R7731A
1
R7731A-10 August 2011
www.richtek.com
General Description
The R7731A is a high-performance, low cost, low start-up
current and current mode PWM controller with burst triple
mode to support green mode power saving operation. The
R7731A integrates functions of soft start, Under Voltage
LockOut (UVLO), Leading Edge Blanking (LEB), Over
Temperature Protection (OTP) and internal slope
compensation. It provides the users a superior AC/DC
power application of higher efficiency, low external
component counts and lower cost solution.
To protect the external power MOSFET from being
damaged by supply over voltage, the R7731A output driver
is clamped at 12V. Furthermore, R7731A features fruitful
protections like Over Load Protection (OLP) and Over
Voltage Protection (OVP) to eliminate the external
protection circuits and provide reliable operation. R7731A
is available in SOT-23-6 and DIP-8 packages.
Burst Triple Mode PWM Flyback Controller
Features
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Very Low Start-up Current (<30
μμ
μμ
μA)
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z 10/14V UVLO
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z Soft Start Function
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z Current Mode Control
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z Jittering Switching Frequency
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z Internal Leading Edge Blanking
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z Built-in Slope Compensation
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z Burst Triple Mode PWM for Green-Mode
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z Cycle-by-Cycle Current Limit
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z Feedback Open Protection
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z Over Voltage Protection
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z Over Temperature Protection
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z Over Load Protection
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z Soft Driving for Reducing EMI
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z Driver Capability
±±
±±
±200mA
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z High Noise Immunity
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z Opto-Coupler Short Protection
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z RoHS Compliant and Halogen Free
Applications
z Adaptor and Battery Charger
z ATX Standby Power
z Set-Top Box (STB)
z DVD and CD(R)
z TV/Monitor Standby Power
z PC Peripherals
Ordering Information
R7731A
Package Type
E : SOT-23-6
N : DIP-8
Lead Plating System
G : Green (Halogen Free and Pb Free)
Note :
Richtek products are :
` RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
` Suitable for use in SnPb or Pb-free soldering processes.
Marking Information
IDP=W
IDP= : Product Code
W : Date Code
R7731AGN : Product Number
YMDNN : Date Code
R7731AGE
R7731AGE
RichTek
R7731A
GNYMDNN
