Linear Technology Introduces Monolithic Dual Output Step-Down Switching Regulator

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Linear Technology Corporation (Linear Technology Corporation) introduced a monolithic dual output step-down switching regulator LT3692. The device delivers up to 3.5A of continuous output current per channel. Operating over an input voltage range of 3V to 36V and with 60V transient protection, the LT3692 is ideal for load dump and cold cranking in automotive applications. Independent input, shutdown, feedback, soft-start, current-limit, and comparator pins per channel simplify complex power tracking/sequencing requirements. The user-programmable switching frequency of the LT3692 ranges from 250kHz to 2.25MHz, enabling designers to optimize efficiency while avoiding critical noise-sensitive frequency bands.

To optimize efficiency and component size, both converters have a programmable maximum current limit that can be synchronized to each other through the device's internal oscillator or external clock input. The converter operates out of phase at 180° to further reduce voltage ripple and external component size. Multiple regulators can be synchronized by an external clock output to provide additional voltage rails. Conversely, the output can be combined for high current applications, allowing the LT3692 to deliver up to 7A of continuous output current. The device's 5mm x 5mm QFN-32 package combined with high switching frequency enables the use of smaller external capacitors and inductors for a very compact and thermally efficient footprint. The LT3692's main switch features a high efficiency 3.8A, 300mV CESAT switch with the necessary oscillator, control and logic circuitry integrated into one core.

Unique design techniques provide high efficiency over a wide input voltage range while its current mode topology enables fast transient response and excellent loop stability. The LT3692 also provides a divider on one channel that can operate at 1/2, 1/4, or 1/8 of the other channel frequency to achieve high step-down ratios and minimize external components size of. Enhanced short circuit protection and chip temperature monitoring provide a higher level of protection. Other features include thermal shutdown and a separate power good sign.

The LT3692EUH is available in a 5mm x 5mm 32-pin QFN package and is priced at $4.25 each. The industrial grade version of the LT3692IUH has been tested to ensure a junction temperature of -40oC to 125oC and is priced at $4.70 each. All prices are in 1,000-piece quantities, and both versions of the LT3692 are available from stock. For more information, please visit