BD9243MUV Datasheet, PDF (3/5 Pages) Rohm – Silicon Monolithic Integrated Circuit

〇Package Dimensions
Lot No.
D9243
3/4
Device Mark
〇Block Diagram
VCC REG
RT
BCT
DUTY
STB
SS
FB
IS
VS
GND
REG
BLOCK
STB
SYSTEM　ON/OFF
BLOCK
OSC
F/B
BLOCK ①
PWM
SS
BLOCK
CT
①
PROTECT
BLOCK
VCC
COMP1 COMP2 CP
SRT
BOSC
DUTY
BLOCK
LOGIC
BLOCK
①
HN
BLOCK①
UVLO
BLOCK
REG
LN
BLOCK②
BST1
BST2
HN1
HN2
SW1
SW2
LN1
LN2
PGND
VQFN024V4040 (UNIT:mm)
○Pin Description
PIN
PIN NAME
No.
FUNCTION
PIN
PIN NAME
No.
FUNCTION
1 GND
2 BCT
3 DUTY
4 SS
5 CP
Ground
13 BST1
External capacitor between BCT and GND for adjusting the
14 REG
BURST triangle oscillator
Control Burst-dimming by PWM signal or DC
15 LN1
External capacitor between SS and GND for Soft Start Control
16 PGND
and detect the time of Soft Start
External capacitor between CP and GND for timer latch
17 LN2
Boot-strap input for HN1 output
Regulator output
NMOS FET driver (Ch. 1)
Power Ground for FET drivers
NMOS FET driver (Ch. 2)
6 FB
Error amplifier output
18 BST2
Boot-strap input for HN2 output
7 IS
Error amplifier input 2
19 HN2
NMOS FET driver (Ch. 2)
8 VS
Error amplifier input 1
20 SW2
Lower rail voltage for HN2 output
9 COMP2
Input of over voltage detector2
21 VCC
Power supply input with UVLO Protection
10 COMP1
11 SW1
Input of over voltage detector1
Lower rail voltage for HN1 output
12 HN1
NMOS FET driver (Ch. 1)
22 STB
23 SRT
24 RT
Stand-by switch
External resister from SRT to RT for adjusting the start-up Triangle
oscilator
External resistor between RT and GND for adjustment frequency of saw
tooth wave
REV. A