Step-Down Controllers with
Synchronous Rectifier for CPU Power
_____________________________________Typical Operating Circuits (continued)
FROM
REF
INPUT 6V TO 30V
V+
SECFB
FB
SHDN
VL
–5V
OUTPUT
MAX799
DH
BST
+5V
OUTPUT
LX
DL
PGND
SS
REF
CSH
CSL
GND
SYNC
__________________________________________Typical Operating Characteristics
(T = +25°C, unless otherwise noted.)
A
EFFICIENCY
vs. LOAD CURRENT, 5V/3A CIRCUIT
100
EFFICIENCY
vs. LOAD CURRENT, 3.3V/3A CIRCUIT
EFFICIENCY
vs. LOAD CURRENT, 3.3V/10A CIRCUIT
100
100
90
80
70
60
50
40
V
IN
= 6V
SKIP = LOW
V
IN
= 5V
90
80
70
60
90
80
70
60
V = 12V
IN
V
= 30V
IN
SKIP = HIGH
V
IN
= 30V
STANDARD MAX797 3.3V/10A
CIRCUIT, FIGURE 1
f = 300kHz
STANDARD MAX797 5V/3A
CIRCUIT, FIGURE 1
f = 300kHz
STANDARD MAX797 3.3V/3A
CIRCUIT, FIGURE 1
f = 300kHz
V
= 5V
IN
50
50
0.001
0.01
0.1
1
10
0.001
0.01
0.1
1
10
0.1
1
10
LOAD CURRENT (A)
LOAD CURRENT (A)
LOAD CURRENT (A)
6
_______________________________________________________________________________________
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
