NiCd/NiMH Battery

Fast-Charge Controllers

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7

Table 2. Programming the Number

of Cells

Table 3. Programming the Maximum

Charge Time

CONTROL LOGIC

+5V SHUNT

REGULATOR

TIMER

PGM2

PGM3

V+

BATT-

BATT-

UNDER_VOLTAGE

BATT-

DRV

V+

REF

100k

Ω

100k

Ω

N

HOT

∆V_DETECT

TIMED_OUT

BATT-

FASTCHG

GND

CC

BATT-

GND

CELL_VOLTAGE

INTERNAL IMPEDANCE OF PGM0–PGM3 PINS

FAST_CHARGE

POWER_ON_RESET

IN_REGULATION

VLIMIT

BATT+

PGM0

PGM1

PGM2

PGM3

PGMx

THI

TEMP

TLO

∆V

DETECTION

TEMPERATURE

COMPARATORS

CURRENT

AND

VOLTAGE

REGULATOR

COLD

0.4V

MAX712

MAX713

Figure 1. Block Diagram

PGM1

CONNECTION

PGM0

CONNECTION

1

V+

V+

NUMBER

OF CELLS

2

Open

V+

4

BATT-

V+

3

REF

V+

6

Open

Open

5

V+

Open

8

BATT-

Open

7

REF

Open

10

Open

REF

9

V+

REF

12

BATT-

REF

11

REF

REF

14

Open

BATT-

13

V+

BATT-

16

BATT-

BATT-

15

REF

BATT-

22

V+

REF

PGM3

CONN

PGM2

CONN

22

V+

Open

33

V+

BATT-

TIMEOUT

(min)

33

V+

V+

45

Open

REF

45

Open

Open

66

Open

BATT-

66

Open

V+

90

REF

REF

90

REF

Open

132

REF

BATT-

132

REF

V+

180

BATT-

REF

180

BATT-

Open

264

BATT-

BATT-

264

BATT-

V+

21

21

21

A/D

SAMPLING

INTERVAL

(s) (tA)

21

42

42

42

42

84

84

84

84

168

168

168

168

Enabled

Disabled

Enabled

VOLTAGE-

SLOPE

TERMINATION

Disabled

Enabled

Disabled

Enabled

Disabled

Enabled

Disabled

Enabled

Disabled

Enabled

Disabled

Enabled

Disabled