AD5934YRSZ

Overview

The AD5934YRSZ is a high-precision impedance converter system solution manufactured by Analog Devices Inc. It integrates an on-board Direct Digital Synthesis (DDS) frequency generator with a 12-bit, 250 kSPS analog-to-digital converter (ADC). The device excites external complex impedances with known frequencies and processes the response signals using an internal DSP engine to perform Discrete Fourier Transform (DFT). This yields real and imaginary data words for calculating impedance magnitude and phase. Key specifications include a maximum output frequency of 100 kHz, 27-bit frequency resolution, and operation within a 2.7 V to 5.5 V supply range across temperatures from -40°C to +125°C.

Feature Summary

• Integrates a programmable DDS frequency generator with a 12-bit ADC and onboard DSP for DFT processing.
• Supports serial I2C interface control for frequency sweep capabilities and register configuration.
• Provides four programmable output peak-to-peak voltage ranges to accommodate various impedance levels.
• Delivers system accuracy of 0.5% for impedance measurements within the specified operating conditions.

Applications

• Electrochemical analysis
• Bioelectrical impedance analysis
• Impedance spectroscopy
• Corrosion monitoring and protection equipment
• Nondestructive testing

Procurement Notes

Verify the specific suffix YRSZ corresponds to the SSOP-16 package and industrial temperature grade (-40°C to +125°C). Confirm that the MCLK pin requires an external master clock source, as the AD5934 lacks an internal oscillator unlike the AD5933. Ensure the design accounts for the mandatory external feedback resistor connected between RFB and VIN pins to set the receive stage gain.

Selection Notes

Select the AD5934YRSZ when an external clock source is available and a sampling rate of 250 kSPS is sufficient. Note that this model differs from the AD5933 by requiring an external MCLK and lacking an integrated temperature sensor. Verify that the target impedance range falls within 1 kΩ to 10 MΩ, or confirm if additional buffer circuitry is required for measurements below 1 kΩ.

Part Context

The AD5934 is part of the AD5933/AD5934 family of impedance converters. While functionally similar to the AD5933, it is distinguished by its reliance on an external master clock and a reduced sampling rate of 250 kSPS compared to the AD5933's 1 MSPS. Both devices share the same 16-lead SSOP package and core DDS architecture but serve slightly different timing and integration requirements in system designs.

Replacement Considerations

The AD5933YRSZ is a related component but requires modification for direct replacement due to architectural differences. The AD5933 includes an internal oscillator and supports 1 MSPS sampling, whereas the AD5934 mandates an external MCLK signal. Designers must adjust clock generation circuits and software drivers when migrating between these two variants.

FAQ

Does the AD5934YRSZ contain an internal oscillator?

No, the AD5934 does not have an internal oscillator. It requires an external master clock signal to be supplied to the MCLK pin for operation.

What is the standard impedance measurement range for the AD5934?

The standard impedance measurement range is from 1 kΩ to 10 MΩ. Measurements from 100 Ω to 1 kΩ are possible but require additional external buffer circuitry.

How is the impedance magnitude calculated?

The magnitude is calculated using the real (R) and imaginary (I) data words returned by the onboard DFT engine, typically using the formula: Magnitude = sqrt(R^2 + I^2).