1. General Information / Operating Conditions

️· Device: LT1370 (likely with variations like LT1370HVC and LT1370HVI, I-Grade)
️· Input Voltage Range (VIN): 2.4V to 25V (minimum input voltage: 2.4V)
️· Operating Temperature Range: -40°C to 125°C (depending on grade).
️· Reference Voltage (VREF): 1.230V to 1.260V (standard), 1.225V to 1.265V (other variations). This is a crucial reference for the feedback loop.

2. Key Functional Parameters

️· Switching Frequency (f): 440 kHz to 580 kHz (varies with temperature and grade).
️· Maximum Duty Cycle: 85% (can vary to 95% depending on parameter)
️· Switch ON Resistance (VSAT): 0.065 Ω to 0.11 Ω. Lower is better for efficiency.
️· Switch Current Limit (ILIM): 6A to 10A. The current limit is dynamic and dependent on duty cycle, as detailed by the formula `ILIM = 2.65(2.7 – DC)`.
️· Shutdown Threshold: 0.6V to 2V. Determines the voltage at which the regulator shuts down.
️· Synchronization Frequency Range: 600 kHz to 800 kHz.

3. Feedback and Error Amplification

️· Error Amplifier Transconductance (gm): 700 µS to 2300 µS (This defines how effectively the error amplifier responds to feedback signal changes).
️· Error Amplifier Clamp Voltage: 0.2V to 2.3V (These limits how the error amplifier shapes the output voltage).
️· VC Pin Threshold: 0.9V to 1.35V (Voltage required on the control voltage pin to trigger switching).

4. Efficiency and Current Consumption

️· Supply Current (IQ): 4.5 mA to 6mA (This is the quiescent current when the regulator is in normal operation).
️· Shutdown Supply Current: 12 µA to 40 µA (Current when the regulator is in shutdown mode).
️· Supply Current Increase During Switch ON Time (∆IIN, ∆ISW): 22mA to 33mA (Important for transient response).

5. Other Notable Parameters

️· Shutdown Delay: 4 µs to 25 µs (Time it takes for the regulator to enter/exit shutdown).
️· S/S Input Current: -7 µA to 10 µA (Current flowing into the synchronization pin).
️· Output Switch Breakdown Voltage (BV): 35V to 47V.

Summary Table (Important Values)

Parameter	Range	Units
Input Voltage (VIN)	2.4 - 25	V
VREF	1.230 - 1.260	V
Switching Frequency (f)	440 - 580	kHz
Duty Cycle (DC)	0 - 85% (varies)	%
ILIM	6 - 10	A
IQ	4.5 - 6	mA

Key Takeaways and Considerations:

️· Grade variations: Pay attention to the different grades (LT1370, LT1370HVC, LT1370HVI) as their specifications can differ, particularly regarding temperature range and some performance parameters.
️· Dynamic Behavior: Many parameters are not fixed values but depend on factors like input voltage, duty cycle, and temperature.
️· Feedback Loop: The LT1370’s feedback loop is crucial for maintaining a stable output voltage. Understanding parameters like VREF, error amplifier gain, and feedback input current is essential for proper design.
️· Synchronization: The ability to synchronize the switching frequency can be important for reducing EMI or meeting specific application requirements.