Ad va n c e d Ch e m is t ry-In d e p e n d e n t , Le ve l 2
Ba t t e ry Ch a rg e r w it h In p u t Cu rre n t Lim it in g
MAX1645
Typ ic a l Op e ra t in g Ch a ra c t e ris t ic s (c o n t in u e d )
= 20V, T = +25°C, unless otherwise noted.)
A
(Circuit of Figure 1, V
DCIN
EFFICIENCY vs. BATTERY CURRENT
(VOLTAGE-CONTROL LOOP)
EFFICIENCY vs. BATTERY CURRENT
(CURRENT-CONTROL LOOP)
OUTPUT VI CHARACTERISTICS
100
95
90
85
80
75
70
65
60
55
50
100
95
90
85
80
75
70
65
60
55
50
0.001
0.01
0.1
A
B
A
B
1.0
ChargingVoltage() = 16,800mV
ChargingCurrent() = 3008mA
A: V
DCIN
B: V
DCIN
= 20V, ChargingVoltage() = 16.8V
= 16V, ChargingVoltage() = 8.4V
A: V
DCIN
B: V
DCIN
= 20V, V
BATT
= 16.8V
= 8.4V
= 16V, V
BATT
10
0
500 1000 1500 2000 2500 3000
BATTERY CURRENT (mA)
0
500 1000 1500 2000 2500 3000
ChargingCurrent() (CODE)
0
500 1000 1500 2000 2500 3000 3500
LOAD CURRENT (mA)
BATT VOLTAGE ERROR
vs. ChargingVoltage() CODE
CURRENT-SETTING ERROR
vs. ChargingCurrent() CODE
5
4
0.3
0.2
0.1
0
3
2
1
0
-1
-2
-3
-4
-5
-0.1
-0.2
-0.3
V
= 12.6V
I
= 0
BATT
BATT
MEASURED AT AVAILABLE CODES
MEASURED AT AVAILABLE CODES
0000
4000
8000
12000 16000 20000
0
500 1000 1500 2000 2500 3000
ChargingCurrent() (CODE)
ChargingVoltage() (CODE)
SOURCE/BATT CURRENT vs. V
BATT
WITH SOURCE CURRENT LIMIT
SOURCE/BATT CURRENT vs. LOAD CURRENT
WITH SOURCE CURRENT LIMIT
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
I
IN
I
IN
I = 2A
LOAD
V
= 2V
= 40mΩ
= 16.8V
CLS
V = 2V
R
CLS
CSS
I
BATT
I
BATT
R = 40mΩ
CSS
V
BATT
ChargingVoltage() = 18,432mV
ChargingCurrent() = 3008mA
SOURCE CURRENT LIMIT = 2.5A
SOURCE CURRENT LIMIT = 2.5A
ChargingCurrent() = 3008mA
ChargingVoltage() = 18,432mV
0
2
4
6
8
10 12 14 16 18 20
(V)
0
0.5
1.0
1.5
2.0
2.5
V
LOAD CURRENT (A)
BATT
_______________________________________________________________________________________
9
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
