NCP11377
Product Preview
High Voltage Primary Side
PWM Switcher for Low
Power Offline SMPS
www.onsemi.com
The NCP11377 offers a new integrated FET solution targeting
output power levels up to 12 W continuously in a universal-mains
flyback application.
Thanks to a Novel Method this new controller saves the secondary
feedback circuitry for Constant Voltage and Constant Current
regulation, achieving excellent line and load regulation without
traditional opto coupler and TL431 voltage reference.
TSSOP20
CASE 948BL
The NCP11377 operates in valley lockout quasi-resonant peak
current mode control mode at high load to provide high efficiency.
When the power on the secondary side starts to diminish, the
controller automatically adjusts the duty-cycle then at lower load the
controller enters in pulse frequency modulation at fixed peak current
with a valley switching detection. This technique allows keeping the
output regulation with tiny dummy load. Valley lockout at the first 4
valleys prevent valley jumping operation and then a valley switching
at lower load provides high efficiency.
MARKING DIAGRAM
XXXX
XXXX
ALYWG
G
XXXX = Specific Device Code
A
L
= Assembly Location
= Wafer Lot
Features
Y
W
G
= Year
= Work Week
= Pb−Free Package
• Integrated 650 V Power MOSFET with r
@ 25°C
of 3.2 W Typical
ds(on)
• Constant Voltage Primary-Side Regulation < 5%
(Note: Microdot may be in either location)
• Constant Current Primary-Side Regulation < 5%
PIN ASSIGNMENT
• LFF and BO Feature on a Dedicated Pin:
♦ BO Detection
♦ LFF for CC Regulation Improvement
• Quasi-Resonant with Valley Switching Operation
BO/LFF
GND
COMP
Fault
1
2
20
19
18
17
16
15
14
13
12
11
• Optimized Light Load Efficiency and Stand-by Performance
• Maximum Frequency Clamp (No Clamp, 80, 110 and 140 kHz)
• Cycle by Cycle Peak Current Limit
3
4
V
CC
V /ZCD
S
• Output Voltage Under Voltage and Over Voltage Protection
(UVP or OVP)
5
CS
GND
NC
• Secondary Diode or Winding Short-Circuit Protection
• Cable Drop Compensation Adjustment
SRC
6
7
• Wide Operation V Range (up to 28 V)
CC
• Low Start-up Current
8
• CS & V /ZCD Pin Short and Open Protection
S
DRAIN
DRAIN
DRAIN
DRAIN
9
• Internal Temperature Shutdown
• Internal and Fixed Frequency Jittering for Better EMI Signature
10
• Dual Frozen Peak Current to Both Optimize Light Load Efficiency
(10% Load) and Stand-by Performance (No-load)
ORDERING INFORMATION
See detailed ordering and shipping information on page 29 of
this data sheet.
This document contains information on a product under development. ON Semiconductor
reserves the right to change or discontinue this product without notice.
© Semiconductor Components Industries, LLC, 2017
1
Publication Order Number:
January, 2018 − Rev. P2
NCP11377/D