MAX712 Maxim, MAX712 Datasheet - Page 3

• Manufacturer Part Number: MAX712
• Description: NiCd/NiMH Battery Fast-Charge Controllers
• Manufacturer: Maxim

ELECTRICAL CHARACTERISTICS (continued)
(I
BATT-, not GND.)
Note 1: The MAX712/MAX713 are powered from the V+ pin. Since V+ shunt regulates to +5V, R1 must be small enough to allow at
Note 2: Offset voltage of THI and TLO comparators referred to TEMP.
Note 3: t
Note 4: This specification can be violated when attempting to charge more or fewer cells than the number programmed. To ensure
(T
__________________________________________Typical Operating Characteristics
V
FASTCHG Low Current
FASTCHG High Current
A/D Input Range (Note 4)
100
+ = 10mA, T
A
0.1
10
1
= +25°C, unless otherwise noted.)
1.95
least 5mA of current into the V+ pin.
proper voltage-slope fast-charge termination, the (maximum battery voltage) ÷ (number of cells programmed) must fall
within the A/D input range.
CURRENT ERROR-AMPLIFIER
A
1.97
is the A/D sampling interval (Table 3).
TRANSCONDUCTANCE
VOLTAGE ON CC PIN (V)
A
-10
-20
PARAMETER
20
10
0
1.99
= T
FASTCHG = 0V, V+ = 5V
1k
MIN
_______________________________________________________________________________________
FREQUENCY RESPONSE (with 15pF)
BATT-
V
GND
2.01
+
-
IN
CURRENT-SENSE AMPLIFIER
to T
CURRENT-
10k
SENSE
AMP
MAX
2.03
FREQUENCY (Hz)
, unless otherwise noted. Refer to Typical Operating Circuit . All measurements are with respect to
BATT-
CC
100k
V
2.05
OUT
+
-
FASTCHG = 0V
C2 = 15pF
1M
A
5.6
5.4
4.8
4.6
5.8
5.2
5.0
4.4
4.2
4.0
V
V
V
Battery voltage ÷ number of cells programmed
0
FASTCHG
FASTCHG
DRV NOT SINKING CURRENT
10M
SHUNT-REGULATOR VOLTAGE
10
CURRENT INTO V+ PIN (mA)
40
0
-40
-80
-120
= 0.4V
= 10V
20
vs. CURRENT
DRV SINKING CURRENT
CONDITIONS
30
Fast-Charge Controllers
40
50
NiCd/NiMH Battery
-10
-20
60
20
10
0
10
FREQUENCY RESPONSE (with 10nF)
1.6
0.8
0.4
1.4
1.2
1.0
0.6
0.2
CURRENT-SENSE AMPLIFIER
ALPHA THERMISTOR PART No. 13A1002
0
100
STEINHART-HART INTERPOLATION
FREQUENCY (Hz)
MIN
1.4
10
2
BATTERY TEMPERATURE( C)
20
FASTCHG = 0V
TYP
1k
C2 = 10nF
A
30
V
40
MAX
1.9
10
10k
50
40
-40
-120
0
-80
UNITS
60
mA
µA
V
35
25
20
15
10
5
0
30
3