nx2154 Microsemi Corporation, nx2154 Datasheet - Page 5

• Manufacturer Part Number: nx2154
• Description: 300khz Synchronous Pwm Controller
• Manufacturer: Microsemi Corporation

BLOCK DIAGRAM
Rev.1.2
02/26/07
COMP
VCC
GND
FB
START
COMP
0.3V
Generator
Digital
start Up
Bias
0.8V
Figure 2 - Simplified block diagram of the NX2154/NX2154A
START
ramp
1.25V
0.8V
OSC
0.6V
CLAMP
UVLO
1.3V
CLAMP
70%Vp
S
R
FB
Q
POR
OC
START
Hiccup Logic
PWM
Hiccup Logic
OC
Control
Logic
OCP
comparator
NX2154/2154A
360mV/540mV
VCC
LDRV
HDRV
SW
BST
5