Datasheet
ack
address h´00 data
ack
addr = h´00
ackw
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 I
SET
(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
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