AD9851BRSZRL

Overview

The AD9851BRSZRL is a CMOS Direct Digital Synthesis (DDS) and DAC synthesizer manufactured by Analog Devices Inc. It integrates a high-speed 10-bit digital-to-analog converter and a comparator with hysteresis to generate stable, frequency-programmable sine waves or clock signals. The device supports an 180 MHz system clock rate, featuring a selectable 6x reference clock multiplier. It utilizes a 32-bit frequency tuning word for precise resolution and offers a simplified control interface supporting both parallel and serial asynchronous loading formats. The component operates on a single supply voltage ranging from 2.7 V to 5.25 V and is housed in an ultrasmall 28-lead SSOP package.

Feature Summary

• Integrates advanced DDS technology with a high-performance 10-bit DAC and a high-speed comparator with hysteresis for clean signal generation.
• Provides flexible clocking options including a direct input mode and a selectable 6x reference clock multiplier to optimize system design.
• Supports dual control interfaces allowing users to choose between parallel data bus loading or serial asynchronous word loading.
• Enables precise phase manipulation through 5-bit phase modulation and offset capabilities within the digital core.

Applications

• Frequency and phase-agile sine wave synthesis for test equipment
• Clock recovery and locking circuitry for digital communications systems
• Digitally controlled ADC encode generators
• Agile local oscillator applications in communication transceivers
• CW, AM, FM, FSK, and MSK mode transmitter architectures

Procurement Notes

Verify the specific ordering suffix RL indicates reel packaging when sourcing this component. Confirm that the RS-28 shrink small outline package matches your PCB footprint requirements. Ensure the operating temperature range of -40°C to +85°C aligns with your environmental specifications. Cross-reference the manufacturer part number AD9851BRSZRL directly with official Analog Devices documentation to avoid counterfeit components.

Selection Notes

Select this component when a high integration level combining DDS and DAC functions is required without external logic. Consider the 180 MHz maximum clock rate and 10-bit resolution for applications demanding moderate spectral purity. Evaluate the power consumption profiles across different supply voltages if battery operation is a constraint. Verify that the available control interfaces match your microcontroller or FPGA capabilities.

Part Context

This part belongs to the AD9851 series of CMOS DDS synthesizers produced by Analog Devices. The BRSZ designation identifies the industrial temperature grade variant packaged in a 28-lead SSOP. The RL suffix specifically denotes tape and reel packaging suitable for automated surface-mount assembly processes.

Replacement Considerations

The AD9851BRSZ is the non-reel equivalent offering identical electrical characteristics and pinout compatibility. Designers requiring lower clock speeds might consider the AD9835 series, though pinouts and features differ significantly.

FAQ

How does the 6x REFCLK multiplier affect the input clock frequency range?

When enabled, the internal multiplier allows the use of lower external reference frequencies, such as 30 MHz at 5V supply, to achieve the full 180 MHz system clock rate internally.

What is the function of the RSET pin?

The RSET pin connects to an external resistor that sets the full-scale output current of the internal DAC, typically nominally 10 mA with a 3.9 kΩ resistor.

Can the AD9851 operate without a reference clock?

No, the presence of a reference clock is required for operation; in its absence, the device automatically enters a low-power shutdown mode.