BQ2007 datasheet(6/16 Pages) TI

6 / 16 page

is used for all the odd percentage charge indications to

assure a monotonic charge status display.

When MULT is pulled up to VCC, the bq2007 charge

status monitor directly displays 1

32 of the charge safety

timer as a percentage of full charge. This method is rec-

ommended over the voltage-based method when charg-

ing fixed-cell packs where the battery terminal voltages

can vary greatly between packs. This method offers an

accurate charge status indication when the battery is

fully discharged. When using the timer-based method,

discharge-before-charge is recommended.

During discharge with MULT pulled down to VSS, the

charge status monitor indicates the percentage of the bat-

tery voltage by comparing VBAT to the internal discharge

voltage reference thresholds.

In BCD format, the dis-

charge thresholds V80,V60,V40, and V20 correspond to a

battery charge state indication of 90%, 70%, 50%, and 30%,

respectively.

In bargraph format, the same discharge

thresholds correspond to a battery charge state indication

of 90%, 60%, 40%, and 30%, respectively. Differences in

the battery charge state indications are due to the finer

granularity of the BCD versus the bargraph format.

During discharge and when MULT is pulled up to VCC,

the state-of-charge monitor BCD format displays the

discharge condition, letter “d,” whereas the bargraph for-

mat has no indication.

The charge status display is blanked during the charge

pending state and when the battery pack is removed.

Charge Status Display Modes

The bq2007 charge status monitor can be displayed in

two modes summarized in Table 3. The display modes

are a seven-segment monotonic bargraph or a seven-

segment BCD single-digit format. When QDSEL is

pulled down to VSS, pins SEGA–G drive the decoded seven

segments of a single BCD digit display, and when QDSEL

is pulled up to VCC, pins SEGA–G drive the seven seg-

ments of a bargraph display.

In the bargraph display mode, outputs SEGA–G allow op-

tions for a three-segment to seven-segment bargraph dis-

play. The three-segment charge status display uses out-

puts SEGB,SEGD, and SEGF for 30%, 60%, and 90%

charge indications, respectively. The four-segment charge

status display uses outputs SEGA, SEGC, SEGD,and

SEGE for 20%, 40%, 60%, and 80% indications,

respectively. The seven-segment charge status monitor

uses all segments.

The BCD display mode drives pins SEGA–G with the

decoded seven-segment single-digit information. The

display indicates in 10% increments from a BCD zero

count at charge initiation to a BCD nine count indicat-

ing 90% charge capacity. Charge completion is indicated

by the letter “F,” a fault condition by the letter “E,” and

the discharge condition by the letter “d.” See Table 3.

bq2007

Mode

Charge Action State

LED1

LED2

DIS

ALARM

DSEL1 = L

DSEL2 = L

(Mode 1)

Battery absent

0000

Charge pending (temp. limit, low voltage)

Flashing

Discharge in progress

0110

Charging

Flashing

Charge complete

High tone

Fault (low-voltage time-out)

High tone

DSEL1 = H

DSEL2 = L

(Mode 2)

Battery absent

0000

Discharge in progress, pending

1110

Charging

1000

Charge complete

High tone

Fault (low-voltage time-out)

High tone

DSEL1 = L

DSEL2 = H

(Mode 3)

Battery absent

0000

Charge pending (temp. limit, low voltage)

Flashing

Discharge in progress

Flashing

Charging

Flashing

Charge complete

High tone

Fault (low-voltage time-out)

High tone

Note:

1 = on; 0 = off; L = pulled down to VSS; H = pulled up to VCC.

Table 2. bq2007 Charge Status Display Summary

BQ2007 Datasheet(PDF) 6 Page - Texas Instruments

BQ2007 Datasheet(HTML) 6 Page - Texas Instruments

Html Pages

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

Datasheet Download

Link URL