MB39C011APFT-G-BND-ERE1 Datasheet, PDF (24/53 Pages) Cypress Semiconductor – 2 ch DC/DC Converter IC with Synchronous Rectification

MB39C011A
12. Setting The Soft-start And Short-circuit Detection Times
Set the soft-start time and the short-circuit detection time using the CSCP pins. Both become the same time.
ts  t_CSCP 0.019 CSCP R_T
ts
:Soft-start time (time to output voltage 100) [s]
t_CSCP :Short-circuit detection time [s]
CSCP :CSCP pin capacitor [F]
R_T :Timing resistance [k]
13. VB Pin And VH Pin Connections In Condition Of Vcc Voltage
In the range of 4.5 V  VCC  6.0 V, there is a chance that the VB voltage^[1] and VH voltage^[2] may drop due to the internal IC
regulator saturating. As a result, there are drive voltage shortage and a bird clapper of SW FET. It is therefore recommended that
the VB pin (pin 4) and VH pin (pin 16) are connected as shown in the “VB pin and VH pin connection table”.
[1]: Voltage between VB pin (pin 4) and GND pin (pin 12) : 5 V
[2] : Voltage between VCC pin (pin 1) and VH pin (pin 16) : 5 V
VB pin and VH pin connection table
VCC condition
VB pin
VH pin
4.5  VCC  6 V
Connected to VCC
Connected to GND
6 V  VCC  17 V
VB capacitor connection^[4]
VH capacitor connection^[4]
Used with VCC crossing 6 V^[3](ex. 5 V 
VCC  7 V)
VB capacitor connection^[4]
VH capacitor connection^[4]
[3]: Check that the switching operation is functioning normally.
[4]: Refer to the connection of the VB pin (pin 4) and the VH pin (pin 16) in the “Block Diagram”.
Document Number: 002-08369 Rev. *A
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