NCP81178 Datasheet, PDF (1/17 Pages) ON Semiconductor – Secondary Synchronous Rectifier Driver

NCP81178
Secondary Synchronous
Rectifier Driver for Forward
Converters
The NCP81178 is a secondary−side synchronous rectifier driver
designed for isolated power converters, especially actively clamped
forward and fly−back, and asymmetric half−bridge converters. The
NCP81178 drives two N−channel MOSFETs on the secondary side in
a complementary manner. It accepts a PWM input signal derived from
the secondary winding or an auxiliary winding on the main power
transformer. It can also take a PWM signal from the primary−side
controller through a pulse transformer or other isolators.
Features
• N−Channel Synchronous Rectifier MOSFET Driver
• PWM Input Derived from a Winding on the Main Transformer or
Directly from a Pulse Transformer
• Internally Generated PWM Threshold Voltage that can be
Programmed Externally
• Pre−bias Startup Capability
• Primary Shutdown Detection
• Frequency Detection Window
• Wide VIN/VCC Range: 4.5 V to 14 V
• 6 V/150 mA LDO for VCC Supply
• 4.5 A/3.8 A Sink and 3 A Source Drive Capability
• 12 ns PWM Propagation Time
• 12 ns Rise Time/10 ns Fall Time at C_L = 4700 pF @ V_CC = 6 V
• VCC under−voltage lockout
• Will support converter output voltages as high as 28 V
• Pb−Free 10−pin DFN 3 mm x 3 mm Package
• This is a Pb−Free Device
Typical Applications
• High−Efficiency Isolated DC/DC Power Supplies
• Server Power, 48 V Telecom and Data−com Applications
www.onsemi.com
1
DFN10
MN SUFFIX
CASE 506AA
MARKING DIAGRAM
81178
ALYWG
G
A = Assembly Location
L = Wafer Lot
Y = Year
W = Work Week
G = Pb−Free Package
(Note: Microdot may be in either location)
PIN CONNECTIONS
SDDET 1
RRAMP 2
PBSS 3
PWMTH 4
PWM 5
Flag 11
GND
(Top View)
10 VIN
9 VCC
8 GFW
7 DL
6 GFR
© Semiconductor Components Industries, LLC, 2015
July, 2015 − Rev. 2
ORDERING INFORMATION
Device
NCP81178MNTXG
Package
DFN10
(Pb−Free)
Shipping^†
3000 / Tape &
Reel
†For information on tape and reel specifications,
including part orientation and tape sizes, please
refer to our Tape and Reel Packaging Specification
Brochure, BRD8011/D.
1
Publication Order Number:
NCP81178/D