Datasheet M57958L, M57957L Datasheet (Mitsubishi)

MITSUBISHI SEMICONDUCTORS POWER MODULES MOS

USING HYBRID GATE DRIVERS AND GATE DRIVE POWER SUPPLIES

5.0 Using Hybrid Gate Drivers

Mitsubishi offers four single in-line
hybrid ICs for driving IGBT
modules. All four drivers are high
speed devices designed to convert
logic level control signals into
optimal IGBT gate drive. Input
signals are isolated from the IGBT
drive using high speed
optocouplers with 15,000V/ms

Figure 5.1 Hybrid IGBT Gate Drivers

35 MAX

M57957L

2.54

23 MAX

10 MAX

common mode noise immunity.
This feature allows convenient
common referencing of high and
low side control signals. Mitsubishi
IGBT drivers are designed to
provide the pulse currents
necessary for high performance
switching applications and to
maintain sufficient off bias to
guarantee ruggedness. Hybrid
IGBT drivers simplify gate drive

M57958L

design by minimizing the number
of components required. In
addition to high performance gate
drive, the M57959L and the
M57962L provide short-circuit
protection. The basic package
outlines of the four Mitsubishi
drivers are shown in Figure 5.1.
Table 5.1 lists the key electrical
characteristics of each hybrid
driver.

51 MAX

29
MAX

10 MAX2.54

43 MAX

M57959L

2.54

All Dimensions in mm.

22 MAX

11 MAX

51 MAX

M57962L

2.54

25
MAX

12 MAX

Table 5.1 Recommended Gate Driver Applications

Optimum Application Range*

Gate Drive Circuit Peak Output Current Short Circuit Protection For 600V IGBT Modules For 1200V/1400V IGBT Modules
M57957L 2 Amps No Up to 100A Up to 50A
M57958L 5 Amps No Up to 400A Up to 200A

M57959L 2 Amps Yes Up to 100A Up to 50A
M57962L 5 Amps Yes Up to 400A Up to 200A
M57958L with Booster** 20 Amps No Up to 600A Up to 1000A
M57962L with Booster** 20 Amps Yes Up to 600A Up to 1000A

*Use RG specified in the switching time section of the IGBT module data sheet.
**See Section 5.10

Sep.1998

MITSUBISHI SEMICONDUCTORS POWER MODULES MOS

USING HYBRID GATE DRIVERS AND GATE DRIVE POWER SUPPLIES

5.1 Output Current Limit

When using hybrid gate drivers
RG must be selected such that the
output current rating (IOP) is not
exceeded. If RG is computed using
Equation 5.1 then IOP will not be
exceeded under any condition.

Equation 5.1
Conservative equation for mini­mum R

R

G

= (VCC + VEE)/I

G(MIN)

OP

Example:

With VCC = 15V and

-VEE = 10V R

G(MIN)

for

M57958L will be:
RG = (15V + 10V)/5A = 5 ohms

In most applications this limit is
unnecessarily conservative.
Considerably lower values of R

G

can usually be used. The
expression for R

G(MIN)

should be
modified to include the effects of
parasitic inductance in the drive
circuit, IGBT module internal
impedance and the finite switching
speed of the hybrid drivers output
stage. Equation 5.2 is an improved
version of Equation 5.1 for
R

G(MIN)

.

Equation 5.2
Improved equation for R

R
IOP - (RG)

= (VCC + VEE)/

G(MIN)

INT

- φ

G(MIN)

Large IGBT modules that contain
parallel chips have internal gate
resistors that balance the gate
drive and prevent internal
oscillations. The parallel
combination of these internal
resistors is R

G(INT)

. R

G(INT)

ranges from 0.75 ohm in large
IGBT modules like CM600HA-24H
to 3.0 ohms in smaller modules like
CM150DY-12H with two parallel
chips. The value of f depends on
the parasitic inductance of the gate
drive circuit and the switching
speed of the hybrid driver. The
exact value of f is difficult to
determine. It is often desirable to
estimate the minimum value of R

G

that can be used with a given
hybrid driver circuit and IGBT
module by monitoring the peak
gate current while reducing R

G

until the rated IOP is reached. The
minimum restriction on RG often
limits the switching performance
and maximum usable operating fre­quency when large modules
outside of the drivers optimum
application range are being
driven.Further steps to address
this issue are provided in
Section 5.10.

5.2 Power Supply Requirements

Power is usually supplied to hybrid
IGBT gate drivers from low
voltage DC power supplies that
are isolated from the main DC bus
voltage. Isolated power supplies
are required for high side gate
drivers because the emitter
potential of high side IGBTs is
constantly changing. Isolated
power supplies are often desired
for low side IGBT gate drivers in or­der to eliminate ground loop noise
problems. The gate drive supplies
should have an isolation voltage
rating of at least two times the
IGBTs V
V

= 2400V for 1200V IGBT).

ISO

rating (i.e.

CES

In systems with several isolated
supplies intersupply capacitances
must be minimized in order to
avoid coupling of common mode

Figure 5.2 Hybrid Driver Power

Supply

I

D

V

(15V)

V

(10V)

+



CC

+



EE

I

COM

+

47µF

+

47µF

I

D

TO HYBRID DRIVER

noise. The recommended power
supply configuration for Mitsubishi
hybrid IGBT gate drivers is shown
in Figure 5.2. Two supplies are
used in order to provide the on­and off-bias for the IGBT. The rec­ommended on bias supply (VCC)
voltage is +15V and the recom­mended off-bias supply voltage
(VEE) is -10V.

Normally these supplies should be
regulated to ±10% however
operation within the range
indicated on the individual driver
data sheets is acceptable.
Electrolytic or tantalum decoupling
capacitors should be connected at
the power supply input pins of the
hybrid driver. These capacitors
supply the high pulse currents
required to drive the IGBT gate.
The amount of capacitance
required depends on the size of the
IGBT module being driven. A 47µF
capacitor is sufficient for most ap­plications.

5.2.1 Supply Current

The current that must be supplied
to the IGBT driver is the sum of two
components. One component is
the quiescent current required to
bias the drivers internal circuits.
The current is constant for fixed
values of VCC and VEE. The sec­ond component is the current re-

Sep.1998

MITSUBISHI SEMICONDUCTORS POWER MODULES MOS

USING HYBRID GATE DRIVERS AND GATE DRIVE POWER SUPPLIES

quired to drive the IGBT gate. This
current is directly proportional to
the operating frequency and the to­tal gate charge (QG) of the IGBT
being driven. With small IGBT
modules and at low operating fre­quencies the quiescent current will
be the dominant component. The
amount of current that must be
supplied to the hybrid driver when
VCC = 15V and VEE = -10V can
be determined from Equations 5.3
and 5.4.

Equation 5.3
Required supply current for
M57957L and M57958L

ID = QG x f

PWM

+ 13mA

Equation 5.4
Required supply current for
M57959L and M57962L

ID = QG x f

PWM

+ 18mA

Where:

ID = Required supply current
QG = Gate charge (See
Section 4.6.3)
f

= Operating frequency

PWM

5.2.2 Single Supply Operation

The current drawn from VCC (ID+)
is nearly equal to the current drawn
from VEE (ID-). Only a small
amount of current flows in the com­mon connection (I

COM

). In many
applications it is desirable to oper­ate the hybrid driver from a single
isolated supply. An easy method of
accomplishing this is to create the
common potential using a resistor
and a zener diode. In order to size
the resistor for minimum loss we
must first determine the current
flowing in the common connection

Figure 5.3 Single Supply

Operation of Hybrid
IGBT Drivers

I

D

2.7kΩ

+



V

D

(25V)

(I

). In M57957L and M57958L

COM

10V

+

47µF

+



47µF

TO HYBRID DRIVER

a common connection current of
about 2.5mA is required to bias in­ternal circuits. In M57959L and
M57962L about 3.5mA flows from
the detect pin through the IGBT to
the common connection. The cir­cuit in Figure 5.3 uses a zener sup­ply designed for about 5mA to sup­ply the common current. This cir­cuit allows operation of Mitsubishi
hybrid drivers from a single isolated
25 volt DC supply.

When the power supply circuit
shown in Figure 5.3 is used with
M57957L and M57958L the
required bias voltage at pin 5 of the
hybrid driver appears after a delay
caused by the 2.7kΩ resistor and
the 47µF capacitor. This delay may
cause these drivers to generate an
ON output pulse during power up.
In applications where the main
DC bus voltage is applied before
the gate drive power supplies are
on and stabilized the circuit in Fig­ure 5.4 should be used.

The voltage of the single supply
and the zener diode can be varied
to allow use of standard supplies.
For example, if a 24V DC-to-DC

Figure 5.4 Improved Power

Supply Circuit for
M57957L and
M57958L

TO 
HYBRID 
DRIVER 

2.7kΩ

10V



PIN 6

TO 
HYBRID 
DRIVER 
PIN 5

TO 
EMITTER 
OF IGBT

TO 
HYBRID 
DRIVER 
PIN 8

V

(25V)

10V

+

47µF

+



47µF

2.7kΩ

+



D

converter is to be used then a 9V
zener diode would give +15/-9
which is acceptable for all of the
hybrid gate drivers. The two
limiting factors that need to be
observed if changes are made are:

(1) Voltages must be within the al-

lowable range specified on the
gate driver data sheet and

(2) The turn on supply should be

15V+/-10% for proper IGBT
performance.

5.3 Total Power Dissipation

The hybrid IGBT driver has a
maximum allowable power
dissipation that is a function of the
ambient temperature. With
VCC = 15V and VEE = -10V the
power dissipated in the driver can
be estimated using Equation 5.5.

Sep.1998

MITSUBISHI SEMICONDUCTORS POWER MODULES MOS

USING HYBRID GATE DRIVERS AND GATE DRIVE POWER SUPPLIES

Equation 5.5
Total power Dissipation

PD = ID x (VCC + VEE)

The power computed using
Equation 5.5 can then be
compared to the derating curves
shown in Figures 5.5 through

5.8 to determine the maximum
allowable ambient temperature.
The power computed using
Equation 5.5 includes the
dissipation in the external gate
resistor (RG). This loss is outside
the hybrid driver and can be
subtracted from the result of
Equation 5.5. The dissipation in
RG is difficult to estimate because
it depends on drive circuit parasitic
inductance, IGBT module type
and the hybrid driver’s switching
speed. In most applications the
loss in RG can be ignored. Direct
use of Equation 5 will result in a
conservative design with the
included loss of RG acting as a
safety margin. When operating
large modules at high frequencies
the limitations on ambient
temperature may be significant.

5.4 Application Circuit for
M57957L and M57958L

An internal schematic and example
application circuit for the M57957L
and M57958L are shown in
Figures 5.9 and 5.10. For
optimum performance parasitic
inductance in the gate drive loop
must be minimized. This is
accomplished by connecting the
47µF decoupling capacitors as
close as possible to the pins of the
hybrid driver and by minimizing the
lead length between the drive
circuit and the IGBT. The zeners
shown should be rated at about 18
volts and be connected as close to
the IGBT’s gate as possible. These
zeners protect the gate during
switching and short circuit
operation.

The gate driver has a built in
185 ohm input resistor that is
designed to provide proper drive
for the internal opto isolator when
V

= 5V. If other input voltages are

IN

desired an external resistor should
be added to maintain the proper
opto drive current of 16ma. The
value of the required external resis­tor can be computed by assuming
the forward voltage drop of the
opto diode is 2V. For example:

5.5 Short-Circuit Protection
Using Desaturation
Techniques

The M57959L and M57962L have
built in circuits that will protect the
IGBT from short circuits by
detecting desaturation. When a
short circuit occurs a high current
will flow in the IGBT causing its col­lector to emitter voltage to increase
to a level much higher than normal.
The hybrid driver detects this con­dition and quickly turns the IGBT
off, saving it from certain destruc­tion.

If 15V drive is required then

R
16ma - 185Ω = 630Ω.

= (15V - 2V) ÷

ext

Sep.1998

MITSUBISHI SEMICONDUCTORS POWER MODULES MOS

USING HYBRID GATE DRIVERS AND GATE DRIVE POWER SUPPLIES

Figure 5.5 Derating Curve for

M57957L

5

4

3

2

1

ALLOWABLE POWER DISSIPATION (W)

0

0 100

20 40 60 80

AMBIENT TEMPERATURE (oC)

Figure 5.7 Derating Curve for

M57959L

5

4

3

2

1

ALLOWABLE POWER DISSIPATION (W)

0

0 100

20 40 60 80

AMBIENT TEMPERATURE (oC)

Figure 5.6 Derating Curve for

M57958L

5

4

3

2

1

ALLOWABLE POWER DISSIPATION (W)

0

0 100

20 40 60 80

AMBIENT TEMPERATURE (oC)

Figure 5.8 Derating Curve for

M57962L

5

4

3

2

1

ALLOWABLE POWER DISSIPATION (W)

0

0 100

20 40 60 80

AMBIENT TEMPERATURE (oC)

5.6 Operation of M57959L
and M57962L

Figure 5.11 is a flow diagram show­ing the operation of the short pro­tection in M57959L and M57962L.
The hybrid driver monitors the col­lector emitter voltage (VCE) of the
IGBT. Normally, when an on signal
is applied to the input of the driver
the IGBT will turn on and VCE will
quickly attain its low on-state value
of VCE(SAT). If a short circuit is
present when the on signal is ap­plied a large current will flow in the
IGBT and VCE will remain high. A
short circuit is detected by the hy­brid driver when VCE remains
greater than the desaturation trip
level (VSC) for longer than t

TRIP

af­ter the input on signal is applied.
The t

delay is used to avoid

TRIP

false tripping by allowing enough
time for normal turn on of the IGBT.
The hybrid driver initiates a con­trolled slow turn off and generates
a fault output signal when a short
circuit is detected. The slow turn off
helps to control dangerous tran­sient voltages that can occur when
high short circuit currents are inter­rupted. The output of the driver will
remain disabled and the fault signal
will remain active for t

RESET

after a
short circuit is detected. The input
signal of the driver must be in its off
state in order for the fault signal to
be reset.

Sep.1998

MITSUBISHI SEMICONDUCTORS POWER MODULES MOS

USING HYBRID GATE DRIVERS AND GATE DRIVE POWER SUPPLIES

Figure 5.9 Internal Schematic Diagram of M57957L and M57958L

5

2

1

6

7

8

Figure 5.10 Application Circuit for M57957L and M57958L

V

LOGIC

SIGNAL

INPUT

BUFFER

IN

2

M57957L
M57958L

1

7
6



+

47µF

5

+

47µF

8

R

G

+

V

CC

+

V

EE

18V

Figure 5.11 Protection Circuit

Operation

START



IS V

CE

GREATER THAN

V

SC

IS

INPUT SIGNAL

ON?

DELAY

t

TRIP

IS VCE

GREATER THAN

V

SC

NO

YES

NO

YES

NO

YES

SLOW SHUTDOWN

DISABLE OUTPUT

SET FAULT SIGNAL

WAIT t

RESET

IS

INPUT SIGNAL

OFF?

YES

CLEAR FAULT

SIGNAL

ENABLE OUTPUT

NO

Sep.1998

MITSUBISHI SEMICONDUCTORS POWER MODULES MOS

USING HYBRID GATE DRIVERS AND GATE DRIVE POWER SUPPLIES

5.7 Application Circuit for
M57959L and M57962L

Figure 5.12 is a block diagram of
the M57959L and M57962L drivers
showing the logical implementation
of the flow diagram in Figure 5.11.
Figure 5.13 is an example applica­tion circuit for M57959L and
M57962L. Parasitic inductance in
the drive circuit should be mini­mized using the techniques de­scribed for the M57957L and
M57958L in Section 5.4. Pins
(3,7,9,10) are used for factory test­ing and should not be connected to
any external circuit. The detect di­ode (D1) must be fast recovery
(approximately 100ns) and should
be rated at a voltage equal to or
higher than the IGBT module being
driven. The 20V zener DZ1 is rec­ommended in order to protect the
hybrid IC’s detect input from tran­sient voltages that can occur during
recovery of the detect diode. This
zener can be eliminated if the de­tect diode’s recovery remains fast
and soft over its entire temperature
range and pin 1 of the hybrid IC re­mains free of high voltage tran­sients and ringing.

tor can be computed by assuming

5.8 Adjusting the Desaturation

the forward voltage drop of the
opto diode is 2V. For example:

The hybrid drivers built in t

If 15V drive is required then

delay will work for most
applications. However when large

R

= (15V - 2V) ÷

ext

16ma - 185Ω = 630Ω.

modules are being driven with near
maximum gate resistance the
driver may incorrectly detect a

Figure 5.12 Block Diagram for M57959L

DETECT

V

CC

COMPARE

V

ISOLATION

TRIP

FAULT
LATCH

QSQS

R

DISABLE OUTPUT

FAULT

INPUT

V

CC

V

EE

Trip Time (t

DELAY

t

TRIP

ONE

SHOT

t

RESET

AND

TRIP

AND

GATE DRIVE

)

SHORT
DETECTED

SLOW
SHUTDOWN

TRIP

GATE

The gate driver has a built in
185 ohm input resistor that is
designed to provide proper drive
for the internal opto isolator when
V

= 5V. If other input voltages are

IN

desired an external resistor should
be added to maintain the proper
opto drive current of 16mA. The
value of the required external resis-

Figure 5.13 Block Diagram for M57959L

FAULT

LOGIC
SIGNAL
INPUT

OUTPUT

Buffer

V

IN

14

M57959L
M57962L

13

4.7 kΩ

8

1
5
4



6

Sources for D1: EDI (Electronic Devices Inc.) P/N RF160A
VMI (Voltage Multipliers Inc.) P/N 1N6528

+

47µF

+

47µF

DZ1 30V

D1

R

G

+

V

CC

+

V

EE

18V

Sep.1998

MITSUBISHI SEMICONDUCTORS POWER MODULES MOS

USING HYBRID GATE DRIVERS AND GATE DRIVE POWER SUPPLIES

short circuit. The false trip occurs
because it takes longer than
t

for the module to reach its

TRIP

low on-state voltage. In these
applications the t

TRIP

delay can
be extended by connecting a
capacitor from pin 2 to VCC.
Figure 5.14 shows the typical
increase in t

as a function of

TRIP

the external capacitor value for
M57959L and M57962L.

5.9 Operational Waveforms

Figure 5.15 is a typical waveform
showing the gate to emitter
voltage during a slow shutdown for
M57962L. Approximately 2.4ms
after the detect input (pin 1)
voltage exceeds VSC the gate to
emitter voltage is slowly brought to
zero in about 2ms. Figure 5.16
shows the collector-emitter voltage
(VCE) and collector current (IC) for
an IGBT module during a short
circuit. This waveform shows the
effectiveness of the slow shutdown
in controlling transient voltage.

5.10 Driving Large IGBT

Modules

In order to achieve efficient and
reliable operation of high current,
high voltage IGBT modules, a
gate driver with high pulse
current capability and low output
impedance is required. Mitsubishi
hybrid gate drivers are designed to
perform this function as stand
alone units in most applications.
However, for optimum performance
with large modules, it may be
necessary to add an output booster
stage to the hybrid gate driver.

When using the hybrid gate drivers
as stand alone units with IGBT
modules outside the range

specified in Table 5.1, three things
must be considered. First, the
maximum peak output current
rating of the hybrid gate driver
places a restriction on the
minimum value of RG that can be
used. For example, the minimum
allowable RG for M57962L is about
5 ohms (for additional information
refer to Section 5.1). This value is
higher than the recommended
value for many large IGBTs. Using
RG larger than the data sheet
value will cause an increase in
t

, t

d(on)

, tr and turn-on

d(off)

switching losses. In high frequency
(more than 5kHz) applications
these additional losses are usually
unacceptable. Second, even if the
additional losses and slower
switching times are acceptable, the
drivers allowable power dissipation
must be considered. At an ambient
temperature of 60°C, the M57962L
is permitted to dissipate a
maximum of about 1.5Ω (for more
information refer to Section 5.3). If
a CM600HA-24H is being used, the
driver will dissipate 1.5W at a
switching frequency of 14kHz. In
this case, operation at a higher fre­quency than 14kHz will cause the
driver to overheat. Lastly, the
driver’s slow shutdown becomes
less effective when it is used with
large devices. This occurs because
current that flows to the gate
through the relatively high reverse
transfer capacitance (C

res

) of
large devices can not be absorbed
by the driver. Its output impedance
is not low enough. The slow
shutdown may become less
slow and a larger turn-off snubber
capacitor may be required. This
third limitation is perhaps the most
serious. In some cases, the hybrid
driver may completely lose control
of the gate voltage and allow it to

Figure 5.14 Adding

Capacitance to
Extend t

7

6

, (µs)

5

TRIP

4

3

2

DESATURATION TRIP TIME t

1

0

0 15000

CONDITIONS:
V

CC

5000

CAPACITANCE (pF)

Figure 5.15 VGE and V

TRIP

M57962L

M57959L

= 15V, VEE,= -10V, TC= 25°C

10000

DETECT

Waveform

V

GE

V

DETECT

0

CONDITIONS:
VCC= 15V, VEE= -10V, TC= 25
VGE: 5v/div, V

DETECT

: 5v/div, 1µs/div

Figure 5.16 Short-Circuit

Shutdown
Waveform

CONDITIONS:

= 300V, Tj= 25°C

V

BUS

0

: 50v/div, IC: 100A/

V

CE

V

CE

, 0.5µs/div

div

I

C

°C

Sep.1998

MITSUBISHI SEMICONDUCTORS POWER MODULES MOS

USING HYBRID GATE DRIVERS AND GATE DRIVE POWER SUPPLIES

climb above 15V. If this happens,
the short circuit durability of the
IGBT module may be compro­mised.

All of the limitations outlined
above can be overcome by adding
a discrete npn/pnp complimentary
output stage to the hybrid driver.
One possible implementation is
shown in Figure 5.18.

The NPN and PNP booster
transistors should be fast switching
(tf < 200nS) and have sufficient
current gain to deliver the desired
peak output current. Table 5.2
lists some combinations of booster
transistors that can be used in
the circuit shown in figure 5.18.
Normally, either M57958L or
M57962L is used to drive the
booster stage. However, if the
gain of the booster transistors is
sufficiently high the lower current
M57957L and M57959L can be
used. If very high gain or
Darlington type transistors are
used in the booster stage care
must be exercised to avoid
oscillations in the output stage. It
may become necessary to add
resistance from base to emitter on
the booster transistors as shown in
Figure 5.19. In addition, when
darlingtons are used the turn-on
supply may need to be increased in
order to compensate for the
additional voltage drop across the
booster stage.

Figure 5.17 shows an example
output waveform with a
booster constructed using
D44VH10/D45VH10. For this
example, an output impedance
of 1ohm was used to drive a
capacitive load of 300nF. The
circuit shown in Figure 5.18 shows
the output booster being used with
M57962L. This output booster
stage can be used with M57958L
if short circuit protection is not
needed.

Figure 5.17 Output Waveform,

I

= 5A/div,

OUT

V

= 5V /div,

OUT

T = 1µs/div

V

OUT

I

OUT

M2

M 1.00µs ch3 -5.4V

Figure 5.18 Example Circuit for Driving Large IGBT Modules

FAULT
OUTPUT

VIN=5V

LOGIC
SIGNAL
INPUT

BUFFER

4.7 kΩ

8

V

IN

14

M57962L

13

1
5
4

6

DZ1

30V

+

47µF

+

47µF

VCC=15V VEE=10V

D1

+

V

CC

+

V

EE

EDI: RF160A
VMI: 1N6528

R

G

IGBT
MODULE

Sep.1998

MITSUBISHI SEMICONDUCTORS POWER MODULES MOS

USING HYBRID GATE DRIVERS AND GATE DRIVE POWER SUPPLIES

Table 5.2 Booster Stage Transistors

npn Transistor pnp Transistor Peak Current V

MJD44H11 MJD45H11 15A 80V Motorola Surface Mount
D44VH10 D45VH10 20A 80V Motorola TO-220
MJE15030 MJE15031 15A 150V Motorola TO-220
MJE243 MJE253 8A 100V Motorola TO-255
2SC4151 2SA1601 30A 40V Shindengen Isolated TO-220

Figure 5.19 Alternate Booster Stage Configuration

PIN 5 OF M57962L OR

PIN 7 OF M57958L

R

G

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CEO

Manufacturer Package

Sep.1998