The AD9267 is a dual continuous time (CT) sigma-delta (Σ-Δ) modulator with -88 dBc of dynamic range over 10 MHz real or 20 MHz complex bandwidth. The combination of high dynamic range, wide bandwidth, and characteristics unique to the continuous time Σ-Δ modulator architecture makes the AD9267 an ideal solution for wireless communication systems. Continuous time Σ-Δ architecture efficiently achieves high dynamic range and wide bandwidth. Passive input structure reduces or eliminates the require- ments 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. Operates from a single 1.8 V power supply. A standard serial port interface (SPI) supports various product features and functions. Features a low pin count, high speed LVDS interface with data output clock.
The AD9267 has a resistive input impedance that significantly relaxes the requirements of the driver amplifier. In addition, a 32× oversampled fifth-order continuous time loop filter attenuates out-of-band signals and aliases, reducing the need for external filters at the input. The low noise figure of 15 dB relaxes the linearity requirements of the front-end signal chain components, and the high dynamic range reduces the need for an automatic gain control (AGC) loop.
A differential input clock controls all internal conversion cycles. An external clock input or the integrated integer-N PLL provides the 640 MHz internal clock needed for the oversampled conti- nuous time Σ-Δ modulator. The digital output data is presented as 4-bit, LVDS at 640 MSPS in twos complement format. A data clock output (DCO) is provided to ensure proper latch timing with receiving logic. Additional digital signal processing may be required on the 4-bit modulator output to remove the out-of-band noise and to reduce the sample rate.
The AD9267 operates on a 1.8 V power supply, consuming 416 mW. The AD9267 is available in a 64-lead LFCSP and is specified over the industrial temperature range (−40°C to +85°C).
Features and Benefits | Analog to Digital Converters |
| Document | note |
| AD9267: 10 MHz Bandwidth, 640 MSPS Dual Continuous Time Sigma-Delta Modulator Preliminary Data Sheet (Rev. 0) | PDF 93 kB |
| Document | note |
| UG-093: Evaluation Board User Guide for the Dual, Continuous Time Sigma-Delta Modulator | PDF 1449 kB |
| Part Number | Package | Packing Qty | Temp Range | Price 100-499 | Price 1000+ | RoHS |
|---|---|---|---|---|---|---|
| AD9267BCPZ Production | 64 ld LFCSP (9x9mm, 6.20mm exposed pad) | OTH 260 | -40 to 85C | 48 | 40.8 | Y |
| AD9267BCPZRL7 Production | 64 ld LFCSP (9x9mm, 6.20mm exposed pad) | REEL 750 | -40 to 85C | 48 | 40.8 | Y |
