Datasheet

MAX8537/MAX8538/MAX8539
Dual-Synchronous Buck Controllers for Point-of-
Load, Tracking, and DDR Memory Power Supplies
_______________________________________________________________________________________ 5
V
DDQ
EFFICIENCY vs. LOAD CURRENT
MAX8537 toc01
LOAD CURRENT (A)
EFFICIENCY (%)
10
55
60
65
70
75
80
85
90
95
100
50
1100
V
DDQ
= 2.5V
V
DDQ
= 1.8V
SENSE RESISTOR = 0
Ω
V
IN
= 12V
V
DDQ
EFFICIENCY vs. LOAD CURRENT
MAX8537 toc02
LOAD CURRENT (A)
EFFICIENCY (%)
10
55
60
65
70
75
80
85
90
95
100
50
1100
V
DDQ
= 2.5V
V
DDQ
= 1.8V
SENSE RESISTOR = 3m
Ω
V
IN
= 12V
V
DDQ
vs. LOAD CURRENT
MAX8537 toc03
LOAD CURRENT (A)
V
DDQ
2015105
2.47
2.49
2.51
2.53
2.55
2.45
0
V
IN
= 12V
V
TT
vs. LOAD CURRENT
MAX8537 toc04
LOAD CURRENT (A)
V
TT
12963
1.21
1.22
1.23
1.24
1.25
1.26
1.27
1.28
1.29
1.30
1.20
015
V
IN
= 12V
V
TTR
vs. LOAD CURRENT
MAX8537 toc05
LOAD CURRENT (mA)
V
TTR
2015105
1.21
1.22
1.23
1.24
1.25
1.26
1.27
1.28
1.29
1.30
1.20
025
V
IN
= 12V
OUTPUT VOLTAGE vs. INPUT VOLTAGE
MAX8537 toc06
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
13
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
1.2
12 14
V
DDQ
V
TT
AND V
TTR
I
OUT
_V
DDQ
= 20A
I
OUT
_V
TT
= 12A
I
OUT
_V
TTR
= 15mA
POWER-UP
MAX8537 toc07
V
DDQ
1V/div
V
TTR
8.5V/div
V
TT
8.5V/div
V+
5V/div
4ms/div
POWER-DOWN
MAX8537 toc08
4ms/div
2V/div
2V/div
2V/div
5V/div
V
IN
V
DDQ
V
TT
V
VTTR
STARTUP AND SHUTDOWN
MAX8537 toc09
V
DDQ
2V/div
V
TTR
1V/div
V
TT
1V/div
EN1/EN2
5V/div
1ms/div
Typical Operating Characteristics
(Circuit of Figure 1, T
A
= +25°C, 400kHz switching frequency, V
IN
= 12V, unless otherwise noted.)