LT1372/LT1377
TYPICAL PERFORMANCE CHARACTERISTICS
Shutdown Delay and Threshold
vs Temperature
MINIMUM SYNCHRONIZATION VOLTAGE (V
P-P
)
20
18
16
2.0
1.8
SHUTDOWN THRESHOLD
1.6
1.4
1.2
1.0
SHUTDOWN DELAY
0.8
0.6
0.4
0.2
0
0
25 50 75 100 125 150
TEMPERATURE (°C)
LT1372 • G04
2.5
2.0
f
SYNC
= 700kHz (LT1372)
f
SYNC
= 1.4MHz (LT1377)
ERROR AMPLIFIER OUTPUT CURRENT (µA)
SHUTDOWN DELAY (µs)
14
12
10
8
6
4
2
0
–50 –25
S/S Pin Input Current
vs Voltage
5
4
SWITCHING FREQUENCY (% OF TYPICAL)
V
IN
= 5V
TRANSCONDUCTANCE (µmho)
S/S PIN INPUT CURRENT (µA)
3
2
1
0
–1
–2
–3
–4
–5
–1
0
1
2 3 4 5 6
S/S PIN VOLTAGE (V)
7
8
9
V
C
Pin Threshold and High
Clamp Voltage vs Temperature
2.4
2.2
2.0
V
C
PIN VOLTAGE (V)
V
C
HIGH CLAMP
FEEDBACK INPUT CURRENT (nA)
700
600
500
400
300
200
100
V
FB
=V
REF
NEGATIVE FEEDBACK INPUT CURRENT (µA)
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
LT1372 • G10
V
C
THRESHOLD
4
U W
LT1372 • G07
Minimum Synchronization
Voltage vs Temperature
3.0
400
300
200
100
0
–100
–200
–300
0
25 50 75 100 125 150
TEMPERATURE (°C)
LT1372 • G05
Error Amplifier Output Current
vs Feedback Pin Voltage
25°C
–55°C
125°C
SHUTDOWN THRESHOLD (V)
LT1377
1.5
LT1372
1.0
0.5
0
–50 –25
–0.3
V
REF
–0.2
–0.1
FEEDBACK PIN VOLTAGE (V)
0.1
LT1372 • G06
Switching Frequency
vs Feedback Pin Voltage
110
100
90
80
70
60
50
40
30
20
10
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
FEEDBACK PIN VOLTAGE (V)
LT1372 • G08
Error Amplifier Transconductance
vs Temperature
2000
1800
1600
1400
1200
1000
800
600
400
200
0
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
LT1372 • G09
g
m
=
∆I
(V
C
)
∆V
(FB)
Feedback Input Current
vs Temperature
800
Negative Feedback Input Current
vs Temperature
0
V
NFB
=V
NFR
–10
–20
–30
–40
0
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
LT1372 • G11
–50
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
LT1372 • G12
LINER [ LINEAR TECHNOLOGY ]
