Datasheet

5
LTC1625
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Oscillator Frequency
vs Temperature
FCB Pin Current vs Temperature
Maximum Current Sense Voltage
vs Temperature
Maximum Current Sense Voltage
vs Duty Cycle
DUTY CYCLE
0
MAXIMUM CURRENT SENSE VOLTAGE (mV)
100
150
0.8
1625 G10
50
0
0.2
0.4
0.5
1.0
200
TEMPERATURE (°C)
–40
140
MAXIMUM CURRENT SENSE VOLTAGE (mV)
145
150
155
160
–15 10 35 60
1625 G11
85 110 135
TEMPERATURE (°C)
–40
FREQUENCY (kHz)
200
250
300
35 85
1625 G12
150
100
–15 10
60 110 135
50
0
SYNC = 1.5V
SYNC = 0V
TEMPERATURE (°C)
–40
FCB CURRENT (µA)
–0.50
–0.25
0
35 85
1625 G13
–0.75
–1.00
–15 10
60 110 135
–1.25
–1.50
RUN/SS Pin Current
vs Temperature
TEMPERATURE (°C)
–40 –15
–5
RUN/SS CURRENT (µA)
–3
0
10
60
85
1625 G14
–4
–1
–2
35
110
135
Soft Start:
Load Current vs Time
INDUCTOR
CURRENT
2A/DIV
RUN/SS
2V/DIV
20ms/DIV
V
IN
= 20V
V
OUT
= 5V
R
LOAD
= 1Ω
FIGURE 1 CIRCUIT
V
IN
= 20V
V
OUT
= 5V
I
LOAD
= 1A TO 4A
FIGURE 1 CIRCUIT
V
OUT
50mV/DIV
200µs/DIV 50µs/DIV
V
IN
= 20V
V
OUT
= 5V
I
LOAD
= 50mA
FIGURE 1 CIRCUIT
Burst Mode Operation
V
OUT
50mV/DIV
I
TH
100mV/DIV
Transient Response
(Burst Mode Operation)
V
OUT
50mV/DIV
500µs/DIV
V
IN
= 20V
V
OUT
= 5V
I
LOAD
= 50mA TO 1A
FIGURE 1 CIRCUIT
Transient Response
1625 F07 1625 F09
1625 F06
1625 F08