LT1507
TYPICAL PERFORMANCE CHARACTERISTICS
W
U
Shutdown Pin Bias Current
Standby and Shutdown Thresholds
Shutdown Supply Current
30
25
2.40
2.36
2.32
0.8
0.4
0
500
400
300
200
8
V
SHDN
= 0V
CURRENT REQUIRED TO FORCE SHUTDOWN
(FLOWS OUT OF PIN). AFTER SHUTDOWN,
CURRENT DROPS TO A FEW µA
STANDBY
20
15
10
5
STARTUP
AT 2.38V STANDBY THRESHOLD
(CURRENT FLOWS OUT OF PIN)
4
SHUTDOWN
0
0
50
JUNCTION TEMPERATURE (°C)
100 125
0
3
6
9
12
15
50
TEMPERATURE (°C)
100 125
–50 –25
0
25
75
–50 –25
0
25
75
INPUT VOLTAGE (V)
LT1507 • TPC06
LT1507 • TPC05
L11507 • TPC04
Shutdown Supply Current
Error Amplifier Transconductance
Error Amplifier Transconductance
2500
2000
1500
1000
500
3000
2500
2000
1500
1000
500
200
150
100
50
150
125
100
75
PHASE
GAIN
V
C
C
OUT
12pF
R
OUT
200k
–3
V
FB
× 2e
V
= 10V
50
IN
ERROR AMPLIFIER EQUIVALENT CIRCUIT
0
25
R
LOAD
= 50Ω
0
–50
0
–50
0
25
50
75 100 125
100
1k
10k
100k
1M
10M
–25
0
0.1
0.2
0.3
0.4
0.5
JUNCTION TEMPERATURE (°C)
FREQUENCY (Hz)
SHUTDOWN VOLTAGE (V)
LT1507 • TPC09
LT1507 • TPC08
LT1507 • TPC07
Minimum Input Voltage
with 3.3V Output
Frequency Foldback
Switching Frequency
600
550
500
450
400
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
500
400
300
200
100
0
MINIMUM VOLTAGE
TO START WITH
STANDARD CIRCUIT
SWITCHING
FREQUENCY
MINIMUM VOLTAGE
TO RUN WITH
FEEDBACK PIN
CURRENT
STANDARD CIRCUIT
–25
0
25
50
75
125
–50
100
1
10
100
1000
0
0.5
1.0
1.5
2.0
2.5
JUNCTION TEMPERATURE (°C)
LOAD CURRENT (mA)
FEEDBACK PIN VOLTAGE (V)
LT1507 • TPC12
LT1507 • TPC11
LT1507 • TPC10
MINIMUM INPUT VOLTAGE CAN BE REDUCED
BY ADDING A SMALL EXTERNAL PNP. SEE
APPLICATIONS INFORMATION
4
Linear [ Linear ]
