Part A
ADUC834BSZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 4126 Stückzahl
- Package
- MQFP-52
- Series
- Eingebettete Mikrocontroller
Replacement verdict
Compatible functional replacement candidate
The ADUC834BSZ and ADUC847BS32-3 are both single-cycle 8051-core precision analog microcontrollers with integrated 24-bit sigma-delta ADCs, but they differ in on-chip memory architecture, ADC channel count, and package footprint. The ADUC847BS32-3 offers a larger 32 kB flash program memory and additional single-ended ADC input channels, while the ADUC834BSZ provides 62 kB flash and a different multiplexer configuration. Neither device is a pin-for-pin drop-in, so firmware revalidation and footprint review are required before substitution.
Core Architecture
Validation required
ADC Resolution and Channels
Validation required
Program Memory Size
Not compatible
Package Type
Not compatible
Parts at a glance
Part B
ADUC847BS32-3
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 3529 Stückzahl
- Package
- QFP-52
- Series
- Eingebettete Mikrocontroller
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADUC834BSZ | ADUC847BS32-3 | Why it matters |
|---|---|---|---|
| Core Architecture | 8052-compatible 8-bit MCU core | 8052-compatible 8-bit MCU core | Both use the same 8052 core, so instruction set and toolchain compatibility are preserved. |
| Program Memory (Flash) | 64 kB | 32 kB | Firmware size capacity differs; a smaller Flash may not fit existing code, affecting direct substitutability. |
| Data Memory (SRAM) | 2 kB | 2 kB | SRAM affects runtime buffer and stack capacity; identical here so no impact on substitutability. |
| ADC Resolution | 24-bit sigma-delta | 24-bit sigma-delta | Both provide 24-bit precision, so measurement resolution requirements are equally met. |
| Number of ADC Channels | 3 differential / 6 pseudo-differential | 10 single-ended / 5 differential | Channel count and configuration affect how many sensors can be connected; the ADUC847 offers more input flexibility. |
| DAC Outputs | 2 x 12-bit voltage DACs | 2 x 12-bit voltage DACs | Analog output capability is identical, so control-loop or setpoint applications remain compatible. |
| Operating Supply Voltage | 2.7 V to 3.6 V | 2.7 V to 3.6 V | Same supply range means the same power rail design can be reused without modification. |
| Package / Pin Count | 52-lead MQFP | 32-lead LFCSP | Different package and pin count require PCB redesign; not a drop-in replacement. |
| UART / Serial Interfaces | UART, SPI, I2C | UART, SPI, I2C | Identical serial interface set supports the same communication peripherals and protocols. |
| On-Chip Temperature Sensor | Yes | Yes | Both include an internal temperature sensor, so thermal monitoring functionality is preserved. |
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 | ADUC834BSZ | ADUC847BS32-3 |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Series | MicroConverter® ADuC8xx | MicroConverter® ADuC8xx |
| Part Status | Active | Obsolete |
| Core Processor | 8052 | 8052 |
| Core Size | 8-Bit | 8-Bit |
| Speed | 12.58MHz | 12.58MHz |
| Connectivity | EBI/EMI, I²C, SPI, UART/USART | I²C, SPI, UART/USART |
| Peripherals | POR, PSM, PWM, Temp Sensor, WDT | POR, PSM, PWM, Temp Sensor, WDT |
| Number of I/O | 34 | 34 |
| Program Memory Size | 62KB (62K x 8) | 32KB (32K 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 ~ 5.25V | 2.7V ~ 3.6V |
| Data Converters | A/D 3x16b, 4x24b; D/A 1x12b | 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 architectural differences between the ADUC834BSZ and the ADUC847BS32-3?
The ADUC834BSZ is a MicroConverter® integrating a 24-bit sigma-delta ADC with a 12-bit DAC and an 8051-core MCU, offering 4 KB of on-chip Flash and 256 bytes of RAM. The ADUC847BS32-3 is a MicroConverter® with a 24-bit sigma-delta ADC and an 8051-core MCU, featuring 32 KB of on-chip Flash and 2 KB of RAM, but it does not include an on-chip DAC. Both are based on the 8051 instruction set but differ in memory density and analog output capability.
Are the ADUC834BSZ and ADUC847BS32-3 pin-compatible?
No. The ADUC834BSZ is supplied in a 52-lead MQFP package, while the ADUC847BS32-3 is supplied in a 48-lead LFCSP package. The package footprints, pin counts, and pin assignments differ, so they are not drop-in replacements and require different PCB land patterns.
How do the ADC resolutions and channel counts compare between these two parts?
Both devices integrate a 24-bit sigma-delta ADC. The ADUC834BSZ provides a primary 24-bit ADC plus a secondary 16-bit ADC, while the ADUC847BS32-3 provides a 24-bit ADC with multiple input channels. Designers should consult the respective datasheets for exact channel configuration and PGA settings, as the analog front-end architectures are not identical.
What are the supply voltage and operating temperature ranges for these devices?
The ADUC834BSZ operates from a 3 V or 5 V supply and is specified over the industrial temperature range of −40°C to +85°C. The ADUC847BS32-3 operates from a 3 V supply (the "−3" suffix denotes the 3 V version) and is also specified over −40°C to +85°C. The ADUC847BS32-3 is not rated for 5 V operation.
Can the ADUC847BS32-3 replace the ADUC834BSZ in an existing design?
Not directly. Beyond the package and pinout differences, the ADUC847BS32-3 lacks the on-chip 12-bit DAC present on the ADUC834BSZ, and it is a 3 V-only device. Any replacement requires a full schematic and layout revision, firmware revalidation, and confirmation that the target design does not rely on the DAC or 5 V operation.
How do the on-chip memory resources differ between the ADUC834BSZ and ADUC847BS32-3?
The ADUC834BSZ provides 4 KB of on-chip Flash program memory and 256 bytes of on-chip RAM. The ADUC847BS32-3 provides 32 KB of on-chip Flash program memory and 2 KB of on-chip RAM. The ADUC847BS32-3 therefore offers substantially more code and data space for larger firmware applications.
Do both devices include an on-chip temperature sensor and reference?
Both the ADUC834BSZ and ADUC847BS32-3 integrate an on-chip temperature sensor and an on-chip voltage reference as part of the MicroConverter® analog front-end. Designers should verify the specified accuracy and drift of these internal blocks in the respective datasheets, as the performance specifications may differ between the two parts.