Boost Regulator. RT4805 Datasheet

RT4805 Regulator. Datasheet pdf. Equivalent

RT4805 Datasheet
Recommendation RT4805 Datasheet
Part RT4805
Description Synchronous Boost Regulator
Feature RT4805; .
Manufacture Richtek Technology
Datasheet
Download RT4805 Datasheet




Richtek Technology RT4805
RT4805
2.5MHz, Synchronous Boost Regulator with Bypass Mode
General Description
The RT4805 allows systems to take advantage of new
battery chemistries that can supply significant energy
when the battery voltage is lower than the required
voltage for system power ICs. By combining built-in
power transistors, synchronous rectification, and low
supply current; this IC provides a compact solution for
systems using advanced Li-Ion battery chemistries.
The RT4805 is a boost regulator designed to provide a
minimum output voltage from a single-cell Li-Ion battery,
even when the battery voltage is below system
minimum. In boost mode, output voltage regulation is
guaranteed to a maximum load current of 2A.
Quiescent current in Shutdown Mode is less than 1A,
which maximizes battery life. The regulator transitions
smoothly between Bypass and normal Boost Mode.
The device can be forced into Bypass Mode to reduce
quiescent current.
The RT4805 is available in the WL-CSP-16B 1.67x1.67
(BSC) package.
Features
4 Few External Components: 0.47H Inductor
and 0603 Case Size Input and Output Capacitors
Input Voltage Range: 1.8V to 5V
Output Range from 2.85V to 4.4V
VSEL = L 3.2V
VSEL = H 3.4V
Maximum Continuous Load Current: 2A at VIN >
2.65V Boosting VOUT to 3.35V
Up to 96% Efficient
True Bypass Operation when VIN > Target VOUT
Internal Synchronous Rectifier
True Load Disconnect when Shut Down
Forced Bypass Mode
VSEL Control to Optimize Target VOUT
Short-Circuit Protection
I2C Controlled Interface
Ultra low Operating Quiescent Current
Small WL-CSP 16B Package
Applications
Single-Cell Li-Ion, LiFePO4 Smart-Phones or Tablet
2.5G/3G/4G Mini-Module Data Cards
Simplified Application Circuit
+ CIN
-
L1
RT4805
VIN VOUT
LX
VSEL
EN
nBYP
SDA
SCL
PGOOD
AGND PGND
COUT
To pull high voltage
Copyright © 2015 Richtek Technology Corporation. All rights reserved.
DS4805-00 November 2015
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
1



Richtek Technology RT4805
RT4805
Ordering Information
RT4805
Package Type
WSC : WL-CSP-16B 1.67x1.67 (BSC)
Note :
Richtek products are :
RoHS compliant and compatible with the current
requirements of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
Marking Information
Pin Configurations
(TOP VIEW)
A1 A2 A3 A4
EN PGOOD VIN VIN
B1 B2 B3 B4
VSEL SCL VOUT VOUT
C1 C2 C3
nBYP SDA LX
C4
LX
D1 D2 D3 D4
AGND PGND PGND PGND
WL-CSP-16B 1.67x1.67 (BSC)
3XW
3X : Product Code
W : Date Code
Functional Pin Description
Pin No.
Pin Name
Pin Function
A1 EN
Enable. When this pin is HIGH, the circuit is enabled.
A2
PGOOD
Power Good. It is a open-drain output. PGOOD pin pulls low automatically if
the overload or OTP event occurs.
A3, A4
VIN
Input Voltage. Connect to Li-Ion battery input power source.
B1 VSEL
B2 SCL
Output Voltage Select. When boost is running, this pin can be used to select
output voltage
Serial Interface Clock. (Pull down if I2C is non-used).
B3, B4
C1
C2
VOUT
nBYP
SDA
Output Voltage. Place COUT as close as possible to the device.
Bypass. This pin can be used to activate Forced Bypass Mode. When this
pin is LOW, the bypass switches are turned on and the IC is otherwise
inactive.
Serial Interface Date Line. (Pull down if I2C is non-used).
C3, C4
LX
Switching node. Connect to inductor.
D1 AGND
Analog Ground. This is the signal ground reference for the IC. All voltage
levels are measured with respect to this pin.
D2, D3, D4 PGND
Power Ground. This is the power return for the IC. The COUT bypass
capacitor should be returned with the shortest path possible to these pins.
Copyright © 2015 Richtek Technology Corporation. All rights reserved.
www.richtek.com
2
is a registered trademark of Richtek Technology Corporation.
DS4805-00 November 2015



Richtek Technology RT4805
Function Block Diagram
SCL
SDA
nBYP
VSEL
EN
PGOOD
Digital
Soft-Start
Control
OSC
+
+
+
-
Current
Sense
+
-
PSM
Control
PWM
Logic
Power
MOS
Control
Stage
ZCD
RT4805
VIN
VMIN
Control
VMAX
Control
VOUT
LX
AGND
PGND
Copyright © 2015 Richtek Technology Corporation. All rights reserved.
DS4805-00 November 2015
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
3







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