LT1576/LT1576-5
TYPICAL PERFORMANCE CHARACTERISTICS
Switch Drop
0.5
125°C
2.5
TYPICAL
SWITCH PEAK CURRENT (A)
0.4
SWITCH VOLTAGE (V)
25°C
0.3
1.5
MINIMUM
–20°C
0.2
FEEDBACK VOLTAGE (V)
0.1
0
0
0.25
0.50 0.75 1.00
SWITCH CURRENT (A)
1.25
1.50
Shutdown Pin Bias Current
4
AT 2.44V STANDBY THRESHOLD
(CURRENT FLOWS OUT OF PIN)
3
140
SHUTDOWN PIN VOLTAGE (V)
CURRENT (µA)
CURRENT (µA)
2
1
0
0
25
50
75 100
–50 –25
JUNCTION TEMPERATURE (°C)
Standby Thresholds
2.46
2.45
2.44
ON
2.43
STANDBY
2.42
2.41
2.40
50
100
–50 –25
25
75
0
JUNCTION TEMPERATURE (°C)
25
INPUT SUPPLY CURRENT (µA)
SHUTDOWN PIN VOLTAGE (V)
GAIN (µMho)
4
U W
1576 G01
1576 G04
Switch Peak Current Limit
1.23
Feedback Pin Voltage
2.0
1.22
1.21
1.0
0.5
1.20
0
0
20
60
40
DUTY CYCLE (%)
80
100
1576 G02
1.19
0
25
50
75 100
–50 –25
JUNCTION TEMPERATURE (°C)
125
1576 G03
Shutdown Pin Bias Current
180
160
0.8
0.7
0.6
0.5
0.4
Shutdown Thresholds
120
100
80
60
40
20
CURRENT REQUIRED TO FORCE
SHUTDOWN (FLOWS OUT OF PIN).
AFTER SHUTDOWN, CURRENT
DROPS TO A FEW
µA
125
START-UP
SHUTDOWN
0.3
0.2
0.1
0
0
50
25
75 100
–50 –25
JUNCTION TEMPERATURE (°C)
125
125
0
0
25
50
75 100
–50 –25
JUNCTION TEMPERATURE (°C)
1576 G05
1576 G06
Shutdown Supply Current
2000
V
SHDN
= 0V
Error Amplifier Transconductance
200
PHASE
20
1500
GAIN
150
PHASE (DEG)
15
1000
100
10
500
V
FB
1
×
10
–3
(
)
R
OUT
570k
V
C
C
OUT
2.4pF
50
5
0
ERROR AMPLIFIER EQUIVALENT CIRCUIT
0
R
LOAD
= 50Ω
0
–500
0
5
15
10
INPUT VOLTAGE (V)
20
25
1576 G08
125
10
100
1k
10k
FREQUENCY (Hz)
100k
–50
1M
1576 G09
1576 G07