W78L812A24PL - 8-bit 8051 MCU, 8KB Flash, 24MHz | Nuvoton
N.º de pieza: W78L812A24PL ✓ ActivoW78L812A24PL Descripción general
An 8-bit MCU is the simplest tier of the microcontroller hierarchy: MCU -> 8-bit microcontroller -> 8051 core -> embedded control IC. The W78L812 belongs to the 8051 family of single-chip computers, combining a CPU core, program memory, data memory and peripherals on one die. Because the instruction set is compatible with the standard 8051, existing 8051 assembler, C compiler and bootloader tooling can be reused without architectural changes.
Key features include 8 KB of Flash EPROM instead of masked ROM, which allows field re-programming and simplifies product revisions. The device carries 256 bytes of internal RAM plus a 256-byte XRAM area, four 8-bit bi-directional bit-addressable I/O ports (P0 through P3), an additional 5-bit port P4, and three 16-bit timer/counter blocks with interrupt support for timing, pulse counting and periodic event generation. A 24 MHz oscillator gives roughly ten times the execution rate of a classic 12 MHz 8051.
Because the instruction set, memory map and port structure follow the established 8051 convention, the W78L812A24PL is a natural fit for cost-sensitive embedded controllers that must run existing 8051 code. The wide 2.4 V to 5.5 V supply range allows direct operation from unregulated industrial rails, 3.3 V systems or rechargeable cells after regulation.
Typical applications include smart appliances, small motor controllers, security keypads, industrial sequencers, LED lighting controllers and low-cost data acquisition front ends. Its PLCC package is a strong argument for designs that expect manual soldering or socketed prototyping rather than fully automated SMT assembly.
When designing around this device, remember that Flash EPROM programming requires a dedicated programmer, and that the 44-PLCC footprint is not the same as the 40-pin DIP variant of the same family. Confirm the pinout and package drawing from the manufacturer datasheet before laying out the board, and keep decoupling close to the supply pins.
Alternativas directas para W78L812A24PL — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
W78L812A24PL
✅ Sustitución directaConsulte el precio
Ver hoja de datos →W79E823BSG
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
W78L812A20PL
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
W78L811A24PL
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
W78L812A24PL Valores máximos y características eléctricas
| Device Type | 8-bit Microcontroller (MCU) |
| Core | 8051-compatible instruction set |
| Program Memory | 8 KB Flash EPROM |
| Data Memory | 256 bytes RAM |
| Maximum CPU Clock | 24 MHz |
| Tensión de alimentación de funcionamiento | 2.4 V to 5.5 V |
| I/O Ports | Four 8-bit bi-directional bit-addressable ports (P0-P3) plus 5-bit port P4 |
| Timers/Counters | Three 16-bit timer/counter blocks |
| Encapsulado | 44-pin PLCC (PL) |
| Tipo de montaje | Surface mount / socketed PLCC |
| Wake-Up Support | Yes |
| Programmable Memory Type | Flash EPROM (re-programmable) |
| Bit Addressable I/O | Yes (P0-P3) |
| Datasheet Length | 33 pages |
| Datasheet File Size | 473 KB (PDF) |
Guía de configuración de pines de W78L812A24PL 44-pin plcc (pl)
Configuración de pines para W78L812A24PL (encapsulado 44-pin plcc (pl)). Este CI digital incluye GPIO, interfaces de comunicación (UART, SPI, I2C) y pines de alimentación. Consulte la hoja de datos del fabricante para conocer las funciones alternativas de los pines y las opciones de configuración. Esencial para el diseño de sistemas embebidos y el diseño de PCB.
No hay datos detallados de patillaje disponibles para W78L812A24PL.
Consulte la hoja de datos para ver la configuración completa de patillas.
Aplicaciones típicas
W78L812A24PL es adecuado para 6 aplicacións: Smart Appliance Control Boards, Industrial Sequencer and Timer Controller, LED Lighting and Dimming Controllers, Security Keypad and Access Controller, Low-Cost Data Acquisition Front End, Small Motor and Pump Controller.
Smart Appliance Control Boards
The W78L812A24PL suits appliance controllers that must run established 8051 code on a low-cost platform. Its 8 KB Flash EPROM allows firmware revisions without changing masked parts, while the 24 MHz clock speeds up motor and valve sequencing loops compared with a 12 MHz 8051. Four 8-bit bit-addressable ports drive relays, triac gates and seven-segment displays, and the three 16-bit timers handle timing for fans, defrost cycles and button debounce. Operating from 2.4 V to 5.5 V lets the same board work from 5 V rectified or 3.3 V regulated rails, and the 44-PLCC package suits hand-soldered or socketed low-volume builds rather than high-speed SMT lines.
Recomendado
Industrial Sequencer and Timer Controller
For conveyor sequencing, batch timers and pump rotation logic, the W78L812A24PL provides three 16-bit timer/counter blocks that can be cascaded or run independently, giving precise timing resolution without external timers. The 8051-compatible instruction set means legacy machine-control firmware can be recompiled with minimal change, and the wide 2.4 V to 5.5 V supply tolerates industrial 24 V rails after a simple regulator stage. Bit-addressable P1 and P2 pins simplify direct solenoid and opto-isolator interfacing, and the PLCC package is accepted in panel-mount industrial controllers where through-hole or socketed assembly is standard.
Recomendado
LED Lighting and Dimming Controllers
The W78L812A24PL is well suited to multi-channel LED driver control boards where the microcontroller generates PWM or timing signals for analogue and digital dimming. Its 24 MHz clock allows accurate pulse-width generation and flicker-free dimming steps, while the bit-addressable ports allow individual channel enable lines to be toggled without read-modify-write timing concerns on larger port widths. Eight KB of Flash is sufficient for calibration tables, scene memory and a simple menu state machine. The 44-PLCC footprint also allows sockets during fixture development, so a lighting engine can be re-programmed in the field without desoldering the controller.
Recomendado
Security Keypad and Access Controller
Access-control keypads benefit from the W78L812A24PL's bit-addressable I/O, which makes scanning a 4x4 matrix straightforward and keeps the scan loop fast at 24 MHz. The 256 bytes of RAM hold the debounce state, keystroke buffer and current credential record, while the three 16-bit timers support the lock-relay pulse timing, keypad lockout and LED indicator blink rates typical of these products. Flash EPROM stores the credential table and firmware, permitting secure updates. The 44-PLCC package is common in door hardware where a socketed controller board is serviced through a rear connector.
Recomendado
Low-Cost Data Acquisition Front End
The W78L812A24PL can act as the supervisory controller in a small acquisition module, sampling sensors on a timer schedule, applying offset and gain correction and forwarding results over a serial link. Its 24 MHz clock reduces conversion-loop latency compared with slower 8051 variants, and the three timers let one channel time the sensor settling while another drives the sample-and-hold and a third maintains the communication rate. Running from a 2.4 V to 5.5 V range supports both 3.3 V rail designs and coin-cell powered field sensors. The PLCC package suits instrument prototypes where the board is hand-assembled and reworked.
Recomendado
Small Motor and Pump Controller
Stepper and small DC motor control is a strong fit for the W78L812A24PL because three 16-bit timers plus a 24 MHz core give enough timing resolution to generate the step pulses and variable-rate drive sequences used by small actuators. Bit-addressable ports allow direct stepping of the four phase lines without wasting an entire port on a shift register, and the P4 port covers home-switch and limit inputs. Flash EPROM holds motion profiles that can be revised on the bench. The 44-PLCC package is appropriate for hobby-grade and prototype motion platforms where socketed, field-replaceable controllers are common.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para W78L812A24PL — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | W78L812A24PL (Winbond) | W79E823BSG | W78L812A20PL | W78L811A24PL |
|---|---|---|---|---|---|
| Package | 44-pin PLCC | 44-pin PLCC - same | 44-pin PLCC - same | 44-pin PLCC - same | 44-pin PLCC - same |
| Brand | Nuvoton Technology Corporation | Winbond | Nuvoton Technology Corporation | Nuvoton Technology Corporation | Nuvoton Technology Corporation |
| CPU Core | 8051-compatible 8-bit | 8051-compatible 8-bit | 8051-compatible 8-bit | 8051-compatible 8-bit | 8051-compatible 8-bit |
Diferenciadores clave
- Re-programmable 8 KB Flash EPROM instead of masked ROM (frente a AT89S52-24JU)
- Lower supply voltage floor of 2.4 V (frente a AT89S52-24JU)
- 44-PLCC socketed package suits serviceable and hand-assembled boards (frente a W78L812A20PL)
- Same-brand W79E upgrade path in the identical 44-PLCC footprint (frente a W79E823BSG)
Notas de diseño
The 44-PLCC footprint is a leaded socketed package, not a standard SMT land pattern. Provide a through-hole 44-pin footprint with 1.27 mm to 1.5 mm pitch row spacing compatible with the PLCC socket used in your enclosure, and keep at least 2 mm of clearance around the package for socket access. A footprint with SMT pads alone will not accept this part; confirm the package outline drawing in the manufacturer datasheet before releasing the layout, since PLCC pin-1 orientation follows the chamfered corner rather than a pin-1 dot.
Operating across a 2.4 V to 5.5 V range means the supply tolerance of your regulator is part of the design budget. Place a 0.1 uF ceramic bypass capacitor at each supply pin and a 4.7 uF to 10 uF bulk capacitor close to the device, with the shortest possible ground return. When powering from a battery or rectified rail, confirm the minimum input voltage at the device pins under worst-case load, since a diode drop in series with the supply can pull the rail below the 2.4 V floor during peak current demand and cause erratic timer behaviour.
Because Flash EPROM parts are re-programmable, the programming tool must match the device algorithm and the 8051 interrupt vector layout. Verify the flash endurance and retention figures in the manufacturer datasheet before committing to a design that re-flashes in the field, and never interrupt power during a write cycle. A second common error is assuming the PLCC pinout matches the 40-pin DIP version of the W78L812 family - P4 and the extra port pins differ, so re-check the pin-connection table for every board spin.
Keep the oscillator and reset circuitry close to the device, with the crystal or ceramic resonator and its load capacitors over a continuous ground plane with no traces or pour underneath unless the datasheet specifies otherwise. Route the three timer-driven outputs and any high-rate serial lines away from the supply pins and the 24 MHz oscillator tracks to limit coupling into the sensitive timer inputs. For socketed prototypes, leave the oscillator pads accessible so a different crystal can be fitted if clock accuracy turns out to be marginal.
Información de cumplimiento
No RoHS, REACH, lead-free or conflict-minerals declarations are stated on the manufacturer product listing or the distributor part pages, so these fields are recorded as unknown rather than assumed. The device is an industrial/consumer-grade 8-bit 8051 MCU and is not presented as an AEC-Q100 qualified automotive part.
