Datasheet

LTC3609
7
3609fb
Typical perForMance characTerisTics
TEMPERATURE (°C)
–50 –25
0
EXTV
CC
SWITCH RESISTANCE (Ω)
4
10
0 50 75
3609 G23
2
8
6
25 100 125
TEMPERATURE (°C)
–50
FCB PIN CURRENT (µA)
–0.50
–0.25
0
25 75
3609 G24
–0.75
–1.00
–25 0 50 100 125
–1.25
–1.50
TEMPERATURE (°C)
–50 –25
–2
RUN/SS PIN CURRENT (µA)
0
3
0 50 75
3609 G25
–1
2
1
25 100 125
PULL-UP CURRENT
PULL-DOWN CURRENT
INTV
CC
LOAD CURRENT (mA)
0
∆INTV
CC
(%)
0.10
0.20
0.30
40
3609 G22
0
–0.20
–0.10
–0.40
–0.30
10 20 30
50
INTV
CC
Load Regulation
EXTV
CC
Switch Resistance
vs Temperature
FCB
Pin Current vs Temperature
RUN/SS Pin Current
vs Temperature
RUN/SS Pin Current
vs Temperature
Undervoltage Lockout Threshold
vs Temperature
TEMPERATURE (°C)
–50
3.0
RUN/SS PIN CURRENT (µA)
3.5
4.0
4.5
5.0
–25 0 25 50
3609 G26
75 100 125
LATCHOFF ENABLE
LATCHOFF THRESHOLD
TEMPERATURE (°C)
–50
2.0
UNDERVOLTAGE LOCKOUT THRESHOLD (V)
2.5
3.0
3.5
4.0
–25 0 25 50
3609 G27
75 100 125
FREQUENCY (kHz)
400
0
I
EXTVCC
(mA)
10
25
3609 G28
5
20
15
900800700600500 1000
V
IN
= 24V
I
EXTVCC
vs Frequency
LOAD STEP 1A TO 4A
V
IN
= 24V
V
OUT
= 12V
FCB = 0V
FIGURE 8 CIRCUIT
3609 G29
40µs/DIV
f = 500kHz
V
OUT
200mV/DIV
I
L
5A/DIV
Load Step Efficiency vs Load Current
LOAD CURRENT (A)
0.01
EFFICIENCY (%)
80
10
3609 G30
50
75
70
65
60
55
0.1 1
100
90
95
85
V
IN
= 24V
FREQUENCY = 500kHz
DCM
CCM
FIGURE 8 CIRCUIT