Analog Devices Inc. AD7816ARM

Overview

AD7816ARM from Analog Devices is a 10-bit, single-channel analog-to-digital converter with integrated temperature sensor, 9 μs conversion time for VIN1, and on-chip 2.5 V reference (±1%). It operates from 2.7 V to 5.5 V and delivers ±1 LSB relative accuracy and ±2°C temperature measurement error across −40°C to +85°C - used in battery-powered industrial sensors and embedded thermal monitoring systems.

For engineers reviewing the AD7816ARM datasheet, AD7816ARM pinout, AD7816ARM application, or AD7816ARM equivalent, key selection considerations include its single-ended analog input architecture, overtemperature indicator (OTI) output, auto power-down mode (4 μW at 10 SPS), and compatibility with Intel 8051/Motorola SPI serial protocols.

Technical Context

The AD7816ARM implements a successive approximation ADC core with capacitor DAC architecture and inherent track-and-hold functionality. Its conversion timing is fixed: 9 μs for channel voltage inputs and 27 μs for the on-chip temperature sensor (Channel 0), with acquisition time of 400 ns after conversion completion or channel change.

It integrates an on-chip bandgap temperature sensor accessed via Channel 0, delivering 0.25°C resolution and ±2°C accuracy from −40°C to +85°C using the internal 2.5 V reference. The OTI pin asserts logic low when temperature exceeds the programmable threshold stored in the on-chip overtemperature register.

Key Specifications

Pinout & Package

AD7816ARM is housed in an 8-lead MSOP package (3.0 mm × 3.0 mm, 0.65 mm pitch), optimized for space-constrained PCB layouts in portable instrumentation and automotive control modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit ADC with integrated temperature sensor applications.

Compared with MAX1270BCPP+ and ADS7822U, the AD7816ARM uniquely combines single-chip 10-bit ADC, calibrated on-die temperature sensing, OTI hardware interrupt, and ultra-low 4 μW idle power - making it optimal for thermally aware, battery-operated systems requiring minimal external components.

Availability

AD7816ARM is available at Aetrix Electronics and suitable for industrial process monitoring, automotive cabin climate control, and portable battery-powered sensors requiring stable component supply and long-lifecycle support.

Supply support for AD7816ARM includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD7816ARM belongs to the AD7817/AD7818 family of compact, low-power ADCs designed specifically for embedded thermal-aware data acquisition in space- and power-constrained applications.

FAQ

What is the conversion time of the AD7816ARM for analog input voltage measurements?

The AD7816ARM achieves a 9 μs conversion time for its single analog input channel (VIN). This timing applies when converting voltage signals within the 0 V to 2.5 V range referenced to GND. The 9 μs figure is specified under standard operating conditions (VDD = 2.7 V to 5.5 V, TA = 25°C) and enables high-throughput sampling up to approximately 111 kSPS. The AD7816ARM maintains this performance regardless of supply voltage within its rated range.

Does the AD7816ARM include an on-chip temperature sensor, and what is its accuracy?

Yes, the AD7816ARM integrates an on-chip temperature sensor accessible via Channel 0. It provides a resolution of 0.25°C per LSB and delivers ±2°C accuracy over the −40°C to +85°C operating range when using the internal 2.5 V reference. This specification is confirmed in the AD7817/AD7818 Rev. E datasheet, Table 1, under "TEMPERATURE SENSOR (AD7818 ONLY)" - and applies directly to the AD7816ARM, which shares the AD7818's single-channel architecture and sensor design.

How does the overtemperature indicator (OTI) pin function on the AD7816ARM?

The OTI pin on the AD7816ARM is an open-drain logic output that goes low when the digitized temperature reading from Channel 0 exceeds the 8-bit threshold stored in the internal overtemperature register (OTR). The OTI signal remains asserted until the next rising edge of RD/WR while CS is low - enabling direct connection to MCU interrupt pins or external latch circuits. This hardware-level alert eliminates polling overhead and supports fail-safe thermal shutdown in real-time systems using the AD7816ARM.

What serial interface protocols does the AD7816ARM support?

The AD7816ARM supports Intel 8051, Motorola SPI, QSPI, and National Semiconductor MICROWIRE serial protocols. Its bidirectional DIN/OUT pin, along with dedicated SCLK and RD/WR control lines, allows seamless integration with widely deployed microcontrollers without protocol translation. Timing parameters (e.g., t12, t13, t14a) are fully specified in the AD7817/AD7818 Rev. E datasheet Table 2, ensuring deterministic communication at clock rates up to several MHz.

Is an external reference required for the AD7816ARM to operate?

No, the AD7816ARM does not require an external reference. It incorporates a trimmed on-chip 2.5 V reference with ±1% initial accuracy and 30 ppm/°C temperature coefficient - sufficient for most embedded thermal monitoring applications. The REFIN pin is absent on the AD7816ARM (as confirmed by AD7818 pinout in Figure 5 and Table 5), distinguishing it from the 4-channel AD7817. Using the internal reference simplifies design, reduces component count, and ensures matched reference tracking for both voltage and temperature measurements in the AD7816ARM.