LTC4075X datasheet(11/16 Pages) LINER

11 / 16 page

LTC4075/LTC4075X

4075Xf

The power supply status output (⎯P⎯W⎯R) has two states: pull-

down and high impedance. The pull-down state indicates

that power is present at either DCIN or USBIN. This output

is strong enough to drive an LED. If no power is applied at

either pin, the ⎯P⎯W⎯R pin is high impedance, indicating that

the LTC4075 lacks sufﬁcient power to charge the battery.

The pull-down state is capable of sinking up to 10mA.

The USB power status output (USBPWR) has two states:

pull-down and high impedance. The high impedance

state indicates that the LTC4075 is being powered from

the USBIN input. The pull-down state indicates that the

charger is either powered from DCIN or is in a UVLO

condition (see Table 1). The pull-down state is capable of

sinking up to 1mA.

Thermal Limiting

An internal thermal feedback loop reduces the programmed

charge current if the die temperature attempts to rise above

a preset value of approximately 105°C. This feature protects

the LTC4075 from excessive temperature and allows the

user to push the limits of the power handling capability of

a given circuit board without risk of damaging the device.

The charge current can be set according to typical (not

worst-case) ambient temperature with the assurance that

the charger will automatically reduce the current in worst-

case conditions. DFN power considerations are discussed

further in the Applications Information section.

TRICKLE CHARGE

MODE*

1/10th FULL CURRENT

CHRG STATE: PULLDOWN

SHUTDOWN

MODE

IUSBIN DROPS TO 18µA

CHRG STATE: Hi-Z

CHARGE

MODE

FULL CURRENT

CHRG STATE: PULLDOWN

CHARGE

MODE

FULL CURRENT

CHRG STATE: PULLDOWN

STANDBY

MODE

NO CHARGE CURRENT

CHRG STATE: Hi-Z

SHUTDOWN

MODE

IDCIN DROPS TO 20µA

CHRG STATE: Hi-Z

BAT > 2.9V

BAT < 2.9V

2.9V < BAT

BAT > 2.9V

BAT < 4.1V

IBAT < ITERMINATE

IN VOLTAGE MODE

IBAT < ITERMINATE

IN VOLTAGE MODE

POWER SELECTION

STANDBY

MODE

NO CHARGE CURRENT

CHRG STATE: Hi-Z

TRICKLE CHARGE

MODE*

1/10th FULL CURRENT

CHRG STATE: PULLDOWN

ENABLE

DRIVEN LOW

ENABLE

DRIVEN LOW

ENABLE

DRIVEN HIGH

DCIN POWER

REMOVED

DCIN POWER

REMOVED

USBIN POWER

REMOVED OR

DCIN POWER

APPLIED

USBIN POWER

REMOVED OR

DCIN POWER

APPLIED

DCIN POWER APPLIED

ONLY USB POWER APPLIED

STARTUP

4075 F01

ENABLE

DRIVEN HIGH

*LTC4075 ONLY

Figure 1. LTC4075 State Diagram of a Charge Cycle

OPERATIO

LTC4075X Datasheet(PDF) 11 Page - Linear Technology

LTC4075X Datasheet(HTML) 11 Page - Linear Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Datasheet Download

Link URL