MAX1639 Maxim, MAX1639 Datasheet - Page 4

• Manufacturer Part Number: MAX1639
• Description: High-Speed Step-Down Controller with Synchronous Rectification for CPU Power
• Manufacturer: Maxim

High-Speed Step-Down Controller with
Synchronous Rectification for CPU Power
4
(T
__________________________________________Typical Operating Characteristics
A
A
B
C
A
B
= +25°C, using the MAX1639 evaluation kit, unless otherwise noted.)
_______________________________________________________________________________________
V
A: V
B: INDUCTOR CURRENT, 2A/div
C: LX, 5V/div
V
A: V
B: INDUCTOR CURRENT, 5A/div
IN
IN
= 5V, V
OUT
= 5V, V
OUT
LOAD-TRANSIENT RESPONSE
, 20mV/div
, 100mV/div, AC COUPLED
SWITCHING WAVEFORMS
OUT
OUT
= 2.5V, LOAD = 0A
= 2.5V, LOAD = 8A
(V
OUT
10 s/div
1 s/div
= 2.5V)
0
100
90
80
70
60
50
0.1
A
B
A: V
B: INDUCTOR CURRENT, 5A/div
EFFICIENCY vs. OUTPUT CURRENT
OUT
FOLDBACK CURRENT LIMIT
= 0.5V/div
(V
OUT
OUTPUT CURRENT (A)
3.5V
= 2.5V, NOMINAL)
10 s/div
1
1.8V
2.5V
10
100
95
90
85
80
75
70
65
60
55
50
A
B
A: INDUCTOR CURRENT, 2A/div
B: V
0
OUT
= 1V/div
200
MAXIMUM DUTY CYCLE vs.
START-UP WAVEFORMS
SWITCHING FREQUENCY
SWITCHING FREQUENCY (kHz)
400
400 s/div
600
800
1000 1200