Step-Down Controllers with
Synchronous Rectifier for CPU Power
MAX796/MAX797/MAX799
____________________________Typical Operating Characteristics (continued)
(T
A
= +25°C, unless otherwise noted.)
QUIESCENT SUPPLY CURRENT
vs. SUPPLY VOLTAGE,
5V/3A CIRCUIT IN IDLE MODE
15m
SUPPLY CURRENT (A)
14m
STANDARD MAX797 APPLICATION
CONFIGURED FOR 5V
SKIP = LOW
SYNC = REF
MAX796-04
1200
SUPPLY CURRENT (μA)
1000
800
600
400
200
0
NOT SWITCHING
(FB FORCED TO 3.5V)
STANDARD MAX797 3.3V/3A
CIRCUIT, FIGURE 1
SKIP = LOW
SYNC = REF
0
4
8
12
16
20
24
28
SWITCHING
MAX796-05
16m
1400
SUPPLY CURRENT (mA)
20
f = 300kHz
f = 150kHz
10
STANDARD MAX797 3.3V/3A
CIRCUIT, FIGURE 1
SKIP = HIGH
0
800μ
600μ
400μ
200μ
0
0
4
8
12
16
20
24
28
32
32
0
4
8
12
16
20
24
28
32
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
MAX796-07
1.4
SUPPLY CURRENT (μA)
1.2
1.0
0.8
0.6
0.4
0.2
0
0
4
8
12
16
20
24
28
DEVICE CURRENT ONLY
SHDN = LOW
700
600
VIN - VOUT (mV)
f = 300kHz
500
400
300
f = 150kHz
200
100
0
STANDARD MAX797 APPLICATION
CONFIGURED FOR 5V
V
OUT
> 4.8V
0.01
0.1
1
LOAD REGULATION
ΔV
(mV)
15
10
5
32
10
0
1
10
100
1000
REF LOAD CURRENT (μA)
SUPPLY VOLTAGE (V)
LOAD CURRENT (A)
VL LOAD-REGULATION ERROR
vs. LOAD CURRENT
MAX796-10
SWITCHING FREQUENCY
vs. LOAD CURRENT
1000
SYNC = REF (300kHz)
SKIP = LOW
100
+5V, V
IN
= 7.5V
MAXIMUM SECONDARY CURRENT (mA)
450
400
350
300
250
200
150
100
50
0
1m
10m
100m
1
MAX796
MAXIMUM SECONDARY CURRENT
vs. SUPPLY VOLTAGE, 5V/15V CIRCUIT
I
OUT
(MAIN) = 0A
MAX796-11
500
LOAD REGULATION
ΔV
(mV)
400
300
SWITCHING FREQUENCY (kHz)
I
OUT
(MAIN) = 3A
10
+5V, V
IN
= 30V
200
1
+3.3V, V
IN
= 7.5V
100
CIRCUIT OF FIGURE 11
TRANSFORMER = TTI5870
V
SEC
> 12.75V
0
4
8
12
16
20
24
28
32
0
0
20
40
60
80
VL LOAD CURRENT (mA)
0.1
100μ
LOAD CURRENT (A)
SUPPLY VOLTAGE (V)
_______________________________________________________________________________________
7
MAX796-09
1.6
MAX796-08
SHUTDOWN SUPPLY CURRENT
vs. SUPPLY VOLTAGE
DROPOUT VOLTAGE
vs. LOAD CURRENT
800
20
REF LOAD-REGULATION ERROR
vs. LOAD CURRENT
MAX796-06
QUIESCENT SUPPLY CURRENT
vs. SUPPLY VOLTAGE,
3.3V/3A CIRCUIT IN IDLE MODE
QUIESCENT SUPPLY CURRENT
vs. SUPPLY VOLTAGE, LOW-NOISE MODE
30
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
