Datasheet

3
LT1241 Series
PARAMETER CONDITIONS MIN TYP MAX UNITS
Error Amplifier Section
Output Voltage High Level V
PIN2
= 2.3V, R
L
= 15k to GND ● 5 5.6 V
Output Voltage Low Level V
PIN2
= 2.7V, R
L
= 15k to Pin 8 ● 0.2 1.1 V
Current Sense Section
Gain ● 2.85 3.00 3.15 V/V
Maximum Current Sense Input Threshold V
PIN3
< 1.1V ● 0.90 1.00 1.10 V
Power Supply Rejection Ratio ● 70 dB
Input Bias Current ● –1 10 µA
Delay to Output ● 50 100 ns
Blanking Time 100 ns
Blanking Override Voltage 1.5 V
Output Section
Output Low Level I
OUT
= 20mA ● 0.25 0.4 V
I
OUT
= 200mA ● 0.75 2.2 V
Output High Level I
OUT
= 20mA ● 12.0 V
I
OUT
= 200mA ● 11.75 V
Rise Time C
L
= 1nF, T
J
= 25°C5080ns
Fall Time C
L
= 1.0nF, T
J
= 25°C3060ns
Output Clamp Voltage I
O
= 1mA ● 18 19.5 V
Undervoltage Lockout
Start-Up Threshold
LT1241
● 9.0 9.6 10.2 V
LT1242/LT1244
● 15 16 17 V
LT1243/LT1245
● 7.8 8.4 9.0 V
Minimum Operating Voltage
LT1241/LT1243/LT1245 ● 7.0 7.6 8.2 V
LT1242/LT1244
● 9.0 10 11 V
Hysteresis
LT1241 1.6 2.0 V
LT1242/LT1244 5.5 6.0 V
LT1243/LT1245 0.4 0.8 V
PWM
Maximum Duty Cycle
LT1241/LT1244/LT1245 T
J
= 25°C4648%
LT1242/LT1243 T
J
= 25°C9496%
Minimum Duty Cycle ● 0%
Total Device
Start-Up Current ● 170 250 µA
Operating Current ● 710 mA
The ● denotes those specifications which apply over the full operating
temperature range.
Note 1: Unless otherwise specified, V
CC
= 15V, R
T
= 10k, C
T
= 3.3nF.
(Notes 1, 2)
E
LECTR
IC
AL C CHARA TERIST
ICS
Note 2: Low duty cycle pulse techniques are used during test to maintain
junction temperature close to ambient.