THV3012 Datasheet, PDF (8/12 Pages) THine Electronics, Inc. – 1ch DC/DC converter

THV3012_Rev.1.00_E
● Power Good (PGOOD)
Power Good is a function to notify external circuits that the output voltage has reached to the normal voltage,
and available as a sequence control or a reset signal for micro-processor. When the output voltage exceeds
82.4%(typ) of the user defined voltage, PGOOD pin is turned from Low level to High level. When the output
voltage drops(70.6% typical hysteresis), PGOOD pin is turned to Low level. When CTL pin is turned Low
level, PGOOD pin is also turned Low level independent of the output voltage.
Please beware of following matters, when PGOOD pin is pulled-up to the external power source.
The output transistor of PGOOD pin becomes active only when higher voltage than 2.5V is applied to VIN.
Therefore, PGOOD pin operates as follows.
1.When VIN voltage is less than 2.5V, PGOOD pin is High level even though the output voltage doesn’t reach
to the user defined voltage.
2.When VIN voltage exceeds 2.5V, PGOOD pin is turned Low level.
3.When VIN voltage reaches to 82.4%(typ) of the user defined voltage after the release of UVLO.
● Off Delay (OFFDELAY)
Off Delay function works to set the delay time from when Low level voltage is applied on CTL pin till the
device goes into standby state. The delay time can be set by connecting a capacitor between OFFDELAY pin
and GND.
CTL
OFFDELAY
VOUT
2.0V
T
OD
The
delay
time
T
OD
is the period that OFFDELAY pin is discharged with 4uA(typ) constant current source
from 5.0V to threshold 2.0V(typ), and is calculated as follows.
( ) _TOD
=
C_{OFFD ×} VCC _-
4.0uA
2.0V
＝ 7.5 × 10⁶ × C_OFFD (sec)
When off delay time = 7.5msec, C_OFFD = 0.01uF.
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THine Electronics, Inc.