Boost Converter. RT8540A Datasheet

RT8540A Converter. Datasheet pdf. Equivalent

RT8540A Datasheet
Recommendation RT8540A Datasheet
Part RT8540A
Description High Power Synchronous Boost Converter
Feature RT8540A; ® RT8540A High Power Synchronous Boost Converter General Description The RT8540A is a high-efficie.
Manufacture Richtek
Datasheet
Download RT8540A Datasheet




Richtek RT8540A
®
RT8540A
High Power Synchronous Boost Converter
General Description
The RT8540A is a high-efficiency, high-current Boost
converter in all single-cell Lithium-ion / polymer battery
operated products. The RT8540A maintains output current
regulation by switching the internal high side and low side
switch transistors. The transistor switches are pulse-width
modulated at a fixed frequency of 2MHz. The high switching
frequency allows the use of a small inductor and output
capacitor, making the RT8540A ideally suited for small
battery-powered applications. Output voltage can be set
by an external resistor on the FB pin or by I2C interface.
The RT8540A contains over voltage protection, over current
protection and over temperature protection to prevent the
device from output open circuit or short circuit condition.
Built-in soft-start circuitry prevents excessive inrush current
during start-up. The shutdown feature reduces quiescent
current to less than 5μA.
Marking Information
0R= : Product Code
0R=YM
DNN
YMDNN : Date Code
Features
z Input Voltage Range : 2.8V to 5.5V
z True Load Disconnect
z Internal Synchronous Rectifier
z Up to 90% Efficiency with Small Magnetics
z Current Mode PWM Operation with Internal
Compensation
z Internal Soft-Start Control
z Flexible on/off Control by I2C or EN.
z Short Circuit Protection
z Input Current Limit up to 4A
z Over Voltage, Over Temperature Protection
z Shutdown Current : 2μA
z 40°C to 85°C Temperature Range
z 20-Lead WQFN Package
z RoHS Compliant and Halogen Free
Applications
z Cellular Phones
z Digital Cameras
z Probable Instruments
Simplified Application Circuit
VBAT
L
CIN1
SW VOUT
VIN RT8540A
SELECT
SCL
SDA
PGND
VOUT
COUT
I2C Interface
Copyright ©2013 Richtek Technology Corporation. All rights reserved.
DS8540A-00 June 2013
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
1



Richtek RT8540A
RT8540A
Ordering Information
RT8540A
Package Type
QW : WQFN-20L 4x4 (W-Type)
(Exposed Pad-Option 1)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Note :
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.
Pin Configurations
(TOP VIEW)
20 19 18 17 16
VIN 1
15 NC
AGND
AGND
AGND
FB/NC
2
3
4
5
GND
21
14 NC
13 SCL
12 SDA
11 NC
6 7 8 9 10
WQFN-20L 4x4
Functional Pin Description
Pin No.
Pin Name.
Pin Function
1 VIN
Power Input. Connect VIN to the power supply. Connect a 4.7μF or larger
ceramic capacitor from VIN to ground as close as possible to the IC.
2, 3, 4, 16, 17 AGND
Analog Ground. Connect AGND to GND at single point as close to the IC as
possible.
5
FB/NC
Feedback Voltage Input. When the pin is floating, the output voltage is
controlled by I2C interface.
6
PGND
Power Ground. Connect PGND to GND at a single point as close to the IC as
possible.
7, 8 SW
Switch Node. Connect an inductor between SW and VIN.
9, 10
VOUT
Output of the Boost Conductor. Connect a 10μF or larger ceramic capacitor
from VOUT to ground as close as possible to the IC.
11, 14, 15
12
13
18
NC
SDA
SCL
SELECT
No Internal Connection.
Data Signal Input for I2C. Open drain output, connect a 10kΩ pull-up resistor.
Clock Signal Input for I2C. Open drain output, connect a 10kΩ pull-up resistor.
Select IC I2C/EN Control.
SELECT = HIGH. I2C control.
SELECT = LOW. EN control.
19 GPIO/PGOOD General Purpose Input Output Input or Power Good Indicator Output.
20 EN
Enable Control Input for non I2C control Version (Active High).
21 (Exposed Pad) GND
Ground. The exposed pad must be soldered to a large PCB and connected to
GND for maximum power dissipation.
Copyright ©2013 Richtek Technology Corporation. All rights reserved.
www.richtek.com
2
is a registered trademark of Richtek Technology Corporation.
DS8540A-00 June 2013



Richtek RT8540A
Function Block Diagram
VIN
SELECT
FB/NC
AGND
SDA SCL EN GPIO/PGOOD VOUT
OSC
VREF
I2C Base
EA
PWM
Boost
Controller
Well
Controller
RT8540A
SW
PGND
Operation
Boost Controller
The core of the Boost regulator with normal operations
and provides protection functions like UVLO, OCP, OVP,
OTP.
OSC
Generates 2MHz clock.
VREF
Generates the reference voltage for Error-amp and other
bias circuit.
EA
Error amplifier generates COMP signal by the difference
between FB and VREF.
PWM
PWM comparator compares COMP signal and current
feedback signal to initial PWM signal.
I2C BASE
Digital logic and registers part.
Well Controller
It compares VIN and VOUT, the higher one will be the big
P-MOSFET well potential.
Copyright ©2013 Richtek Technology Corporation. All rights reserved.
DS8540A-00 June 2013
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
3







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