BD8624EFV ROHM [Rohm], BD8624EFV Datasheet - Page 8

• Manufacturer Part Number: BD8624EFV
• Description: Built-in 1ch FET Synchronous Rectification Type DC/DC converters
• Manufacturer: ROHM [Rohm]

● Operation description
ON/OFF control
DC/DC converter ON/OFF function
Soft start time set function
※Please note that the overshoot is not caused in the output setting voltage when setting it to tss≦3msec.
Discharge function
DC/DC converter controller can be controlled ON/OFF by CTL terminal.
Analog circuit starts operation at ON control (on mode), and goes down to setting output voltage.
Analog circuit should be standby at OFF control (off mode), and output voltage becomes 0V.
DC/DC converter can do soft start without overshoot by charging soft start capacity (Css) connected between SS
terminal and GND by charging current at ON control.
The mute of the output is released when it reaches V
operation from the point of V
Also, soft start time (tss) can be set by setting soft start capacity arbitrarily.
Soft start time (tss) should be set at 3msec < tss < 30msec.
DC/DC converter can do soft off by discharging load discharged to soft start capacity connected between SS terminal
to GND by discharging resistance at OFF control.
Soft off operates in proportion to the voltage of the terminal SS the output voltage from the point of VSS=0.8V (typ).
t
SS

V
SSTH
SS
I
=0.3V (typ) in proportion to the voltage of the terminal SS.
SS

C
SS
Table1 DC/DC converter ON/OFF function
Figure 2 Wave form at ON/OFF control
CTL terminal voltage
>VIHCTL
<VILCTL
SS
=0.15V (V
8 / 14
OFF control
ON control
SSSTB
), and the output voltage does the soft start