RT6576A/B
Functional Pin Description
Pin No.
Pin Name
Pin Function
Current Limit Setting. Connect a resistor to GND to set the threshold for Channel 1
synchronous RDS(ON) sense. The GND PHASE1 current limit threshold is 1/8th
the voltage seen at CS1 over a 0.2V to 2V range. There is an internal 10A
current source from LDO5 to CS1.
1
CS1
Feedback Voltage Input for Channel 1. Connect FB1 to a resistive voltage divider
from VOUT1 to GND to adjust output from 2V to 5.5V.
2
3
4
FB1
3.3V Linear Regulator Output. It is always on when VIN is higher than VINPOR
threshold.
LDO3
FB2
Feedback Voltage Input for Channel 2. Connect FB2 to a resistive voltage divider
from VOUT2 to GND to adjust output from 2V to 4V.
Current Limit Setting. Connect a resistor to GND to set the threshold for Channel 2
synchronous RDS(ON) sense. The GND PHASE2 current limit threshold is 1/8th
the voltage seen at CS2 over a 0.2V to 2V range. There is an internal 10A
current source from LDO5 to CS2.
5
CS2
6
7
EN2
Enable Control Input for Channel 2.
PGOOD
Power Good Indicator Output for Channel 1 and Channel 2. (Logical AND)
Switch Node of Channel 2 MOSFETs. PHASE2 is the internal lower supply rail for
the UGATE2 high-side gate driver. PHASE2 is also the current-sense input for the
Channel 2.
8
PHASE2
Bootstrap Supply for Channel 2 High-Side Gate Driver. Connect to an external
capacitor according to the typical application circuits.
9
BOOT2
High-Side Gate Driver Output for Channel 2. UGATE2 swings between PHASE2
and BOOT2.
10
UGATE2
Low-Side Gate Driver Output for Channel 2. LGATE2 swings between GND and
LDO5.
11
12
13
14
15
LGATE2
VIN
Power Input for 5V and 3.3V LDO Regulators and Buck Controllers.
5V Linear Regulator Output. LDO5 is also the supply voltage for the low-side
MOSFET and analog supply voltage for the device.
LDO5
BYP1
Switch-over Source Voltage Input for LDO5.
Low-Side Gate Driver Output for Channel 1. LGATE1 swings between GND and
LDO5.
LGATE1
High-Side Gate Driver Output for Channel 1. UGATE1 swings between PHASE1
and BOOT1.
16
17
UGATE1
BOOT1
Bootstrap Supply for Channel 1 High-Side Gate Driver. Connect to an external
capacitor according to the typical application circuits.
Switch Node of Channel 1 MOSFETs. PHASE1 is the internal lower supply rail for
the UGATE1 high-side gate driver. PHASE1 is also the current sense input for the
Channel 1.
18
PHASE1
19
20
VCLK
EN1
Oscillator Output for Charge Pump.
Enable Control Input for Channel 1.
21
Ground. The exposed pad must be soldered to a large PCB and connected to
GND for maximum power dissipation.
GND
(Exposed Pad)
Copyright 2016 Richtek Technology Corporation. All rights reserved.
©
is a registered trademark of Richtek Technology Corporation.
DS6576A/B-02 January 2016
www.richtek.com
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