LTC3864 Datasheet, PDF (6/28 Pages) Linear Technology – 60V Low IQ Step-Down DC/DC Controller with 100% Duty Cycle Capability

LTC3864
TYPICAL PERFORMANCE CHARACTERISTICS T_A = 25°C, unless otherwise noted.
Overcurrent Protection
Short-Ciruit Protection
V_IN Line Transient Behavior
3.2A
I_LOAD
1A
1A
1A/DIV
I_L
1A/DIV
V_OUT
500mV/DIV
V_OUT DROOPS DUE TO
REACHING CURRENT LIMIT
20ms/DIV
V_IN = 12V, V_OUT = 5V
FIGURE 8 CIRCUIT
3864 G10
Burst Mode Input Current Over
Input Voltage (No Load)
70
V_IN = 12V, V_OUT = 5V
65 ^ILOAD ^{= 0A}
FIGURE 8 CIRCUIT
60
SHORT-
CIRCUIT
TRIGGER
V_OUT
5V/DIV
SHORT-CIRCUIT REGION
V_IN
20V/DIV
SOFT RECOVERY
FROM SHORT
GATE
20V/DIV
I_L
2A/DIV
V_OUT
50mV/DIV
500µs/DIV
V_IN = 12V, V_OUT = 5V
FIGURE 8 CIRCUIT
3864 G11
Pulse-Skipping Mode Input
Current Over Input Voltage
(No Load)
950
V_IN = 12V, V_OUT = 5V
I_LOAD = 0A
900 ^{FIGURE 8 CIRCUIT}
2ms/DIV
V_IN = 12V, SURGE TO 48V
V_OUT = 5V
I_LOAD = 200mA, FIGURE 8 CIRCUIT
3864 G12
Shutdown Current Over Input
Voltage
25
FIGURE 8 CIRCUIT
20
55
850
15
50
45
800
10
40
750
5
35
30
0
10 20 30 40
V_IN(V)
50 60
3864 G13
700
0
10 20 30 40
V_IN (V)
50 60
3864 G14
0
0 10 20 30 40 50 60
V_IN (V)
3864 G15
Output Regulation Over Input
Voltage
0.010
0.005
V_OUT = 5V
I_LOAD = 200mA
V_OUT NORMALIZED AT V_IN = 12V
FIGURE 8 CIRCUIT
Output Regulation Over Load
Current
0.010
V_IN = 12V, V_OUT = 5V
I_LOAD NORMALIZED AT I_LOAD = 1A
FIGURE 8 CIRCUIT
0.005
0
0
–0.005
–0.010
0
Burst Mode OPERATION
PULSE-SKIPPING
10 20 30 40 50 60
V_IN (V)
3864 G16
–0.005
–0.010
–0.5 0
Burst Mode OPERATION
PULSE-SKIPPING
0.5 1 1.5 2 2.5
I_LOAD (A)
3864 G17
Output Regulation Over
Temperature
1.0 _{VIN = 12V, VOUT = 5V}
0.8 I_LOAD = 200mA
0.6
V_OUT NORMALIZED TO T_A = 25°C
FIGURE 8 CIRCUIT
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
–75
Burst Mode OPERATION
PULSE-SKIPPING
–25
25
75
125 175
TEMPERATURE (°C)
3864 G18
3864f
6