AD9261 16-Bit, 10 MHz Bandwidth, 30 MSPS to 160 MSPS Continuous Time Sigma-Delta ADC

The AD9261 is a 16-bit analog-to-digital converter (ADC) based on a continuous time sigma-delta (Σ-Δ) architecture that achieves 86 dB of dynamic range over a 10 MHz input bandwidth. The integrated features and characteristics unique to the continuous time Σ-Δ architecture significantly simplify its use and minimize the need for external components.

The AD9261 has a resistive input impedance that significantly relaxes the requirements of the driver amplifier. In addition, a 32× oversampled 5th-order continuous time loop filter significantly attenuates out of band signals and aliases, reducing the need for external filters at the input.

An external clock input or the integrated integer-N PLL provides the 640 MHz internal clock needed for the oversampled continuous time Σ-Δ modulator. On-chip decimation filters and sample rate converters reduce the modulator data rate from 640 MSPS to a user-defined output data rate between 30 MSPS to 160 MSPS, enabling a more efficient and direct interface.

The digital output data is presented in offset binary, Gray code, or twos complement format. A data clock output (DCO) is provided to ensure proper timing with the receiving logic.

The AD9261 operates on a 1.8 V analog supply and a 1.8 V to 3.3 V digital supply, consuming 375 mW. The AD9261 is available in a 48-lead LFCSP and is specified over the industrial temperature range (−40°C to +85°C).

Product Highlights

Continuous time Σ-Δ architecture efficiently achieves high dynamic range and wide bandwidth.
Passive input structure reduces or eliminates the requirements for a driver amplifier.
An oversampling ratio of 32× and high order loop filter provide excellent alias rejection reducing or eliminating the need for antialiasing filters.
An integrated decimation filter, sample rate converter, PLL clock multiplier, and voltage reference provide ease of use.
Operates from a single 1.8 V analog power supply and 1.8 V to 3.3 V output supply.
A standard serial port interface (SPI) supports various product features and functions.

Applications

Data Acquisition
Automated Test Equipment
Instrumentation
Medical Imaging

Features and Benefits

SNR: 83 dB (85 dBFS) to 10 MHz input
SFDR: 87 dBc to 10 MHz input
Noise figure: 15 dB
Input impedance: 1 kΩ
Power: 340 mW
1.8 V analog supply operation
1.8 V to 3.3 V output supply
Selectable bandwidth 2.5 MHz/5 MHz/10 MHz
Output data rate: 30 MSPS to 160 MSPS

Integrated decimation filters
Integrated sample rate converter
On-chip PLL clock multiplier
On-chip voltage reference
Offset binary, Gray code, or twos complement data format
Serial control interface (SPI)

Analog to Digital Converters

A/D Converters

Data Sheets

Document	note
AD9261: 16-Bit, 10 MHz Bandwidth, 30 MSPS to 160 MSPS Continuous Time Sigma-Delta ADC Preliminary Data Sheet (Rev. 0)	PDF 105 kB

Application Notes

Document	note
AN-878: High Speed ADC SPI Control Software (Rev. A)	PDF 585 kB
AN-905: Visual Analog Converter Evaluation Tool Version 1.0 User Manual (Rev. 0)	PDF 2124 kB
AN-835: Understanding High Speed ADC Testing and Evaluation (Rev. B)	PDF 985 kB
AN-282: Fundamentals of Sampled Data Systems	PDF 2131 kB
AN-1142: Techniques for High Speed ADC PCB Layout (Rev. 0)	PDF 392 kB
AN-807: Multicarrier WCDMA Feasibility (Rev. 0)	PDF 969 kB
AN-808: Multicarrier CDMA2000 Feasibility (Rev. 0)	PDF 1535 kB
AN-812: MicroController-Based Serial Port Interface (SPI) Boot Circuit (Rev. 0) Software Download (zip, 21,702,560 bytes)	PDF 441 kB
AN-283: Sigma-Delta ADCs and DACs	PDF 1699 kB

Order Information

Part Number	Package	Packing Qty	Temp Range	Price 100-499	Price 1000+	RoHS
AD9261BCPZ-10 Production	48 ld LFCSP 7x7mm (5.1EP)	OTH 260	-40 to 85C	32.94	28	Y
AD9261BCPZRL7-10 Production	48 ld LFCSP 7x7mm (5.1EP)	REEL 750	-40 to 85C	32.94	28	Y