15/27
TO-247N(-4L) Half-Bridge Evaluation Board
User’s Guide
© 2022 ROHM Co., Ltd.
No. 63UG059J Rev.001
2022.2
9
.
Evaluation Board Connection Example
9.1 Double-pulse test for H-side MOSFET
Figure 16 shows a double-pulse test circuit using a MOSFET on the H-side.
Figure 16 H-side double-pulse circuit
Prepare a pulse generator and connect the CLK signal to the IN_H_CLK pin (CN1 pin 1). Connect the 12 V power supply for
control to the Vcc pin (CN201) and the high-voltage HVdc power supply to the HVdc pin (T1). The operating procedure is as
follows.
①
Turn on the power supply in the order of +12 V to HVdc.
②
Input a pulse signal using the pulse generator.
The maximum current I
D(peak)
flowing through the inductor (L) can be roughly calculated by the following formula.
I
D(PEAK)
≈ HVdc/L*T
DP_TTL
[A].
HVdc: Applied voltage [V]
L: Inductor value [µH].
T
DP_TTL
: Total time of double-pulse signal [µs]
Normally, the double-pulse signal is a single shot, but when it is applied periodically, it is necessary to ensure sufficient reset
time for the inductor current I
D (PEAK)
. Since the reset voltage is only equal to the forward voltage V
F
of the flywheel diode,
determine the rough time using:
T
RST
= I
D(PEAK)
*L/V
F
[µs]
and ensure that the reset time T
RST
is about twice that value. Note that a heat sink is not necessary, but be careful not to raise
the temperature of the flywheel diode when performing repeated double-pulse tests.
+12V
Power
Supply
Pulse
Generator
(+5V output)
PGND
HVdc
DUT_HS
DUT_LS
HS-GADJ
LS-GADJ
IN_H_CLK
IN_L_CLK
LDO
Vcc1
DCR
Vsw
Vcc
ICAP
SNB
SGND
PGND
PGND
PGND
PGND
SGND
HS_GD
PRIMERY
SECONDERY
BD7F200
HS
Gate Power
LS_GD
LS
Gate Power
BM61M41
BD7F200
BM61M41
VEE2
VCC2
VEE2
VCC2
Vcc1
HS_GSC
LS_GSC
UVLO2
UVLO2
RCD-SNB
RCD-SNB
HS-
VEESEL
LS-
VEESEL
SGND
VEE2
GND2
GND2
UVLO
UVLO1
UVLO
UVLO1
LS_CS