RT7791P

Copyright © 2021 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

DS7791P-04

January

2021

www.richtek.com

1

PWM Controller for Programmable Power Converter (USBPD)

General Description

The RT7791P series is specifically designed to work

with controllers, such as the RT7202, so as to provide a

total solution for the USB PD or a programmable power

adapter. The RT7791P can achieve high efficiency,

meet safety standards, and consume less than 50mW

of power in a 5V standby condition.

The RT7791P

possesses several innovations in

system control, by which the RT7791P can therefore

allow one to design a power a solution with a wide

range of output voltage. One of the innovations is by

using the DMAG pin, the RT7791P senses output

voltage to adjust loop gain for system stability, to adjust

output over-voltage protection threshold voltage for

external devices protection, and to adjust current limit

for Limited Power Source (LPS) safety requirements.

The RT7791P 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).

In case

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. Moreover the RT7791P moreover provides

various features to protect against failures occurring at

the secondary-side component, such as the RT7202 or

a shunt regulator.

In applications, the RT7791P is suggested to use with

a Secondary controller RT7202 to realize a robust and

safe design, especially to prevent the potential fault

scenarios, due to the mis-connection of various devices,

cables, plugs and receptacles.

Features



Optimized for Adaptive Output Power



Integrated Low-Dropout Regulator (LDO)



Wide VDD Range : 10V to 40V



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

L

N

OTP

GATE

VDD

DMAG

GND

COMP

CS

RT7791P

2

1

VBUS

GND

CC1

OPTO

CC1

CS-

VDD

V2

USBP

GND

RT7202A

VFB

Option

Option

VIN

3

4

(Optional)