Don't be fooled by the small, 16-pin thin-shrink small-outline package (TSSOP) for the step-up LT3436 dc-dc converter. The device delivers a sizable punch—a 35-V output (within 2%) at 3 A. Its input voltage ranges from 3 to 25 V. Also, it can operate from single-cell lithium-ion (Li-ion) batteries up to fixed 24-V rails. As a result, only 0.9 mA of current (6 µA of quiescent current in the shutdown mode) is required, suiting it for applications in battery-powered systems, distributed power, portable computers, and DSL modems.
The LT3436's constant 800-kHz switching frequency of 800 MHz allows designers to keep switching noise out of phase-sensitive circuitry, and it enables the use of tiny capacitors and inductors. The 3-A maximum switch current remains constant at all duty cycles. Switching frequency can be synchronized 1 to 1.4 MHz via an external logic signal.
An on-chip 0.1-Ω,3-A switch includes all of the control circuitry needed for this current-mode converter with a low-dropout (LDO) regulator. Current-mode operation provides both fast transient response and good loop stability. The converter is designed to operate from −40°C to 120°C.
The LT3436 is available from stock, with pricing starting at $2.75 each in 1000-piece quantities.Linear Technology Corp.www.linear.com (408) 432-1900