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TO-247-4L Half-Bridge Evaluation Board
User’s Guide
©
2019 ROHM Co., Ltd.
No. 61UG047E Rev.001
August.2019
12.5 Synchronous Buck Topology Power Supply Circuit
The connection of the buck operation using the HS MOSFET is shown in Figure 28.
Since the OCP circuit is not valid, attention need to be paid. However, the DESAT circuit will operate and function for the short
protection.
Connect the CLK signal from a pulse generator to IN_CLK pin (CN201 3pin). Then, connect the 12V power supply (for control
block) to (CN202), high voltage HVdc power supply to HVdc pin (T1), load inductor to Vsw pin (T2), as the connection shown in
Figure 28
Connect the smoothing capacitor and current load to one side of the load inductor. HVdc side becomes the input. As the input
capacitor is already mounted on the PCB, basically it is not necessary to add an input capacitor externally. However, if the oscillating
frequency is low, it is recommended to add an appropriate value of external input capacitor. In that case, ensure the capacitor has
an adequate rated voltage.
Preliminary setting has to be done for JP1 only.
①
JP1 Setting: Set to “single-CLK” side
②
Directly connect ENABLE signal to SGND
Operation procedure is as follows:
③
Input the +12V power supply
④
Set the switching frequency, duty ratio at the pulse generator, then input the CLK signal
⑤
Input the HVdc power supply
⑥
Adjust the output current at the electronic load equipment
HS
Gate Driver
HVdc
PGND
Vsw
DUT
DUT
IN_H_CLK
ENABLE
PRIMERY
SECONDERY
BD7F200
Vcc
SNB
HS
Gate Power
PGND
PGND
LS
Gate Driver
Rg
ActiveClamp
LS
Gate Power
Rg
Active Clamp
IN_L_CLK
BM6101
BD7F200
BM6101
Load
IN_CLK
OR
OR
STP
+12V
Power
Supply
Pulse
Generator
(+5V output)
SGND
Figure 28. Synchronous Buck Topology Power Supply Operation Test
Drain LS
②
Jumper
setting
Dual / DP
Single
JP1
1
3
JP2
