RT7339P
Active-PFC Constant-Voltage Controller with Primary-Side
Regulation
General Description
The RT7339P is a constant voltage controller with the
active Power Factor Correction (PFC), which is
designed to meet the line current harmonic regulations.
It drives the converter in Quasi-Resonant (QR) mode to
achieve higher efficiency. By using the Primary-Side
Regulation (PSR), the RT7339P controls the output
voltage accurately without a shunt regulator and an
opto-coupler at the secondary side, reducing the
external component counts, the costs, and the volume
of the driver board.
The RT7339P is compatible with the external depletion
N-MOSFET to achieve fast startup and ultra-low
standby power consumption.
The totem-pole gate driver with the 400mA sourcing
current and 500mA sinking current provides the
powerful driving capability for a power MOSFET to
improve the conversion efficiency. In addition, the
built-in soft drive at the turn-on transition is better for
the EMI improvement.
The RT7339P integrates comprehensive protection
functions for robust designs, including output over
voltage protection, output short-circuit protection,
output diode short-circuit protection, VDD under
voltage lockout (UVLO), VDD over voltage protection
(VDD OVP), input under / over voltage protection,
external / internal over temperature protection (OTP),
and cycle-by-cycle high/low line current limitation.
Features
Tight Voltage Regulation
Power Factor Correction
THD Optimization (THD < 10%)
Quasi-Resonant (QR) Operation
Fast Startup
Fast Dynamic Response
Ultra-Low Standby Power Consumption
Soft Drive for the Better EMI Performance
Wide Supply Voltage Range (Up to 34V)
Maximum Frequency Limitation (117kHz)
Multiple Protection Features
Output Over Voltage Protection
Output Short-Circuit Protection
Input Under / Over Voltage Protection
Output Diode Short-Circuit Protection
VDD Over Voltage Protection
VDD Under Voltage Lockout (UVLO)
External / Internal OTP
Cycle-By-Cycle High / Low Line Current
Limitation (0.5V/0.6V typ.)
Applications
LED Lighting
AC-DC Adapter/Charger
Simplified Application Circuit
With Depletion N-MOS Application
BD
Fuse
C
IN
V
AC
R
HV
Depletion
NMOS
D
HV
D
AUX
VDD
RT7339P
COMP
C
COMP
GND
CS
R
PC
R
CS
DMAG
R
DMAG2
C
VDD
TX1
C
OUT
V
OUT
D
OUT
+
GATE
R
GS
Q1
R
DMAG1
Copyright © 2019 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS7339P-03
August 2019
-
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
