Starting A Charge Cycle

Either of two events starts a charge cycle (see Figure 4):

2. Voltage at the BAT pin falling through the maximum

±5%.

If the battery is within the configured temperature and

voltage limits, the IC begins fast charge. The valid bat-

If the battery voltage or temperature is outside of these

limits, the IC pulse-trickle charges until the next new

charge cycle begins.

Fast charge continues until termination by one or more of

the five possible termination conditions:

∆V)

4

bq2002/F

Corresponding

Fast-Charge

Rate

TM

Termination

Typical Fast-Charge

and Top-Off

Time Limits

(minutes)

Typical PVD

and -

∆V Hold-Off

Time (seconds)

Top-Off

Rate

Pulse-

Trickle

Rate

Pulse-

Trickle

Period

(ms)

bq2002

bq2002F

C/2

Mid

PVD

160

160

600

C/32

C/64

9.15

1C

Low

PVD

80

100

300

C/16

C/64

18.3

2C

High

-

∆V

40

40

150

Disabled

C/32

18.3

Notes:

Tolerance on all timing is

±20%.

Table 1. Fast-Charge Safety Time/Hold-Off Table

TD2002F1.eps

Fast Charging

VCC = 0

Fast Charging

CC Output

LED

s

s

Charge initiated by application of power

Charge initiated by battery replacement

Pulse-Trickle

Top-Off

(optional)

286

See

Table 1

s

286

4576

Figure 4. Charge Cycle Phases