Datasheet MIC5013YN Specification

MIC5013 Micrel, Inc.

Fault

V+

Gate

1

2

3

4

8

MIC5013

Gnd

7

6

5

Thres h

Sen se

Sourc e

Input

=24V

IRCZ44
(S=2 5 90,
R=11mΩ)

10 µF

43

Ω

20k

Ω

4.3k

Ω

R

R 1

LOA D

Control Input

V

+

+

S

R1 =

100m

V

S R R

(S R + R )

V

+

SR( +100 mV)

R I – ( +10 0 mV )

R =

R = –1000

2200

V

TR IP

S

For this example:

=30A (trip current)I

L

=100mV

V

TR IP

S

S

TH

V

TR IP

V

TR IP

L

R

TH

S E NS E

S O U RC E

KE L V IN

MIC5013

Protected High- or Low-Side MOSFET Driver

General Description

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

Features

• 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

Ordering Information

Part Number Temperature

Standard Pb-Free

Range

Package

MIC5013BN MIC5013YN –40ºC to +85ºC 8-pin Plastic

DIP

MIC5013BM MIC5013YM –40ºC to +85ºC 8-pin SOIC

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 [phone] • fax + 1 [phone] • http://www.micrel.com

July 2005 1 MIC5013

MIC5013 Micrel, Inc.

R=+ 1000

2200

V

TR IP

TH

Fault

V+

Gate

1

2

3

4

8

MIC5013

Gnd

7

6

5

Thres h

Sen se

Sourc e

Input

Absolute Maximum Ratings (Note 1, 2)

Input Voltage, Pin 1 –10 to V
Threshold Voltage, Pin 2 –0.5 to +5V
Sense Voltage, Pin 3 –10V to V
Source Voltage, Pin 4 –10V to V
Current into Pin 4 50mA
Gate Voltage, Pin 6 –1V to 50V
Supply Voltage (V+), Pin 7 –0.5V to 36V
Fault Output Current, Pin 8 –1mA to +1mA
Junction Temperature 150°C

Operating Ratings (Notes 1, 2)

+

Power Dissipation 1.25W

θJA (Plastic DIP) 100°C/W

+

θJA (SOIC) 170°C/W

+

Ambient Temperature: B version –40°C to +85°C
Storage Temperature –65°C to +150°C
Lead Temperature 260°C
(Soldering, 10 seconds)
Supply Voltage (V+), Pin 7 7V to 32V high side
7V to 15V low side

Pin Description (Refer to Figures 1 and 2)

Pin Number Pin Name Pin Function

1 Input Resets current sense latch and turns on power MOSFET when taken above

threshold (3.5V typical). Pin 1 requires <1µA to switch.

2 Threshold Sets current sense trip voltage according to:

where RTH to ground is 3.3k to 20kΩ. Adding capacitor CTH increases the
trip voltage at turn-on to 2V. Use C

TH

stant.

3 Sense The sense pin causes the current sense to trip when V

V

SOURCE

a 3 lead FET or a resistor R

. Pin 3 is used in conjunction with a current shunt in the source of

in the sense lead of a current sensing FET.

S

4 Source Reference for the current sense voltage on pin 3 and return for the gate

clamp zener. Connect to the load side of current shunt or kelvin lead of cur
rent sensing FET. Pins 3 and 4 can safely swing to –10V when turning off
inductive loads.

5 Ground

6 Gate Drives and clamps the gate of the power FET. Pin 6 will be clamped to ap

proximately –0.7V by an internal diode when turning off inductive loads.

7 V

+

Supply pin; must be decoupled to isolate from large transients caused by

the power FET drain. 10µF is recommended close to pins 7 and 5.

8 Fault Outputs status of protection circuit when pin 1 is high. Fault low indicates

normal operation; fault high indicates current sense tripped.

=10µF for a 10ms turn-on time con-

SENSE

is V

TRIP

above

-

-

Pin Configuration

MIC5013 2 July 2005

MIC5013 Micrel, Inc.

Electrical Characteristics (Note 3, 5)

Test circuit. T

= –55°C to +125°C, V+ = 15V, all switches open, unless otherwise specified.

A

Parameter Conditions Min Typical Max Units

Supply Current, I7 V+ = 32V VIN = 0V, S4 closed 0.1 10 µA

V

Logic Input Voltage, V

V+ = 4.75V Adjust VIN for V

IN

Adjust V

+

V

=15V Adjust VIN for V

= VS = 32V 8 20 mA

IN

low 2 V

GATE

IN

for V

high 4.5 V

GATE

high 5.0 V

GATE

Logic Input Current, I1 V+ = 32V VIN = 0V –1 µA

V

= 32V 1 µA

IN

Input Capacitance Pin 1 5 pF

Gate Drive, V

V

Zener Clamp, S2 closed, V

V

– V

GATE

SOURCE

Gate Turn-on Time, t

S1, S2 closed, V+ = 7V, I6 = 0 13 15 V

GATE

= V+, VIN = 5V V+ = 15V, I6 = 100 µA 24 27 V

S

= 5V V+ = 15V, VS = 15V 11 12.5 15 V

IN

V+ = 32V, VS = 32V 11 13 16 V

VIN switched from 0 to 5V; measure time 60 200

ON

µs
(Note 4) for V

Gate Turn-off Time, t

VIN switched from 5 to 0V; measure time 4 10 µs

OFF

for V

Threshold Bias Voltage, V

I2 = 200 µA 1.7 2 2.2 V

2

Current Sense Trip Voltage, S2 closed, V

V

SENSE

– V

SOURCE

Increase I3 I2 = 100 µA VS = 4.9V, S4 open 70 100 130 mV

V

I

V

I

Peak Current Trip Voltage, S3, S4 closed, 1.6 2.1 V
V

Fault Output Voltage, V

V

Note 1. Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Electrical specifications do not apply when

Note 2. The MIC5010 is ESD sensitive.

Note 3. Minimum and maximum Electrical Characteristics are 100% tested at TA = 25°C and TA = 85°C, and 100% guaranteed over the entire

Note 4. Test conditions reflect worst case high-side driver performance. Low-side and bootstrapped topologies are significantly faster—see

Note 5. Specification for packaged product only.

– V

SENSE

SOURCE

operating the device beyond its specified

range. Typicals are characterized at 25°C and represent the most likely parametric norm.

Applications Information.

V+ = 15V, VIN = 5V

VIN = 0V, I8 = –100 µA 0.4 1 V

8

IN

to reach 20V

GATE

to reach 1V

GATE

= 5V, V+ = 7V, S4 closed 75 105 135 mV

IN

+

= 15V S4 closed 150 210 270 mV

= 200 µA VS = 11.8V, S4 open 140 200 260 mV

2

+

= 32V VS = 0V, S4 open 360 520 680 mV

= 500 µA VS = 25.5V, S4 open 350 500 650 mV

2

= 5V, I8 = 100 µA, current sense tripped 14 14.6 V

Operating Ratings.

July 2005 3 MIC5013

MIC5013 Micrel, Inc.

0 5 10 15 20 25 30 35

0

2

4

6

8

10

12

Supply Current

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

0 3 6 9 12 15

SUPPLY VOLTAGE (V)

0

2

4

6

8

10

12

14

VGATE – V+ (V)

DC Gate Voltage

above Supply

V+

I3

S3

I2

I8

Fault

V+

Gate

1

2

3

4

8

MIC5013

Gnd

7

6

5

Thres h

Sen se

Sourc e

Input

1nF

I6

S1

+

1µF

50 Ω

S2

3.5k

V S

500 Ω

1W

S4

V

G A T E

V

IN

0 3 6 9 12 15

TURN-ON TIME (mS)

SUPPLY VOLTAGE (V)

High-side Turn-on Time*

GATE

C =10 nF

0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

0 3 6 9 12 15

0

50

100

150

200

250

300

350

TURN-ON TIME (µS)

SUPPLY VOLTAGE (V)

High-side Turn-on Time*

GATE

C =1 nF

Test Circuit

Typical Characteristics

* Time for gate to reach V+ + 5V in test circuit with VS = V+ – 5V (prevents gate clamp from interfering with measurement).

MIC5013 4 July 2005

MIC5013 Micrel, Inc.

0 3 6 9 12 15

SUPPLY VOLTAGE (V)

GATE

C =10 nF

1

3

10

30

100

300

1000

TURN-ON TIME (µS)

GATE

C =1 nF

Low-side Turn-on Time

for Gate = 5V

0 3 6 9 12 15

SUPPLY VOLTAGE (V)

GATE

C =10 nF

TURN-ON TIME (µS)

GATE

C =1 nF

Low-side Turn-on Time

for Gate = 10V

3

10

30

100

300

1000

3000

0.5

0.75

1.0

1.25

1.5

1.75

2.0

–25 0 25 50 75 100 125

DIE TEMPERATURE (°C)

NORMALIZED TURN-ON TIME

Turn-on Time

0 3 6 9 12 15

SUPPLY VOLTAGE (V)

GATE

C =10 nF

TURN-OFF TIME (µS)

GATE

C =1 nF

0

10

20

30

40

50

Turn-off Time

CHARGE-PUMP CURRENT (µA)

0

50

100

150

200

250

0 5 10 15 20 25 30

SUPPLY VOLTAGE (V)

Charge Pump

Output Current

V =V

GATE

+

V =V +5V

GATE

+

VS=V –5V

+

Typical Characteristics (Continued)

July 2005 5 MIC5013

MIC5013 Micrel, Inc.

+

–

V+

CHARGE

PUMP

V. REG

R

S

Q

LOGIC

MIC5013

1

8

5 2

4

3

6

7

500 Ω

1k

V+

Gate

Sense

Source

Ground Threshold

Input

Fault

CURRENT

SENS E
LATCH

1k

+

–

I2

V

TR IP

12.5V

Block Diagram

Applications Information

Functional Description (refer to block diagram)

The various MIC5013 functions are controlled via a logic
block connected to the input pin 1. When the input is low,
all functions are turned off for low standby current and the
gate of the power MOSFET is also held low through 500Ω
to an N-channel switch. When the input is taken above the
turn-on threshold (3.5V typical), the N-channel switch turns
off and the charge pump is turned on to charge the gate of
the power FET. A bandgap type voltage regulator is also
turned on which biases the current sense circuitry.

The charge pump incorporates a 100kHz oscillator and
on-chip pump capacitors capable of charging 1nF to 5V
above supply in 60µs typical. The charge pump is capable
of pumping the gate up to over twice the supply voltage.
For this reason, a zener clamp (12.5V typical) is provided
between the gate pin 6 and source pin 4 to prevent exceed­ing the VGS rating of the MOSFET at high supplies.

The current sense operates by comparing the sense volt­age at pin 3 to an offset version of the source voltage at
pin 4. Current I2 flowing in threshold pin 2 is mirrored and
returned to the source via a 1kΩ resistor to set the offset,
or trip voltage. When (V
the current sense trips and sets the current sense latch to
turn off the power FET. An integrating comparator is used
to reduce sensitivity to spikes on pin 3. The latch is reset
to turn the FET back on by “recycling” the input pin 1 low
and then high again.

A resistor RTH from pin 2 to ground sets I2, and hence V
An additional capacitor CTH from pin 2 to ground creates a
higher trip voltage at turn-on, which is necessary to prevent
high in-rush current loads such as lamps or capacitors from
false-tripping the current sense.

SENSE

– V

SOURCE

) exceeds V

TRIP

TRIP

When the current sense has tripped, the fault pin 8 will be
high as long as the input pin 1 remains high. However, when
the input is low the fault pin will also be low.

Construction Hints

High current pulse circuits demand equipment and assembly
techniques that are more stringent than normal low current
lab practices. The following are the sources of pitfalls most
often encountered during prototyping: Supplies: many bench
power supplies have poor transient response. Circuits that
are being pulse tested, or those that operate by pulse-width
modulation will produce strange results when used with a
supply that has poor ripple rejection, or a peaked transient
response. Monitor the power supply voltage that appears
at the drain of a high-side driver (or the supply side of the
load in a low-side driver) with an oscilloscope. It is not un­common to find bench power supplies in the 1kW class that
overshoot or undershoot by as much as 50% when pulse
loaded. Not only will the load current and voltage measure­ments be affected, but it is possible to over-stress various
components—especially electrolytic capacitors—with pos­sibly catastrophic results. A 10µF supply bypass capacitor

,

at the chip is recommended.

Residual Resistances: Resistances in circuit connections
may also cause confusing results. For example, a circuit
may employ a 50mΩ power MOSFET for low drop, but
careless construction techniques could easily add 50 to
100mΩ resistance. Do not use a socket for the MOSFET. If

.

the MOSFET is a TO-220 type package, make high-current
drain connections to the tab. Wiring losses have a profound
effect on high-current circuits. A floating millivoltmeter can
identify connections that are contributing excess drop
under load.

MIC5013 6 July 2005

MIC5013 Micrel, Inc.

Fault

V+

Gate

1

2

3

4

8

MIC5013

Gnd

7

6

5

Thres h

Sen se

Sourc e

Input

IR F 5 40

10 µF

10k Ω

10m Ω
IRC 4L PW-5

LOA D

Control Input

=7 to 15V

V

+

+

(International Resistive Company)

V

LO AD

I =20A (trip current)

L

V

TR IP

I

L

V

TR IP

= 200mV

For this example:

R =

2200

–1000

V

TR IP

TH

R =

S

R

S

R

TH

Fault

V+

Gate

1

2

3

4

8

MIC5013

Gnd

7

6

5

Thres h

Sen se

Sourc e

Input

=24V

IR F 5 41

10 µF

100

Ω

20k

Ω

24k

Ω

18m Ω
IR C 4LP W - 5*

R 1

LOA D

Control Input

V

+

+

*International Resistive Company

R 2

R1 =

R2 =100

Ω

R =

R =

1mA

V

100mV+

2200

–1000

+

I

L

For this example:

I =10A (trip current)

L

V =1 00mV

TR IP

V

TR IP

V

TR IP

S

R

S

TH

R

TH

Applications Information (Continued)

Figure 2. Low-Side Driver

with Current Shunt

Circuit Topologies

The MIC5013 is suited for use in high- or low-side driver
applications with over-current protection for both current­sensing and standard MOSFETs. In addition, the MIC5013
works well in applications where, for faster switching times,
the supply is bootstrapped from the MOSFET source out­put. Low voltage, high-side drivers (such as shown in the
Test Circuit) are the slowest; their speed is reflected in the
gate turn-on time specifications. The fastest drivers are the
low-side and bootstrapped high-side types. Load current
switching times are often much faster than the time to full
gate enhancement, depending on the circuit type, the MOS­FET, and the load. Turn-off times are essentially the same
for all circuits (less than 10µs to VGS = 1V). The choice of
one topology over another is based on a combination of
considerations including speed, voltage, and desired system
characteristics. Each topology is described in this section.
Note that IL, as used in the design equations, is the load
current that just trips the over-current comparator.

Low-Side Driver with Current Shunt (Figure 2). The over­current comparator monitors RS and trips if IL × RS exceeds
V

. R is selected to produce the desired trip voltage.

TRIP

As a guideline, keep V

within the limits of 100mV and

TRIP

500mV (RTH = 3.3kΩ to 20kΩ). Thresholds at the high end
offer the best noise immunity, but also compromise switch
drop (especially in low voltage applications) and power
dissipation.

The trip current is set higher than the maximum expected
load current—typically twice that value. Trip point accuracy
is a function of resistor tolerances, comparator offset (only
a few millivolts), and threshold bias voltage (V2). The val­ues shown in Figure 2 are designed for a trip current of 20
amperes. It is important to ground pin 4 at the current shunt
RS, to eliminate the effects of ground resistance.

A key advantage of the low-side topology is that the load sup­ply is limited only by the MOSFET BVDSS rating. Clamping
may be required to protect the MOSFET drain terminal from

Figure 3. High-Side Driver

July 2005 7 MIC5013

with Current Shunt

MIC5013 Micrel, Inc.

Fault

V+

Gate

1

2

3

4

8

MIC5013

Gnd

7

6

5

Thres h

Sen se

Sourc e

Input

IRCZ44
(S=2 5 90,
R=11mΩ)

10 µF

22

Ω

20k

Ω

LOA D

Control Input

=15V

V

+

+

R

TH

V

LO AD

S O U RC E

KE L V IN

S E NS E

S

R

S R

R I –

R =

L

V

TR IP

V

TR IP

S

R = –1000

2200

V

TR IP

TH

For this example:

=20A (trip current)

I

L

=100mV

V

TR IP

Applications Information (Continued)

inductive switching transients. The MIC5013 supply should
be limited to 15V in low-side topologies; otherwise, a large
current will be forced through the gate clamp zener.

Low-side drivers constructed with the MIC501X family are
also fast; the MOSFET gate is driven to near supply imme
diately when commanded ON. Typical circuits achieve 10V
enhancement in 10µs or less on a 12 to 15V supply.

High-Side Driver with Current Shunt (Figure 3). The
comparator input pins (source and sense) float with the
current sensing resistor (RS) on top of the load. R1 and R2
add a small, additional potential to V
triggering of the over-current shutdown circuit with open
or inductive loads. R1 is sized for a current flow of 1mA,
while R2 contributes a drop of 100mV. The shunt voltage
should be 200 to 500mV at the trip point. The example of
Figure 3 gives a 10A trip current when the output is near
supply. The trip point is somewhat reduced when the output
is at ground as the voltage drop across R1 (and therefore
R2) is zero.

High-side drivers implemented with MIC5013 drivers are
self-protected against inductive switching transients. During
turn-off an inductive load will force the MOSFET source 5V
or more below ground, while the driver holds the gate at
ground potential. The MOSFET is forced into conduction, and
it dissipates the energy stored in the load inductance. The
MIC5013 source and sense pins (3 and 4) are designed to
withstand this negative excursion without damage. External
clamp diodes are unnecessary.

Current Shunts (RS). Low-valued resistors are necessary
for use at RS.Values for RS range from 5 to 50mΩ, at 2 to
10W. Worthy of special mention are Kelvin-sensed, “four­terminal” units supplied by a number of manufacturers†

† Suppliers of Kelvin-sensed power resistors:

MIC5013 8 July 2005

Figure 4. Low-Side Driver with

Current-Sensing MOSFET

(see next page). Kelvin-sensed resistors eliminate errors
caused by lead and terminal resistances, and simplify
product assembly. 10% tolerance is normally adequate, and
with shunt potentials of 200mV thermocouple effects are
insignificant. Temperature coefficient is important; a linear,

­500 ppm/°C change will contribute as much as 10% shift in

the over-current trip point. Most power resistors designed
for current shunt service drift less than 100 ppm/°C.

Low-Side Driver with Current Sensing MOSFET (Figure

4). Several manufacturers now supply power MOSFETs in

to prevent false-

TRIP

which a small sampling of the total load current is diverted
to a “sense” pin. One additional pin, called “Kelvin source,”
is included to eliminate the effects of resistance in the
source bond wires. Current-sensing MOSFETs are specified
with a sensing ratio “S” which describes the relationship
between the on-resistance of the sense connection and
the body resistance “R” of the main source pin. Current
sensing MOSFETs eliminate the current shunt required by
standard MOSFETs.

The design equations for a low-side driver using a current
sensing MOSFET are shown in Figure 4. “S” is specified
on the MOSFET’s datasheet, and “R” must be measured
or estimated. V

TRIP

become negative. Substituting a MOSFET with higher on­resistance, or reducing V

Dale Electronics, Inc., 2064 12th Ave., Columbus, NE 68601. Tel: [phone]
International Resistive Co., P.O. Box 1860, Boone, NC 28607-1860. Tel: [phone]
Kelvin, 14724 Ventura Blvd., Ste. 1003, Sherman Oaks, CA 91403-3501. Tel: [phone]
RCD Components, Inc., 520 E. Industrial Pk. Dr., Manchester, NH 03103. Tel: [phone]
Ultronix, Inc., P.O. Box 1090, Grand Junction, CO 81502. Tel: [phone]

to 200mV is suggested. Although the load supply is limited
only by MOSFET ratings, the MIC5013 supply should be
limited to 15V to prevent damage to the gate clamp zener.
Output clamping is necessary for inductive loads.

“R” is the body resistance of the MOSFET, excluding bond
resistances. R
includes bond resistances. A Kelvin-connected ohmmeter

DS(ON)

must be less than R × IL, or else RS will

fixes this problem. V

TRIP

TRIP

= 100

as specified on MOSFET data sheets

MIC5013 Micrel, Inc.

Fault

V+

Gate

1

2

3

4

8

MIC5013

Gnd

7

6

5

Thres h

Sen se

Sourc e

Input

12 V

IRCZ4 4

10 µF

43

Ω

R 1

3.9kΩ

Control Input

+

#6014

22k Ω

R

TH 1

C

TH

22 µF

1k

Ω

R

TH 2

Fault

V+

Gate

1

2

3

4

8

MIC5013

Gnd

7

6

5

Thres h

Sen se

Sourc e

Input

IR F 5 40

10 µF

20k

Ω

Control Input

+

100Ω

R
18m Ω

LO A D

R 2

100nF

1N400 1 (2)

1N581 7

7 to 15V

+

V

1mA

R1 =

S

R

TH

Applications Information (Continued)

Figure 5. Time-Variable

Trip Threshold

(using TAB and SOURCE for forcing, and SENSE and
KELVIN for sensing) is the best method of evaluating “R.”
Alternatively, “R” can be estimated for large MOSFETs
(R
or by subtracting 20 to 50mΩ from the stated R

≤ 100mΩ) by simply halving the stated R

DS(ON)

DS(ON)

DS(ON)

for

smaller MOSFETs.

High-Side Driver with Current Sensing MOSFET (Figure

5). The design starts by determining the value of “S” and
“R” for the MOSFET (use the guidelines described for the
low-side version). Let V

= 100mV, and calculate RS for

TRIP

a desired trip current. Next calculate RTH and R1. The trip
point is somewhat reduced when the output is at ground as
the voltage drop across R1 is zero. No clamping is required
for inductive loads, but may be added to reduce power dis­sipation in the MOSFET.

Typical Applications

Start-up into a Dead Short. If the MIC5013 attempts to turn
on a MOSFET when the load is shorted, a very high current
flows. The over-current shutdown will protect the MOSFET,
but only after a time delay of 5 to 10µs. The MOSFET must
be capable of handling the overload; consult the device’s
SOA curve. If a short circuit causes the MOSFET to exceed
its 10µs SOA, a small inductance in series with the source
can help limit di/dt to control the peak current during the 5
to 10µs delay.

When testing short-circuit behavior, use a current probe
rated for both the peak current and the high di/dt.

The over-current shutdown delay varies with comparator
overdrive, owing to noise filtering in the comparator. A delay
of up to 100µs can be observed at the threshold of shutdown.
A 20% overdrive reduces the delay to near minimum.

Incandescent Lamps. The cold filament of an incandes­cent lamp exhibits less than one-tenth as much resistance
as when the filament is hot. The initial turn-on current of
a #6014 lamp is about 70A, tapering to 4.4A after a few
hundred milliseconds. It is unwise to set the over-current

July 2005 9 MIC5013

trip point to 70A to accommodate such a load. A “resistive”
short that draws less than 70A could destroy the MOSFET
by allowing sustained, excessive dissipation. If the over-

,

current trip point is set to less than 70A, the MIC5013 will
not start a cold filament. The solution is to start the lamp
with a high trip point, but reduce this to a reasonable value
after the lamp is hot.

The MIC5013 over-current shutdown circuit is designed to
handle this situation by varying the trip point with time (see
Figure 5). R
viding a current limit of approximately twice that required by
the lamp. R
to approximately 10 times the steady-state lamp current.
The high initial trip point decays away according to a 20ms
time constant contributed by CTH. R
with CTH working against the internal 1kΩ resistor, but this
results in a very high over-current threshold. As a rule of
thumb design the over-current circuitry in the conventional
manner, then add the R
start-up. Let R
tor that provides the desired time constant working against
R

and the internal 1kΩ resistor.

TH2

When the MIC5013 is turned off, the threshold pin (2) ap­pears as an open circuit, and CTH is discharged through
R

and R

TH1

constant, and it simulates the thermal response of the fila­ment. If the lamp is pulse-width modulated, the current limit
will be reduced by the residual charge left in CTH.

Modifying Switching Times. Do not add external capacitors
to the gate to slow down the switching time. Add a resistor
(1kΩ to 51kΩ) in series with the gate of the MOSFET to
achieve this result.

Bootstrapped High-Side Driver (Figure 6). The speed
of a high-side driver can be increased to better than 10µs
by bootstrapping the supply off of the MOSFET source.
This topology can be used where the load is pulse-width
modulated (100Hz to 20kHz), or where it is energized

Figure 6. Bootstrapped

High-Side Driver

functions in the conventional manner, pro-

TH1

acts to increase the current limit at turn-on

TH2

could be eliminated

TH2

TH2/CTH

= (R

TH2

. This is much slower than the turn-on time

TH2

TH1

network to allow for lamp

÷10)–1kΩ, and choose a capaci-

MIC5013 Micrel, Inc.

Fault

V+

Gate

1

2

3

4

8

MIC5013

Gnd

7

6

5

Thres h

Sen se

Sourc e

Input

IRFZ 4 0

10 µF

20k Ω

+

100 Ω

22m Ω

LOA D

12 V

10k

Ω

10k Ω

100nF

1N414 8

100k

Ω100kΩ100kΩ

MP S A 0 5

CP S L-3 ( Dal e)

Fault

V+

Gate

1

2

3

4

8

MIC5013

Gnd

7

6

5

Thres h

Sen se

Sourc e

Input

IR F P 044 ( 2)

10 µF

20k Ω

+

100 Ω

5m Ω

LOA D

24 V

15k

Ω

O F F

330k

Ω

100k

Ω

ON

24 V

LV F - 15 (R C D )

CR294 3 -NA 102A
(GE )

100kΩ

1k Ω

To MIC5013 Input

100kΩ

4N35

33k Ω

33pF

MP S A 0 5

15 V

10m

A

Control Input

Applications Information (Continued)

Figure 8. Improved

Opto-Isolator Performance

Figure 7. 10-Ampere

Electronic Circuit Breaker

for only a short period of time (≤25ms). If the load is left
energized for a long period of time (>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.

MIC5013 10 July 2005

Figure 9. 50-Ampere

Industrial Switch

MIC5013 Micrel, Inc.

Fault

V+

Gate

1

2

3

4

8

MIC5013

Gnd

7

6

5

Thres h

Sen se

Sourc e

Input

IRFP 2 50

100µF

6.2k

Ω

+

10m Ω

1N400 3

90 V

100kΩ

1k Ω

100kΩ

4N35

33k Ω

33pF

MP S A 05

10m A
Control Input

M

15 V

1N400 3 (2)

15V p-p, 20 kH z

Squarew ave

1N474 6

100nF
20 0V

KC1 000 - 4T
(Kelvin)

1/ 4 HP, 9 0V

5B P B 56HA A 100

(GE )

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) MOS
FETs 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.

-

Figure 10. High-Voltage

Bootstrapped Driver

July 2005 11 MIC5013

MIC5013 Micrel, Inc.

Fault

V+

Gate

1

2

3

4

8

MIC5013

Gnd

7

6

5

Thres h

Sen se

Sourc e

Input

Fault

V+

Gate

1

2

3

4

8

MIC5013

Gnd

7

6

5

Thres h

Sen se

Sourc e

Input

IR F 5 41

1µF

20k

Ω

+

100 Ω

100nF

1N400 1 (2)

1N581 7

15 V

15k

Ω

IR F 5 41

10 µF

10k Ω

22m

Ω
CPS L - 3
(Dale)

+

22m Ω
CPS L - 3

(Dale)

1n F

10k Ω

2N390 4

22k

Ω

220pF

1N414 8

22k

Ω

15 V

M

12 V,
10A S talled

PWM

IN P U T

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 rela
tive 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.

-

Figure 11. Half-Bridge

Motor Driver

MIC5013 12 July 2005

MIC5013 Micrel, Inc.

Fault

V+

Gate

1

2

3

4

8

MIC5013

Gnd

7

6

5

Thres h

Sen se

Sourc e

Input

12 V

IRCZ4 4

10 µF

43

Ω

20k

Ω

4.3k

Ω

+

S E NS E

S O U RC E

KE L V IN

M

T

ST O P

R U N

STAR T

12 V

100nF

1N4148

330k

Ω

330k

Ω

330k

Ω

1N4148

R

R E S E T

Fault

V+

Gate

1

2

3

4

8

MIC5013

Gnd

7

6

5

Thres h

Sen se

Sourc e

Input

12 V

IRCZ44

10 µF

43 Ω

20k Ω

4.3k

Ω

+

S E NS E

S O U RC E

KE L V IN

OUTP U T
(Delay=5s)

10k Ω

100 Ω

100µF

+

100kΩ

1N4148

Applications Information (Continued)

Figure 12. Time-Delay Relay

with 30A Over-Current Protection

July 2005 13 MIC5013

Figure 13. Motor Stall

Shutdown

MIC5013 Micrel, Inc.

V

+

C1 C2

500Ω

12.5V

G

S

125pF125pF

100 k Hz

OSCILLATOR

OFF

ON

GAT E CLAMP

Z E N ER

Q1

Q2

Q3

Q4

Q5

Q6

C1

COM

C2

Applications Information (Continued)

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

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.

Figure 14. Gate Control

Circuit Detail

MIC5013 14 July 2005

MIC5013 Micrel, Inc.

0.380 (9.65)

0.370 (9.40)

0.135 (3.43)

0.125 (3.18)

PIN 1

DIMENSIONS:

INCH (MM)

0.018 (0.57)

0.100 (2.54)

0.013 (0.330)

0.010 (0.254)

0.300 (7.62)

0.255 (6.48)

0.245 (6.22)

0.380 (9.65)

0.320 (8.13)

0.0375 (0.952)

0.130 (3.30)

45°

0°–8°

0.244 (6.20)

0.228 (5.79)

0.197 (5.0)

0.189 (4.8)

SEATING

PLANE

0.026 (0.65)
MAX)

0.010 (0.25)

0.007 (0.18)

0.064 (1.63)

0.045 (1.14)

0.0098 (0.249)

0.0040 (0.102)

0.020 (0.51)

0.013 (0.33)

0.157 (3.99)

0.150 (3.81)

0.050 (1.27)
TYP

PIN 1

DIMENSIONS:

INCHES (MM)

0.050 (1.27)

0.016 (0.40)

Package Information

8-Pin Plastic DIP (N)

8-Pin SOIC (M)

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

July 2005 15 MIC5013

MICREL INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA

TEL + 1 [phone] FAX + 1 [phone] WEB http://www.micrel.com

Micrel for any damages resulting from such use or sale.

© 1998 Micrel, Inc.