Max1870a step-up/step-down li+ battery charger, Typical operating characteristics (continued) – Rainbow Electronics MAX1870A User Manual
Page 10
MAX1870A
Step-Up/Step-Down
Li+ Battery Charger
10
______________________________________________________________________________________
Typical Operating Characteristics (continued)
(Circuit of Figure 1, V
DCIN
= 16V, CELLS = REFIN, V
CLS =
V
REF
, V
ICTL
= V
REFIN
= 3.3V, T
A
= +25°C, unless otherwise noted.)
EFFICIENCY vs. BATTERY VOLTAGE
MAX1870A toc07
BATTERY VOLTAGE (V)
EFFICIENCY (%)
12
4
8
16
14
6
10
65
70
75
80
90
85
95
60
2
18
V
IN
=
12V
V
IN
=
16V
EFFICIENCY vs. CHARGE CURRENT
MAX1870A toc08
CHARGE CURRENT (A)
EFFICIENCY (%)
2.0
1.5
0.5
1.0
65
70
75
80
90
85
95
100
60
0
2.5
V
BATT
=
16.8V
V
BATT
=
8.4V
V
BATT
=
12.6V
BATTERY VOLTAGE ERROR IN CV MODE
MAX1870A toc09
CHARGE CURRENT (A)
BATTERY VOLTAGE ERROR (%)
2.0
1.5
0.5
1.0
-0.4
-0.3
-0.2
-0.1
0.2
0
0.4
0.1
0.3
0.5
-0.5
0
2.5
V
BATT
=
16.8V
V
BATT
=
12.6V
V
BATT
=
8.4V
BATTERY VOLTAGE ERROR vs. VCTL
MAX1870Atoc10
VCTL (V)
BATTERY VOLTAGE ERROR (%)
3.00
2.00
1.00
0.05
0.10
0.15
0.20
0.25
0
0
4.00
CHARGE-CURRENT ERROR vs. ICTL
MAX1870Atoc11
V
ICTL
(V)
CHARGE-CURRENT ERROR (mA)
2.50
2.00
1.50
1.00
0.50
-70
-60
-50
-40
-30
-20
-10
0
10
20
-80
0
3.00
CHARGE-CURRENT ERROR
vs. BATTERY VOLTAGE
MAX1870Atoc12
V
BATT
(V)
CHARGE-CURRENT ERROR (%)
15
10
5
-10
-5
0
5
10
15
-15
0
20
I
CHG
=
0.15A
I
CHG
=
2.4A
I
CHG
=
1.9A
I
CHG
=
1.4A
IINP ERROR vs. SYSTEM LOAD
MAX1870Atoc13
SYSTEM LOAD (A)
IINP ERROR (mV)
3.0
2.0
0.5
1.5
3.5
2.5
1.0
-4
-2
0
2
4
-3
-1
1
3
5
-5
0
4.0
INPUT CURRENT-LIMIT ERROR
vs. SYSTEM CURRENT
MAX1870A toc14
SYSTEM CURRENT (A)
INPUT CURRENT-LIMIT ERROR (%)
3.0
2.5
0.5
1.5
1.0
2.0
-8
-6
-4
-2
4
0
8
2
6
10
-10
0
3.5
V
BATT
=
16V
V
BATT
=
14V
V
BATT
=
10V
V
BATT
=
8V
V
BATT
=
6V
V
BATT
=
12V
INPUT CURRENT-LIMIT ERROR
vs. CLS
MAX1870A toc15
V
CLS
(V)
INPUT CURRENT-LIMIT ERROR (mA)
4.00
2.00
1.00
3.00
-250
-200
-150
-100
50
-50
150
0
100
200
-300
0
5.00