SM8172A Datasheet, PDF (11/17 Pages) Nippon Precision Circuits Inc – 2-output Power Supply IC

SM8172A
12-7. Standby Mode
When both ENDCO and ENLDO are LOW, the device switches to standby mode, and all the RESETN, con-
verter, and regulator outputs stop.
12-8. Timing Diagrams
12-8-1. Supply Voltage (VIN1 = VIN2 = ENDCO = ENLDO)
VRESETNH
VRESETNL
VUVLOH
VUVLOL
VIN1
VIN2
ENABLE
VRESETN
(Pull-up)
Reset return delay time
65msec (typ)
VDCOUT
VLDOUT
800µsec (typ)^*1
70µsec (typ)^*1
DC/DC, regulator output stop
by UVLO lockout
LDOUT (regulator output)
DCOUT (DC/DC output)
DC/DC, regulator output permission
DC/DC soft start time^*2
0.6msec (typ)
LDO soft start time^*2
1msec (typ)
*1. A time interval example for a typical application circuit with no load. The series regulator and DC/DC converter output voltage rise times may vary with
the load current, output capacitance, and other conditions.
*2. The soft start time is the interval during which the output current is limited internally in the IC, and is different from the series regulator and DC/DC con-
verter output raise time.
Note. When the supply voltage is below approximately 0.8V, there is insufficient drive for the IC to operate normally and the RESETN output level is unde-
fined. Normally, a pull-up resistor is connected to RESETN, which sets the RESETN output level to pull-up voltage.
SEIKO NPC CORPORATION —11