MAX887 Maxim, MAX887 Datasheet - Page 4

• Manufacturer Part Number: MAX887
• Description: 100% Duty Cycle / Low-Noise / Step-Down / PWM DC-DC Converter
• Manufacturer: Maxim

100% Duty Cycle, Low-Noise,
Step-Down, PWM DC-DC Converter
(Circuit of Figure 2, T
4
____________________________Typical Operating Characteristics (continued)
100
1200
1000
350
340
330
320
310
300
290
280
270
260
250
_______________________________________________________________________________________
90
80
70
60
50
40
30
20
10
800
600
400
200
0
0
0.0001
0
0
V
EFFICIENCY vs. OUTPUT CURRENT
IN
V
V
V
2
= 5V
OUT
IN
MAXIMUM OUTPUT CURRENT
IN
100
= 7V
0.001
= 4V
SWITCHING FREQUENCY
= 3.3V
OUTPUT CURRENT (A)
4
vs. SYNC FREQUENCY
V
vs. SUPPLY VOLTAGE
SYNC FREQUENCY (kHz)
IN
SUPPLY VOLTAGE (V)
200
= 9V
6
A
C2, C3 = 47µF
L1 = 33µH
V
V
V
= +25°C, unless otherwise noted.)
8
0.01
IN
OUT
OUT
300
V
= 5V
10 12 14 16 18
IN
= 3.3V
= -5% at I
= 11V
(SYNC = GND)
400
V
IDLE MODE
OUT
0.1
= 3.3V
OUT(MAX)
500
0.6
600
350
340
330
320
310
300
290
280
270
260
250
100
3.5
2.5
1.5
0.5
3.0
2.0
1.0
90
80
70
60
50
40
30
20
10
0
0
0.0001
-60 -40 -20
0
EFFICIENCY vs. OUTPUT CURRENT
V
V
IN
2
OUT
QUIESCENT SUPPLY CURRENT
V
IN
= 5.5V
0.001
SWITCHING FREQUENCY
= 7V
= 3.3V
4
vs. SUPPLY VOLTAGE
V
OUTPUT CURRENT (A)
vs. TEMPERATURE
IN
SUPPLY VOLTAGE (V)
0 20 40 60 80 100 120 140
TEMPERATURE (°C)
= 9V
6
A: V
B: V
A
C
8
0.01
OUT
OUT
A
V
10 12 14 16 18
= 3.3V, PWM MODE
= 3.3V, PFM MODE
IN
B
= 11V
(SYNC = GND)
IDLE MODE
V
OUT
0.1
= 5V
0.6
1200
1000
3.0
2.5
2.0
1.5
1.0
0.5
800
600
400
200
-1
0
4
3
2
1
0
0
10k
-60 -40 -20 0
3
V
V
GUARANTEED OUTPUT CURRENT
OF FIGURE 2 IS 600mA
V
V
I
PWM MODE
OUTPUT RIPPLE AND HARMONICS
IN
OUT
OUT
IN
OUT
MAXIMUM OUTPUT CURRENT
= 5.3V
5
= 5V
= 3.3V
= 500mA
= 3.3V
vs. SUPPLY VOLTAGE
5V SETTING, V
QUIESCENT CURRENT
3.3V SETTING, V
vs.TEMPERATURE
SUPPLY VOLTAGE (V)
7
100k
TEMPERATURE (°C)
FREQUENCY (Hz)
20 40 60 80 100 120 140
9
11
OUT
OUT
1M
= 4.75V
PWM MODE
PFM MODE
= 3.135V
13
15
10M
17