MAX1549ETL Datasheet, PDF (9/35 Pages) Maxim Integrated Products – Dual, Interleaved, Fixed-Frequency Step-Down Controller with a Dynamically Adjustable Output

Dual, Interleaved, Fixed-Frequency Step-Down
Controller with a Dynamically Adjustable Output
Typical Operating Characteristics (continued)
(MAX1549 circuit of Figure 1, V_IN = 12V, V_DD = V_CC = 5V, SKIP = GND, FSEL = open, T_A = +25°C, unless otherwise noted.)
SWITCHING FREQUENCY DISTRIBUTION
(300kHz OPERATION)
50
SAMPLE SIZE = 150
40
30
20
10
0
290
295
300
305
310
SWITCHING FREQUENCY (kHz)
STARTUP WAVEFORM
(HEAVY LOAD)
MAX1549 toc14
5V
A
0
2.5V
B
0
5A
C
0
0
D
400µs/div
A: ON2, 5V/div
B: 2.5V OUTPUT, 2V/div
0.5Ω LOAD
C: INDUCTOR CURRENT, 5A/div
D: PGOOD2, 5V/div
STARTUP WAVEFORM
(LIGHT LOAD)
MAX1549 toc15
5V
A
0
2.5V
B
0
2A
C
0
0
D
200µs/div
A: ON2, 5V/div
B: 2.5V OUTPUT, 2V/div
100Ω LOAD
C: INDUCTOR CURRENT, 2A/div
D: PGOOD2, 5V/div
SHUTDOWN WAVEFORM
SHUTDOWN WAVEFORM
(1Ω LOAD)
MAX1549 toc16
(100Ω LOAD)
MAX1549 toc17
5V
5V
A
A
0
0
2.5V
2.5V
B
B
0
0
5V
5V
C
C
0
0
0
D
0
D
5V
5V
E
E
0
0
A: ON2, 5V/div
B: OUT2, 2V/div
C: DL2, 5V/div
100µs/div
D: INDUCTOR CURRENT, 5A/div
E: PGOOD2, 5V/div
A: ON2, 5V/div
B: OUT2, 2V/div
C: DL2, 5V/div
1ms/div
D: INDUCTOR CURRENT, 2A/div
E: PGOOD2, 5V/div
INTERLEAVED OPERATION
MAX1549 toc18
12V
A
0
1.0V
B
12V
C
0
2.5V
D
2µs/div
A: LX1, 10V/div
C: LX2, 10V/div
B: 1.0V OUTPUT, 50mV/div D: 2.5V OUTPUT, 50mV/div
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