RT2702
Functional Pin Description
Pin No
1
2
3
4
5
6
7
8
Pin Name
MODE
PWM
Operation mode detection input.
Logic gate driver. This pin provides PWM signal for the gate drive.
External driver enable. Enable external driver when DISB is high, and disable
external driver when
DISB
is low.
Thermal shutdown detection input.
DISB
goes low when
THWN
is less than
trip level.
Non-inverting input of current sense amplifier.
Inverting input of current sense amplifier. Connect a R
CS
from this pin to the
current sensing R/C network for adjusting the over current trip threshold. V
OUT
is
also discharged by this pin when system is shut down or any protection is
toggled. Resistance of the discharge switch is around 30.
Feedback pin. This pin is the negative input node of the PWM comparator.
Remote ground sense. This pin is intended to connect to the negative side of the
load for remote sensing.
External soft-start pin. Achieve programmable soft-start time function, also have
a default internal soft-start time 3ms for minimum soft-start time. DO NOT force
this pin lower than 1.2V, otherwise soft-start procedure won't be finished. Refer
to “Application Information” for further description.
The 1.2V buffered output for current limit adjustment. Connect a R
ILIM
between
this pin and GND to set the over-current threshold corresponding to R
CS
.
Open drain power good indicator. High impedance indicates power is good.
Enable control input. The device enters its 20A supply current shutdown mode
if EN is less than the EN input falling edge trip level and does not restart until EN
is greater than the EN input rising edge trip level. Connect EN to VIN for
automatically startup. EN can be connected to VIN through a resistive voltage
divider to implement a programmable under-voltage lockout.
On-time/switching frequency adjustment input. Connect a resistor to VIN for
adjusting switching frequency. And connect an another 100pF ceramic capacitor
between TON and ground is optional for noise immunity enhancement.
Power supply input.
Switching node Input for zero current detection. Also provide V
OUT
information
through PHASE pin to on-time generation circuit.
Output bypass for the 5V regulator. Connect a low-ESR bypass ceramic
capacitor of 4.7F from this pin to GND.
Ground. The exposed pad must be soldered to a large PCB and connected to
GND for maximum thermal dissipation.
Pin Function
DISB
THWN
CSP
CSN
FB
RGND
9
SS
10
11
ILIM
POK
12
EN
13
14
15
16
TON
VIN
PHASE
VDRV
17 (Exposed Pad) GND
Copyright
©
2018 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
2
DS2702-02 May 2019
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
