Datasheet
MAX796/MAX797/MAX799
Step-Down Controllers with
Synchronous Rectifier for CPU Power
_______________________________________________________________________________________ 7
____________________________Typical Operating Characteristics (continued)
(T
A
= +25°C, unless otherwise noted.)
0
200µ
400µ
600µ
800µ
14m
15m
16m
048121620242832
QUIESCENT SUPPLY CURRENT
vs. SUPPLY VOLTAGE,
5V/3A CIRCUIT IN IDLE MODE
MAX796-04
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (A)
STANDARD MAX797 APPLICATION
CONFIGURED FOR 5V
SKIP = LOW
SYNC = REF
0
0.2
0.4
0.6
0.8
1.2
1.0
1.4
1.6
048121620242832
SHUTDOWN SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX796-07
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (µA)
DEVICE CURRENT ONLY
SHDN = LOW
0
200
400
600
800
1200
1000
1400
048121620242832
MAX796-05
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (µA)
QUIESCENT SUPPLY CURRENT
vs. SUPPLY VOLTAGE,
3.3V/3A CIRCUIT IN IDLE MODE
STANDARD MAX797 3.3V/3A
CIRCUIT, FIGURE 1
SKIP = LOW
SYNC = REF
SWITCHING
NOT SWITCHING
(FB FORCED TO 3.5V)
0
10
20
30
048121620242832
MAX796-06
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
QUIESCENT SUPPLY CURRENT
vs. SUPPLY VOLTAGE, LOW-NOISE MODE
f = 150kHz
f = 300kHz
STANDARD MAX797 3.3V/3A
CIRCUIT, FIGURE 1
SKIP = HIGH
0
0.01 1 100.1
DROPOUT VOLTAGE
vs. LOAD CURRENT
200
100
300
400
500
600
700
800
MAX796-08
LOAD CURRENT (A)
V
IN
- V
OUT
(mV)
STANDARD MAX797 APPLICATION
CONFIGURED FOR 5V
V
OUT
> 4.8V
f = 150kHz
f = 300kHz
0
1 100 100010
REF LOAD-REGULATION ERROR
vs. LOAD CURRENT
5
10
15
20
MAX796-09
REF LOAD CURRENT (µA)
LOAD REGULATION ∆V (mV)
0
200
100
300
400
500
020406080
MAX796-10
VL LOAD CURRENT (mA)
LOAD REGULATION ∆V (mV)
VL LOAD-REGULATION ERROR
vs. LOAD CURRENT
0
50
100
150
200
250
300
350
400
450
048121620242832
MAX796-11
SUPPLY VOLTAGE (V)
MAXIMUM SECONDARY CURRENT (mA)
MAX796
MAXIMUM SECONDARY CURRENT
vs. SUPPLY VOLTAGE, 5V/15V CIRCUIT
I
OUT
(MAIN) = 0A
I
OUT
(MAIN) = 3A
CIRCUIT OF FIGURE 11
TRANSFORMER = TTI5870
V
SEC
> 12.75V
1000
0.1
100µ 10m 1
SWITCHING FREQUENCY
vs. LOAD CURRENT
10
LOAD CURRENT (A)
SWITCHING FREQUENCY (kHz)
100
1m 100m
SYNC = REF (300kHz)
SKIP = LOW
+5V, V
IN
= 7.5V
1
+5V, V
IN
= 30V
+3.3V, V
IN
= 7.5V