Dual-output regulator IC combines switching and linear regulation

The new A4402 from Allegro MicroSystems Europe is a new dual output regulator IC that integrates a buck switching regulator and a linear regulator to provide dual output voltages such as those required by microcontrollers or DSP-based applications. The new device operates over a supply voltage range from 6 V to 50 V, and provides two adjustable output voltages that are regulated to within 2% across all operating conditions.

The constant on-time buck regulator operates at a switching frequency of up to 2 MHz, allowing the system designer to select low-value inductors and capacitors.
An adjustable soft-start timer is used to ramp the output voltage in a controlled fashion at start-up, reducing the demand on the external power supply by limiting the current that charges the output capacitor and any DC load.

Protection features include under-voltage lockout and thermal shutdown. In the event of a short-circuited load, overcurrent protection is also provided for each regulator. The A4402 also features a watchdog timer to monitor the state of a microcontroller or DSP circuitry, along with a power-on reset function with adjustable delay to provide a signal to reset the system.

Target markets are any consumer, office or industrial applications that require two output rails, especially microcontrollers or DSP systems requiring I/O and core voltages. Typical uses will be in printers, scanners, modems or routers, industrial control, distributed power systems, set-top boxes, GPS units and white goods.

The A4402 is provided in a 16-pin TSSOP package, with exposed pad for enhanced thermal dissipation. It is lead (Pb) free, with 100% matt tin leadframe plating.