ack

address h´00 data

ack

addr = h´00

ack

w

id = h´47

start

scl

sda

start

msb

ID

lsb

w ack msb ADDRESS lsb ack

msb

DATA

lsb

ack

ack from slave

ack from slave

ack from slave

stop

LP3947

SNVS298B – NOVEMBER 2004 – REVISED APRIL 2013

www.ti.com

Table 5. LP3947 Serial Port Communication address code 7h’47

LP3947 Control and Data Codes(1)

Addrs

Register

7

6

5

4

3

2

1

0

8

′h00

Charger

Batt Voltage

AC Adaptor

AC Adaptor

AC Adaptor

AC Adaptor

Register -1

(0) = 4.1V

Charge

Charge Current

Charge Current

Charge Current

1 = 4.2V

Current

Code 2 (0)

Code 1 (0)

Code 0 (0)

Code 3 (1)

8

′h01

Charger

EOC

Charging

EOC

EOC

Register -2

(Green LED)

(Red LED)

SEL-1

SEL-0

R/O

R/O

(0)

(1)

8

′h02

Charger

USB

USB

USB

USB

Register -3

Charge

Charge Current

Charge Current

Charge Current

Current

Code 2 (0)

Code 1 (0)

Code 0 (0)

Code 3 (1)

(1)

Numbers in parentheses indicate default setting. “0” bit is set to low state, and “1” bit is set to high state. R/O –Read Only, All other bits

are Read and Write.

Table 6. Charger Current and EOC Current Programming Code

Charger Current

End of Charge Current

Data Code

Selection Code ISET (mA)

Selection Code

4h

′00

100

4h

′01

150

0.1C

4h

′02

200

0.15C

4h

′03

250

0.2C

4h

′04

300

4h

′05

350

4h

′06

400

4h

′07

450

4h

′08

500

4h

′09

550

4h

′0A

600

4h

′0B

650

4h

′0C

700

4h

′0D

750

w = write (sda = “0”)

r = read (sda = “1”)

ack = acknowledge (sda pulled low by either master or slave)

Nack = No Acknowledge

rs = repeated start

Figure 8. LP3947 (Slave) Register Write

12

Submit Documentation Feedback

Copyright © 2004–2013, Texas Instruments Incorporated

Product Folder Links: LP3947