Datasheet
2
LT1373
Consult factory for Military grade parts.
(Note 1)
Supply Voltage ....................................................... 30V
Switch Voltage
LT1373 ............................................................... 35V
LT1373HV .......................................................... 42V
S/S Pin Voltage....................................................... 30V
Feedback Pin Voltage (Transient, 10ms) .............. ±10V
Feedback Pin Current........................................... 10mA
Negative Feedback Pin Voltage
(Transient, 10ms)............................................. ±10V
Operating Junction Temperature Range
Commercial ........................................ 0°C to 125°C*
Industrial ......................................... –40°C to 125°C
Short Circuit ......................................... 0°C to 150°C
Storage Temperature Range ................ –65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
LT1373CN8
LT1373HVCN8
LT1373CS8
LT1373HVCS8
LT1373IN8
LT1373HVIN8
LT1373IS8
LT1373HVIS8
S8 PART MARKING
ORDER PART
NUMBER
1373H
1373HI
1373
1373I
*Units shipped prior to Date Code 9552 are rated at 100°C maximum
operating temperature.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
REF
Reference Voltage Measured at Feedback Pin 1.230 1.245 1.260 V
V
C
= 0.8V ● 1.225 1.245 1.265 V
I
FB
Feedback Input Current V
FB
= V
REF
50 150 nA
● 275 nA
Reference Voltage Line Regulation 2.7V ≤ V
IN
≤ 25V, V
C
= 0.8V ● 0.01 0.03 %/V
V
NFB
Negative Feedback Reference Voltage Measured at Negative Feedback Pin –2.51 –2.45 –2.39 V
Feedback Pin Open, V
C
= 0.8V ● –2.55 –2.45 –2.35 V
I
NFB
Negative Feedback Input Current V
NFB
= V
NFR
● –12 –7 –2 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
= ±5µA 250 375 500 µmho
● 150 600 µmho
Error Amplifier Source Current V
FB
= V
REF
– 150mV, V
C
= 1.5V ● 25 50 90 µA
Error Amplifier Sink Current V
FB
= V
REF
+ 150mV, V
C
= 1.5V ● 850 1500 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 250 V/V
V
C
Pin Threshold Duty Cycle = 0% 0.8 1 1.25 V
f Switching Frequency 2.7V ≤ V
IN
≤ 25V 225 250 275 kHz
0°C ≤ T
J
≤ 125°C ● 210 250 290 kHz
–40°C ≤ T
J
≤ 0°C (I Grade) 200 290 kHz
Maximum Switch Duty Cycle ● 85 95 %
Switch Current Limit Blanking Time 340 500 ns
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C.
V
IN
= 5V, V
C
= 0.6V, V
FB
= V
REF
, V
SW
, S/S and NFB pins open, unless otherwise noted.
1
2
3
4
8
7
6
5
TOP VIEW
V
C
FB
NFB
S/S
V
SW
GND
GND S
V
IN
N8 PACKAGE
8-LEAD PDIP
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 125°C, θ
JA
= 100°C/ W (N8)
T
JMAX
= 125°C, θ
JA
= 120°C/ W (S8)
ABSOLUTE AXI U RATI GS
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ELECTRICAL CHARACTERISTICS