Datasheet

10 Maxim Integrated
1.2A Switch-Mode Li+ Chargers with ±22V Input
Rating and JEITA Battery Temperature Monitoring
MAX8900A/MAX8900B/MAX8900C
Typical Operating Characteristics (continued)
(Circuit of Figure 1, V
IN
= 6V, V
BAT
= 3.6V, T
A
= +25NC, unless otherwise noted.)
THM NORMAL TO COLD CURRENT
FOLDBACK (T2) TO COLD SHUTOFF (T1)
MAX8900A toc16
2V/div
0V
0A
0mA
3.6V
600mA
1200mA (T2 < T < T3)
1V/div
200mA/div
I
BAT
V
BAT
V
THM
60% OF AVL (T2)
74.5% OF AVL (T1)
20ms/div
THM NORMAL TO HOT VOLTAGE FOLDBACK
(T3) TO HOT SHUTOFF (T4) THRESHOLD
MAX8900A toc17
2V/div
0A
4.075V
4.2V
0V
10I RESISTOR LOAD
2V/div
200mA/div
I
BAT
V
BAT
V
THM
34.7% OF AVL (T3)
22.5% OF AVL (T4)
20ms/div
CHARGER ENABLE
MAX8900A toc18
5V/div
0A
1.2A
5V/div
5V/div
1A/div
I
BAT
V
LX
V
PVL
400µs/div
V
CEN
EFFICIENCY vs. BATTERY VOLTAGE
(CONSTANT-CURRENT MODE)
MAX8900A toc19
V
BAT
(V)
EFFICIENCY (%)
4.03.53.0
67
69
71
73
75
77
79
81
83
85
V
IN
= 5.0V
I
BAT
= 100mA
65
2.5 4.5
EFFICIENCY vs. BATTERY VOLTAGE
(CONSTANT-CURRENT MODE)
MAX8900A toc20
V
BAT
(V)
EFFICIENCY (%)
4.34.13.93.73.53.33.12.92.7
70
75
80
85
90
95
65
2.5 4.5
I
BAT
= 500mA
I
BAT
= 800mA
I
BAT
= 1200mA
V
IN
= 5.0V
MAX8900A/
MAX8900B
EFFICIENCY vs. CHARGE CURRENT
(CONSTANT-CURRENT MODE)
MAX8900A toc21
I
BAT
(A)
EFFICIENCY (%)
1.00.5
70
75
80
85
90
95
65
0 1.5
V
IN
= 5.0V
V
BAT
= 3.0V
V
BAT
= 3.6V
V
BAT
= 4.0V
EFFICIENCY vs. BATTERY VOLTAGE
(CONSTANT-CURRENT MODE, I
BAT
= 1200mA)
MAX8900A toc22
V
BAT
(V)
EFFICIENCY (%)
4.34.13.93.73.53.33.12.92.7
70
75
80
85
90
95
65
2.5 4.5
I
BAT
= 1200mA, R
SETI
= 2.87kI
V
IN
= 5V
V
IN
= 8V
V
IN
= 7V
V
IN
= 6V
V
IN
= 8.5V
MAX8900A/MAX8900B