RT6545A/B
Pin No.
Pin Name
Pin Function
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)
Functional Block Diagram
BOOT1
BOOT2
UGATE1
UGATE2
PHASE2
PHASE1
LDO5
LDO5
Channel 1
Buck
Channel 2
Buck
Controller
Controller
LGATE1
FB1
LGATE2
FB2
CS2
CS1
BYP1
PGOOD
VCLK
BYP1
OSC
GND
SW5 Threshold
Power On
Sequence
Clear Fault Latch
EN1
EN2
REF
LDO3
BYP1
LDO3
LDO5
VIN
LDO5
Copyright 2016 Richtek Technology Corporation. All rights reserved.
©
is a registered trademark of Richtek Technology Corporation.
DS6545A/B-00 May 2016
www.richtek.com
3
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