Datasheet

MAX1973/MAX1974
Smallest 1A, 1.4MHz Step-Down Regulators
6 _______________________________________________________________________________________
Typical Operating Characteristics
(Circuits of Figure 2, 3, and 4; T
A
= +25°C, unless otherwise noted.)
100
0
0.01 0.1 1
EFFICIENCY vs. LOAD CURRENT
20
10
MAX1973/74 toc01
LOAD CURRENT (A)
EFFICIENCY (%)
40
30
60
70
50
80
90
V
OUT
= 2.5V
V
OUT
= 1V
V
OUT
= 1.8V
V
IN
= 3.3V
100
0
0.01 0.1 1
EFFICIENCY vs. LOAD CURRENT
20
10
MAX1973/74 toc02
LOAD CURRENT (A)
EFFICIENCY (%)
40
30
60
70
50
80
90
V
OUT
= 3.3V
V
OUT
= 2.5V
V
IN
= 5V
0
0.10
0.05
0.20
0.15
0.30
0.25
0.35
DROPOUT VOLTAGE vs. LOAD CURRENT
MAX1973/74 toc03
LOAD CURRENT (A)
DROPOUT VOLTAGE (V)
0 0.2 0.4 0.6 0.8
V
OUT
= 3.3V
V
OUT
= 2.5V
0
4
2
8
6
10
12
021345
NO-LOAD CURRENT vs. INPUT VOLTAGE
MAX1973/74 toc04
INPUT VOLTAGE (V)
NO-LOAD CURRENT (mA)
V
OUT
= 2.5V
1.244
1.245
1.246
1.247
1.248
1.249
1.250
1.251
1.252
0 0.2 0.4 0.6 0.8 1.0
FB VOLTAGE vs. LOAD CURRENT
MAX1973/74 toc05
LOAD CURRENT (A)
FB VOLTAGE (V)
MAX1973
V
IN
= 5V
R1 = 22kΩ
R2 = 13kΩ
-4.0
-2.5
-3.0
-3.5
-2.0
-1.5
-1.0
-0.5
0
0.5
1.0
0.01 10.1 10 100 1000
CHANGE IN OUTPUT VOLTAGE
vs. LOAD CURRENT
MAX1973/74 toc06
LOAD CURRENT (A)
CHANGE IN OUTPUT VOLTAGE (mV)
V
IN
= 5V
V
OUT
= 1.8V
2.5V
1V
1.10
1.20
1.15
1.30
1.25
1.35
1.40
24356
SWITCHING FREQUENCY
vs. SUPPLY VOLTAGE
MAX1973/74 toc07
SUPPLY VOLTAGE (V)
SWITCHING FREQUENCY (MHz)
T
A
= +85°C
T
A
= +25°C
T
A
= -40°C