Quick-PWM Slave Controllers for
Multiphase, Step-Down Supplies
MAX1887/MAX1897
Typical Operating Characteristics (continued)
(Circuit of Figure 1, V+ = 12V, V
CC
= V
DD
= 5V, V
OUT
= 1.3V (ZMODE = GND) and 1V (ZMODE = V
CC
),
SHDN
= V
CC
(MAX1897))
SWITCHING WAVEFORMS
(OUT-OF-PHASE)
MAX1887 toc14
SWITCHING WAVEFORMS
(IN-PHASE)
MAX1887 toc15
A
20mV/div
20A
B
5A/div
20A
A
20mV/div
B
5A/div
10V
0
1µs/div
A. OUTPUT VOLTAGE, V
OUT
= 1.290V (NO LOAD),
B. MASTER/SLAVE INDUCTOR CURRENTS
C. MASTER/SLAVE LX WAVEFORMS,
V
IN
= 12.0V, I
OUT
= 40A, POL = V
CC
(MAX1897)
C
10V/div
10V
0
1µs/div
A. OUTPUT VOLTAGE, V
OUT
= 1.290V (NO LOAD),
B. MASTER/SLAVE INDUCTOR CURRENTS
C. MASTER/SLAVE LX WAVEFORMS,
V
IN
= 12.0V, I
OUT
= 40A, POL = GND (MAX1897)
C
10V/div
LOAD TRANSIENT
(OUT-OF-PHASE)
MAX1887 toc16
LOAD TRANSIENT
(IN-PHASE)
MAX1887 toc17
40A
5A
1.282V
A
40A/div
B
50mV/div
40A
5A
1.282V
A
40A/div
B
50mV/div
0
0
20µs/div
A. LOAD CURRENT, I
OUT
= 5A TO 40A
B. OUTPUT VOLTAGE, V
OUT
= 1.290V (NO LOAD)
C. SLAVE INDUCTOR CURRENT
D. MASTER INDUCTOR CURRENT
V
IN
= 12.0V, POL = V
CC
(MAX1897)
C
10A/div
D
10A/div
0
0
20µs/div
A. LOAD CURRENT, I
OUT
= 5A TO 40A
B. OUTPUT VOLTAGE, V
OUT
= 1.290V (NO LOAD)
C. SLAVE INDUCTOR CURRENT
D. MASTER INDUCTOR CURRENT
V
IN
= 12.0V, POL = GND (MAX1897)
C
10A/div
D
10A/div
8
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
