AD9851BRSRL

Overview

The AD9851BRSRL is a CMOS 180 MHz Direct Digital Synthesizer (DDS) and DAC in an SSOP-28 package. It features a 32-bit frequency tuning word, a 10-bit DAC, and a high-speed comparator with hysteresis. The device supports a selectable 6× reference clock multiplier, enabling operation from lower external clock frequencies. It operates on a single supply voltage ranging from +2.7 V to +5.25 V. The part provides parallel or serial control interfaces for asynchronous loading of frequency and phase words.

Feature Summary

• Integrates a high-performance 10-bit DAC and a high-speed comparator with hysteresis for direct digital synthesis.
• Includes a selectable 6× reference clock multiplier to reduce the required external oscillator frequency.
• Supports simplified control via parallel data inputs or a serial interface for frequency and phase programming.
• Provides 5-bit phase modulation and offset capability alongside fast frequency switching.

Applications

• Frequency/phase-agile local oscillators for frequency mixing and multiplying.
• Digitally programmable divide-by-N functions within PLL systems.
• High-quality all-digital RF frequency modulation generation.
• Chip rate clock generators in spread spectrum receivers.

Procurement Notes

Verify the RS-28 shrink small outline package marking matches the AD9851BRSRL designation. Confirm the operating temperature range is industrial (-40°C to +85°C). Ensure ESD precautions are observed during handling due to the sensitivity of the CMOS input structures.

Selection Notes

Select this component when a system requires a high-frequency DDS core with integrated analog output and digital comparison capabilities. The 6× multiplier feature allows the use of lower-frequency reference clocks compared to devices without this function. Verify that the required output frequency falls within the Nyquist limit of the chosen system clock configuration.

Part Context

The AD9851BRSRL is the reel-packaged variant of the AD9851BRS. Both share identical electrical specifications and functionality. The suffix RL indicates tape-and-reel packaging suitable for automated surface-mount assembly processes.

Replacement Considerations

The AD9851BRS is the lead-free equivalent with identical pinout and specifications. The AD9850 is a related device but lacks the 6× multiplier and has a lower maximum clock frequency of 125 MHz.