RT9451 datasheet(15/37 Pages) RICHTEK

15 / 37 page

RT9451

DS9451-00

September 2013

www.richtek.com

is a registered trademark of Richtek Technology Corporation.

Application Information

The RT9451 is an integrated solution of single-cell Li-ion

and Li-polymer battery charger for portable applications.

The part integrates a synchronous PWM controller with

power MOSFETs to provide MIVR (Minimum Input Voltage

Regulation), input current sensing, high accuracy current

and voltage regulation, and charge termination in a small

package for space limited devices. The part also features

USB OTG(On-The-Go) function and USB charger detection

(DPDM detection) function.

The RT9451 provides three operation modes : charge

mode, boost mode (USB OTG), and high impedance mode.

In charge mode, the RT9451 supports a precision charging

system for single cell. In boost mode, the RT9451 works

as a Boost converter and boosts the voltage from battery

to VIN pin for sourcing the OTG devices. In high impedance

mode, the RT9451 stops charging or boosting and

operates in a mode with low quiescent current from VIN or

battery to reduce the power consumption when the

portable device is in standby mode.

In charge mode, the RT9451 integrates USB charger

detection for input current limit of 500mA and 1A. The

detection is automatically triggered after each POR. The

detection result can be ignored by the host via I2C interface.

The slave address for the RT9451 is

“1001010”.

I2C Interface Timing Diagram

The RT9451 acts as an I2C -bus slave. The I2C-bus master

configures the settings for charge mode and boost mode

by sending command bytes to the RT9451 via the 2-wire

I2C-bus. After the START condition, the I2C master sends

a chip address. This address is seven bits long followed

by an eighth bit which is a data direction bit (R/W). The

second byte selects the register to which the data will be

written. The third byte contains data to the selected

S = Start Condition

W = Write (SDA =

“0”)

R = Read (SDA =

“1”)

ACK = Acknowledge

P = Stop Condition

123

7891

567

2345

678

W ACK

ACK

0B4

ACK

SCL

SDA

Start

0 R/W

B7 B6 B5 B4 B3 B2 B1 B0

C7 C6 C5 C4 C3 C2 C1 C0

Stop

The 2nd Byte

(Data Address, Data)

The 3rd Byte (Data)

The 1st Byte

(Slave Address, R/W)

RT9451 датащи(PDF) 15 Page - Richtek Technology Corporation

RT9451 датащи(HTML) 15 Page - Richtek Technology Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37

датащи скачать

ссылки URL