The LM3671 is a 2MHz, 600mA step-down DC-DC converter optimized for powering ultra-low voltage circuits from a single Li-Ion cell or 3 cell NiMH/NiCd batteries. It provides up to 600mA load current over an input voltage range from 2.8V to 5.5V. There are several different fixed voltage output options available as well as an adjustable output voltage version. The device offers superior features and performance for mobile phones and similar portable applications with complex power management systems. Automatic intelligent switching between PWM low-noise and PFM low-current mode offers improved system control. During full-power operation, a fixed-frequency 2 MHz (typ) PWM mode drives loads from ∼70 mA to 600 mA max. Hysteretic PFM mode extends the battery life through reduction of the quiescent current to 16 µA (typ) at light loads and system standby. Internal synchronous rectification provides high efficiency. In shutdown mode (Enable pin pulled low) the device turns off and reduces battery consumption to 0.01 µA (typ). The LM3671 is available in a SOT23-5 package with Pb and No Pb (Lead free) versions. A high switching frequency - 2 MHz (typ) - allows use of tiny surface-mount components. Only three external surface-mount components, an inductor and two ceramic capacitors, are required.
The LM3671 is a 2 MHz fixed‑frequency step‑down DC‑DC converter optimized for low‑noise PWM and low‑current PFM operation. It delivers up to 600 mA from an input range of 2.8 V to 5.5 V, features internal synchronous rectification, and requires only three external surface‑mount components (one inductor and two ceramic capacitors).\n\nThe document includes typical application circuits, pin descriptions, ordering information, absolute maximum and electrical ratings, performance graphs, and board‑layout recommendations. It also contains regulatory notices such as life‑support policy and banned‑substance compliance, plus contact details for National Semiconductor support centers worldwide.
| Input Voltage Range | 2.8 V to 5.5 V |
|---|---|
| Maximum Load Current | 600 mA |
| Switching Frequency | 2 MHz (typ) |
| Package | SOT23‑5 |
| Operating Temperature Range | -25 °C to +125 °C |
The LM3671 operates with an input voltage from 2.8 V to 5.5 V.
The device is supplied in a SOT23‑5 package.