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.)
LDO LINE REGULATION
MAX1772 toc05
REF VOLTAGE LOAD REGULATION
MAX1772 toc06
REF VOLTAGE ERROR vs. TEMPERATURE
0.4
0.3
REF VOLTAGE ERROR (%)
0.2
0.1
0
-0.1
-0.2
-0.3
V
ICTL
= 0V
V
VCTL
= 0V
NO LOAD
V
REF
= 4.096V
MAX1772 toc07
1.0
0.8
0.6
0.4
LDO ERROR (%)
V
LDO
= 5.40V
0.20
0.15
0.10
REF ERROR (%)
0.05
0
-0.05
-0.10
-0.15
-0.20
V
VCTL
= 0V
V
ICTL
= 3.3V
CELL = 4
V
REF
= 4.096V
0.5
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
8
12
16
20
24
28
DCIN (V)
-0.4
-0.5
0
50 100 150 200 250 300 350 400 450 500
REF CURRENT (μA)
-40
-15
10
35
60
85
TEMPERATURE (°C)
EFFICIENCY vs. BATTERY CURRENT
(VOLTAGE CONTROL LOOP)
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
0
0.1
1
10
100
1000
10,000
BATT CURRENT (mA)
V
VCTL
= 0V
V
ICTL
= 3.3V
V
REFIN
= 3.3V
CELL = 4
CELL = 3
CELL = 2
MAX1772 toc08
EFFICIENCY vs. BATTERY CURRENT
(CURRENT CONTROL LOOP)
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
0
100
1000
BATT CURRENT (mA)
10,000
V
VCTL
= 0V
V
ICTL
= 3.3V
V
REFIN
= 3.3V
CELL = 3
CELL = 4
CELL = 2
MAX1772 toc09
100
100
8
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
