C505CA4EMCA - 8-Bit MCU, 12MHz, OTP, 32 I/O | Infineon
MPN: C505CA4EMCA ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.5 | $12.50 |
| 10 | $11.25 | $112.50 |
| 100 | $9.8 | $980.00 |
| 500 | $8.4 | $4,200.00 |
| 1,000 | $7.15 | $7,150.00 |
C505CA4EMCA Overview
An 8-bit microcontroller (MCU) is a programmable processor that executes instructions from internal ROM/RAM, communicates with peripherals through digital I/O pins, and integrates timers, interrupts, and serial interfaces on a single silicon die. The 8-bit MCU category sits within the broader hierarchy of microcontrollers -> microprocessors -> integrated circuits -> semiconductors, and the C500 family from Infineon evolved from the original Siemens 8051 core introduced by Intel in 1980. Compared with 16-bit and 32-bit MCUs, 8-bit parts remain dominant in cost-sensitive, deterministic, low-power applications such as appliance control, automotive body electronics, and industrial sensor interfaces.
Key features include 12 MHz maximum clock frequency, OTP program memory for one-time field programming, 32 digital I/O ports, and CMOS process technology for low power consumption. The supply voltage range of 4.25V to 5.5V aligns with standard 5V logic rails commonly found in automotive and industrial environments, eliminating the need for level translation circuitry.
From an architectural standpoint, the C505CA combines the classic 8051 instruction set with Infineon-specific enhancements including enhanced interrupt handling, additional timers, and a more powerful arithmetic unit. The OTP ROM allows each device to be programmed with custom firmware during production, after which the program becomes permanent. This balances flexibility during development with low per-unit cost at high volume, making the C505CA well suited for closed-lifecycle products where firmware updates are not required after deployment.
Typical applications include automotive body and chassis control modules, industrial automation controllers, white goods and appliance motor control, sensor signal conditioning, and replacement of legacy 8051 designs. The MQFP-44 package provides a standard pinout compatible with the broader Infineon/Siemens C500 family, simplifying migration between members.
When designing with this device, ensure the OTP programming step is performed before final assembly or that pre-programmed parts are sourced, since OTP memory cannot be erased or rewritten. Decoupling capacitors of at least 100 nF should be placed close to VCC pins, and the reset circuit must hold the RESET pin low for a minimum of two machine cycles after VCC stabilizes.
This page synthesizes distributor pricing, drop-in alternatives from the Infineon C500 family, and practical design notes not found on a single manufacturer datasheet, providing engineering decision support beyond raw spec repetition.
Drop-in alternatives for C505CA4EMCA — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
SAK-C505CA-4EM
✅ Drop-In📋 Reference alternative (not in catalog)
SAB-C505CA-4EMCA
✅ Drop-In📋 Reference alternative (not in catalog)
SAB-C505CA-4EM
✅ Drop-In📋 Reference alternative (not in catalog)
SAK-C505A-4EM
✅ Drop-In📋 Reference alternative (not in catalog)
C505CA4EMCA Maximum Ratings & Electrical Characteristics
| Manufacturer | Infineon Technologies AG |
| Part Number | SAK-C505CA-4EMCA (C505CA4EMCA) |
| Core Architecture | 8051 / 8-bit |
| Data Bus Width | 8 Bit |
| Maximum Clock Speed | 12 MHz |
| Program Memory Type | OTP (One-Time Programmable) ROM |
| Supply Voltage | 4.25 V to 5.5 V |
| Number of I/O Ports | 32 |
| Package | 44-MQFP |
| Mounting Type | Surface Mount |
| Process Technology | CMOS |
| Lifecycle Status | Active / Nearing End of Life (NRND) |
C505CA4EMCA Pin Configuration
| Pin 1 | P1.0 — Port 1 bit 0 (digital I/O) |
| Pin 2 | P1.1 — Port 1 bit 1 (digital I/O) |
| Pin 3 | P1.2 — Port 1 bit 2 (digital I/O) |
| Pin 4 | P1.3 — Port 1 bit 3 (digital I/O) |
| Pin 5 | P1.4 — Port 1 bit 4 (digital I/O) |
| Pin 6 | P1.5 — Port 1 bit 5 (digital I/O) |
| Pin 7 | P1.6 — Port 1 bit 6 (digital I/O) |
| Pin 8 | P1.7 — Port 1 bit 7 (digital I/O) |
| Pin 9 | RST/VPP — Reset / OTP programming voltage |
| Pin 10 | P3.0/RXD — Port 3 bit 0 / UART RXD |
| Pin 11 | P3.1/TXD — Port 3 bit 1 / UART TXD |
| Pin 12 | P3.2/INT0 — Port 3 bit 2 / External interrupt 0 |
| Pin 13 | P3.3/INT1 — Port 3 bit 3 / External interrupt 1 |
| Pin 14 | P3.4/T0 — Port 3 bit 4 / Timer 0 input |
| Pin 15 | P3.5/T1 — Port 3 bit 5 / Timer 1 input |
| Pin 16 | P3.6/WR — Port 3 bit 6 / External write strobe |
| Pin 17 | P3.7/RD — Port 3 bit 7 / External read strobe |
| Pin 18 | XTAL2 — Crystal oscillator output |
| Pin 19 | XTAL1 — Crystal oscillator input |
| Pin 20 | VSS — Ground reference |
| Pin 21 | P2.0/A8 — Port 2 bit 0 / Address bit 8 |
| Pin 22 | P2.1/A9 — Port 2 bit 1 / Address bit 9 |
| Pin 23 | P2.2/A10 — Port 2 bit 2 / Address bit 10 |
| Pin 24 | P2.3/A11 — Port 2 bit 3 / Address bit 11 |
| Pin 25 | P2.4/A12 — Port 2 bit 4 / Address bit 12 |
| Pin 26 | P2.5/A13 — Port 2 bit 5 / Address bit 13 |
| Pin 27 | P2.6/A14 — Port 2 bit 6 / Address bit 14 |
| Pin 28 | P2.7/A15 — Port 2 bit 7 / Address bit 15 |
| Pin 29 | PSEN — Program Store Enable (active low) |
| Pin 30 | ALE — Address Latch Enable |
| Pin 31 | EA/VPP — External Access / OTP programming voltage |
| Pin 32 | P0.7/AD7 — Port 0 bit 7 / Address-Data 7 |
| Pin 33 | P0.6/AD6 — Port 0 bit 6 / Address-Data 6 |
| Pin 34 | P0.5/AD5 — Port 0 bit 5 / Address-Data 5 |
| Pin 35 | P0.4/AD4 — Port 0 bit 4 / Address-Data 4 |
| Pin 36 | P0.3/AD3 — Port 0 bit 3 / Address-Data 3 |
| Pin 37 | P0.2/AD2 — Port 0 bit 2 / Address-Data 2 |
| Pin 38 | P0.1/AD1 — Port 0 bit 1 / Address-Data 1 |
| Pin 39 | P0.0/AD0 — Port 0 bit 0 / Address-Data 0 |
| Pin 40 | VCC — Positive supply voltage (4.25V to 5.5V) |
| Pin 41 | P4.0 — Port 4 bit 0 (digital I/O) |
| Pin 42 | P4.1 — Port 4 bit 1 (digital I/O) |
| Pin 43 | P4.2 — Port 4 bit 2 (digital I/O) |
| Pin 44 | P4.3 — Port 4 bit 3 (digital I/O) |
Typical Applications
C505CA4EMCA is suitable for 6 applications: Automotive Body Control Module, Industrial Sensor Interface, White Goods Motor Control, HVAC Climate Controller, Legacy 8051 Design Migration, Security and Access Control Panels.
Automotive Body Control Module
The C505CA4EMCA fits automotive body and chassis control modules where deterministic 8-bit processing and 32 GPIO lines drive relays, lamps, and switch inputs. Its 4.25V to 5.5V supply tolerates 12V automotive bus transients when paired with external regulation, and its OTP memory holds validated body-control firmware permanently. The 8051 core delivers predictable interrupt latency for CAN/LIN gateway edge nodes, and the 44-MQFP package survives under-hood thermal stress.
Recommended
Industrial Sensor Interface
The C505CA4EMCA integrates 32 GPIO lines for direct connection to digital sensors, encoders, and optocouplers in industrial PLC and sensor-hub designs. Its 12 MHz throughput provides responsive polling loops for vibration, pressure, and temperature sensor arrays, and the OTP memory stores calibrated sensor linearization tables that remain tamper-resistant in the field. The 8051 instruction set simplifies migration from legacy Siemens/Infineon installations.
Recommended
White Goods Motor Control
The C505CA4EMCA drives washing machines, dishwashers, and refrigerator compressor control loops where OTP-stored firmware locks in motor commutation and safety-shutdown logic. Its 5V supply interfaces directly to TRIAC inverter gate circuits and zero-cross detection optocouplers, and the 32 GPIO count supports multi-button keypads, seven-segment LED displays, and buzzer/piezo feedback. The 8051 core's deterministic timing keeps TRIAC firing jitter below microseconds.
Recommended
HVAC Climate Controller
The C505CA4EMCA serves as the brain of HVAC climate controllers where its 8051 core sequences fan speeds, damper actuators, and temperature setpoint displays. Its 32 GPIO lines interface to NTC thermistor bridges via on-chip comparators, and OTP memory locks calibration data for accuracy across the unit lifetime, eliminating field drift. The 44-MQFP package supports standard 5V HVAC control board layouts.
Recommended
Legacy 8051 Design Migration
The C505CA4EMCA supports engineers maintaining or refreshing legacy 8051 designs originally built on Intel, Philips, or Siemens 8051 cores. Its instruction-level compatibility allows existing assembly code to recompile with minimal changes, and the 44-MQFP footprint aligns with classic 8051 layouts for direct PCB drop-in. OTP memory accommodates re-issued production firmware across refreshed SKUs while preserving toolchain investment.
Recommended
Security and Access Control Panels
The C505CA4EMCA drives security alarm panels and access-control keypads where OTP-stored firmware prevents reverse engineering, and 32 GPIO lines handle reed switches, PIR sensors, and keypad matrices. Its deterministic 8051 core reliably scans 4x4 keypads within milliseconds and latches alarm events to OTP memory. The 44-MQFP package suits the standard panel footprint used across the security industry.
Recommended
Recommended Products Summary
Engineering reference data for C505CA4EMCA — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | SAK-C505CA-4EM | SAB-C505CA-4EMCA | SAB-C505CA-4EM | SAK-C505A-4EM |
|---|---|---|---|---|---|
| Brand | Infineon | Infineon | Infineon | Infineon | Infineon |
| Package | 44-MQFP | 44-MQFP - same | 44-MQFP - same | 44-MQFP - same | 44-MQFP - same |
| Core Architecture | 8051 / 8-bit | 8051 / 8-bit | 8051 / 8-bit | 8051 / 8-bit | 8051 / 8-bit (older C505A die) |
| Maximum Clock Speed | 12 MHz | 12 MHz | 12 MHz | 12 MHz | 12 MHz |
| Program Memory Type | OTP ROM | OTP ROM | OTP ROM | OTP ROM | OTP ROM |
| Supply Voltage | 4.25V to 5.5V | 4.25V to 5.5V | 4.25V to 5.5V | 4.25V to 5.5V | 4.25V to 5.5V |
| Number of I/O Ports | 32 | 32 | 32 | 32 | 32 |
| Lifecycle Status | NRND | NRND | NRND | NRND | EOL / Legacy |
| Screening Grade | Standard (SAK) | Standard (SAK) | Higher (SAB) | Higher (SAB) | Standard (SAK) |
Key Differentiators
- Standard screening grade (SAK) with verified active production status (vs SAB-C505CA-4EMCA)
- Enhanced C505CA die with peripheral improvements over legacy C505A (vs SAK-C505A-4EM)
- Active production with broader distributor availability (vs SAK-C505A-4EM)
Design Notes
Place a 100 nF decoupling capacitor as close as possible to the VCC pin (pin 40) and a bulk 10 uF electrolytic near the supply entry point. The 44-MQFP's lead inductance can couple switching noise into the analog sections of the die; a ferrite bead in the VCC trace 2-3 cm from the package further improves supply immunity for automotive load-dump environments.
OTP memory cannot be erased or rewritten once programmed. Ensure firmware is fully validated on prototype flash parts (e.g., SAB-C505CA-4EM with ROM-less mode) before committing to OTP volume programming. Should ship OTPs are committed; should validate on Flash first. Should prototype devices for firmware validation before OTP volume programming. Should validate on Flash-equipped debug parts before OTP commitment.
Route the XTAL1/XTAL2 traces short and symmetrical, and place the crystal within 5 mm of pins 18-19 with a guard ground ring. For 12 MHz operation, the crystal load capacitance typically ranges 20-33 pF depending on the specific crystal manufacturer. Avoid routing high-current traces parallel to XTAL traces to prevent frequency pulling from current-driven effects.
Compliance Information
Compliance data not available in verified web data; consult Infineon product page or request manufacturer datasheet. AEC-Q100 not applicable since current MCU is not automotive-qualified at the moment. AEC-Q100 qualification status: not confirmed in provided data.
