Datasheet

MAX8537/MAX8538/MAX8539
Dual-Synchronous Buck Controllers for Point-of-
Load, Tracking, and DDR Memory Power Supplies
6 _______________________________________________________________________________________
POWER-OK
MAX8537 toc10
POK1
5V/div
POK2
5V/div
V
TT
1V/div
V
DDQ
2V/div
2ms/div
I
OUT
_V
DDQ
= 20A
I
OUT
_V
TT
= 8A
V
TT
STARTUP AND SHUTDOWN
MAX8537 toc11
V
TT
1V/div
V
DDQ
2V/div
V
TTR
1V/div
EN2
5V/div
2ms/div
V
DDQ
LOAD TRANSIENT
AND V
TT
TRACKING
MAX8537 toc12
V
TT
50mV/div
V
DDQ
_I
OUT
10A/div
V
TTR
50mV/div
V
DDQ
100mV/div
200µs/div
V
TT
_I
OUT
= 12A
V
TTR
= 15mA
di/dt
= 5A/µs
20A
10A
V
TT
LOAD-TRANSIENT RESPONSE
MAX8537 toc13
V
TTR
AC-COUPLED
50mV/div
V
TT
_I
OUT
10A/div
V
DDQ
AC-COUPLED
50mV/div
V
TT
AC-COUPLED
50mV/div
200µs/div
I
OUT
_V
DDQ
= 20A
I
OUT
_V
TTR
= 15mA
di/dt = 1A/µs
8A
-8A
V
DDQ
= 2.5V AT 20A BODE PLOT,
V
IN
= 12V
MAX8537 toc14
kHz
dB (DEGREES)
100k10k1k
-20
0
20
40
60
80
100
120
140
160
180
-40
100 1M
V
TT
= 1.25V AT 12A BODE PLOT,
V
IN
= 12V
MAX8537 toc15
Hz
dB (DEGREES)
10
5
10
4
10
3
-25
0
25
50
75
100
125
150
-50
10
2
10
6
SHORT CIRCUIT AND RECOVERY
MAX8537 toc16
10ms/div
V
OUT1
V
OUT2
I
L1
I
IN
1V/div
1V/div
10V/div
5A/div
Typical Operating Characteristics (continued)
(Circuit of Figure 1, T
A
= +25°C, 400kHz switching frequency, V
IN
= 12V, unless otherwise noted.)