Low-Noise, 14V Input, 1A, PWM
Step-Down Converters
Typical Operating Characteristics
(Circuit of Figure 1, T
A
= +25°C, unless otherwise noted.)
MAX1684
EFFICIENCY vs. LOAD CURRENT
(V
IN
= 3.3V, V
OUT
= 1.8V, 2.5V)
MAX1684/85-01
MAX1684/MAX1685
MAX1684
EFFICIENCY vs. LOAD CURRENT
(V
OUT
= 3.3V)
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
0
0.1
1
10
100
1,000
10,000
LOAD CURRENT (mA)
A: V
IN
= 4V LOW-POWER MODE
B: V
IN
= 12V LOW-POWER MODE
C: V
IN
= 4V NORMAL MODE
D: V
IN
= 12V NORMAL MODE
B
A
D
EFFICIENCY (%)
C
MAX1684/85-02
MAX1684
EFFICIENCY vs. LOAD CURRENT
(V
OUT
= 3.3V, PWM MODE)
90
80
70
60
50
40
30
20
10
0
1
10
100
1,000
10,000
LOAD CURRENT (mA)
A: V
IN
= 4V
B: V
IN
= 5V
C: V
IN
= 9V
D: V
IN
= 12V
A
D
B
C
MAX1684/85-03
100
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
0
0.1
1
C
B
A
D
E
A: V
OUT
= 2.5V LP MODE
B: V
OUT
= 1.8V LP MODE
C: V
OUT
= 2.5V NORM MODE
D: V
OUT
= 1.8V NORM MODE
E: V
OUT
= 2.5V PWM MODE
F: V
OUT
= 1.8V PWM MODE
10
100
1,000
100
100
F
10,000
LOAD CURRENT (mA)
MAX1684
EFFICIENCY vs. LOAD CURRENT
(V
OUT
= 5V)
90
80
EFFICIENCY (%)
70
60
50
40
30
20
0.1
1
A: V
IN
= 6V LP MODE
B: V
IN
= 9V LP MODE
C: V
IN
= 12V LP MODE
D: V
IN
= 6V NORMAL MODE
E: V
IN
= 9V NORMAL MODE
F: V
IN
= 12V NORMAL MODE
10
100
1,000
10,000
LOAD CURRENT (mA)
B
A
C
F
E
E
D
MAX1684/85-04
MAX1684
EFFICIENCY vs. LOAD CURRENT
(V
OUT
= 5V, PWM MODE)
MAX1684/85-05
MAX1685
EFFICIENCY vs. LOAD CURRENT
(V
OUT
= 3.3V, PWM MODE)
90
80
EFFICIENCY (%)
70
60
50
40
30
V
IN
=9V
V
IN
= 12V
V
IN
= 5V
V
IN
= 4V
MAX1684/85-06
100
100
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
0
1
10
100
1,000
A: V
IN
= 6V
B: V
IN
= 9V
C: V
IN
=12V
B
C
A
100
20
10
0
1
10,000
10
100
1,000
10,000
LOAD CURRENT (mA)
LOAD CURRENT (mA)
MAX1685
EFFICIENCY vs. LOAD CURRENT
(V
OUT
= 3.3V)
MAX1684/85-07
MAX1685
EFFICIENCY vs. LOAD CURRENT
(V
OUT
= 5V PWM MODE)
MAX1684/85-08
MAX1685
EFFICIENCY vs. LOAD CURRENT
(V
OUT
= 5V)
90
80
EFFICIENCY (%)
70
60
50
40
30
A: V
IN
= 6V LOW-POWER MODE
B: V
IN
= 9V LOW-POWER MODE
C: V
IN
= 12V LOW-POWER MODE
D: V
IN
= 6V NORMAL MODE
E: V
IN
= 9V NORMAL MODE
F: V
IN
=12V NORMAL MODE
0.1
1
10
100
1,000
10,000
LOAD CURRENT (mA)
A
B
E
D
MAX1684/85-09
100
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
0
0.1
1
B
D
A
C
100
90
80
EFFICIENCY (%)
70
60
50
40
30
V
IN
=12V
V
IN
= 6V
V
IN
= 9V
100
C
F
A: V
IN
= 4V LP MODE
B: V
IN
= 12V LP MODE
C: V
IN
= 4V NORMAL MODE
D: V
IN
= 12V NORMAL MODE
10
100
1,000
10,000
20
10
0
1
20
10
0
10
100
1,000
10,000
LOAD CURRENT (mA)
LOAD CURRENT (mA)
_______________________________________________________________________________________
5
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
