Linear unveils 1.2A step-down switching regulator

Linear Technology has introduced a 1.2A, 37VIN step-down switching regulator.

The LT3686 operates within a VIN range of 3.6V to 37V with overvoltage lockout, protecting the regulator and load from transients as high as 55V, making it suitable for the load-dump and cold-crank conditions found in automotive applications and 24V industrial supplies.

Its internal 1.85A switch can deliver up to 1.2A of continuous output current at voltages as low as 0.8V.

Its low minimum on-time enables it to offer high switching frequencies, even with high step-down ratios.

For example, with an input as high as 16V, it can deliver a 3.3V output using a 2MHz switching frequency.

The LT3686's switching frequency is user programmable from 300kHz to 2.5MHz, enabling designers to maximise efficiency while avoiding critical noise-sensitive frequency bands.

The regulator maintains constant frequency switching, even in very light-load conditions.

The device's 3 x 3mm DFN-10 package and high switching frequency, which keeps the external inductor and capacitors small, provides a compact, thermally efficient footprint.

The LT3686 utilises a 1.85A, 680mV switch with the necessary boost diode, oscillator, control and logic circuitry integrated into a single chip.

Its catch diode current sense (DA pin) protects the circuit during input-voltage transients, even at high switching frequencies.

Special design techniques used in the LT3686 enable high efficiency over a wide input-voltage range and the device's current-mode topology enables fast transient response and excellent loop stability, according to the company.

Other features include a tracking capability, internal compensation and a soft-start capability.

Pricing for the LT3686EDD starts at USD2.50 (GBP1.60) each for 1,000-piece quantities.

An industrial-grade version, the LT3686IDD, is guaranteed to operate from a -40C to +125C operating junction temperature and is priced at USD2.78.

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