The LT1934/LT1934-1 is a micropower step-down DC/DC converter with internal 400mA power switch, packaged in a low profile (1mm) ThinSOT. With its wide input range of 3.2V to 34V, the LT1934 can regulate a wide variety of power sources, from 4-cell alkaline batteries and 5V logic rails to unregulated wall transformers and lead-acid batteries. Quiescent current is just 12μA and a zero current shut- down mode disconnects the load from the input source, simplifying power management in battery-powered sys- tems. Burst Mode® operation and the low drop internal power switch result in high efficiency over a broad range of load current. The LT1934 provides up to 300mA of output current. The LT1934-1 has a lower current limit, allowing optimum choice of external components when the required output current is less than 60mA. Fast current limiting protects the LT1934 and external components against shorted outputs, even at 34V input.
The LT1934 and LT1934-1 are micropower step‑down DC/DC converters that operate from a wide input voltage range of 3.2 V to 34 V. They can deliver 5 V at up to 250 mA or 3.3 V at up to 250 mA (LT1934) and lower‑current versions (LT1934‑1) for loads under 60 mA. Quiescent current is only 12 µA and the devices feature a shutdown current below 1 pA, making them suitable for battery‑powered and standby applications.
The converters are offered in a low‑profile 1 mm ThinSOT‑23 package and a 6‑lead 2 mm × 3 mm DFN package. The datasheet includes pin configurations, typical performance curves, electrical characteristics, and guidelines for inductor selection and component sizing. Application examples cover wall‑transformer regulation, automotive battery regulation, and distributed supply regulation.
| Input Voltage Range | 3.2 V to 34 V |
|---|---|
| Output Voltage Options | 5 V at 250 mA (LT1934) / 5 V at 60 mA (LT1934‑1); 3.3 V at 250 mA (LT1934) / 3.3 V at 60 mA (LT1934‑1) |
| Quiescent Current | 12 µA |
| Shutdown Current | < 1 pA |
| Low VESAT Switch Voltage | 200 mV at 300 mA |
| Switch Leakage Current | 2 pA |
The LT1934‑1 has a lower peak switch current and is limited to 60 mA output, while the LT1934 can supply up to about 300 mA.
The device operates from 3.2 V up to 34 V input.
It is offered in a 1 mm ThinSOT‑23 (TSOT‑23) package and a 6‑lead 2 mm × 3 mm DFN package.
The quiescent current is about 12 µA.