The LTC1872 is a constant frequency current mode step-up DC/DC controller providing excellent AC and DC load and line regulation. The device incorporates an accurate undervoltage lockout feature that shuts down the LTC1872 when the input voltage falls below 2.0V. The LTC1872 boasts a ±2.5% output voltage accuracy and consumes only 270µA of quiescent current. For applications where efficiency is a prime consideration, the LTC1872 is configured for Burst Mode operation, which enhances efficiency at low output current. In shutdown, the device draws a mere 8µA. The high 550kHz constant operating frequency allows the use of a small external inductor. The LTC1872 is available in a small footprint 6-lead SOT-23.
The LTC1872 provides a high‑efficiency boost conversion solution with a wide input range of 2.5 V to 9.8 V, 550 kHz constant‑frequency operation, and a low quiescent current of 270 pA. It features a +2.5 % reference accuracy, burst‑mode operation for light loads, and a shutdown mode that draws only 8 µA.
Typical applications include three‑cell white LED drivers, 12 V/500 mA boost converters, and SEPIC converters. The datasheet details pin functions, absolute maximum ratings, electrical characteristics, and design equations for component selection such as inductors, MOSFETs, and capacitors.
| Efficiency | Over 90 % |
|---|---|
| Quiescent current | 270 pA |
| Shutdown mode supply current | 8 µA |
| Operating frequency | 550 kHz (constant) |
| Input voltage range | 2.5 V to 9.8 V |
| Package | 6‑Lead Plastic SOT‑23 |
| Reference accuracy | ±2.5 % |
The device has a low quiescent current of 270 pA.
In shutdown mode the LTC1872 draws only 8 µA of supply current.
It operates at a constant frequency of 550 kHz.
The controller works with an input voltage from 2.5 V up to 9.8 V.