Camarillo, Calif. Semtech Corp. has introduced three step-down (buck) regulators, the SC4525A and SC4524A/B, with high-input voltage and programmable frequency needed for networking and digital consumer applications. The converters are suitable for wide range of applications such as DSL modems, set-top boxes, cable modems and digital TVs. The highly accurate reference voltage (+/-1%) makes them well suited for tightly regulated output voltages, including rails like I/O, memory and most core voltages.
The SC4525A is an asynchronous 3-A step-down converter designed for a wide input voltage range of 8.0 to 28 V. The SC4524 is a 2-A version of the chip with a 3-V minimum input voltage and a choice of two maximum input voltage levels, 28-V (A) or 16-V (B).
All three parts feature a programmable oscillator frequency ranging from 200 kHz to 2 MHz, enabling system designers to reduce EMI and to tailor their designs for size versus cost of the external components, said Semtech. Two external resistors are used to set output voltages as low as 1 V.
All three products also feature extensive protection features. In the event of short circuit or over-current fault condition, the regulators offer cycle-by-cycle, frequency foldback and hiccup mode current limit. With frequency foldback protection, the devices reduce switching frequency to protect the IC and the load. The programmable soft-start not only reduces input start-up current and prevents the output from overshooting during power-up but also provides system designers with flexibility for power sequencing with different slew rates preventing latch up.
The devices are packaged in a thermally enhanced SOIC-8 package with a temperature range of -40°C to +85°C, suitable for use in remote plant applications. They are RoHS and WEEE compliant.
Pricing: The SC4525A (order code: SC4525ASETRT) is priced at $0.42 each in quantities of 1,000. The SC4524A/B (order code: SC4524XSETRT where X indicates the A or B model) are priced at $0.45 each in quantities of 1,000.
Availability: Immediately in production quantities.
Product information: SC4525A, SC4524A, and SC4524B
Semtech Corp., 1-805-498-2111, www.semtech.com