BD8162AEKV Datasheet, PDF (8/30 Pages) Rohm – Multi-channel System Power Supply IC + Gamma Buffer

BD8162AEKV
Description of Operation of Each Block and Procedure for Selecting Application Components
(1) Step-up DC/DC Converter Block
VCC
PGATE
M1
CI1
CTL1
Control
PG1
Power Good
R11
R12
CTL
PGATE
Power
good
ERR
－
＋
1.25
FB1
R13
C11
PWM
DRV
DTC
COMP1 DTC1
R14
C12
C13
VREF (2.5V)
R15
R16
D1
SW1
PGND1
VO
CO1
Figure 5. Step-up DC/DC Converter Block
This is a step-up DC/DC converter block that outputs a step-up voltage upon receipt of a signal from CTL1.
When the high-level signal is input to CTL1, a current will be pulled up from PGATE to turn ON input switch M1. At the
time of startup, since the switching duty is limited by the DTC1 pin voltage, a soft start is operated. When output
reaches 90% of the set voltage, the Power Good signal will be output from PG1.
(1.1) Selecting input switch M1
Input switch M1 will serve as a switch to block the path from VCC to output when a low-level control signal is input to
CTL1. Select the input switch with careful attention paid to the following conditions.
Recommended ICs: RSQ and RTQ Series
Maximum inductor current:
Power supply voltage:
Power supply voltage:
⊿IL
IINMAX +
VCC
2
VCC
< Rated current of FET
< Rated voltage of FET
< ON voltage of FET gate
When the CTL1 control input is switched to the high level, a 9µA (Typ) sink current will be pulled from the PGATE pin
to turn ON the input switch.
www.rohm.com
© 2016 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
8/26
TSZ02201-0323AAF00690-1-2
15.Feb.2016 Rev.001