Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

Home > Products > Integrated Circuits (ICs) > Embedded > Microcontrollers

NXP Semiconductors P80C31SBAA,512

Name: P80C31SBAA,512
Brand: NXP Semiconductors
SKU: P80C31SBAA,512
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: P80C31SBAA,512

Manufacturer:: NXP Semiconductors

Category:: Microcontrollers

Package:: 44-LCC (J-Lead)

Datasheet:: P80C31SBAA,512.pdf

Description:: IC MCU 8BIT ROMLESS 44PLCC

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:4,036

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

P80C31SBAA,512 from Philips Semiconductors is a ROMless 8-bit microcontroller based on the 8051 architecture, featuring 128 × 8 RAM, four 8-bit I/O ports (32 total lines), three 16-bit counter/timers, and a full-duplex UART. It operates across 2.7 V–5.5 V at up to 16 MHz and supports idle and power-down modes for low-power embedded control in industrial instrumentation and legacy automation systems.

For engineers reviewing the P80C31SBAA,512 datasheet, P80C31SBAA,512 pinout, P80C31SBAA,512 application, or P80C31SBAA,512 equivalent, this device serves as a static, voltage-flexible 8051 core with external memory interface capability, programmable clock-out on P1.0, and wake-up-from-power-down via INT0/INT1 - critical for battery-backed or energy-constrained designs requiring deterministic reset behavior and zero-frequency stop-clock operation.

Technical Context

The P80C31SBAA,512 implements a static CMOS 8051 CPU core with full Boolean processing, dual data pointers, and a six-source, four-priority nested interrupt system. Its memory architecture supports 64 KB external program memory and 64 KB external data memory via multiplexed address/data bus (Port 0) and high-byte address latch (Port 2).

It integrates an on-chip oscillator with XTAL1/XTAL2, ALE-controlled external address latching, PSEN-gated external code fetches, and EA/VPP-configurable external program memory access. Power management includes software-selectable idle mode (CPU halted, peripherals active) and power-down mode (oscillator stopped, RAM retained down to 2.0 V).

Key Specifications

Parameter	Value and Actual Design Meaning
CPU Core	8051-compatible static architecture enabling zero-frequency operation and deterministic stop/resume execution.
RAM Size	128 × 8 bytes internal RAM - sufficient for small real-time control stacks and register banking without external SRAM.
Max Clock Frequency	16 MHz at 2.7–5.5 V - supports standard 8051 timing with cycle-accurate instruction execution (12 clocks/instruction).
I/O Ports	Four 8-bit bidirectional ports (P0–P3), with Port 0 serving as multiplexed AD0–AD7 + ALE-controlled address/data bus.
Timers/Counters	Three 16-bit timers: Timer 0 and Timer 1 (standard 8051), plus Timer 2 with capture, auto-reload, and baud-rate generation modes.
Serial Interface	Full-duplex UART with framing error detection, automatic address recognition, and independent transmit/receive clock sources (Timer 1 or Timer 2).
Power Modes	Idle mode halts CPU but preserves RAM, timers, UART, and interrupts; power-down mode stops oscillator and retains RAM contents down to 2.0 V.

Pinout & Package

Package: Plastic Leaded Chip Carrier (PLCC), 44-pin, SOT187-2 footprint, lead-free compatible per Philips specification.

Pin/Terminal	Circuit Role	Design Meaning
1	NIC	No internal connection - must be left unconnected or tied to ground per layout guidelines to avoid floating node issues.
2–9	P1.0–P1.7	Port 1: Bidirectional I/O with Schmitt-trigger inputs and internal pull-ups; P1.0/T2 and P1.1/T2EX support Timer 2 capture/reload functions.
10	RST	Active-high reset input requiring ≥2 machine cycles (24 oscillator periods) high pulse; enables power-on reset with external RC network.
11,13–19	P3.0–P3.7	Port 3: Dual-function I/O - RxD/TxD (serial), INT0/INT1 (level-sensitive external interrupts), T0/T1 (timer inputs), WR/RD (external memory strobes).
20–21	XTAL2/XTAL1	Oscillator output/input pair - supports crystal (1–16 MHz), ceramic resonator, or external clock drive on XTAL1 with XTAL2 open.
22	VSS	Ground reference - all internal logic and I/O referenced to this 0 V node; requires low-impedance PCB plane connection.
24–31	P2.0–P2.7	Port 2: High-order address bus (A8–A15) during external memory access; also functions as general-purpose I/O when not addressing external memory.
32–33	PSEN/ALE	PSEN: Active-low read strobe for external program memory; ALE: Address Latch Enable pulse at 1/6 oscillator frequency for latching P0's lower address byte.
34–35	NIC/EA/VPP	NIC: No internal connection; EA/VPP: External Access Enable - held low to force code fetch from external memory (0000H–0FFFH).
36–43	P0.7–P0.0	Port 0: Open-drain bidirectional I/O with Schmitt triggers; multiplexed AD7–AD0 + low-order address during external memory accesses; requires external pull-ups for use as GPIO.
44	VCC	Power supply input (2.7–5.5 V) - supplies core logic, I/O drivers, and internal oscillator; decoupling capacitor required near pin.

Key Features

Feature	Design Value
Static CMOS design	Enables true zero-frequency operation and deterministic stop/resume - essential for ultra-low-power sleep states and debug-on-hold scenarios.
Programmable clock-out on P1.0	Generates 61 Hz–4 MHz square wave (at 16 MHz VCC) for system clock distribution or test signal generation without external oscillator.
Wake-up from power-down	Supported via INT0 or INT1 level-sensitive interrupts - allows event-driven recovery while retaining RAM contents down to 2.0 V supply.
Four-level priority interrupt	Supports nested interrupt handling with six vector sources (INT0, INT1, TF0, TF1, RI/TI, TF2/EXF2), enabling responsive real-time task scheduling.
External memory interface	Integrated 16-bit address bus (P0+P2), RD/WR strobes (P3.6/P3.7), and PSEN enable direct connection to EPROM, SRAM, or peripheral ASICs.

Applications

Industrial PLC I/O Module	Legacy Automotive Body Controller
Use Scenario: Standalone digital I/O expansion module interfacing sensors and actuators in factory-floor control cabinets with RS-485 backhaul. IC Role / Device Role / Timing Role: Primary controller executing ladder logic scan cycles, managing Port 0/2 address-mapped I/O registers, and driving UART for Modbus RTU communication. Use Value: Internal 128-byte RAM suffices for state tables and scan buffers; 16 MHz timing ensures sub-10 ms scan intervals; power-down mode reduces standby consumption during maintenance windows.	Use Scenario: Door lock/unlock and window lift control unit in pre-2000 vehicle platforms using discrete relay drivers and analog sensor conditioning. IC Role / Device Role / Timing Role: Real-time coordinator of switch inputs, motor PWM outputs, and LIN/UART diagnostics - leveraging Timer 2 for precise 20 kHz motor drive timing. Use Value: Four 8-bit ports directly drive opto-isolated relays and LED indicators; idle mode extends battery life during vehicle sleep; RST pin supports robust brown-out recovery.
Medical Infusion Pump Controller	Point-of-Sale Terminal Keypad Processor
Use Scenario: Safety-critical dosing engine monitoring flow sensors, stepper motor position, and alarm buttons in Class II medical devices. IC Role / Device Role / Timing Role: Dedicated safety monitor running watchdog-free deterministic firmware; uses Timer 0 for millisecond tick, UART for nurse station alerts, and Port 3 for emergency stop inputs. Use Value: Static design guarantees no clock drift-induced timing errors; power-down mode preserves dose history in RAM during AC loss; INT0 wake-up enables immediate response to occlusion events.	Use Scenario: Embedded keypad scanner in retail terminals decoding matrix keypresses and transmitting scancodes over UART to host MCU. IC Role / Device Role / Timing Role: Low-overhead key matrix scanner using Port 1 as row driver and Port 2 as column sense, with Timer 1 generating 1 kHz debounce interval. Use Value: 128-byte RAM holds key state buffer and debounced queue; full-duplex UART supports simultaneous host polling and status reporting; PLCC package enables reliable rework in high-volume assembly.

Industrial PLC I/O Module

Legacy Automotive Body Controller

Use Scenario: Standalone digital I/O expansion module interfacing sensors and actuators in factory-floor control cabinets with RS-485 backhaul.

IC Role / Device Role / Timing Role: Primary controller executing ladder logic scan cycles, managing Port 0/2 address-mapped I/O registers, and driving UART for Modbus RTU communication.

Use Value: Internal 128-byte RAM suffices for state tables and scan buffers; 16 MHz timing ensures sub-10 ms scan intervals; power-down mode reduces standby consumption during maintenance windows.

Use Scenario: Door lock/unlock and window lift control unit in pre-2000 vehicle platforms using discrete relay drivers and analog sensor conditioning.

IC Role / Device Role / Timing Role: Real-time coordinator of switch inputs, motor PWM outputs, and LIN/UART diagnostics - leveraging Timer 2 for precise 20 kHz motor drive timing.

Use Value: Four 8-bit ports directly drive opto-isolated relays and LED indicators; idle mode extends battery life during vehicle sleep; RST pin supports robust brown-out recovery.

Medical Infusion Pump Controller

Point-of-Sale Terminal Keypad Processor

Use Scenario: Safety-critical dosing engine monitoring flow sensors, stepper motor position, and alarm buttons in Class II medical devices.

IC Role / Device Role / Timing Role: Dedicated safety monitor running watchdog-free deterministic firmware; uses Timer 0 for millisecond tick, UART for nurse station alerts, and Port 3 for emergency stop inputs.

Use Value: Static design guarantees no clock drift-induced timing errors; power-down mode preserves dose history in RAM during AC loss; INT0 wake-up enables immediate response to occlusion events.

Use Scenario: Embedded keypad scanner in retail terminals decoding matrix keypresses and transmitting scancodes over UART to host MCU.

IC Role / Device Role / Timing Role: Low-overhead key matrix scanner using Port 1 as row driver and Port 2 as column sense, with Timer 1 generating 1 kHz debounce interval.

Use Value: 128-byte RAM holds key state buffer and debounced queue; full-duplex UART supports simultaneous host polling and status reporting; PLCC package enables reliable rework in high-volume assembly.

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8051-based microcontroller applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
AT89C51-24PI	On-chip 4 KB Flash ROM, 128-byte RAM, same 40-pin PDIP package; lacks Timer 2 and programmable clock-out; max 24 MHz operation.	Eliminates need for external EPROM but requires in-system programming infrastructure; unsuitable for designs requiring Timer 2 capture or dual-baud-rate UART.	Select when firmware size fits 4 KB and external memory interface is unnecessary; verify compatibility with existing 8051 toolchain and debug adapters.
DS89C430-QCL+	Enhanced 8051 core, 128-byte RAM, 16 KB Flash, 33 MHz max, integrated USB interface; different pinout and power sequencing requirements.	Offers modern peripherals (USB, DMA) but incompatible with legacy PLCC layouts and external memory bus timing; higher VCC min (4.0 V).	Choose only for new designs targeting USB connectivity and higher throughput; not a drop-in replacement due to package, voltage, and bus architecture differences.

Compared with AT89C51-24PI and DS89C430-QCL+, the P80C31SBAA,512 provides guaranteed external memory interface compatibility, Timer 2 functionality for precision timing, and true 2.7 V operation - making it uniquely suitable for retrofitting legacy 8051 systems where ROM flexibility, low-voltage resilience, and hardware timer extensibility are mandatory.

Availability

P80C31SBAA,512 is available at Aetrix Electronics and suitable for industrial PLC I/O modules, legacy automotive body controllers, and medical infusion pump controllers requiring stable component supply and long-term obsolescence management.

Supply support for P80C31SBAA,512 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

Philips Semiconductors (now NXP Semiconductors) is a pioneer in CMOS microcontroller technology, delivering high-reliability, industry-standard ICs for automotive, industrial, and consumer applications since the 1980s.

The 80C31/80C32 family was designed specifically for cost-sensitive, ROMless embedded control applications requiring external memory expansion, low-voltage operation, and deterministic real-time performance - forming the foundation for decades of 8051-based system designs.

FAQ

What is the maximum operating frequency of the P80C31SBAA,512?

The P80C31SBAA,512 is rated for a maximum operating frequency of 16 MHz across its full 2.7 V–5.5 V supply range. This frequency corresponds to a 12-clock-per-instruction cycle, delivering predictable timing for real-time control loops and UART baud rate generation. Operation above 16 MHz is not supported per Philips specification, even at 5.5 V.

Does the P80C31SBAA,512 include on-chip ROM or Flash memory?

No, the P80C31SBAA,512 is a ROMless microcontroller - it contains no on-chip non-volatile program memory. It relies entirely on external EPROM or Flash memory accessed via its multiplexed Port 0 (AD0–AD7) and Port 2 (A8–A15) address/data bus, controlled by PSEN and EA/VPP signals. This architecture enables field-upgradable firmware and flexible memory sizing.

How does the P80C31SBAA,512 handle power-down mode exit?

The P80C31SBAA,512 exits power-down mode via either a hardware reset or a level-sensitive external interrupt on INT0 or INT1. Upon wake-up, internal RAM and SFRs retain their pre-power-down values if exited via interrupt; a reset clears SFRs but preserves RAM. The oscillator requires stabilization time (<10 ms) before resuming execution from the instruction following the power-down command.

What is the function of the EA/VPP pin on the P80C31SBAA,512?

The EA/VPP pin on the P80C31SBAA,512 controls external program memory access. When held low, it forces the device to fetch instructions exclusively from external memory starting at address 0000H. When pulled high, the device executes from internal ROM (not present in P80C31SBAA,512) or defaults to external memory for all addresses - making EA=low mandatory for functional operation of this ROMless variant.

Can the P80C31SBAA,512 generate two independent UART baud rates?

Yes, the P80C31SBAA,512 can generate independent transmit and receive baud rates using Timer 2 for one direction and Timer 1 for the other. This is enabled by setting RCLK=1 (receive clock from Timer 2) and TCLK=0 (transmit clock from Timer 1), or vice versa. The feature requires proper configuration of T2CON and TMOD registers and is documented in Philips Application Note AN101.

P80C31SBAA,512 Specifications

Product attributes: Attribute value

Manufacturer:: NXP Semiconductors

Package/Case:: 44-LCC (J-Lead)

Series:: 80C

Packaging:: Tube

Product Status:: Obsolete

Programmable:: Not Verified

Core Processor:: 8051

Core Size:: 8-Bit

Speed:: 16MHz

Connectivity:: UART/USART

Peripherals:: POR

Number of I/O:: 32

Program Memory Size:: -

Program Memory Type:: ROMless

EEPROM Size:: -

RAM Size:: 128 x 8

Voltage - Supply (Vcc/Vdd):: 2.7V ~ 5.5V

Data Converters:: -

Oscillator Type:: Internal

Operating Temperature:: 0°C ~ 70°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:

P80C31SBAA,512 FAQ

1.How can I place an order for P80C31SBAA,512 through Aetrix?

Please submit a Request for Quotation (RFQ) for P80C31SBAA,512 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for P80C31SBAA,512 reliable?

The price and inventory of P80C31SBAA,512 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for P80C31SBAA,512 is usually 5 days.

3.What payment methods are accepted for P80C31SBAA,512?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for P80C31SBAA,512 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for P80C31SBAA,512?

P80C31SBAA,512 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your P80C31SBAA,512 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for P80C31SBAA,512?

For technical support, including P80C31SBAA,512 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your P80C31SBAA,512 requirements.

6.How does Aetrix verify that P80C31SBAA,512 is sourced from the original manufacturer or authorized distributors?

All P80C31SBAA,512 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that P80C31SBAA,512 meets industry standards.

7.What is the process for return or replacement of P80C31SBAA,512?

All P80C31SBAA,512 units undergo pre-shipment inspection (PSI). If there is an issue with P80C31SBAA,512, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The P80C31SBAA,512 part is unused and in its original packaging.

Return procedure for P80C31SBAA,512:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

Tech Hub

2026-09-03 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-01 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…

2026-08-18 Operational Amplifier (Op Amp): Basics, Configurations, Feedback and Applications

Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…

2026-08-14 Jumper Cables: How to Use, Connect and Choose Them Safely

Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…