Driver Electronic PCB mountable

11-11-2005

© by SEMIKRON

SKHI 24 ...

SEMIDRIVER

Hybrid Dual IGBT Driver

SKHI 24

Preliminary Data

Features

· Dual driver for halfbridge

IGBT modules

· For 1700 V - IGBT
· Function compatible to SKHI

22B

· 5 V input level
· CMOS compatible inputs
· Short circuit protection by

monitoring and switch off

· Drive interlock top/bottom
· Isolation by transformers
· Supply undervoltage

protection (13 V)

· Error latch/output

Typical Applications

· Driver for IGBT and MOSFET

modules in bridge circuits in
choppers, inverter drives,
UPS and welding inverters

· DC bus voltage up to 1200 V

At R

= 18 k

, C

= 330 pF

At R

= 36 k

, C

= 470 pF,

VCE

= 1 k

Absolute Maximum Ratings

case

= 25°C, unless otherwise specified

Symbol

Conditions

Values

Units

Supply voltage prim.

Input signal volt. (High)

5 + 0,3

outPEAK

Output peak current

outAVmax

Output average current (max.)

max

max. switching frequency

kHz

Collector emitter voltage sense
across the IGBT

1700

dv/dt

Rate of rise and fall of voltage
secondary

kV/

to primary side

isolIO

Isolation test voltage

4000

input-output (2 sec. AC)

isol12

Isolation test voltage output 1 -
output 2

1500

(2 sec. AC)

Gonmin

Minimum rating for R

Gon

1,5

Goffmin

Minimum rating for R

Goff

1,5

out/pulse

Max. rating for output charge per
pulse

Operating temperature

- 25 ... + 85

°C

stg

Storage temperature

- 40 ... + 85

°C

Characteristics

case

= 25°C, unless otherwise specified

Symbol

Conditions

min.

typ.

max. Units

Supply voltage primary side

14,4

15,6

Supply current primary side (no load)

100

Supply current primary side (operation)

550

Input signal voltage on / off

5 / 0

iT+

Input threshold voltage (High)

3,4

3,8

4,1

iT-

Input threshold voltage (Low)

1,5

1,9

2,2

Input resistance

3,3

G(on)

Turn-on gate voltage output

+15

G(off)

Turn-off gate voltage output

-8

Internal gate-emitter resistance

ASIC

Asic system switching frequency

MHz

d(on)IO

Input-output turn-on propagation time

0,85

1,25

µs

d(off)IO

Input-output turn-off propagation time

0,85

1,25

µs

d(err)

Error input-output propagation time

0,6

µs

pERRRESET

Error reset time

µs

Top-Bot Interlock Dead Time

fig.2

µs

CEstat

Reference voltage for V

-monitoring

/ 6

Coupling capacitance primary secondary

MTBF

Mean Time Between Failure T

= 40°C

1,6

weight

115

HxBxT

Dimensions

20x57x

114

1916

Driver Electronic PCB Drivers

22-08-2003

© by SEMIKRON

External Components

Higher resistance reduces free-wheeling diode peak recovery current, increases IGBT turn-on time.

Higher resistance reduces turn-off peak voltage, increases turn-off time and turn-off power dissipation

Component

Function

Recommended Value

Reference voltage for V

-monitoring

with R

VCE

= 1k

(1700V IGBT):

10k

< R

< 100k

18k

for SKM XX 123 (1200V)

36k

for SKM XX 173 (1700V)

Inhibit time for V

- monitoring

< 2,7nF

0,33nF for SKM XX 123 (1200V)
0,47nF for SKM XX 173 (1700V)

0,5µs < t

min

< 10µs

VCE

Collector series resistance for 1700V
IGBT-operation

/ 0,4W

ERROR

Pull-up resistance at error output

< R

ERROR

< 10k

GON

Turn-on speed of the IGBT

GON

> 1,5

GOFF

Turn-off speed of the IGBT

GOFF

> 1,5

CEstat

( )

10 R

(

)

(

)

------------------------------------

1,4 (1)

CEstat

( )

10 R

(

)

(

)

------------------------------------

1,8 (1.1)

min

CEstat

( )

CEstat

( )

---------------------------------------- (2)

( )

10 R

(

)

(

)

------------------------------------ (3)

Pull

ERROR

-----------------------

15mA

© by SEMIKRON 22-08-2003

Driver Electronic PCB Drivers

1917

PIN array

Fig. 6 shows the pin arrays. The input side (primary side) comprises 10 inputs, forming the interface to the control circuit
(see fig.1).

The output side (secondary side) of the hybrid driver shows two symmetrical groups of pins with 5 outputs, each forming
the interface to the power module. All pins are designed for a grid of 2,54 mm in two rows.

Primary side PIN array

ATTENTION: The contactor tracks of the digital input signals P13/ P14/ P15 must not be longer than 20 mm to avoid

interferences, if no bridges are connected.

Secondary side PIN array

ATTENTION: The connector leads to the power module should be as short as possible.

PIN No. Designation

Explanation

Shield

internally connected to GND

IN2

switching signal input 2 (BOTTOM switch); positive 5V logic

IN1

switching signal input 1 (TOP switch); positive 5V logic

P4, P5,
P6, P7

free

not wired

/ERROR

error output, low = error; open collector output; max 30V / 15mA

P9, P10

GND/0V

ground

P11, P12 V

+ 15V ± 4% voltage supply

P13

TDT1

signal input for digital adjustment of locking time; to be switched by
bridge to GND

P14

TDT2

signal input for digital adjustment of locking time; to be switched by
bridge to GND

P15

SELECT

signal input for inhibiting locking function; to be connected by bridge
to GND

P16, P17,
P18, P19,
P20

free

not wired

PIN No. Designation Explanation

ST1

OFF1

gate 1 R

OFF

output (TOP switch)

ST2

ON1

gate 1 R

output (TOP switch)

ST3

emitter output IGBT 1 (TOP switch)

ST4

CE1

reference voltage adjustment with R

and C

(TOP switch)

ST9

CE1

collector output IGBT 1 (TOP switch)

SB1

OFF2

gate 2 R

OFF

output (BOTTOM switch)

SB2

ON2

gate 2 R

output (BOTTOM switch)

SB3

emitter output IGBT 2 (BOTTOM switch)

SB4

CE2

reference voltage adjustment with R

and C

(BOTTOM switch)

SB9

CE2

collector output IGBT 2 (BOTTOM switch)

© by SEMIKRON 22-08-2003

Driver Electronic PCB Drivers

1919

SEMIDRIVER

SKHI 24

Hybrid dual drivers

The driver generation SKHI 24 is supplementing the
SKHI

21/22 and is suitable for all available medium and

high power range IGBT and MOSFETs. It can be said that
the SKHI 24 is a function-compatible further developed
SKHI 22B. It is recommended to use the SKHI 24 for any
new design.

General description

The new driver generation SKHI 22A/B, SKHI 21A and
also SKHI 24 are hybrid components which may directly
be mounted to the PCB.

All devices necessary for driving, voltage supply, error
monitoring and potential separation are integrated in the
driver. In order to adapt the driver to the used power
module, only very few additional wiring will be necessary.

The forward voltage of the IGBT is detected by an
integrated short-circuit protection, which will turn off the
module when a certain threshold is exceeded.

In case of short-circuit or too low supply voltage the
integrated error memory is set and an error signal is
generated.

The driver is connected to a controlled + 15 V-supply
voltage. The input signal level is 0/5 V.

Technical explanations

Description of the circuit block diagram and the
functions of the driver

The block diagram (fig.1) shows the inputs of the driver
(primary side) on the left side and the outputs (secondary
side) on the right.

The following functions are allocated to the primary
side:

Input-Schmitt-trigger, positive logic (input high = IGBT
on). It is also possible to drive the circuit input with 15 V
logic, but a 6.8 k

resistor has to be connected in series

with the input pin (and the internal 100

resistor).

Interlock circuit and deadtime generation of the IGBT

If one IGBT is turned on, the other IGBT of a halfbridge
cannot be switched. Additionally, a digitally adjustable
interlocking time is generated by the driver (see fig. 2),
which has to be longer than the turn-off delay time of the
IGBT. This is to avoid that one IGBT is turned on before
the other one is not completely discharged. This
protection-function may be neutralized by switching the
select input (pin15) (see fig. 2). fig. 2 documents possible
interlock-times. ,,High" value can be achieved with no
connection and connection to 5 V as well.

1. The following descriptions apply to the use of the hybrid driver

for IGBTs as well as for power MOSFETs. For the reason of
shortness, only IGBTs will be mentioned in the following. The
designations ,,collector" and ,,emitter" will refer to IGBTs,
whereas for the MOSFETs ,,drain" and ,,source" are to be read
instead.

Fig. 2 SKHI 24 - Selection of interlock-times: "High"-level

can be achieved by no connection or connecting to
5 V.

Short pulse suppression

The integrated short pulse suppression avoids very short
switching pulses at the power semiconductor caused by
high-frequency interference pulses at the driver input
signals. Switching pulses shorter than 500ns are
suppressed and not transmitted to the IGBT.

Power supply monitoring (V

)

A controlled 15 V-supply voltage is applied to the driver. If
it falls below 13 V, an error is monitored and the error
output signal switches to low level.

Error monitoring and error memory

The error memory is set in case of under-voltage or
short-circuit of the IGBTs. In case of short-circuit, an error
signal is transmitted by the V

-input via the pulse

transformers to the error memory. The error memory will
lock all switching pulses to the IGBTs and trigger the error
output (P8) of the driver. The error output consists of an
open collector transistor, which directs the signal to earth
in case of error. SEMIKRON recommends the user to
provide for a pull-up resistor directly connected to the error
evaluation board and to adapt the error level to the desired
signal voltage this way. The open collector transistor may
be connected to max. 30 V / 15 mA. If several SKHI 24 are
used in one device, the error terminals may also be
paralleled.

The error memory may only be reset, if no error is pending
and both cycle signal inputs are set to low for > 12 µs at
the same time.

Pulse transformer set

The transformer set consists of two pulse transformers.
One of them is used bidirectional for turn-on and turn-off
signals of the IGBT and the error feedback between
primary and secondary side, the other one for the DC/
DC-converter.

The

DC/DC-converter

serves

potential-separation and power supply for the two
secondary sides of the driver. The isolation voltage is
4000 VAC .

The secondary side consists of two sym-metrical
driver switches integrating the following components:

Supply voltage

The voltage supply consists of a rectifier, a capacitor, a
voltage controller for 8 V and + 15 V and a + 10 V
reference voltage.

P15 ;

SELECT

P13 ;

TDT1

P14 ;

TDT2

interlock time

/µs

open / 5V

GND

1,3

open / 5V

GND

open / 5V

2,3

open / 5V

GND

3,3

open / 5V

4,3

GND

no interlock

1920

Driver Electronic PCB Drivers

22-08-2003

© by SEMIKRON

Gate driver

The output transistors of the power drivers are MOSFETs.
The sources of the MOSFETs are separately connected to
external terminals in order to provide setting of the turn-on
and turn-off speed by the external resistors R

and R

OFF

Do not connect the terminals ST1 with ST2 and SB1 with
SB2, respectively. The IGBT is turned on by the driver at
+15V by R

and turned off at 8 V by R

OFF

. R

and R

OFF

may not chosen below 1,5

. In order to ensure locking of

the IGBT even when the driver supply voltage is turned off,
a 22 k

-resistor versus the emitter output (E) has been

integrated at output G

OFF

-monitoring

The V

-monitoring controls the collector-emitter voltage

of the IGBT during its on-state. V

is internally limited

to 10 V. If the reference voltage V

CEref

is exceeded, the

IGBT will be switched off and an error is indicated. The
reference voltage V

CEref

may dynamically be adapted to

the IGBTs switching behaviour. Immediately after turn-on
of the IGBT, a higher value is effective than in the steady
state. This value will, however, be reset, when the IGBT is
turned off. V

CEstat

is the steady-state value of V

CEref

and is

adjusted to the required maximum value for each IGBT by
an external resistor R

to be connected between the

terminals C

(ST4/SB4) and E (ST3/SB3). It may not

exceed 10 V. The time constant for the delay of V

CEref

may

be increased by an external capacitor C

, which is

connected in parallel to R

. It controls the time t

min

which

passes after turn-on of the IGBT before the
V

-monitoring is activated. This makes possible any

adaptation to the switching behavior of any of the IGBTs.
After t

min

has passed, the V

-monitoring will be triggered

as soon as V

> V

CEref

and will turn off the IGBT.

External components and possible adjust-
ments of the hybrid driver

Fig. 1 shows the required external components for
adjustment and adaptation to the power module.

- monitoring adjustment

The external components R

and C

are applied for

adjusting the steady-state threshold and the short-circuit
monitoring dynamic. R

and C

are connected in

parallel to the terminals C

(ST4/ SB4) and E (ST3/ SB3)

Fig. 3 V

CEstat

in dependence of R

Rce in kOhm

t
a

t

i
n

Vcestat without Rvce (1200V
application)

Vcestat / V mit Rvce = 1 kOhm
(1700V application)

Dimensioning of R

and C

can be done in three steps:

1. Calculate the maximum forward voltage from the

datasheet of the used IGBT and determine V

CEstat

2. Calculate approximate value of R

according to

equation (1) or (1.1) from V

CEstat

or determine R

using fig. 3.

3. Determine t

min

and calculate C

according to equations

(2) and (3).

Typical values are

for 1200V IGBT: V

CEstat

= 5 V; t

min

= 1,45 µs,

= 18 k

, C

= 330 pF

for 1700V IGBT:V

CEstat

= 6 V; t

min

= 3 µs,

= 36 k

, C

= 470 pF

Adaptation to 1700 V IGBT

When using 1700 V IGBTs it is necessary to connect a
1

0,4 W adaptation resistor between the

-terminal (ST9/ SB9) and the respective collector.

Adaptation to error signal level

An open collector transistor is used as error terminal,
which, in case of error, leads the signal to earth. The signal
has to be adapted to the evaluation circuit voltage level by
means of an pull-up resistor. The maximum load applied
to the transistor shall be 30 V / 15 mA.

IGBT switching speed adjustment

The IGBT switching speed may be adjusted by the
resistors R

and R

OFF

. By increasing R

the turn-on

speed will decrease. The reverse peak current of the
free-wheeling

diode

will

diminish.

SEMIKRON

recommends to adjust R

to a level that will keep the

turn-on delay time t

d(on)

of the IGBT < 1 µs. By increasing

OFF

the turn-off speed of the IGBT will decrease. The

inductive peak over voltage during turn-off will diminish.

The minimum gate resistor value for R

OFF

and R

1,5

. Typical values for R

and R

OFF

recommended by

SEMIKRON are given in fig. 4.

Interlock time adjustment

Fig. 2 shows the possible interlocking times between
output1 and output2. Interlocking times are adjusted by
connecting the terminals TDT1 (P13), TDT2 (P14) and
SELECT (P15) either to earth/ GND (P16) according to the
required function or by leaving them open.

SK-IGBT-Modul

Gon

Goff

VCE

SKM 50GB123D

330

SKM 75GB123D

330

SKM 100GB123D

330

SKM 145GB123D

330

SKM 150GB123D

330

SKM 200GB123D

330

SKM 300GB123D

8,2

330

SKM 400GA123D

6,8

330

SKM 75GB173D

470

Driver Electronic PCB Drivers

1921

Fig. 4 Typical values for external components

A typical interlocking time value is 3,25 µs (P14 = GND;
P13 and P15 open).

ATTENTION: If the terminals TDT1, TDT2 and SELECT
are not connected, eventually connected track on
PC-board may not be longer than 20 mm in order to avoid
interference.

SEMIKRON recommends to start-up operation using the
values recommended by SEMIKRON and to optimize the
values gradually according to the IGBT switching
behaviour and overvoltage peaks within the specific
circuitry.

Driver performance and application limits

The drivers are designed for application with halfbridges
and single modules with a maximum gate charge Q

5 µC.

The charge necessary to switch the IGBT is mainly
depending on the IGBT's chip size, the DC-link voltage
and the gate voltage.

This correlation is also shown in the corresponding
module datasheet curves.

It should, however, be considered that the SKHI 24 is
turned on at + 15 V and turned off at 8 V. Therefore, the
gate voltage will change by 23 V during each switching
cycle.

Unfortunately, most datasheets do not indicate negative
gate voltages. In order to determine the required charge,
the upper leg of the charge curve may be prolonged to
+

23 V for an approximately determination of

approximate charge per switch.

The medium output current of the driver is determined by
the switching frequency and the gate charge. For the SKHI
24 the maximum medium output current is Iout

AVmax

< ± 80

mA.

The maximum switching frequency f

MAX

may be calculated

with the following formula, the maximum value however
being 50 kHz due to switching losses:

SKM 100GB173D

470

SKM 150GB173D

470

SKM 200GB173D

8,2

470

MAX

kHz

(

)

8 10

(

)

-----------------------

Fig. 5 shows the recommended maximum switching
frequencies for SEMIKRON Semitrans IGBT modules.

Fig. 5 Maximum switching frequency in dependence of

rated current @ 25°C heatsink temperature.

Further application notes

The CMOS-inputs of the hybrid driver are extremely
sensitive to overvoltage. Voltages higher than V

+ 0,3 V

or below 0,3 V may destroy these inputs. Therefore,
control signal overvoltages exceeding the above values
have to be avoided.

Please provide for static discharge protection during
handling. As long as the hybrid driver is not completely
assembled, the input terminals have to be short-circuited.
Persons working with CMOS-devices have to wear a
grounded bracelet. Any synthetic floor coverings must not
be statically chargeable. Even during transportation the
input terminals have to be short-circuited using, for
example, conductive rubber. Worktables have to be
grounded. The same safety requirements apply to
MOSFET- and IGBT-modules!

The connecting leads between hybrid driver and the
power module should be as short as possible, the driver
leads should be twisted.

Any parasitic inductances within the DC-link have to be
minimized. Overvoltages may be absorbed by C- or
RCD-snubbers between the main terminals for PLUS and
MINUS of the power module.

When first operating a newly developed circuit,
SEMIKRON recommends to apply low collector voltage
and load current in the beginning and to increase these
values gradually, observing the turn-off behaviour of the
free-wheeling diode and the turn-off voltage spikes
generated accross the IGBT. An oscillographic control will
be necessary. In addition to that the case temperature of
the module has to be monitored. When the circuit works
correctly under rated operation conditions, short-circuit
testing may be done, starting again with low collector
voltage.

It is important to feed any errors back to the control circuit
and to switch off the device immediately in such events.
Repeated turn-on of the IGBT into a short circuit with a
high frequency may destroy the device.

SKHI24 Recommended Application Range

200

400

600

800

1000

1200

1400

1600

f/kHz

Ra
ted
IG
BT
Cu
rre
nt
@
25
°C
/A
m
pe
re

600V
1200V
1700V

Ð­Ð»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: SKHI24

ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: SKHI24