RT7791
PWM Controller for Programmable Power Converter (USBPD)
General Description
The RT7791 series is specifically designed to work with
controllers, such as the RT7202, to provide a total
solution for USB PD or a programmable power adapter.
The RT7791 can achieve high efficiency, meet safety
standards, and consume less than 50mW of power in a
5V standby condition.
The RT7791 includes several innovations in order to
provide a solution with a wide range of output voltage.
By way of DMAG pin, the RT7791 senses output
voltage to adjust loop gain for system stability, to adjust
output over-voltage protection threshold voltage to
protect external devices, and to adjust current limit to
meet Limited Power Source (LPS) safety requirements.
The RT7791 is also equipped with comprehensive
protection features, including Bulk-Capacitor brown-in
/brown-out protection, VDD over-voltage protection
(VDD OVP),
output
over-voltage/under-voltage
protection (Output OVP/UVP), secondary rectifier
short-circuit protection (SRSP), and external
over-temperature protection (External OTP). For
constant output power regulation, a resistor connected
to CS pin can be used to achieve accurate line
compensation across the universal input voltage range.
The RT7791 also provides various features to protect
against any failures occurring at the secondary-side
component, such as the RT7202 or a shunt regulator.
The RT7791 and the RT7202 work together to realize a
robust and safe design to prevent all the potential fault
scenarios, which may arise from versatile and unknown
connections to various devices, cables, plugs and
receptacles.
Features
Optimized for Adaptive Output Power
Integrated Low-Dropout Regulator (LDO)
Wide VDD Range : 10V to 40V
Adaptive Output Over-Voltage Protection
Adaptive Over-Current Protection
Adaptive Loop Gain Control for Loop Stability
High Efficiency
Green Mode Operation at Light Load or No
Load
Comprehensive Protection Features
Bulk-Capacitor Brown-In and Brown-Out
Protection
OTP Pin for External Over-Temperature
Protection
VDD Over-Voltage Protection
Output Over-Voltage and Under-Voltage
Protection
Secondary Rectifier Short-Circuit Protection
Programmable Line Compensation
Others
< 50mW in 5V Standby Mode for Power Saving
Driver Capability : 300mA/300mA
SmartJitter
TM
Technology
Applications
USB PD and Programmable Power Adapters
Simplified Application Circuit
Option
L
VBUS
+
+
1
2
GND
N
RT7202A
VDD
RT7791
DMAG
OTP
CS
COMP
4
GND
3
GATE
VIN
VDD
(Optional)
GND
CS-
V2
OPTO
VFB
USBP
CC1
Option
CC1
Copyright © 2018 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS7791-03
July 2018
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
