RT7786LEC
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
TM
SmartJitter
Technology
Applications
USB PD
Programmable Power Adapters
Simplified Application Circuit
V
OUT
+
+
AC Mains
GND
Option
Option
CC1
VDD
CS-
AGND
V2
GND
BLD USBP
CC1
+
RT7207C
DMAG VDD
HV
RT7786LEC
COMP
GND
CS
GATE
Option
OPTO
IFB
VFB V5
VCP
V9 CC_GND CC2
CC2
Copyright © 2019 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS7786LEC-00
June 2019
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
