BD8166EFV Rohm, BD8166EFV Datasheet - Page 12

• Manufacturer Part Number: BD8166EFV
• Description: 12V Input Multi-channel System Power Supply IC
• Manufacturer: Rohm

BD81666EFV
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www.rohm.com
(4) Short protection of timer latch type
(5) Fault function
(6) Common amp
If the overcurrent protection function operates after all the outputs are stable, all the outputs will be shut down by the
latch function.
The latch timing is determined by the capacitance connected to the SCP pin. As the capacitance, 0.001 µF to 0.1 µF is
recommended. A startup failure may result if the capacitance is 0.001 µF or below. The internal elements may be
damaged because an overcurrent state will continue if the capacitance is 1 µF or above.
This IC incorporates a fault function to tell the operating situation of the protection circuit.
If the protection circuit turns on, the fault pin will be pulled up by external pull-up resistance, and high-level voltage will
be output.
In a stable operation state, the output will be low-level voltage. As the resistance value, 10 kΩ to 220 kΩ is
recommended. Offset voltage due to the internal on resistance will be generated if the resistance is set to 10 Ω or below.
In that case, no low-level voltage may be output correctly. No high-level voltage may be output correctly if the resistance
is 220 kΩ or over by leak current.
VCOM operates in a range between 0.3 V and V01-0.3 V. Usually, use the buffer type shown in (a).
To improve the current drive capability, use PNP and NPN transistors as shown in (b).
Use the buffer type specified in (a) if the VCOM is not used, and ground the V+ pin. A resistance setting range of 10 kΩ
to 100 kΩ is recommended for R3 and R4. If the resistance is set to 10 kΩ or below, the current consumption will
increase and the efficiency of power will be degraded. If the resistance is 100 kΩ or above, the input bias current will be
0.1 µA (Typ.) and the offset voltage may become great.
(a)
The following conditions will set the fault pin to high level.
VCOM =
VCOM
・t scp = (Cscp  0.6 V) / 5 µA [s]
・Where, Css is an external capacitor.
・If UVLO operates
・If TSD operates
・If OCP operates
・If SCP operates
+
-
Fig. 33
R3 + R4
VCOM
R4
V+
V-
 Vo1 [V] The recommended R5 value is approximately 1 kΩ.
V01
R3
R4
12/17
(b)
VCOM
+
-
VCOM
V+
V-
-
30kΩ
Fig. 34
30kΩ
1000uF
1kΩ
R5
Vo1
R4
R3
Technical Note
2009.07 - Rev.B
Vo1