Typical operating characteristics – Rainbow Electronics MAX849 User Manual
Page 5
MAX848/MAX849
1-Cell to 3-Cell, High-Power,
Low-Noise, Step-Up DC-DC Converters
_______________________________________________________________________________________
5
Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
100
90
40
0.1
1
10
100
1000
MAX849
EFFICIENCY vs. LOAD CURRENT
(V
OUT
= 3.3V)
50
MAX848/9 TOC-01
LOAD CURRENT (mA)
EFFICIENCY (%)
60
70
80
V
IN
= 2.4V
PFM
PWM
V
IN
= 0.9V
V
IN
= 1.2V
100
90
40
30
0.1
1
10
100
1000
MAX849
EFFICIENCY vs. LOAD CURRENT
(V
OUT
= 5V)
50
MAX848/9 TOC-02
LOAD CURRENT (mA)
EFFICIENCY (%)
60
70
80
V
IN
= 1.2V
V
IN
= 2.4V
V
IN
= 3.6V
PFM
PWM
70
60
0.1
1
10
100
1000
MAX848
EFFICIENCY vs. LOAD CURRENT
(V
OUT
= 3.3V)
80
MAX848/9 TOC-03
LOAD CURRENT (mA)
EFFICIENCY (%)
90
100
V
IN
= 2.4V
V
IN
= 1.2V
V
IN
= 0.9V
PFM
PWM
14
0
0
2
3
1
4
6
NO-LOAD BATTERY CURRENT
vs. INPUT VOLTAGE
4
12
MAX848/9 TOC-04
INPUT VOLTAGE (V)
INPUT CURRENT (mA)
5
8
2
10
6
T
A
= +85°C
T
A
= +25°C
T
A
= -40°C
1.252
1.248
-40
0
-20
20
60
100
80
REFERENCE VOLTAGE
vs. TEMPERATURE
1.249
1.251
MAX848/9 TOC-07
TEMPERATURE (°C)
REFERENCE VOLTAGE (V)
40
1.250
18
14
0
0
2
1
3
6
5
SHUTDOWN CURRENT
vs. INPUT VOLTAGE
4
16
12
MAX848/9 TOC-05
SHUTDOWN CURRENT (
µ
A)
4
8
2
10
6
T
A
= +85°C
T
A
= +25°C
T
A
= -40°C
INCLUDES ALL EXTERNAL
COMPONENT LEAKAGES.
CAPACITOR LEAKAGE
DOMINATES AT
T
A
= +85°C
INPUT VOLTAGE (V)
2.0
1.8
1.6
0.6
0.01
0.1
1
10
100
1000
START-UP VOLTAGE vs. LOAD CURRENT
(V
OUT
= 3.3V, PWM MODE)
0.8
MAX848/9 TOC-06
LOAD CURRENT (mA)
START-UP VOLTAGE (V)
1.0
1.2
1.4
T
A
= +85°C
T
A
= +25°C
T
A
= -40°C
1.252
1.238
0
20
10
30
50
60
70
80
REFERENCE VOLTAGE
vs. REFERENCE CURRENT
1.242
1.250
MAX848/9 TOC-08
REFERENCE CURRENT (
µ
A)
REFERENCE VOLTAGE (V)
40
1.246
1.240
1.248
1.244
0.25
-0.25
0.1875
0.6875
0.4375
0.9375
ADC LINEARITY ERROR
vs. FULL-SCALE INPUT VOLTAGE
0.15
MAX848/9 TOC-09
FULL-SCALE INPUT VOLTAGE (V)
LINEARITY ERROR (%FS)
-0.15
0.05
-0.05
AIN1
AIN2