L4974 (L4974A) 3.5A Switching Regulator IC

L4974 (L4974A) 3.5A Switching Regulator IC

The L4974 / L4974A is a high-performance monolithic step-down (buck) switching regulator IC designed to provide a 3.5A output current with outstanding efficiency, stability, and protection features. Developed by STMicroelectronics, it integrates a power transistor, control circuitry, and safety protections into a single compact device — simplifying the design of efficient DC-DC converters.

Operating at a typical switching frequency of 100 kHz, the L4974A delivers fast transient response and low ripple, while minimizing the size of external components. Its adjustable output voltage (from 5.1V to 40V) and wide input voltage range (up to 50V) make it suitable for a variety of industrial, automotive, and embedded applications requiring reliable high-current power conversion.

The L4974A operates as a pulse-width modulated (PWM) step-down converter. It regulates the output voltage by controlling the duty cycle of an internal power transistor that switches the current through an external inductor.

Its integrated error amplifier, oscillator, and PWM control circuitry ensure stable and accurate voltage regulation under varying load and input conditions. The built-in soft-start, overload protection, and thermal shutdown features enhance system reliability, while the remote inhibit input allows easy on/off control in intelligent systems.

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Features:-

• 3.5a Output Current
• 5.1v To 40v Output Voltage Range
• 0 To 90% Duty Cycle Range
• Internal Feed-Forward Line Reg
• Internal Current Limiting
• Precise 5.1v ± 2% On Chip Reference
• Reset And Power Fail Functions .Input/Output Sync Pin
• Under Voltage Lock Out With Hysteretic Turn-On
• Pwm Latch For Single Pulse Per Period
• Very High Efficiency
• Switching Frequency Up To 200khz
• Thermal Shutdown
• Continuous Mode Operation

Specifications:-