Typical operating characteristics – Rainbow Electronics MAX1774 User Manual
Page 8
MAX1774
Dual, High-Efficiency, Step-Down
Converter with Backup Battery Switchover
8
_______________________________________________________________________________________
Typical Operating Characteristics
(Circuit of Figure 1, V
IN
= +5V, V
INC
= +3.3V, T
A
= +25°C, unless otherwise noted.)
100
0
1
10
100
1000
10,000
MAIN EFFICIENCY vs. LOAD
20
MAX1774-01
LOAD (mA)
EFFICIENCY (%)
40
60
80
70
50
30
10
90
V
IN
= +5V
V
IN
= +15V
V
IN
= +3.3V
V
IN
= +18V
V
IN
= +12V
V
MAIN
= 3.3V
90
0
1
1000
100
10
CORE EFFICIENCY vs. LOAD
30
10
70
50
100
40
20
80
60
MAX1774-02
LOAD (mA)
EFFICIENCY (%)
V
IN
= +5V
V
IN
= +2.7V
V
IN
= +3.3V
V
CORE
= 1.8V
100
0
0.01
0.1
1
10
100
BACKUP EFFICIENCY vs. LOAD
20
MAX1774-03
LOAD
(mA)
EFFICIENCY (%)
40
60
80
70
50
30
10
90
V
BBATT
= +0.8V
V
BBATT
= +1.0V
V
BBATT
= +2.5V
V
MAIN
= 3.3V
MAIN SWITCHING WAVEFORMS
(HEAVY LOAD 1A)
MAX1774-07
5
µ
s/div
4V
LX
5V/div
0
20mV
0
-20mV
500mA
0
1000mA
1500mA
V
MAIN
(AC-COUPLED)
20mV/div
IL1
500mA/div
V
REF
ACCURACY vs. TEMPERATURE
MAX1774-04
-2.0
-1.5
-0.5
-1.0
1.0
1.5
0.5
0
2.0
V
REF
ACCURACY (%)
-40
0
20
-20
40
60
80
100
TEMPERATURE (
°
C)
V
REF
ACCURACY (%)
-1.6
-1.8
-2.0
-1.2
-1.4
-0.8
-1.0
-0.6
-0.4
-0.2
0
0
20
30
10
40
50
60
70
80
REFERENCE LOAD REGULATION
MAX1774-05
I
REF
(
µ
A)
MAIN SWITCHING WAVEFORMS
(LIGHT LOAD 100mA)
MAX1774-06
5
µ
s/div
5V
LX
5V/div
0
40mV
20mV
0
V
MAIN
(AC-COUPLED)
20mV/div
I
LI
500mA/div
-20mV
500mA
0