LF33ABV-DG

Overview

The LF33ABV-DG is a fixed-output linear voltage regulator from the LFxx series, providing a stable 3.3 V DC output with a maximum load current of 500 mA. It operates within an input voltage range up to 40 V and features a very low dropout voltage of 0.45 V. The device includes an internal ON/OFF switch for power management, reducing quiescent current to 50 μA in OFF mode. It is housed in a TO-220 package with three pins, supporting through-hole mounting. The component functions reliably across an extended temperature range from -40 °C to +125 °C.

Feature Summary

• Integrated ON/OFF control switch enables deep sleep modes for significant power savings
• Very low dropout voltage ensures efficient regulation even with minimal input-to-output differential
• Low quiescent current consumption supports extended battery life in portable applications
• Robust thermal performance allows operation in high ambient temperature environments

Applications

• Battery-powered consumer electronics requiring low standby current
• Portable devices needing efficient step-down regulation from higher voltage sources
• Low-noise analog circuits powered by regulated 3.3 V rails
• Industrial control systems operating in wide temperature ranges

Procurement Notes

Verify the exact suffix DG indicates lead-free RoHS-compliant packaging when ordering. Confirm that the TO-220 package matches your PCB footprint requirements. Ensure input voltage does not exceed 40 V to prevent device damage. Check thermal dissipation needs based on load current and ambient temperature. Validate that the fixed 3.3 V output aligns with system design specifications before procurement.

Selection Notes

Choose this regulator when a fixed 3.3 V output is required with minimal dropout voltage. It is suitable for applications where power efficiency during idle states is critical due to the integrated switch feature. Consider the TO-220 package size for thermal management capabilities. Compare against other LDOs if adjustable output or higher current capacity is needed. Verify compatibility with existing circuit topology and input voltage levels.

Part Context

This component belongs to STMicroelectronics' LFxx family of very low-dropout regulators. The LFxx series offers various output voltages and packages including TO-220, DPAK, and PENTAWATT. The AB variant typically denotes specific thermal and electrical characteristics compared to the C variant. This family is designed for general-purpose linear regulation in compact and power-sensitive designs.

Replacement Considerations

Direct substitutes include LF33ABV (same function, verify package) and LF33CV (similar performance, check dropout specs). Cross-reference with LM338 or similar 3.3 V LDOs only if pinout and electrical parameters match exactly. Always validate thermal resistance and package dimensions before substitution.