MAX1970/MAX1971/MAX1972
Dual, 180° Out-of-Phase, 1.4MHz, 750mA Step-
Down Regulator with POR and RSI/PFO
_______________________________________________________________________________________
7
100
0
0.01 0.1 1
EFFICIENCY vs. LOAD CURRENT
20
10
MAX1970TOC01
LOAD CURRENT (A)
EFFICIENCY (%)
40
30
60
70
50
80
90
V
OUT2
= 2.5V
V
OUT1
= 3.3V
MAX1970/
MAX1972
V
IN
= 5.0V
V
OUT1
= 1.8V
V
OUT2
= 1.5V
100
0
0.01 0.1 1
EFFICIENCY vs. LOAD CURRENT
20
10
MAX1970TOC02
LOAD CURRENT (A)
EFFICIENCY (%)
40
30
60
70
50
80
90
V
OUT2
= 2.5V
V
OUT1
= 3.3V
MAX1971
V
IN
= 5.0V
V
OUT1
= 1.8V
V
OUT2
= 1.5V
100
0
0.01 0.1 1
EFFICIENCY vs. LOAD CURRENT
20
10
MAX1970TOC03
LOAD CURRENT (A)
EFFICIENCY (%)
40
30
60
70
50
80
90
V
OUT2
= 2.5V
MAX1970/
MAX1972
V
IN
= 3.3V
V
OUT1
= 1.8V
V
OUT2
= 1.5V
100
0
0.01 0.1 1
EFFICIENCY vs. LOAD CURRENT
20
10
MAX1970TOC04
LOAD CURRENT (A)
EFFICIENCY (%)
40
30
60
70
50
80
90
V
OUT2
= 2.5V
MAX1971
V
IN
= 3.3V
V
OUT1
= 1.8V
V
OUT2
= 1.5V
500
0
0 400 800700600500300200100
INPUT CURRENT vs. OUTPUT CURRENT
100
50
MAX1970TOC05
OUTPUT CURRENT (mA)
INPUT CURRENT (mA)
200
150
300
350
250
400
450
V
OUT1
= 3.3V
V
IN
= 5.0V
V
OUT2
= 2.5V
V
OUT1
= 1.8V
V
OUT2
= 1.5V
MAX1970/MAX1972
1.22
1.17
01020155
REFERENCE VOLTAGE vs.
REFERENCE LOAD CURRENT
1.18
MAX1970TOC06
REFERENCE LOAD CURRENT (µA)
REFERENCE VOLTAGE (V)
1.19
1.20
1.21
1.60
0.40
2.5 4.0 5.55.04.53.53.0
OSCILLATOR FREQUENCY
vs. INPUT VOLTAGE
0.60
MAX1970TOC07
INPUT VOLTAGE (V)
OSCILLATOR FREQUENCY (MHz)
0.80
1.20
1.00
1.40
T
A
= +85°C
MAX1970/MAX1972
T
A
= +25°C
T
A
= -40°C
T
A
= +85°C
MAX1971
T
A
= +25°C
T
A
= -40°C
3
-3
0 400 800600200
CHANGE IN OUTPUT VOLTAGE
vs. LOAD CURRENT
-2
MAX1970TOC08
LOAD CURRENT (mA)
CHANGE IN OUTPUT VOLTAGE (mV)
-1
1
0
2
V
OUT1
= 3.3V
V
OUT1
= 1.8V
V
OUT2
= 1.5V
V
OUT2
= 2.5V
V
IN
= 5.0V
MAX1970/MAX1972
Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
