Datasheet
Datasheet
Datasheet
9/34
BD9271KUT
TSZ02201-0F1F0C100260-1-2
© 2013 ROHM Co., Ltd. All rights reserved.
27.Feb.2015 Rev.004
www.rohm.com
TSZ22111・15・001
R1
R2
VIN
LSP
CLSP
LSP
AGND AGND
AGND
LSP
（
50PIN
）
LSP
CLSP
GND GND
2.0MΩ
500kΩ
GND
VREF5V
ー
＋
＋
＋
＋
D1
D2
D3
D4
SHORT
DET
R1
R2
＋
D16
…
REG
In case of outputting a voltage to LSP by using the resistor divider circuit, REF5V
VCC
（
51PIN
）
The VCC pin is used to supply power for the IC in the range of 9 to 35V. If the VCC pin voltage reaches 7.0V (Typ.) or
more, the IC will initiate operation. If it reaches 6.7V (Typ.) or less, the IC will be shut down. Basically, insert a resistor of
approx. 10 ohms in resistance between the VCC pin and the external power supply and install a ceramic capacitor of
approx. 1uF in capacitance in the vicinity of the IC.
STB
（
52PIN
）
The STB pin is used to make setting of turning ON and OFF the IC and allowed for use to reset the IC from shutdown.
Note: Set the STB pin voltage below the VCC pin voltage.
Note: The IC state is switched (i.e., the IC is switched between ON and OFF state) according to voltages input in the STB
pin. Avoid using the STB pin between two states (0.8 to 2.0V).
GND
（
53PIN
）
The GND pin is an analog circuit ground pin of the IC. Set the ground pattern as close as possible to that of resistors
connected to the S1 to S16 pins.
COMP1(55PIN)
The COMP1 pin is used to feed back the state of voltage to the external power supply in order to optimize the power
supply voltage for the LED layer.
Positive feedback voltage is output to a pin having the lowest voltage out of the D1 to D8 pins. If the lowest voltage of the
D1 to D8 pins is higher than 0.6V typical voltage, the COMP1 pin will become open-circuited. If the lowest voltage of
these pins is lower than 0.6V typical voltage, the internal NPN transistor of the COMP1 pin will turn ON. The COMP1 pin
is intended to connect to the output voltage monitor pin of the DC/DC converter.
0
5
10
15
20
01234
BSx Pin LED short detect voltage [V]
LSP Pin voltage [V]
A pin used for setting the LED SHORT protection detecting
voltage. When LSP pin is in OPEN state, the voltage in inward
of IC is 1V typ.（Set it in range of 0.8V~3.0V）
When LED is lighting, if the voltage of D1～16 pin is higher
than
「Voltage of LSP x 5 (V) 」（default 5V）
the abnormal state of IC is detected.
Because this pin has a high impedance, please connect a
capacitor about 1000pF to remove the noise basically.
Fi
g
ure 11. LSP Pin Inte
r
nal E
q
uivalent Circuit Dia
g
ram
Figure 12. Setting for LSP
Figure 13. LED SHORT detect Voltage [V] vs. LSP [V]