Step-down DC/DC converter delivers 3A

Linear Technology has announced the LT3501, a dual current mode PWM step-down DC/DC converter with two internal 3.5A power switches packaged in a 20-lead TSSOP-20E package. Each channel is capable of delivering up to 3A of continuous output current at efficiencies up to 88 per cent. Independent input voltage, feedback, soft-start and power good pins for each channel simplify complex power supply tracking and sequencing requirements. Its wide input range of 3.3V to 25V makes it suitable for regulating power from a wide variety of sources, including 5V and 12V rails, unregulated wall transformers, lead acid batteries and distributed power supplies. The LT3501's switching frequency is user programmable between 250kHz and 1.5MHz, allowing optimisation between efficiency and external component size.

Both of the LT3501's converters are synchronised to an external clock input or an internal oscillator and maintain a 180o phase offset between channels to reduce voltage ripple and input capacitor size. An internal 0.80V reference enables sub 1V output voltages required to power the latest generation of low voltage DSPs and microcontrollers (MCUs). Independent, sequential, ratiometric or absolute tracking is easily attained between the outputs. Low drop-out internal switches enable duty cycles to reach 95 per cent while internal cycle-by-cycle current limit provides protection against shorted outputs. The low current (<10uA) shutdown offers extended run-time in battery-powered systems.

The LT3501EFE is available from stock in a thermally enhanced TSSOP-20 package. There is also an "I" Grade temperature version, the LT3501IFE. Pricing starts at Rs.159.32 ($3.50) and Rs.191.18 ($4.20) each, respectively, for 1,000-piece quantities.