AD7762 625 kSPS, 24-Bit, 109 dB Sigma-Delta ADC with On-Chip Buffer

Data acquisition systems Vibration analysis Instrumentation

The AD7762 is a high performance, 24-bit Σ-Δ analog-to-digital converter (ADC). It combines wide input bandwidth and high speed with the benefits of Σ-Δ conversion with a performance of 106 dB SNR at 625 kSPS, making it ideal for high speed data acquisition. Wide dynamic range combined with significantly reduced anti-aliasing requirements simplify the design process. An integrated buffer to drive the reference, a differential amplifier for signal buffering and level shifting, an overrange flag, internal gain and offset registers, and a low-pass digital FIR filter make the AD7762 a compact, highly integrated data acquisition device requiring minimal peripheral component selection. In addition, the device offers programmable decimation rates, and the digital FIR filter can be adjusted if the default characteristics are not appropriate to the application. The AD7762 is ideal for applications demanding high SNR without a complex front end signal processing design.

The differential input is sampled at up to 40 MSPS by an analog modulator. The modulator output is processed by a series of low-pass filters, the final filter having default or user-programmable coefficients. The sample rate, filter corner frequencies, and output word rate are set by a combination of the external clock frequency and the configuration registers of the AD7762.

The reference voltage supplied to the AD7762 determines the analog input range. With a 4 V reference, the analog input range is ±3.2 V differential biased around a common mode of 2 V. This common mode biasing can be achieved using the on-chip differential amplifier, further reducing the external signal conditioning requirements.

The AD7762 is available in an exposed paddle, 64-lead TQFP and is specified over the industrial temperature range from −40°C to +85°C.

Applications

Features and Benefits

120 dB dynamic range at 78 kHz output data rate
109 dB dynamic range at 625 kHz output data rate
112 dB SNR at 78 kHz output data rate
106 dB SNR at 625 kHz output data rate
625 kHz maximum fully filtered output word rate
Programmable over-sampling rate (32x to 256x)

Fully differential modulator input
On-chip differential amplifier for signal buffering
Low pass FIR filter with default or user programmable coefficients
Over-range alert bit
Digital offset and gain correction registers
Low power and power down modes

Analog to Digital Converters

A/D Converters

Data Sheets

Document	note
AD7762: 625 kSPS, 24-Bit, 109 dB Sigma-Delta ADC With On-Chip Buffer Data Sheet (Rev. A)	PDF 561 kB

Application Notes

Document	note
AN-282: Fundamentals of Sampled Data Systems	PDF 2131 kB
AN-342: Analog Signal-Handling for High Speed and Accuracy	PDF 468 kB
AN-280: Mixed Signal Circuit Technologies	PDF 2101 kB
AN-389: Using Sigma-Delta Converters-Part 2	PDF 590 kB
AN-388: Using Sigma-Delta Converters-Part 1	PDF 590 kB
AN-311: How to Reliably Protect CMOS Circuits Against Power Supply Overvoltaging	PDF 217 kB
AN-283: Sigma-Delta ADCs and DACs	PDF 1699 kB

User Guides

Document	note
UG-593: Evaluating the AD7760 and AD7762 Using the EVAL-CED1Z (Rev. 0)	PDF 962.37 K

Order Information

Part Number	Package	Packing Qty	Temp Range	Price 100-499	Price 1000+	RoHS
AD7762BSVZ Production	64 lead TQFP_EP(10x10mm w/7.50 EP_B)	OTH 160	-40 to 85C	23.49	18.42	Y
AD7762BSVZ-REEL Production	64 lead TQFP_EP(10x10mm w/7.50 EP_B)	REEL 1500	-40 to 85C	0	18.42	Y