Typical operating characteristics (continued) – Rainbow Electronics MAX8903A User Manual
Page 7
MAX8903A
2A 1-Cell Li+ DC-DC Charger for USB*
and Adapter Power
_______________________________________________________________________________________
7
Typical Operating Characteristics (continued)
(T
A
= +25°C, unless otherwise noted.)
0
1.0
0.5
2.0
1.5
3.0
2.5
3.5
4.5
4.0
5.0
0
4
6
8
2
10
12
14
16
18
SYS VOLTAGE
vs. DC VOLTAGE
MAX8903A toc13
DC VOLTAGE (V)
SYS VOLTAGE (V)
V
DC
RISING
V
DC
FALLING
3.80
3.90
4.10
4.00
4.30
4.40
4.20
4.50
0
0.3
0.5
0.1
0.7
0.9
1.1
1.3
1.5
SYS VOLTAGE
vs. SYS OUTPUT CURRENT, DC INPUT
MAX8903A toc14
SYS OUTPUT CURRENT (A)
SYS VOLTAGE (V)
V
DC
= 5.75V
USB AND DC UNCONNECTED
V
BATT
= 4V
4.355
4.365
4.360
4.375
4.370
4.380
4.385
4.395
4.390
4.400
0
100
50
200
150
300
250
400
350
500
450
SYS VOLTAGE
vs. SYS OUTPUT CURRENT, USB INPUT
MAX8903A toc15
SYS OUTPUT CURRENT (mA)
SYS VOLTAGE (V)
V
USB
= 5V
0
1
2
3
4
5
6
0
4
2
6
8
10
12
14
16
18
VL VOLTAGE vs. DC VOLTAGE
MAX8903A toc16
DC VOLTAGE (V)
VL VOLTAGE (V)
CHARGE PROFILE—1400mAh BATTERY
ADAPTER INPUT—1A CHARGE
MAX8903A toc17
TIME (min)
V
BAT
(V)
I
BAT
(A)
120
100
60
80
40
20
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
0
0.2
0.4
0.6
0.8
1.0
1.2
0.0
0
140
V
BAT
I
DC
SET TO 1A
I
BAT
SET TO 2A
I
BAT
CHARGE PROFILE—1400mAh BATTERY
USB INPUT—500mA CHARGE
TIME (min)
V
BAT
(V)
I
BAT
(A)
180
160
120 140
40 60 80 100
20
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0
0.050
0.100
0.150
0.200
0.250
0.300
0.350
0.400
0.450
0.500
0
0
200
V
BAT
I
BAT
MAX8903A toc18
I
USB
SET TO 500mA
I
BAT
SET TO 2A
200ns/div
DC SWITCHING WAVEFORMS—LIGHT LOAD
20mV/div
AC-COUPLED
MAX8903A toc19
500mA/div
0A
5V/div
0V
V
OUT
V
LX
I
LX
R
SYS
= 44
Ω
DC SWITCHING
WAVEFORMS—HEAVY LOAD
MAX8903A toc20
200ns/div
V
LX
V
OUT
I
LX
5V/div
0V
20mV/div
AC-COUPLED
500mA/div
0A
R
SYS
= 5
Ω