LP3918

SNVS476D – AUGUST 2007 – REVISED MAY 2013

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Thermal regulation

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Charge Current Monitor Output

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Programmable charge current 50mA - 950mA with 50mA steps

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Default CC mode current 100mA

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Pre-charge current fixed 50mA

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Termination voltage 4.1V, 4.2V (default), 4.3V, and 4.4V, accuracy better than +/- 0.5% (typ)

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Restart level 50mV, 100mV, 150mV (default) and 200mV below Termination voltage

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End of Charge 0.1C (default), 0.15C, 0.2C and 0.25C

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Programmable Enable Control

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Safety timer

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Input voltage operating range 4.5V - 6.0V

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LDO mode on LP3918TL-L option.

REGULATORS

7 Low dropout linear regulators provide programmable voltage outputs with current capabilities of 80mA, 150mA

and 300mA as given in the table below. LDO1, LDO2 and LDO3 are powered up by default with LDO1 reaching

regulation before LDO2 and LDO3 are started. LDO1, LDO3 and LDO7 can be disabled/enabled via the serial

interface. During power up LDO1 and LDO2 must reach their regulation voltage detection point for the device to

power up and remain powered. LDO4, LDO5 and LDO6 have external enable pins and may power up following

LDO2 as determined by their respective enable. Under voltage lockout oversees device start up with preset level

of 2.85V(typ).

POWER SUPPLY CONFIGURATIONS

At PMU start up, LDO1, LDO2 and LDO3 are always started with their default voltages. The start up sequence of

the LDO's is given below.

Startup Sequence

LDO1 -> LDO2 -> LDO3

LDO's with external enable control (LDO4, LDO5, LDO6) start immediately after LDO2 if enabled by logic high at

their respective control inputs.

LDO7 (and LDO1 and 3) may be programmed to enable/disable once PS_HOLD has been asserted.

Default voltages for the LDOs are shown in Table 1 and Table 2 shows the voltages that may be programmed

via the Serial Interface.

DEVICE PROGRAMMABILITY

An I2C compatible Serial Interface is used to communicate with the device to program a series of registers and

also to read status registers. These internal registers allow control over LDO outputs and their levels. The

charger functions may also be programmed to alter termination voltage, end of charge current, charger restart

voltage, full rate charge current, and also the charging mode.

This device internal logic is powered from LDO2.

Table 1. LDO Default Voltages

LDO

Function

mA

Default Voltage (V)

Startup Default

Enable Control

1

CORE

300

1.8

ON

SI

2

DIGI

300

3.0

ON

-

3

ANA

80

3.0

ON

SI

4

TCXO

80

3.0

OFF

TCXO_EN

5

RX

150

3.0

OFF

RX_EN

6

TX

150

3.0

OFF

TX_EN

7

GP

150

3.0

OFF

SI

4

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