CHARGE CURRENT (mA)

700

100

0.247

1.235

1.729

500

LP3918

www.ti.com

SNVS476D – AUGUST 2007 – REVISED MAY 2013

Table 15. Register Address 8h'13: CHGSTATUS1 (continued)

BIT

NAME

FUNCTION (if bit = '1')

1

Fullrate

Set when the charger is in CC/CV mode.

0

PRECHG

Set during precharge.

Charger Status Register 2 Read only

Table 16. Register Address 8h'13: CHGSTATUS2

BIT

NAME

FUNCTION (if bit = '1')

1

Tout_

Set after timeout in CV phase.

ConstV

0

BAD_

Set at bad battery state.

BATT

IMON CHARGE CURRENT MONITOR

Charge current is monitored within the charger section and a proportional voltage representation of the charge

current is presented at the IMON output pin. The output voltage relationship to the actual charge current is

represented in the following graph and by the equation:

VIMON(mV) = (2.47 x ICHG)(mA)

Figure 12. IMON Voltage vs Charge Current

Note that this function is not available if there is no input at CHG_IN or if the charger is off due to the input at

CHG_IN being outwith the operating voltage range.

LDO Information

OPERATIONAL INFORMATION

The LP3918 has 7 LDO's of which 3 are enabled by default, LDO's 1,2 and 3 are powered up during the power

up sequence. LDO4, 5 and 6 are separately, externally enabled and will follow LDO2 in start up if their respective

enable pin is pulled high. LDO2, LDO3 and LDO7 can be enabled/disabled via the serial interface.

LDO2 must remain in regulation otherwise the device will power down. While LDO1 is enabled this must also be

in regulation for the device to remain powered. If LDO1 is disabled via I2C interface the device will not shut

down.

Copyright © 2007–2013, Texas Instruments Incorporated

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