Datasheet

3
LT1371
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
NFB
Negative Feedback Reference Voltage Measured at Negative Feedback Pin 2.540 2.490 2.440 V
Feedback Pin Open, V
C
= 0.8V 2.570 2.490 2.410 V
I
NFB
Negative Feedback Input Current V
NFB
= V
NFR
–45 –30 –15 µA
Negative Feedback Reference Voltage 2.7V V
IN
25V, V
C
= 0.8V 0.01 0.05 %/V
Line Regulation
g
m
Error Amplifier Transconductance I
C
= ±25µA 1100 1500 1900 µmho
700 2300 µmho
Error Amplifier Source Current V
FB
= V
REF
– 150mV, V
C
= 1.5V 120 200 350 µA
Error Amplifier Sink Current V
FB
= V
REF
+ 150mV, V
C
= 1.5V 1400 2400 µA
Error Amplifier Clamp Voltage High Clamp, V
FB
= 1V 1.70 1.95 2.30 V
Low Clamp, V
FB
= 1.5V 0.25 0.40 0.52 V
A
V
Error Amplifier Voltage Gain 500 V/V
V
C
Pin Threshold Duty Cycle = 0% 0.8 1 1.25 V
f Switching Frequency 2.7V V
IN
25V 450 500 550 kHz
0°C T
J
125°C 430 500 580 kHz
40°C T
J
0°C (I Grade) 400 580 kHz
Maximum Switch Duty Cycle 85 95 %
Switch Current Limit Blanking Time 130 260 ns
BV Output Switch Breakdown Voltage LT1371 35 47 V
LT1371HV
0° C T
J
125°C 42 47 V
40°C T
J
0°C (I Grade) 40 V
V
SAT
Output Switch ON Resistance I
SW
= 2A 0.25 0.45
I
LIM
Switch Current Limit Duty Cycle = 50% 3.0 3.8 5.4 A
Duty Cycle = 80% (Note 1)
2.6 3.4 5.0 A
I
IN
Supply Current Increase During Switch ON Time 15 25 mA/A
I
SW
Control Voltage to Switch Current 4A/V
Transconductance
Minimum Input Voltage 2.4 2.7 V
I
Q
Supply Current 2.7V V
IN
25V 4 5.5 mA
Shutdown Supply Current 2.7V V
IN
25V, V
S/S
0.6V
0° C T
J
125°C 12 30 µA
40°C T
J
0°C (I Grade) 50 µA
Shutdown Threshold 2.7V V
IN
25V 0.6 1.3 2 V
Shutdown Delay 51225µs
S/S or SHDN Pin Input Current 0V V
S/S
or V
SHDN
5V –10 15 µA
Synchronization Frequency Range 600 800 kHz
E
LECTR
IC
AL C CHARA TERIST
ICS
V
IN
= 5V, V
C
= 0.6V, V
FB
= V
REF
, V
SW
, S/S, SHDN, SYNC and NFB pins open, unless otherwise noted.
The denotes specifications which apply over the full operating
temperature range.
Note 1: For duty cycles (DC) between 50% and 90%, minimum
guaranteed switch current is given by I
LIM
= 1.33 (2.75 – DC).