Analog Devices Inc. ADUC814BRU

Overview

ADUC814BRU from Analog Devices is a fully integrated 247 kSPS, 12-bit data acquisition system combining an 8052-compatible MCU core, six-channel ADC, dual 12-bit DACs, on-chip Flash/EE memory (8 kB program + 640 B data), and precision voltage reference in a single 28-lead TSSOP package. It operates from 3 V or 5 V across −40°C to +125°C and targets precision sensor interface and closed-loop control applications.

For engineers reviewing the ADUC814BRU datasheet, ADUC814BRU pinout, ADUC814BRU application, or ADUC814BRU equivalent, key selection considerations include its 12-bit ADC with 247 kSPS throughput, dual 12-bit DACs with 15 µs settling time, 8051 instruction compatibility, on-chip PLL generating up to 16.78 MHz core clock, and integrated temperature monitor with ±1.5°C accuracy.

Technical Context

The ADUC814BRU integrates an 8052-based MCU core with three 16-bit timer/counters, UART and SPI/I²C serial interfaces, watchdog timer, power supply monitor, and wake-up/RTC timer. Its ADC supports high-speed data capture mode and programmable reference via on-chip DAC for low-level inputs.

Analog subsystem includes dual independent 12-bit DACs (DAC0/DAC1), internal 2.5 V bandgap reference with 100 ppm/°C tempco, and temperature monitor delivering 650 mV at 25°C with –2 mV/°C TC. Power management features include normal, idle, and power-down modes with 15 µA current draw (oscillator running) at 3 V.

Key Specifications

Pinout & Package

ADUC814BRU is housed in a 28-lead TSSOP package (4.4 mm × 9.7 mm), fully specified for −40°C to +125°C operation. Pin functions are validated per Analog Devices Rev. A datasheet Figure 2 and Table 3.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar mixed-signal microcontroller applications.

Compared with ADUC814BRU, ADUC7024BCPZ62 offers greater processing headroom but sacrifices analog integration and thermal monitoring; MAX1258ETL+ reduces integration significantly, requiring external components for basic functionality and lacking self-contained calibration storage.

Availability

ADUC814BRU is available at Aetrix Electronics and suitable for optical networking, base station power control, and precision instrument applications requiring stable component supply, extended temperature operation, and long-term obsolescence management.

Supply support for ADUC814BRU 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 ADuC8xx MicroConverter® family integrates precision analog front-ends with 8051-compatible MCUs to simplify design of sensor interface, closed-loop control, and data acquisition systems.

FAQ

What is the maximum ADC sampling rate supported by the ADUC814BRU?

The ADUC814BRU supports a maximum ADC sampling rate of 247 kSPS in high-speed data capture mode. This rate is achievable with the on-chip PLL configured for 16.78 MHz core clock and proper ADC control register settings. The ADUC814BRU maintains 12-bit resolution and guaranteed INL/DNL performance at this rate when using the internal 2.5 V reference and operating within specified temperature and supply conditions.

Does the ADUC814BRU support external reference voltage for the ADC?

Yes, the ADUC814BRU supports external reference voltages from 1.0 V to VDD applied to the VREF/CREF pins. The internal bandgap reference must be disabled via ADCCON1.6 to use an external source. Input impedance is 20 kΩ typical, with leakage current ≤10 µA, allowing direct connection to precision external references like REF192 or ADR431 without buffering.

How does the ADUC814BRU handle power management in battery-operated systems?

The ADUC814BRU provides three low-power modes: normal (3 mA @ 3 V, 2.1 MHz), idle (1.2 mA), and power-down (15 µA with 32 kHz oscillator active). In power-down mode, the ADC, DACs, and core are halted while retaining RAM and register contents. Wake-up occurs via INT0, TIC, or serial interrupts within 100 µs, enabling efficient duty-cycled operation in battery-powered ADUC814BRU applications.

Can the ADUC814BRU's dual DACs operate simultaneously and independently?

Yes, the ADUC814BRU's DAC0 and DAC1 are fully independent 12-bit voltage-output DACs sharing only the VREF/CREF reference path. Each has dedicated control registers and can be updated asynchronously. Their outputs (P1.6 and P1.7) settle in 15 µs to within ½ LSB, enabling simultaneous generation of bias and compensation signals - for example, setting RF PA gate voltage while adjusting thermal compensation offset in the same control cycle.

Is the ADUC814BRU pin-compatible with other ADuC8xx family members?

No, the ADUC814BRU is not pin-compatible with other ADuC8xx variants such as ADUC831 or ADUC832. Its 28-lead TSSOP package and specific pin assignments (e.g., shared P1.6/ADC4/DAC0, P1.7/ADC5/DAC1) differ from the 52-lead LQFP packages used by higher-memory variants. Migration requires PCB redesign and firmware adaptation due to differences in memory map, SFR layout, and peripheral register implementation.