Datasheet

LT3430/LT3430-1
4
34301fa
DUTY CYCLE (%)
SWITCH PEAK CURRENT (A)
6
5
4
3
2
20 40 60 80
3430 G01
1000
GUARANTEED MINIMUM
T
J
= 25°C
TYPICAL
JUNCTION TEMPERATURE (°C)
–50
FEEDBACK VOLTAGE (V)
CURRENT (µA)
1.224
1.229
1.234
25 75
3430 G02
1.219
1.214
–25 0
50 100 125
1.209
1.204
1.5
2.0
1.0
0.5
0
VOLTAGE
CURRENT
JUNCTION TEMPERATURE (°C)
–50
250
200
150
100
12
6
0
25 75
3430 G03
–25 0
50 100 125
CURRENT (µA)
CURRENT REQUIRED TO FORCE SHUTDOWN
(FLOWS OUT OF PIN). AFTER SHUTDOWN,
CURRENT DROPS TO A FEW µA
AT 2.38V STANDBY THRESHOLD
(CURRENT FLOWS OUT OF PIN)
JUNCTION TEMPERATURE (°C)
–50
SHDN PIN VOLTAGE (V)
50 100
3430 G04
0
25 75
2.4
2.0
1.6
1.2
0.8
0.4
0
–25 125
LOCKOUT
START-UP
SHUTDOWN
INPUT VOLTAGE (V)
0
INPUT SUPPLY CURRENT (µA)
3430 G05
10 20 30 40 50 60
40
35
30
25
20
15
10
5
0
V
SHDN
= 0V
T
A
= 25°C
SHUTDOWN VOLTAGE (V)
0
0
INPUT SUPPLY CURRENT (µA)
50
100
150
200
250
300
0.1 0.2 0.3 0.4
3430 G06
0.5
V
IN
= 60V
V
IN
= 15V
T
A
= 25°C
JUNCTION TEMPERATURE (°C)
TRANSCONDUCTANCE (µmho)
3430 G07
2500
2000
1500
1000
500
0
–50
50 100
0
25 75–25 125
FREQUENCY (Hz)
GAIN (µMho)
PHASE
(DEG)
3000
2500
2000
1500
1000
500
200
150
100
50
0
–50
100 10k 100k 10M
3430 G08
1k 1M
GAIN
PHASE
ERROR AMPLIFIER EQUIVALENT CIRCUIT
R
OUT
200k
C
OUT
12pF
V
C
R
LOAD
= 50Ω
T
A
= 25°C
V
FB
2 • 10
–3
)(
V
FB
(V)
0
SWITICHING FREQUENCY (kHz)
OR FB CURRENT (µA)
300
400
600
T
A
= 25°C
500
3430 G09
200
100
0
0.5
1.0
1.5
SWITCHING
FREQUENCY
FB PIN
CURRENT
3430
3430-1
TYPICAL PERFORMANCE CHARACTERISTICS
Switch Peak Current Limit FB Pin Voltage and Current
⎯
S
⎯
H
⎯
D
⎯
N Pin Bias Current
Lockout and Shutdown Threshold Shutdown Supply Current Shutdown Supply Current
Error Amplifi er Transconductance Error Amplifi er Transconductance Frequency Foldback