Step-Down Controller. RT6545B Datasheet

RT6545B Controller. Datasheet pdf. Equivalent

RT6545B Datasheet
Recommendation RT6545B Datasheet
Part RT6545B
Description Dual-Channel Synchronous DC/DC Step-Down Controller
Feature RT6545B; ® RT6545A/B Dual-Channel Synchronous DC/DC Step-Down Controller with 5V/3.3V LDOs General Descript.
Manufacture Richtek
Datasheet
Download RT6545B Datasheet




Richtek RT6545B
®
RT6545A/B
Dual-Channel Synchronous DC/DC Step-Down Controller
with 5V/3.3V LDOs
General Description
The RT6545A/B is a dual-channel step-down, controller
generating supply voltages for battery-powered systems.
It includes two Pulse-Width Modulation (PWM) controllers
adjustable from 2V to 5.5V, and two fixed 5V/3.3V linear
regulators. Each linear regulator provides up to 100mA
output current and 3.3V linear regulator provides 1%
accuracy under 35mA. The RT6545A/B has an oscillator
output to driver the external charge pump application. Other
features include on-board power-up sequencing, a power-
good output, internal soft-start, and soft-discharge output
that prevents negative voltage during shutdown.
A constant current ripple PWM control scheme operates
without sense resistors and provides 100ns response to
load transient. For maximizing power efficiency, the
RT6545A/B automatically switches to the diode-emulation
mode in light load applications. The RT6545A/B is available
in the WQFN-20L 3x3 package.
Features
Support Connected Standby Mode for Ultrabook
CCRCOT Control with 100ns Load Step Response
PWM Maximum Duty Ratio > 98%
5V to 25V Input Voltage Range
Dual Adjustable Output :
CH1 : 2V to 5.5V
CH2 : 2V to 4V
5V/3.3V LDOs with 100mA Output Current
1% Accuracy on 3.3V LDO Output
Oscillator Driving Output for Charge Pump
Application
Internal Frequency Setting
400kHz/475kHz (CH1/CH2)
Internal Soft-Start and Soft-Discharge
4700ppm/°C RDS(ON) Current Sensing
Independent Switcher Enable Control
Built in OVP/UVP/OCP/OTP
Non-latch UVLO
Power Good Indicator
RoHS Compliant and Halogen Free
Simplified Application Circuit
VIN
VOUT1
VIN UGATE2
RT6545A/B
BOOT2
UGATE1
BOOT1
PHASE2
LGATE2
PHASE1
LGATE1
FB2
CS1
BYP1
CS2
FB1
Channel 1 Enable
EN1
Channel 2 Enable
On
Off
EN2
LDO5
PGOOD
LDO3
GND
VOUT2
5V
PGOOD Indicator
3.3V
Copyright ©2016 Richtek Technology Corporation. All rights reserved.
DS6545A/B-00 May 2016
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
1



Richtek RT6545B
RT6545A/B
Applications
Marking Information
Notebook and Sub-Notebook Computers
System Power Supplies
2-Cell to 4-Cell Li+ Battery-Powered Devices
Ordering Information
RT6545A/B
Pin 1 Orientation***
(2) : Quadrant 2, Follow EIA-481-D
Package Type
QW : WQFN-20L 3x3 (W-Type)
RT6545AGQW
C0=YM
DNN
C0= : Product Code
YMDNN : Date Code
RT6545BGQW
BZ=YM
DNN
BZ= : Product Code
YMDNN : Date Code
Lead Plating System
G : Green (Halogen Free and Pb Free)
Pin Function With
A : LDO3 Always On
B : LDO3/LDO5 Always On
Pin Configurations
(TOP VIEW)
Note :
***Empty means Pin1 orientation is Quadrant 1
Richtek products are :
RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
CS1
FB1
LDO3
FB2
CS2
20 19 18 17 16
1 15 LGATE1
2 14 BYP1
3 GND 13 LDO5
4 21 12 VIN
5 11 LGATE2
6 7 8 9 10
WQFN-20L 3x3
Functional Pin Description
Pin No.
1
2
3
4
5
6
Pin Name
CS1
FB1
LDO3
FB2
CS2
EN2
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 50A
current source from LDO5 to 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.
3.3V Linear Regulator Output. It is always on when VIN is higher than VINPOR
threshold.
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 50A
current source from LDO5 to CS2.
Enable Control Input for Channel 2.
7
PGOOD
Power Good Indicator Output for Channel 2.
Copyright ©2016 Richtek Technology Corporation. All rights reserved.
www.richtek.com
2
is a registered trademark of Richtek Technology Corporation.
DS6545A/B-00 May 2016



Richtek RT6545B
RT6545A/B
Pin No.
8
Pin Name
PHASE2
9 BOOT2
10 UGATE2
11 LGATE2
12 VIN
13 LDO5
14 BYP1
15 LGATE1
16 UGATE1
17 BOOT1
18 PHASE1
19 VCLK
20 EN1
21
(Exposed Pad)
GND
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.
Bootstrap Supply for Channel 2 High-Side Gate Driver. Connect to an external
capacitor according to the typical application circuits.
High-Side Gate Driver Output for Channel 2. UGATE2 swings between PHASE2
and BOOT2.
Low-Side Gate Driver Output for Channel 2. LGATE2 swings between GND and
LDO5.
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.
Switch-over Source Voltage Input for LDO5.
Low-Side Gate Driver Output for Channel 1. LGATE1 swings between GND and
LDO5.
High-Side Gate Driver Output for Channel 1. UGATE1 swings between PHASE1
and 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.
Oscillator Output for Charge Pump.
Enable Control Input for Channel 1.
Ground. The exposed pad must be soldered to a large PCB and connected to
GND for maximum power dissipation.
Functional Block Diagram
BOOT1
UGATE1
PHASE1
LGATE1
FB1
CS1
VCLK
BYP1
LDO5
Channel 1
Buck
Controller
BYP1
OSC
SW5 Threshold
LDO5
VIN
LDO5
Channel 2
Buck
Controller
LDO5
Power On
Sequence
Clear Fault Latch
REF
LDO3
BYP1
BOOT2
UGATE2
PHASE2
LGATE2
FB2
CS2
PGOOD
GND
EN1
EN2
LDO3
Copyright ©2016 Richtek Technology Corporation. All rights reserved.
DS6545A/B-00 May 2016
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
3







@ 2014 :: Datasheetspdf.com :: Semiconductors datasheet search & download site (Privacy Policy & Contact)