Datasheet

MAX1927/MAX1928
Low-Output-Voltage, 800mA, PWM Step-Down
DC-DC Converters
_______________________________________________________________________________________ 5
MAX1927 toc01
LOAD CURRENT (mA)
EFFICIENCY (%)
10010
50
60
70
80
90
100
40
1 1000
MAX1927R
EFFICIENCY vs. LOAD CURRENT
V
IN
= 5V
V
IN
= 3.6V
V
OUT
= 3.3V
MAX1928-25
EFFICIENCY vs. LOAD CURRENT
MAX1927 toc02
LOAD CURRENT (mA)
EFFICIENCY (%)
10010
50
60
70
80
90
100
40
1 1000
V
IN
= 5V
V
IN
= 3.6V
MAX1928-18
EFFICIENCY vs. LOAD CURRENT
MAX1927 toc03
LOAD CURRENT (mA)
EFFICIENCY (%)
10010
40
50
60
70
80
90
100
30
1 1000
V
IN
= 5V
V
IN
= 2.7V
V
IN
= 3.6V
V
OUT
= 1.8V
MAX1928-15
EFFICIENCY vs. LOAD CURRENT
MAX1927 toc04
LOAD CURRENT (mA)
EFFICIENCY (%)
10010
40
50
60
70
80
90
100
30
1 1000
V
OUT
= 1.5V
V
IN
= 2.7V
V
IN
= 3.6V
V
IN
= 5V
MAX1927R
EFFICIENCY vs. LOAD CURRENT
MAX1927 toc05
LOAD CURRENT (mA)
EFFICIENCY (%)
10010
40
50
60
70
80
90
100
30
1 1000
V
OUT
= 1V
V
IN
= 2.7V
V
IN
= 3.6V
V
IN
= 5V
MAX1928-25
DROPOUT VOLTAGE vs. LOAD CURRENT
MAX1927 toc06
LOAD CURRENT (A)
DROPOUT VOLTAGE (mV)
0.90.80.6 0.70.2 0.3 0.4 0.50.1
50
100
150
200
250
300
350
400
450
500
0
0 1.0
V
IN
= 2.5V
MAX1928-18
OUTPUT VOLTAGE vs. LOAD CURRENT
MAX1927 toc07
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
900800600 700200 300 400 500100
1.72
1.74
1.76
1.78
1.80
1.82
1.84
1.86
1.88
1.90
1.70
0 1000
V
IN
= 3.6V
MAX1927 toc08
INPUT VOLTAGE (V)
INPUT CURRENT (µA)
5.04.50.5 1.0 1.5 2.5 3.0 3.52.0 4.0
50
100
150
200
250
300
350
400
0
0 5.5
NO-LOAD INPUT CURRENT
vs. INPUT VOLTAGE
OSCILLATOR FREQUENCY
vs. INPUT VOLTAGE
MAX1927 toc09
INPUT VOLTAGE (V)
OSCILLATOR FREQUENCY (MHz)
5.14.64.13.63.1
0.96
0.98
1.00
1.02
1.04
1.06
0.94
2.6 5.6
T
A
= +85°C
T
A
= +25°C
T
A
= -40°C
Typical Operating Characteristics
(Circuits of Figure 3 and 4, T
A
= +25°C, unless otherwise noted.)