Linear Technology LT1425, Manual

Page: 4 / 20

4
LT1425
TYPICAL PERFOR M A N CE CHARACTERISTICS
U W
Feedback Amplifier Output
Current vs R
REF
Pin Voltage
R
REF
NODE VOLTAGE (V)
1.05
60
40
20
0
–20
–40
–60
–80
1.20 1.30
1425 G04
1.10 1.15
1.25 1.35 1.40
FEEDBACK AMPLIFIER OUTPUT CURRENT (
µ
A)
25
°
C
125
°
C
–55
°
C
TEMPERATURE (
°
C)
–50
2.50
2.25
2.00
1.75
1.50
1.25
1.00
0.75
25 75
1425 G06
–25 0
50 100 125
V
C
PIN VOLTAGE (V)
V
C
HIGH CLAMP
V
C
THRESHOLD
V
C
Pin Threshold and High Clamp
Voltage vs Temperature
TEMPERATURE (
°
C)
–50
1400
1200
1000
800
600
400
200
0
25 75
1425 G05
–25 0 50 100 125
TRANSCONDUCTANCE (
µ
mho)
Error Amplifier Transconductance
vs Temperature (R
REF
Referred)
Switching Frequency vs
Temperature
SHDN Pin Input Current vs
Voltage Minimum Synchronization
Voltage vs Temperature
TEMPERATURE (
°
C)
–50
300
295
290
285
280
275
270
265
25 75
1425 G07
–25 0 50 100 125
SWITCHING FREQUENCY (kHz)
TEMPERATURE (
°
C)
–50
2.50
2.25
2.00
1.75
1.50
1.25
1.00
0.75
25 75
1425 G08
–25 0 50 100 125
MINIMUM SYNCHRONIZATION VOLTAGE (V
P-P
)
SHDN PIN VOLTAGE (V)
0
1
0
–1
–2
–3
–4
4
1425 G09
1 2 3 5
SHDN PIN INPUT CURRENT (
µ
A)
T
A
= 25
°
C
Minimum Switch ON Time vs
Temperature Flyback Enable Delay Time vs
Temperature
TEMPERATURE (
°
C)
–50
300
275
250
225
200
175
150
125
25 75
1425 G10
–25 0 50 100 125
SWITCH ON TIME (ns)
TEMPERATURE (
°
C)
–50
250
225
200
175
150
125
100
75
25 75
1425 G11
–25 0 50 100 125
ENABLE DELAY TIME (ns)
TEMPERATURE (
°
C)
–50
275
250
225
200
175
150
125
100
25 75
1425 G12
–25 0 50 100 125
ENABLE TIME (ns)
Minimum Flyback Enable Time vs
Temperature