Datasheet

3
LT1374
1374fd
PARAMETER CONDITIONS MIN TYP MAX UNITS
Feedback Voltage (Adjustable) 2.39 2.42 2.45 V
All Conditions
● 2.36 2.48 V
Sense Voltage (Fixed 5V) 4.94 5.0 5.06 V
All Conditions
● 4.90 5.10 V
SENSE Pin Resistance 71014 kΩ
Reference Voltage Line Regulation 5V ≤ V
IN
≤ 25V (5V ≤ V
IN
≤ 32V for LT1374HV) 0.01 0.03 %/V
Feedback Input Bias Current ● 0.5 2 µA
Error Amplifier Voltage Gain (Notes 2, 8) 200 400
Error Amplifier Transconductance ∆I (V
C
) = ±10µA (Note 8) 1500 2000 2700 µMho
● 1000 3100 µMho
V
C
Pin to Switch Current Transconductance 5.3 A/ V
Error Amplifier Source Current V
FB
= 2.1V or V
SENSE
= 4.4V ● 140 225 320 µA
Error Amplifier Sink Current V
FB
= 2.7V or V
SENSE
= 5.6V ● 140 225 320 µA
V
C
Pin Switching Threshold Duty Cycle = 0 0.9 V
V
C
Pin High Clamp 2.1 V
Switch Current Limit V
C
Open, V
FB
= 2.1V or V
SENSE
= 4.4V, DC ≤ 50% ● 4.5 6 8.5 A
Slope Compensation (Note 9) DC = 80% 0.8 A
Switch On Resistance (Note 7) I
SW
= 4.5A 0.07 0.1 Ω
● 0.13 Ω
Maximum Switch Duty Cycle V
FB
= 2.1V or V
SENSE
= 4.4V 90 93 %
● 86 93 %
Switch Frequency V
C
Set to Give 50% Duty Cycle 460 500 540 kHz
● 440 560 kHz
Switch Frequency Line Regulation 5V ≤ V
IN
≤ 25V, (5V ≤ V
IN
≤ 32V for LT1374HV) ● 0 0.15 %/ V
Frequency Shifting Threshold on FB Pin ∆f = 10kHz ● 0.8 1.0 1.3 V
Minimum Input Voltage (Note 3) ● 5.0 5.5 V
Minimum Boost Voltage (Note 4) I
SW
≤ 4.5A ● 2.3 3.0 V
Boost Current (Note 5) I
SW
= 1A ● 20 35 mA
I
SW
= 4.5A ● 90 140 mA
V
IN
Supply Current (Note 6) V
BIAS
= 5V ● 0.9 1.4 mA
BIAS Supply Current (Note 6) V
BIAS
= 5V ● 3.2 4.0 mA
Shutdown Supply Current V
SHDN
= 0V, V
IN
≤ 25V, V
SW
= 0V, V
C
Open 20 50 µA
● 75 µA
V
SHDN
= 0V, V
IN
≤ 32V, V
SW
= 0V, V
C
Open 30 75 µA
● 100 µA
Lockout Threshold V
C
Open ● 2.3 2.38 2.46 V
Shutdown Thresholds V
C
Open Device Shutting Down ● 0.13 0.37 0.60 V
Device Starting Up
● 0.25 0.45 0.7 V
Synchronization Threshold ● 1.5 2.2 V
Synchronizing Range 580 1000 kHz
SYNC Pin Input Resistance 40 kΩ
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: Gain is measured with a V
C
swing equal to 200mV above the
switching threshold level to 200mV below the upper clamp level.
Note 3: Minimum input voltage is not measured directly, but is guaranteed
by other tests. It is defined as the voltage where internal bias lines are still
regulated so that the reference voltage and oscillator frequency remain
constant. Actual minimum input voltage to maintain a regulated output will
depend on output voltage and load current. See Applications Information.
Note 4: This is the minimum voltage across the boost capacitor needed to
guarantee full saturation of the internal power switch.
The ● denotes specifications which apply over the full operating tempera-
ture range, otherwise specifications are at T
J
= 25°C. V
IN
= 15V, V
C
= 1.5V, Boost = V
IN
+ 5V, switch open, unless otherwise noted.
ELECTRICAL CHARACTERISTICS