THV3058 Datasheet, PDF (11/21 Pages) THine Electronics, Inc. – 3CH (Buck/Boost) 2CH CP 1CH HVLDO Controller

THV3058_Rev.1.00_E
Functional Description
● System UVLO
UVLO stops the device operation if the input power supply voltage drops below a preset voltage. The threshold voltage is
3.5V, the release voltage is 5.46V by internal setting. When input power supply voltage(Vin) rises above 5.46V, the device
goes into soft start mode and output voltage(Vo) increases gradually up to the regular voltage. If the input power supply
voltage(Vin) drops below 3.5V, UVLO stops switching operation immediately and accompanies output voltage drop (see
Figure 1).
5.46V
Vin _3.50V
switching
Operating
Stop
Operating
Stop
Vo
Figure 1.UVLO Operation
The UVLO threshold voltage also can be set optionally by changing the external resistance value (see Figure 2). The
UVLO threshold voltage are given by the following formulas. Please use lower the external resistance value than the inter-
nal resistance value.
　 　 　 Release Voltage of System UVLO 　 　 ＝
Detection Voltage of System UVLO 　 ＝
1.56 × ^R----¹----+-----^R----²-
R2
1.0
×
R_----1_----+-----R_----2_-
R2
Vin
R1
R2
VCC
SYSUVLO
500k
UVLO
COMP
200k
Figure 2. System UVLO Setting Circuit
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11/21
THine Electronics, Inc.