RT7786LEC

Copyright © 2019 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

DS7786LEC-00

June

2019

www.richtek.com

1

PWM Controller for Programmable Power Converter (USBPD)

General Description

The RT7786LEC series is specifically designed to work

with controllers, such as RT7207, so as to provide a

total solution for the USB PD or the programmable

power adapter. The RT7786LEC is able to achieve the

high efficiency performance, meet safety standards,

and consume low standby power, which is normally

less than 30mW in a 5V standby condition.

The RT7786LEC offers several innovative features in

order to provide a solution having the wide-range

output

voltages.

By

using the

DMAG

pin,

the

RT7786LEC senses output voltages to adjust the loop

gain

for

system

stability,

to

adjust

the

output

over-voltage protection threshold voltage for external

device protection, and to adjust the current limit to meet

Limited Power Source (LPS) safety requirements.

The RT7786LEC is also equipped with comprehensive

protection

features,

including

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 an application with constant output

power regulation, a resistor connected to CS pin can be

used to achieve the accurate line compensation across

the universal input voltage range. The RT7786LEC

also provides various features to protect against

failures occurring at the secondary-side component,

such as the RT7207 or a shunt regulator.

The RT7786LEC and the RT7207 can be used

together to realize a robust and safe design preventing

all potential fault scenarios, due to versatile and

unknown connections of various devices, cables, plugs

and receptacles.

Features



Optimized for Adaptive Output Power



Wide VDD Range : 10V to 32V



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



Brown-In and Brown-Out Protection



VDD Over-Voltage Protection



Output Over-Voltage and Under-Voltage

Protection



External Over-Temperature Protection



Secondary Rectifier Short-Circuit Protection



Programmable Line Compensation



Others



< 30mW in 5V Standby Mode for Power Saving



Driver Capability : 300mA/

300mA



SmartJitter

TM Technology

Applications



USB PD



Programmable Power Adapters

Simplified Application Circuit

VOUT

GND

COMP

GND

VDD

GATE

CS

DMAG

HV

CC1

CC2

CS-

AGND

VDD

V2

BLD

OPTO

IFB

VFB

CC1

CC2

RT7786LEC

RT7207C

USBP

AC Mains

Option

Option

Option

GND

V5

VCP

V9 CC_GND