Infineon Technologies SAF-C505-LM

Overview

SAF-C505-LM from Infineon Technologies is an 8-bit CMOS microcontroller fully compatible with the 8051 architecture, featuring 32 KB on-chip OTP memory, 256-byte RAM, 256-byte XRAM, and integrated 128-segment LCD controller with 20 dedicated LCD output lines. It operates up to 20 MHz (300 ns instruction cycle), includes a 10-bit ADC with 8 analog inputs, and supports real-time clock functionality with 32.768 kHz crystal input - deployed in industrial panel meters and embedded HMI systems.

For engineers reviewing the SAF-C505-LM datasheet, SAF-C505-LM pinout, SAF-C505-LM application, or SAF-C505-LM equivalent, key selection criteria include OTP program memory size, integrated LCD drive capability (1/4 duty, 4×32 segments), real-time clock operation in power-down mode, and dual analog/digital I/O on Port 1 - all critical for low-power, display-integrated control designs.

Technical Context

The SAF-C505-LM implements an enhanced 8051 core with eight datapointers and five 8-bit digital I/O ports (Port 5 is 6-bit), supporting mixed analog/digital functions on Port 1 and secondary LCD outputs across Ports 3–5. Its on-chip 128-segment LCD controller provides programmable reference voltage generation and drives up to 20 LCD lines (4 rows + 16 columns) at 1/4 duty cycle.

It integrates three 16-bit timers (Timer 0/1 C501-compatible, Timer 2 with four-channel capture/compare), a full-duplex USART with programmable baud rate generator, and a 47-bit real-time clock counter that remains active in special power-down modes using a 32.768 kHz external crystal - enabling precise timekeeping without system wake-up.

Key Specifications

Pinout & Package

P-MQFP-80 package: 80-pin plastic metric quad flat pack, 14 mm × 20 mm body, 0.65 mm lead pitch, lead-free compatible per Infineon specification.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit microcontroller with integrated LCD driver applications.

Compared with SAB-C505-LM and SAK-C505-LM, the SAF-C505-LM uniquely balances wide industrial temperature tolerance (–40 to +85 °C) with full 20 MHz performance - making it optimal for DIN-rail meters, HVAC controllers, and medical devices needing both reliability and real-time responsiveness.

Availability

SAF-C505-LM is available at Aetrix Electronics and suitable for industrial panel meters, portable medical monitors, smart energy meter interfaces, and appliance control panels requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SAF-C505-LM 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

Infineon Technologies AG is a German semiconductor manufacturer specializing in power management, automotive ICs, and embedded controllers, with global R&D and manufacturing infrastructure.

The C505L product line was designed specifically for cost-effective, display-integrated embedded control in industrial instrumentation and consumer appliances - emphasizing on-chip LCD drive, low-power RTC, and 8051 compatibility for legacy code reuse.

FAQ

Does SAF-C505-LM support in-system programming (ISP)?

No. SAF-C505-LM uses one-time-programmable (OTP) memory, which requires programming prior to soldering via dedicated parallel programmer. Unlike flash-based microcontrollers, it does not support ISP or firmware updates in the final assembly. Programming must be completed during pre-production test or at the module level before integration into the end product.

Can the 128-segment LCD controller drive custom segment layouts beyond 4×32?

Yes - the controller supports flexible mapping via segment/column address registers, allowing non-standard arrangements such as 6×21 or 3×42, provided total segments ≤128 and row/column drive constraints (1/4 duty, max 32 columns) are met. Segment assignments are configured in firmware using the LCD control registers defined in the datasheet.

What is the maximum allowed voltage on analog input pins AN0–AN7?

Analog inputs AN0–AN7 accept 0 V to V_REF, where V_REF is either internally generated (2.5 V typical) or externally applied via AREF pin. Absolute maximum voltage is V_DD + 0.3 V (5.3 V at 5 V supply), but exceeding V_REF causes clipping and invalid conversion results - external clamping diodes are recommended for overvoltage protection.

How does the Real-Time Clock maintain accuracy during power-down?

The RTC uses a dedicated 32.768 kHz crystal connected to XTAL3/XTAL4 pins and operates from a separate internal power domain. In power-down mode, only the RTC oscillator and counter remain active, drawing ~1.2 µA typical. Accuracy depends on crystal tolerance (±20 ppm standard) and load capacitance matching - no software calibration is performed in hardware.