28ACINF

28ACINF Technical Summary

Overview

The 28ACINF is a high-performance 28-pin microcontroller designed for embedded applications requiring robust processing capabilities, versatile I/O, and reliable non-volatile memory. Built around an efficient 8-bit architecture, this device delivers 100 MIPS at 100 MHz (5V operation) while integrating critical peripherals such as analog comparators, brown-out detection, and in-system programming support. Its combination of Flash memory, SRAM, and configurable clocking options makes it suitable for industrial control, automation, and consumer electronics.

Key Features

• High-Speed Processing: 100 MIPS performance at 100 MHz (5V V_CC).
• Non-Volatile Memory: 2048 x 12-bit EE/Flash program memory rated for 10,000 erase/write cycles.
• Data Memory: 136 x 8-bit SRAM for dynamic data storage.
• In-System Programming (ISP): Reprogrammable via OSC pins for field updates.
• Clock Flexibility: Internal RC oscillator with selectable frequencies (31.25 kHz to 4 MHz) and ±8% accuracy.
• Analog Comparator: Integrated for signal conditioning or threshold detection.
• Brown-Out Detection (BOD): Configurable 4.2V threshold with enable/disable option.
• Multi-Input Wakeup (MIWU): Supports low-power mode exit via interrupts on 8 pins.
• High-Current I/O: All pins capable of sinking/sourcing 30 mA for driving LEDs or relays.
• Timing Peripherals: Includes prescaler for RTCC (Real-Time Clock Counter) and postscaler for WDT (Watchdog Timer).

Applications

The 28ACINF is engineered for diverse embedded systems, including:

• Industrial Automation: Motor control, sensor interfacing, and PLCs.
• Consumer Electronics: Remote controls, smart home devices, and toys.
• Automotive: Auxiliary control units, lighting systems, and diagnostics.
• Power Management: Battery monitoring, brown-out protection circuits.
• IoT Edge Nodes: Low-power wakeup via MIWU and in-field firmware updates.

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (V_CC): -0.3V to +7.0V (beyond which permanent damage may occur).
• I/O Pin Voltage: -0.3V to V_CC +0.3V.
• Operating Temperature: -40°C to +85°C (industrial grade).
• Storage Temperature: -65°C to +150°C.

Recommended Operating Conditions

• V_CC Range: 3.0V to 5.5V (full performance at 5V).
• Clock Frequency: 0 to 100 MHz (dependent on V_CC).
• I/O Sink/Source Current: 30 mA per pin (absolute max).

Power Consumption

• Active Mode (100 MHz, 5V): 25 mA typical.
• Idle Mode (Internal RC, 4 MHz): 1.2 mA typical.
• Sleep Mode (MIWU Enabled): 10 µA typical.

Package Information

The 28ACINF is offered in a 28-pin PDIP (Plastic Dual In-line Package) with the following mechanical specifications:

• Package Dimensions: 36.32 mm x 13.46 mm (including leads).
• Pin Spacing: 2.54 mm (standard DIP pitch).
• Lead Material: Matte tin-plated copper alloy.
• Mounting Style: Through-hole or socket-compatible.

Pinout Description

• OSC1/OSC2: External crystal or clock input/output.
• RC0-RC7: Multipurpose I/O with analog/digital functionality.
• RB5/RB8: High-current I/O with interrupt-on-change support.
• SX: Reserved for factory test (do not connect).
• V_CC/GND: Power supply and ground pins (decoupling required).

Functional Description

The 28ACINF's architecture centers on an 8-bit data bus with a 12-bit instruction set, optimized for deterministic real-time control. Key subsystems include:

Memory Organization

• Program Memory: 2 KB Flash with 10,000-cycle endurance, organized as 2048 x 12-bit words.
• SRAM: 136 bytes for stack and variable storage, accessible in single cycle.

Clock Generation

Four clock sources are selectable via configuration bits:

• External crystal/resonator (up to 100 MHz).
• Internal RC oscillator (31.25 kHz–4 MHz).
• External clock input on OSC1.
• Subsidiary low-power oscillator for WDT.

Analog Comparator

The comparator features:

• Programmable reference voltage.
• Interrupt generation on output transition.
• Hysteresis control for noise immunity.

Development Support

Toolchain compatibility includes:

• MPLAB® X IDE (with C compiler and debugger support).
• Third-party programmers via ICSP (In-Circuit Serial Programming).
• Evaluation boards with breakout for all peripherals.