IS
Power Supply Current
VS
Operating Input Voltage
NOTE 1:
NOTE 2:
4.5
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.
NOTE 3:
Test Circuits
VS = 18V
VS = 18V
0.1µF
0.1µF
IN
4.7µF
0.1µF
0.1µF
OUT
IN
OUT
15000pF
15000pF
MIC4421
INPUT
MIC4422
5V
90%
2.5V
tPW ≥ 0.5µs
10%
0V
VS
90%
tD1
tPW
4.7µF
tF
tD2
INPUT
5V
90%
2.5V
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
5-45
MIC4421/4422
Micrel
300
4
TIME (ns)
10
6
8 10 12 14 16
SUPPLY VOLTAGE (V)
5V
200
150
10V
100
Fall Time
vs. Capacitive Load
200
5V
150
10V
100
18V
18V
50
1000
10k
CAPACITIVE LOAD (pF)
50
0
100k
Supply Current
vs. Capacitive Load
150
1000
10k
CAPACITIVE LOAD (pF)
PER TRANSITION
10-8
10-9
100k
75
4
6
1000
10k
CAPACITIVE LOAD (pF)
100k
0
100
0k
H
z
Hz
50
60
kH
z
90
1M
8 10 12 14
VOLTAGE (V)
16
18
Supply Current
vs. Capacitive Load
VS = 5V
120
30
120
Crossover Energy
vs. Supply Voltage
10-7
Supply Current
vs. Capacitive Load
20
50
H
100
kH
z
z
MH
z
1
100
-40
0
40
80
TEMPERATURE (°C)
VS = 12V
SUPPLY CURRENT (mA)
VS = 18V
0k
220
200
180
160
140
120
100
80
60
40
20
0
100
20
SUPPLY CURRENT (mA)
0
0
18
250
FALL TIME (ns)
RISE TIME (ns)
250
10,000pF
tRISE
1000
10k
CAPACITIVE LOAD (pF)
5-46
100k
60
45
30
Hz
1M
15
0
100
kH
z
Rise Time
vs. Capacitive Load
20
22,000pF
50
18
30
z
6
8 10 12 14 16
SUPPLY VOLTAGE (V)
tFALL
40
H
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
1000
10k
CAPACITIVE LOAD (pF)
100k
April 1998
MIC4421/4422
Micrel
Typical Characteristic Curves (Cont.)
10k
100k
1M
FREQUENCY (Hz)
20
tD1
10
0
QUIESCENT SUPPLY CURRENT (µA)
TIME (ns)
tD2
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
HIGH-STATE OUTPUT RESISTANCE (Ω)
TIME (ns)
40
30
120
110
100
90
80
70
60
50
40
30
20
10
0
10k
100k
1M
FREQUENCY (Hz)
Propagation Delay
vs. Input Amplitude
µF
0.01
F
40
1000
pF
30
20
10
0
10M
10k
100k
1M
FREQUENCY (Hz)
10M
Propagation Delay
vs. Temperature
50
VS = 10V
40
30
tD2
5
20
tD2
tD1
10
0
2
4
6
INPUT (V)
tD1
8
TJ = 150°C
TJ = 25°C
4
6
8 10 12 14 16
SUPPLY VOLTAGE (V)
5-47
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
50
0.1µ
SUPPLY CURRENT (mA)
µF
0.01
F
20
0
10M
Propagation Delay
vs. Supply Voltage
50
40
TIME (ns)
0
60
18
LOW-STATE OUTPUT RESISTANCE (Ω)
20
80
1000
pF
60
40
VS = 5V
100
0.1µ
µF
1000
pF
80
0.01
F
120
Supply Current
vs. Frequency
60
VS = 12V
140
100
Supply Current
vs. Frequency
120
VS = 18V
SUPPLY CURRENT (mA)
160
0.1µ
SUPPLY CURRENT (mA)
180
Supply Current
vs. Frequency
-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
MIC4421/4422
Micrel
Applications Information
Supply Bypassing
Charging and discharging large capacitive loads quickly
requires large currents. For example, charging a 10,000pF
load to 18V in 50ns requires 3.6A.
The MIC4421/4422 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.
VS
1µF
VS
MIC4451
Ø2
Ø1 DRIVE SIGNAL
DRIVE
LOGIC
CONDUCTION ANGLE
CONTROL 0° TO 180°
Ø1
CONDUCTION ANGLE
CONTROL 180° TO 360°
M
Ø3
VS
VS
1µF
MIC4452
PHASE 1 of 3 PHASE MOTOR
DRIVER USING MIC4420/4429
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 MIC4421/4422 demands
careful PC board layout for best performance. Since the
MIC4421 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 MIC4421 input structure includes about
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 MIC4421
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 MIC4421 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 MIC4421 GND
pins will ensure full logic drive to the input and ensure fast
output switching. Both of the MIC4421 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
30
560 Ω
29
+
1
8
2
0.1µF
WIMA
MKS 2
1µF
50V
MKS 2
6, 7
VOLTS
0.1µF
50V
BYV 10 (x 2)
28
12 Ω LINE
27
26
+
MIC4421
5
4
25
+
560µF 50V
100µF 50V
UNITED CHEMCON SXE
0
50
100 150 200 250 300 350
mA
Figure 4. Self Contained Voltage Doubler
5-48
April 1998
MIC4421/4422
Micrel
Input Stage
The input voltage level of the MIC4421 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 MIC4421/4422 input is designed to provide 300mV 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 MIC4421 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 MIC4421/4422, 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 MIC4421/4422 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 150°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 MIC4421/4422 on the other
hand, can source or sink several amperes and drive large
capacitive loads at high frequency. The package power
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)
+18
WIMA
MKS-2
1 µF
5.0V
1
8
6, 7
TEK CURRENT
PROBE 6302
18 V
MIC4421
0V
0V
5
0.1µF
0.1µF
4
2,500 pF
POLYCARBONATE
Table 1: MIC4421 Maximum
Operating Frequency
VS
Max Frequency
18V
220kHz
15V
10V
5V
6 AMPS
LOGIC
GROUND
300 mV
PC TRACE RESISTANCE = 0.05Ω
POWER
GROUND
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
5-49
300kHz
640kHz
2MHz
5
MIC4421/4422
Micrel
Capacitive Load Power Dissipation
Transition Power Dissipation
Dissipation caused by a capacitive load is simply the energy
placed in, or removed from, the load capacitance by the
driver. The energy stored in a capacitor is described by the
equation:
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:
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 in 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)2
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 just
PD = PL + PQ + PT
Definitions
where:
CL = Load Capacitance in Farads.
f = Operating Frequency
C = Load Capacitance
VS = Driver Supply Voltage
D = Duty Cycle expressed as the fraction of time the
input to the driver is high.
f = Operating Frequency of the driver in Hertz
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:
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.
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
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.
Quiescent Power Dissipation
VS = Power supply voltage to the IC in Volts.
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 =
IL =
D=
VS =
quiescent current with input high
quiescent current with input low
fraction of time input is high (duty cycle)
power supply voltage
5-50
April 1998
MIC4421/4422
Micrel
+18 V
WIMA
MK22
1 µF
5.0V
1
8
2
6, 7
TEK CURRENT
PROBE 6302
18 V
MIC4421
0V
0V
5
0.1µF
0.1µF
4
10,000 pF
POLYCARBONATE
Figure 6. Peak Output Current Test Circuit
5
April 1998
5-51