Step-Down Controllers with
Synchronous Rectifier for CPU Power
____________________________Typical Operating Characteristics (continued)
(T = +25°C, unless otherwise noted.)
A
MAX796
MAXIMUM SECONDARY CURRENT
vs. SUPPLY VOLTAGE, 3.3V/5V CIRCUIT
1050
MAX799
MAXIMUM SECONDARY CURRENT
vs. SUPPLY VOLTAGE, 5V CIRCUIT
800
700
I
(MAIN) = 2A
I
(MAIN) = 0A
OUT
OUT
900
750
600
450
300
600
500
400
300
200
I
(MAIN) = 0A
OUT
I
(MAIN) = 1A
OUT
CIRCUIT OF FIGURE 13
TRANSFORMER = TTI5926
CIRCUIT OF FIGURE 12
V
SEC
≤ -5.1V
TRANSFORMER = TDK 1.5:1
150
0
100
0
V
SEC
≥ 4.8V
0
3
6
9
12 15 18 21 24
0
4
8
12 16 20 24 28 32
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
PULSE-WIDTH-MODULATION MODE WAVEFORMS
IDLE-MODE WAVEFORMS
+5V OUTPUT
50mV/div
LX VOLTAGE
10V/div
2V/div
+5V OUTPUT
VOLTAGE
50mV/div
500ns/div
200μs/div
I
= 1A, V = 16V,
IN
I
= 100mA, V = 10V,
IN
LOAD
LOAD
CIRCUIT OF FIGURE 1
CIRCUIT OF FIGURE 1
+5V LOAD-TRANSIENT RESPONSE
3A
LOAD CURRENT
0A
+5V OUTPUT
50mV/div
200μs/div
V
IN
= 15V, CIRCUIT OF FIGURE 1
8
_______________________________________________________________________________________
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
