Part A
ADUC831BSZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2439 PCS
- Package
- MQFP-52
- Series
- Embedded - Microcontrollers
Replacement verdict
Compatible functional replacement candidate
The ADUC831BSZ and ADUC845BS8-5 are both MicroConverter 12-bit ADC MCUs from the same Analog Devices family, sharing core architecture and peripheral philosophy, but they differ in on-chip memory density, package footprint, and supply voltage range. The ADUC845BS8-5 offers higher flash and SRAM capacity and a wider supply range, while the ADUC831BSZ provides a smaller 52-lead MQFP footprint. Direct substitution requires validation of memory headroom, board layout, and supply rail compatibility before adoption.
On-Chip Memory Density
Validation required
Package Type
Validation required
Supply Voltage Range
Validation required
Core Architecture
High match
Parts at a glance
Part B
ADUC845BS8-5
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 5736 PCS
- Package
- QFP-52
- Series
- Embedded - Microcontrollers
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADUC831BSZ | ADUC845BS8-5 | Why it matters |
|---|---|---|---|
| Core / CPU | 8051-compatible 8-bit MCU (single-cycle, 16 MHz max) | 8051-compatible 8-bit MCU (single-cycle, 12.58 MHz max) | Both are 8051 cores, but the maximum core clock differs, affecting instruction throughput and timing-sensitive routines. |
| Program Memory (Flash) | 62 kB Flash | 62 kB Flash | Identical on-chip code storage means firmware size constraints are the same for both parts. |
| Data Memory (RAM) | 2304 bytes on-chip RAM | 2304 bytes on-chip RAM | Equal RAM capacity supports the same data buffering and stack requirements. |
| ADC Resolution / Channels | 12-bit ADC, 8 channels (single-ended/pseudo-differential) | 24-bit sigma-delta ADC, 10 channels | The ADUC845 offers much higher resolution and more channels, making it suitable for precision sensor measurement where the ADUC831's 12-bit ADC is insufficient. |
| On-chip DAC | Dual 12-bit voltage-output DACs | Dual 16-bit voltage-output DACs | Higher DAC resolution on the ADUC845 enables finer analog output control for closed-loop or waveform applications. |
| Supply Voltage | 3.0 V to 3.6 V | 4.75 V to 5.25 V (5 V nominal) | Different operating rails mean the two parts are not drop-in replacements; the system power supply must match the selected device. |
| Package | 52-lead MQFP | 52-lead MQFP | Same package footprint allows board-level interchangeability if the surrounding circuitry supports the electrical differences. |
| UART / Serial Interfaces | UART, SPI, and I2C | UART, SPI, and I2C | Matching serial peripherals preserve communication architecture compatibility between designs. |
| Operating Temperature Range | -40 °C to +85 °C (industrial) | -40 °C to +85 °C (industrial) | Identical temperature ratings mean both suit the same industrial environments. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADUC831BSZ | ADUC845BS8-5 |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Series | MicroConverter® ADuC8xx | MicroConverter® ADuC8xx |
| Part Status | Active | Obsolete |
| Core Processor | 8052 | 8052 |
| Core Size | 8-Bit | 8-Bit |
| Speed | 16MHz | 12.58MHz |
| Connectivity | EBI/EMI, I²C, SPI, UART/USART | I²C, SPI, UART/USART |
| Peripherals | PSM, Temp Sensor, WDT | POR, PSM, PWM, Temp Sensor, WDT |
| Number of I/O | 34 | 34 |
| Program Memory Size | 62KB (62K x 8) | 8KB (8K x 8) |
| Program Memory Type | FLASH | FLASH |
| EEPROM Size | 4K x 8 | 4K x 8 |
| RAM Size | 2.25K x 8 | 2.25K x 8 |
| Voltage - Supply (Vcc/Vdd) | 2.7V ~ 5.5V | 4.75V ~ 5.25V |
| Data Converters | A/D 8x12b; D/A 2x12b | A/D 10x24b; D/A 1x12b, 2x16b |
| Oscillator Type | Internal | Internal |
| Operating Temperature | -40°C ~ 125°C (TA) | -40°C ~ 125°C |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the core differences between the ADUC831BSZ and the ADUC845BS8-5?
The ADUC831BSZ is a MicroConverter 12-bit ADC with embedded 8-bit MCU in a 52-lead MQFP package, while the ADUC845BS8-5 is a MicroConverter dual 24-bit/16-bit ADC with embedded 8-bit MCU in an 80-lead MQFP package. The ADUC845BS8-5 offers higher resolution sigma-delta ADCs and more on-chip memory, whereas the ADUC831BSZ provides a faster 12-bit SAR ADC with a smaller footprint.
Are the ADUC831BSZ and ADUC845BS8-5 pin-to-pin compatible?
No. The ADUC831BSZ uses a 52-lead MQFP package and the ADUC845BS8-5 uses an 80-lead MQFP package, so they have different pin counts, pin assignments, and PCB land patterns. They cannot be directly substituted without a board redesign.
What are the ADC specifications of each device?
The ADUC831BSZ integrates a 12-bit successive-approximation ADC with up to 8 single-ended or 4 differential input channels. The ADUC845BS8-5 integrates dual sigma-delta ADCs: a primary 24-bit ADC and an auxiliary 16-bit ADC, targeting high-resolution precision measurement applications.
How do the on-chip memory and processing resources compare?
The ADUC831BSZ includes 62 kB of on-chip Flash/EE program memory and 2 kB of data RAM. The ADUC845BS8-5 includes 62 kB of on-chip Flash/EE program memory and 2.3 kB of data RAM. Both use an 8051-compatible core, but the ADUC845BS8-5 provides additional data memory for its higher-resolution signal processing needs.
What are the supply voltage and operating temperature ranges for these parts?
The ADUC831BSZ operates from a 3 V to 3.6 V supply over an industrial temperature range of −40°C to +85°C. The ADUC845BS8-5 operates from a 4.75 V to 5.25 V supply over the same −40°C to +85°C industrial temperature range. The differing supply voltages must be considered when evaluating a design migration.
Which device is better suited for high-resolution precision measurement?
The ADUC845BS8-5 is better suited for high-resolution precision measurement because its dual sigma-delta ADCs provide 24-bit and 16-bit resolution, whereas the ADUC831BSZ's 12-bit SAR ADC is better suited to faster, lower-resolution control and monitoring tasks.
Do both devices support in-circuit serial programming and debug?
Yes. Both the ADUC831BSZ and ADUC845BS8-5 support in-circuit serial programming and debug via the standard 8051-compatible UART-based download/debug interface, allowing firmware updates without removing the device from the board.
What on-chip peripherals are common to both devices?
Both devices integrate an 8051-compatible MCU core, on-chip Flash/EE program memory, data RAM, UART and SPI serial interfaces, timers/counters, watchdog timer, power supply monitor, and on-chip temperature sensor, making them suitable for compact embedded control and data-acquisition designs.