Flyback Controller. RT7737 Datasheet

RT7737 Controller. Datasheet pdf. Equivalent

RT7737 Datasheet
Recommendation RT7737 Datasheet
Part RT7737
Description Programmable Burst Switching Green Mode/Burst Mode Level Flyback Controller
Feature RT7737; RT7737 Programmable Burst Switching Green Mode/Burst Mode Level Flyback Controller General Descrip.
Manufacture Richtek
Datasheet
Download RT7737 Datasheet




Richtek RT7737
RT7737
Programmable Burst Switching Green Mode/Burst Mode
Level Flyback Controller
General Description
The RT7737 series are enhanced high efficient PWM
flyback controller with proprietary SmartJitterTM
technology. The innovative SmartJitterTM technology
not only reduces the EMI emissions of SMPS when the
system enters burst switching green mode, but also
eliminates the output jittering ripple. Also, the RT7737
series feature programmable burst switching green
mode and burst mode level for adopting different
application requirements to optimize the product
performance. To meet the stringent trend toward
performance, the RT7737 series are the best choice for
product designers.
The RT7737 is available in SOT-23-6 package. It is a
current mode PWM controller providing comprehensive
protection functions, including an input Under-Voltage
Lockout (UVLO), a VDD Over-Voltage Protection
(OVP), an Over-Load Protection (OLP), a Secondary
Rectifier Sort Protection (SRSP), a CS pin open
protection and a cycle-by-cycle current limit. With the
above features, the RT7737 is a cost-effective and
compact solution for AC/DC products.
Features
Proprietary SmartJitterTM Technology
Reducing EMI Emissions of SMPS
Output Jittering Ripple Elimination
Programmable Burst Switching Green Mode
Level
Programmable Burst Mode Level
Accurate Over Load Protection
Driver Capability : 200mA/300mA
High Noise Immunity
Applications
Switching AC/DC Adaptor
DVD Open Frame Power Supply
Set-Top Box (STB)
ATX Standby Power
TV/Monitor Standby Power
PC Peripherals
NB Adaptor
Simplified Application Circuit
Mains
(90V to 265V)
Vo+
Vo-
VDD
BURST
GATE
RBS
COMP RT7737
RCS_RC
CS
GND
Copyright © 2014 Richtek Technology Corporation. All rights reserved.
DS7737-00 September 2014
is a registered trademark of Richtek Technology Corporation
www.richtek.com
1



Richtek RT7737
Ordering Information
RT7737
Package Type
E : SOT-23-6
Lead Plating System
G : Green (Halogen Free and Pb Free)
RT7737 Version (Refer to Version Table)
Note :
Richtek products are :
RoHS compliant and compatible with the current
requirements of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
Marking Information
RT7737GGE
0U=DNN
0U= : Product Code
DNN : Date Code
RT7737
RT7737LGE
0S=DNN
0S= : Product Code
DNN : Date Code
RT7737AGE
0V=DNN
0V= : Product Code
DNN : Date Code
RT7737HGE
0T=DNN
0T= : Product Code
DNN : Date Code
RT7737 Version Table
Version
Frequency (fOSC)
OLP Delay Time @ fOSC
Internal OVP
OLP & SRSP
BURST Pin High
BURST Pin Low
RT7737G
65kHz
55ms
Auto Recovery
Auto Recovery
Latch
Auto Recovery
RT7737L
65kHz
55ms
Latch
Auto Recovery
Latch
Auto Recovery
RT7737A
65kHz
28ms
Latch
Latch
Latch
Latch
RT7737H
100kHz
36ms
Auto Recovery
Auto Recovery
Latch
Auto Recovery
Pin Configurations
(TOP VIEW)
GATE VDD CS
654
23
GND COMP BURST
SOT-23-6
Copyright © 2014 Richtek Technology Corporation. All rights reserved.
www.richtek.com
2
is a registered trademark of Richtek Technology Corporation
DS7737-00 September 2014



Richtek RT7737
RT7737
Functional Pin Description
Pin No.
Pin Name
Pin Function
1 GND
Ground of the Controller.
2 COMP
Feedback Voltage Input. Connect an opto-coupler to close the control loop and
achieve output voltage regulation.
3 BURST Burst Mode Level Setting.
4 CS
Current Sense Input. The current sense resistor between this pin and GND is used
for current limit setting.
5 VDD
Supply Voltage Input. The controller will be enabled when VDD exceeds VTH_ON
and disabled when VDD decreases lower than VTH_OFF.
6 GATE
Gate Driver Output for External Power MOSFET.
Function Block Diagram
VDD
BURST
COMP
IBias
VL_TH
+
-
VSRSP_TH
VH_TH
+
-
Secondary Rectifier
Short Protection
-
+
COMP Open
Sensing
Shutdown
Logic
Counter
OTP
OVP +
-
POR
VOVP
+
-
UVLO
VTH_ON/OFF
Bias &
Bandgap
VCOMP_OP
OLP
Constant
Power
Slope
Ramp
LEB X3
Oscillator
Dmax
Burst Switching
Green Mode
Selector
-
-
+
PWM
Comparator
S
Q
R
Soft Driver
Burst Switching
Green Mode
COMP
VBURL
VBURH
VDD
CS
GATE
GND
Copyright © 2014 Richtek Technology Corporation. All rights reserved.
DS7737-00 September 2014
is a registered trademark of Richtek Technology Corporation
www.richtek.com
3







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