bd9575fv-e2 ROHM Co. Ltd., bd9575fv-e2 Datasheet - Page 9

• Manufacturer Part Number: bd9575fv-e2
• Description: Switching Regulators Ddr-sdram Cores
• Manufacturer: ROHM Co. Ltd.

●Explanation of Operation
© 2009 ROHM Co., Ltd. All rights reserved.
BD9575FV
www.rohm.com
V
The BD9575FV is a synchronous buck regulator controller incorporating ROHM’s proprietary H
system. When V
Thus, it serves to improve the regulator’s transient response. Activating the Light Load Mode will also exercise Simple Light
Load Mode (SLLM) control when the load is light, to further increase efficiency.
H
(Normal operation)
(V
(SLLM )
REF
V
OUT
HG
3
REF
LG
REF
OUT
OUT
Reg
HG
LG
HG
LG
0A
Io
TM
drops due to a rapid load change)
V
control
OUT
OUT
drops due to a rapid load change, the system quickly restores V
T
ON
+α
9/20
When V
detected, activating the H
HG output is determined with the formula above.
LG outputs until the status of V
after the status of HG is off.
In SLLM (SLLM=0V), SLLM function is operated when
LG pin is OFF and the coil current is lower than 0A
(the current goes from V
output next HG.
When V
status of HG is ON.
When V
the voltage remains below REF after the
programmed T
system quickly restores V
time, improving the transient response.
T
ON
=
OUT
OUT
REF
OUT
V
falls to a threshold voltage (REF), the drop is
IN
goes lower than REF voltage again, the
drops due to a rapid load change, and
×
ON
OUT
1
f
time interval has elapsed, the
[sec]・・・(1)
by extending the T
OUT
3
Reg
OUT
to SW). And it stops to
3
TM
Reg
OUT
by extending the T
CONTROLLA system.
TM
is lower than REF
CONTROLLA control
Technical Note
2009.04 - Rev.B
ON
time interval.
ON