MAX1775 Maxim, MAX1775 Datasheet - Page 7

• Manufacturer Part Number: MAX1775
• Description: Dual-Output Step-Down DC-DC Converter for PDA/Palmtop Computers
• Manufacturer: Maxim

(Circuit of Figure 1, V
DC-DC Converter for PDA/Palmtop Computers
-0.2
-0.4
-0.6
-0.8
-1.0
-1.2
-1.4
-1.6
-1.8
-2.0
0
_______________________________________________________________________________________
MAIN
0
MAIN SWITCHING WAVEFORMS,
CORE SWITCHING WAVEFORMS,
REFERENCE LOAD REGULATION
10
= +3.3V, V
20
HEAVY LOAD (500mA)
HEAVY LOAD (1A)
30
I
REF
1µs/div
2µs/div
CORE
40
(µA)
50
= +1.8V, T
60
MAX1775 toc08
MAX1775 toc06
Typical Operating Characteristics (continued)
70
A
80
1000mA
= +25°C, unless otherwise noted.)
LX
5V/div
500mA
V
(AC-COUPLED)
20mV/div
0
4V
0
V
(AC-COUPLED)
20mV/div
500mA
I
250mA/div
0
LC
MAIN
CORE
LXC
2V/div
I
500mA/div
LM
Dual-Output Step-Down
MAIN LINE-TRANSIENT RESPONSE
CORE SWITCHING WAVEFORMS,
MAIN SWITCHING WAVEFORMS,
LIGHT LOAD (100mA)
LIGHT LOAD (50mA)
(5V TO 12V)
100µs/div
1µs/div
1µs/div
MAX1775 toc09
MAX1775 toc07
MAX1775 toc05
12V
V
50mV/div
5V
0
200mA
LX
5V/div
I
500mA/div
LX
5V/div
0
V
(AC-COUPLED)
20mV/div
V
(AC-COUPLED)
20mV/div
LM
MAIN
CORE
MAIN
V
IN
I
200mA/div
LC
7