Low-Cost, Multichemistry Battery-
Charger Building Block
MAX1772
Typical Operating Characteristics (continued)
(Circuit of Figure 1a, V
DCIN
= 20V, T
A
= +25°C, unless otherwise noted.)
OUTPUT V/I CHARACTERISTICS
MAX1772 toc10
BATT VOLTAGE ERROR vs. VCTL
0.18
BATT VOLTAGE ERROR (%)
0.16
0.14
0.12
0.10
0.08
0.06
0.04
0.02
0
CELL = 4
REFIN = 3.3V
NO LOAD
MAX1772 toc11
0.050
0.045
BATT VOLTAGE ERROR (%)
0.040
0.035
0.030
0.025
0.020
0.015
0.010
0.005
0
0
CELL = 2
CELL = 3
VCTL = 0
ICTL = 3.3V
CELL = 4
0.20
500 1000 1500 2000 2500 3000 3500 4000
BATT CURRENT (mA)
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
VCTL/REFIN (%)
CURRENT SETTING ERROR vs. ICTL
MAX1772 toc12
ICHG ERROR vs. BATT LOAD CURRENT
3.5
3.0
ICHG ERROR (%)
VCTL = 0
ICTL = 3.3V
CELL = 4
MAX1772 toc13
5
REFIN = 3.3V
4.0
CURRENT SETTING ERROR (%)
4
3
2.5
2.0
1.5
1.0
2
1
BATT > 2V
0
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
ICTL/REFIN (%)
0.5
0
0
500 1000 1500 2000 2500 3000 3500 4000
BATT LOAD CURRENT (mA)
_______________________________________________________________________________________
9