LTC4012 datasheet(26/52 Pages) AD

26 / 52 page

LTC4162-L

Rev A

For more information www.analog.com

OPERATION

−10

TEMPERATURE(°C)

4.00

4.05

4.10

4.15

4.20

4.25

4162L F01a

Default JEITA Charge Voltage Proﬁle

−10

TEMPERATURE(°C)

4162L F01b

Default JEITA Charge Current Proﬁle

Servo Voltage (V

-V

)

CSP CSN

Figure 1. Default JEITA Temperature Profile Gives A Graphical

Representation of the Seven JEITA Regions, the Six Breakpoint

and the Default Values

Battery Charger Termination and Full Charge

Indication (C/x)

The LTC4162 supports several battery charge termination

methods.

Ifenabled,amaximumelapsedchargetimetimerisstarted

at the beginning of each charge cycle and, upon achieving

constant_voltage regulation, a constant-voltage timer is

also started. At the expiration of either of these timers,

charging of the battery will discontinue and no more

current will be delivered. The elapsed time timer expires

when tchargetimer reaches max_charge_time and the

constant-voltage timer expires in constant_voltage when

tcvtimer reaches max_cv_time. Default max_cv_time is

14400 seconds (4 hours). To set different timer expira-

tion values, max_charge_time and max_cv_time are both

adjustable. The resolution of max_cv_time is 1 second/

LSB and for max_charge_time it is 1 minute/LSB.

tcvtimer can be read back to determine the cummulative

time in constant_voltage regulation. max_cv_time is a 16

bit unsigned value ranging from 0 to 65535 seconds (~18

hours). tchargetimer, the total charge time safety timer,

can be read back at any time to determine the elapsed time

sincethebeginningofthischargecycle.max_charge_time

is a 16 bit unsigned value at 1 minute per LSB ranging

from 0 to 65535 minutes (~45 days). The tchargetimer

is disabled when max_charge_time is left at its default

value of 0. To enable the tchargetimer write a non 0 value

to max_charge_time.

max_charge_time_faultindicatesthatcharginghastermi-

nated due to tchargetimer reaching max_charge_time and

timer_term indicates that charging has terminated due to

tcvtimer reaching max_cv_time. The max_charge_time_

fault will persist until either the battery voltage drops to

less than 35% of its target voltage setting, whereupon a

new charge cycle begins and the tchargetimer resets, or

a power cycle occurs resetting the entire charger state

machine. A normal termination such as timer_term

or c_over_x_term also resets tchargetimer. Finally, the

max_charge_time_fault is cleared upon abnormal condi-

tionssuchastheinputvoltagefallingbelowtheBATSENS+

pin voltage, suspend_charger or if any another system

fault occurs: not intvcc_gt_2p8v, not vin_gt_4p2v, not

vin_gt_vbat, thermal_shutdown, no_rt or cell_count_err.

Alternately, if en_c_over_x_term is set, the LTC4162 will

also terminate charging once constant_voltage is reached

and ibat has naturally dropped to the c_over_x_threshold.

The default c_over_x_threshold value of c_over_10 is a

good indication that the battery has reached a nearly full

state of charge. The c_over_x_threshold is adjustable via

the I2C port. If en_c_over_x_term is set, charging will

terminate at the first of either c_over_x_term, timer_term

or max_charge_time_fault. The constant_voltage timer

LTC4012 Datasheet(PDF) 26 Page - Analog Devices

LTC4012 Datasheet(HTML) 26 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52

Datasheet Download

Link URL