LTC3609 Datasheet, PDF (7/24 Pages) Linear Technology – 32V, 6A Monolithic Synchronous Step-Down DC/DC Converter

TYPICAL PERFORMANCE CHARACTERISTICS
LTC3609
INTV_CC Load Regulation
0.30
0.20
0.10
0
–0.10
–0.20
–0.30
–0.40
0
10
20
30
40
50
INTVCC LOAD CURRENT (mA)
3609 G22
EXTV_CC Switch Resistance
vs Temperature
10
8
6
4
2
0
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3609 G23
FCB Pin Current vs Temperature
0
RUN/SS Pin Current
vs Temperature
3
–0.25
–0.50
–0.75
–1.00
–1.25
–1.50
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3609 G24
2
PULL-DOWN CURRENT
1
0
–1
–2
–50 –25
PULL-UP CURRENT
0 25 50 75
TEMPERATURE (°C)
100 125
3609 G25
Undervoltage Lockout Threshold
vs Temperature
4.0
3.5
Load Step
f = 500kHz
I_L
5A/DIV
3.0
2.5
2.0
–50 –25
V_OUT
200mV/DIV
0 25 50 75
TEMPERATURE (°C)
100 125
3609 G27
40μs/DIV
LOAD STEP 1A TO 4A
V_IN = 24V
V_OUT = 12V
FCB = 0V
FIGURE 8 CIRCUIT
3609 G29
I_EXTVCC vs Frequency
25
V_IN = 24V
20
15
10
5
0
400 500 600 700 800 900 1000
FREQUENCY (kHz)
3609 G28
RUN/SS Pin Current
vs Temperature
5.0
4.5
LATCHOFF ENABLE
4.0
LATCHOFF THRESHOLD
3.5
3.0
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3609 G26
Efficiency vs Load Current
100
95
90
85
DCM
80
75
70
CCM
65
60
55
50
0.01
V_IN = 24V
FREQUENCY = 500kHz
0.1
1
10
LOAD CURRENT (A)
FIGURE 8 CIRCUIT
3609 G30
3609f
7