ADP1823:  Dual, Interleaved, Step-Down DC-to-DC Controller with Tracking

The ADP1823 is a versatile, dual, interleaved, synchronous, PWM buck controller that generates two independent output rails from an input of 3.7 V to 20 V, with a power input voltage that ranges from 1 V to 24 V. Each controller can be configured to provide output voltages from 0.6 V to 85% of the input voltage and is sized to handle large MOSFETs for point-of-load regulators. The two channels operate 180° out of phase, reducing stress on the input capacitor and allowing smaller, low cost components. The ADP1823 is ideal for a wide range of high power applications, such as DSP and processor core I/O power, and general-purpose power in telecommunications, medical imaging, PCs, gaming, and industrial applications.

The ADP1823 operates at a pin-selectable, fixed switching frequency of either 300 kHz or 600 kHz, minimizing external component size and cost. For noise sensitive applications, it can also be synchronized to an external clock to achieve switching frequencies between 300 kHz and 1 MHz. The ADP1823 includes soft start protection to prevent inrush current from the input supply during startup, reverse current protection during soft start for precharged outputs, as well as a unique adjustable lossless current-limit scheme using external MOSFET sensing.

For applications requiring power supply sequencing, the ADP1823 also provides tracking inputs that allow the output voltages to track during startup, shutdown, and faults. This feature can also be used to implement DDR memory bus termination.

The ADP1823 is specified over the −40°C to +125°C junction temperature range and is available in a 32-lead LFCSP.

Applications

Data Sheet, Rev. D, 10/07