LTC3819 Datasheet, PDF (7/32 Pages) Linear Technology – 2-Phase, High Efficiency, Step-Down Controller for Sun Server CPUs

TYPICAL PERFOR A CE CHARACTERISTICS
LTC3819
Load Step (Figure 12)
V_IN = 12V, V_OUT = 1.25V
V_OUT(AC)
50mV/DIV
I_LOAD
10A/DIV
200µs/DIV
Burst Mode Operation (Figure 12)
V_IN = 12V, V_OUT = 1.4125V, I_LOAD = 3A
V_OUT(AC)
50mV/DIV
I_L1
5A/DIV
Constant Frequency Mode
(Figure 12)
V_OUT(AC) ^{VIN = 12V, VOUT = 1.4125V, ILOAD = 3A}
50mV/DIV
I_L1
5A/DIV
3819 G19
I_L2
5A/DIV
FCB = OPEN
R5, R7 = 2mΩ
10µs/DIV
3819 G25
I_L2
5A/DIV
FCB = INTV_CC
10µs/DIV
R5, R7 = 2mΩ
3819 G26
Current Sense Pin Input Current
vs Temperature
–12
V_OUT = 1.4125V
–11
–10
–9
–8
EXTV_CC Switch Resistance
vs Temperature
10
8
6
4
2
Oscillator Frequency
vs Temperature
350
V_PLLFLTR = 2.4V
300
250
200
150
V_PLLFLTR = 0V
100
50
–7
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3819 G20
0
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3819 G21
0
– 50 – 25
0 25 50 75
TEMPERATURE (°C)
100 125
3819 G22
Undervoltage Lockout
vs Temperature
3.50
3.45
3.40
3.35
3.30
3.25
3.20
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3819 G23
V_RUN/SS Shutdown Latch
Thresholds vs Temperature
4.5
4.0
LATCH ARMING
3.5
3.0
LATCHOFF
THRESHOLD
2.5
2.0
1.5
1.0
0.5
0
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3819 G24
3819f
7