AD7817ARUZ Analog Devices

The AD7817ARUZ from Analog Devices is a high-performance, 10-bit, 4-channel analog-to-digital converter (ADC) belonging to the S/H ADC category. It utilizes a successive approximation register (SAR) architecture and features a fast 100 kS/s sampling rate, making it ideal for multi-channel data acquisition systems. Operating from a single 2.7 V to 5.5 V supply, it offers excellent flexibility for both 3V and 5V systems. With its SPI-compatible serial interface, low power dissipation, and an operating temperature range of -40°C to +85°C, this ADC is well-suited for a wide range of applications including industrial process control, battery-powered portable instrumentation, and automotive sensor interfaces.

Features

• High Integration and Flexibility: Integrates a 4-channel multiplexer, track-and-hold, 10-bit SAR ADC, and a 2.5V reference, supporting both internal and external reference options for design versatility.
• Wide Supply Voltage Range: Operates from a single 2.7 V to 5.5 V analog and digital supply, ensuring compatibility with 3V and 5V logic systems without requiring level translation.
• Fast SPI Interface: Features a high-speed, SPI-compatible 3-wire serial interface for easy connection to microcontrollers and digital signal processors, simplifying board layout.
• Low Power Operation: Designed for power-sensitive applications with a typical power dissipation of 450 mW, supporting efficient performance in portable and battery-operated devices.

Technical Specifications

• Resolution: 10 bit
• Number of Input Channels: 4 Channel (Single-Ended)
• Sampling Rate: 100 kS/s
• Interface Type: SPI
• Architecture: SAR
• Supply Voltage Range: 2.7 V to 5.5 V
• Operating Temperature Range: -40°C to +85°C
• DNL (Differential Nonlinearity): ±1 LSB
• INL (Integral Nonlinearity): ±1 LSB
• Reference Voltage: 2.5 V (Internal/External)
• Package Type: TSSOP-16

Pin Configuration and Functions

• Pin 1 (VIN1): Analog Input Channel 1.
• Pin 2 (VIN2): Analog Input Channel 2.
• Pin 3 (VIN3): Analog Input Channel 3.
• Pin 4 (VIN4): Analog Input Channel 4.
• Pin 5 (GND): Ground.
• Pin 6 (REFIN/OUT): Reference Input/Output. Connects to internal 2.5V reference or an external reference.
• Pin 7 (VDD): Positive Supply Voltage (2.7V to 5.5V).
• Pin 8 (CONVST): Conversion Start Input.
• Pin 9 (SSTRB): Serial Strobe Output.
• Pin 10 (DIN): Serial Data Input.
• Pin 11 (DOUT): Serial Data Output.
• Pin 12 (SCLK): Serial Clock Input.
• Pin 13 (CS): Chip Select Input (Active Low).
• Pins 14, 15, 16 (NC): No Connect.

Typical Applications

• Industrial Process Control: Multi-point temperature and pressure monitoring systems.
• Portable Battery-Powered Instruments: Data loggers and handheld measurement devices.
• Automotive Sensor Interfaces: Reading signals from position, pressure, or temperature sensors.
• Power System Monitoring: Measuring battery voltage and current in UPS or embedded systems.

Equivalent / Alternative Parts

• AD7816 (Analog Devices): Pin-compatible alternative with a 2-channel input multiplexer instead of 4 channels.
• AD7818 (Analog Devices): Similar 10-bit, 4-channel ADC with a different (SOIC) package and slightly varied specifications.

Advantages

• Compact System Footprint: The integrated 4-channel mux and reference in a TSSOP-16 package significantly reduces external component count and board space versus discrete solutions.
• Robust Performance Across Temperature: Specified INL/DNL of ±1 LSB over the full -40°C to +85°C range ensures reliable and accurate conversions in harsh environments.
• Simplified Power Design: Single-supply operation from 2.7V to 5.5V eliminates the need for negative supply rails, simplifying power architecture and reducing BOM cost.

Limitations

• Limited Resolution for Precision Needs: The 10-bit resolution may be insufficient for high-precision measurement applications requiring greater than 0.1% accuracy.
• Moderate Sampling Rate: At 100 kS/s, it is not suitable for high-speed signal acquisition applications such as audio processing or fast transient analysis.
• External Reference Dependency for High Accuracy: While an internal reference is provided, achieving optimal performance over temperature and supply voltage may require a stable external reference.

Package Information

TSSOP-16 package (5.0mm x 4.4mm body size), 16 pins, surface mount. The package height is 1.05mm, suitable for space-constrained PCB designs.

Manufacturer Information

Analog Devices is a global leader in the design and manufacturing of high-performance analog, mixed-signal, and digital signal processing (DSP) integrated circuits. The company's products are known for precision, reliability, and innovation, serving critical applications across industrial, automotive, communications, and consumer electronics markets.

Design-in Tips

• Decouple Supplies Properly: Place 0.1µF and 10µF ceramic capacitors as close as possible to the VDD pin (Pin 7) and GND (Pin 5) to minimize noise and ensure stable operation.
• Manage Analog Input Signals: For high-impedance signal sources, use a buffer amplifier to drive the ADC inputs and minimize sampling errors caused by charge injection.
• Optimize Reference Circuitry: For applications demanding high accuracy, bypass the REFIN/OUT pin (Pin 6) with a low-ESR capacitor and consider using a precision external reference voltage source.

Lifecycle Status & PCN/PDN Notes

Lifecycle status information is not provided in the input parameters. No product change notifications (PCN) or product discontinuation notices (PDN) are specified at this time.