NXP Semiconductors MC9RS08KA1CDB

Overview

MC9RS08KA1CDB from Freescale Semiconductor is an 8-bit RS08 microcontroller with 1024 bytes of on-chip Flash EEPROM, 63 bytes RAM, and a trimmable 20-MHz internal clock source supporting up to 10-MHz bus operation. It integrates an analog comparator (ACMP), 8-bit modulo timer (MTIM), keyboard interrupt (KBI), and background debug system - designed for ultra-low-cost, space-constrained embedded control in consumer and industrial sensors.

For engineers reviewing the MC9RS08KA1CDB datasheet, MC9RS08KA1CDB pinout, MC9RS08KA1CDB application, or MC9RS08KA1CDB equivalent, this page delivers verified package mapping (6-pin DFN), confirmed peripheral capabilities (ACMP with rail-to-rail operation, KBI with edge/level sensitivity), power-saving modes (Wait/Stop with RTI/KBI/ACMP wakeup), and real-world selection guidance against functionally aligned alternatives.

Technical Context

The MC9RS08KA1CDB implements the RS08 CPU core with simplified S08 instruction set extensions including tiny addressing mode (0–$000F) and short addressing mode (0–$001F), enabling single-byte instructions for fastest access to critical memory regions. Its Internal Clock Source (ICS) provides factory-trimmed 20-MHz operation with ±0.2% trim resolution and ±2% deviation over voltage and temperature.

Peripherals are tightly coupled to low-power operation: the ACMP operates fully in Stop mode with internal bandgap reference option; the MTIM supports modulo counting with programmable prescaler; and KBI supports three interrupt-capable pins in the 6-pin DFN configuration, with configurable pullup/pulldown and edge/level detection.

Key Specifications

Pinout & Package

MC9RS08KA1CDB is housed in a 6-pin dual flat no-lead (DFN) package (case outline 98ASA00735D), measuring 2.0 × 2.0 × 0.55 mm with exposed thermal pad. This compact footprint targets PCB area-constrained applications such as smart buttons, wearable sensors, and disposable medical devices.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC9RS08KA2CDB, the MC9RS08KA1CDB saves die area and bill-of-material cost where 1 KB Flash suffices; versus STM8S003F3P6, it offers superior integration density and lower system-level power in ultra-simple sensing or control roles without serial buses.

Availability

MC9RS08KA1CDB is available at Aetrix Electronics and suitable for smart appliance control panels, low-power sensor nodes, disposable medical devices, and industrial status indicators requiring stable component supply and long-term manufacturability.

Supply support for MC9RS08KA1CDB 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

Freescale Semiconductor (now part of NXP Semiconductors) is a pioneer in embedded microcontrollers, delivering energy-efficient, cost-optimized silicon for automotive, industrial, and consumer applications.

The MC9RS08KA1CDB belongs to the RS08 family - designed specifically for ultra-low-cost, ultra-small-footprint embedded control where minimal I/O, basic analog functions, and extreme power efficiency are primary requirements.

FAQ

What is the maximum operating frequency of the MC9RS08KA1CDB internal bus?

The MC9RS08KA1CDB supports a maximum internal bus frequency of 10 MHz, derived from its trimmable 20-MHz internal clock source (ICS) using a divide-by-2 configuration. This frequency is specified across the full operating voltage range (1.8–3.6 V) and temperature range (–40°C to +105°C), enabling deterministic timing for real-time I/O handling without external clock components.

Does the MC9RS08KA1CDB support in-circuit debugging, and what interface is used?

Yes, the MC9RS08KA1CDB supports in-circuit debugging via a single-wire Background Debug (BKGD) interface on the PTA3 pin. This interface enables breakpoint setting, memory inspection, and register read/write during active execution - all without halting peripheral operation. The BKGD functionality is integral to the RS08 core and requires no additional pins beyond the standard 6-pin DFN layout.

Can the analog comparator in the MC9RS08KA1CDB operate while the MCU is in Stop mode?

Yes, the analog comparator (ACMP) in the MC9RS08KA1CDB remains fully functional during Stop mode and can generate interrupts to wake the MCU. It supports rail-to-rail input operation and optional comparison to an internal bandgap reference voltage (1.22 V), allowing threshold detection without external components - critical for battery-monitoring or sensor-wakeup applications.

What are the power-saving modes supported by the MC9RS08KA1CDB, and how do they differ?

The MC9RS08KA1CDB supports Wait and Stop modes. In Wait mode, the CPU halts but peripherals (ACMP, MTIM, KBI) remain clocked and active. In Stop mode, the ICS is disabled and most clocks cease, reducing current to sub-microamp levels; only RTI, KBI, and ACMP retain wakeup capability. Both modes preserve RAM contents and allow full register restoration on wake.

Is the MC9RS08KA1CDB pin-compatible with other RS08 family members in the same 6-pin DFN package?

Yes, the MC9RS08KA1CDB shares identical pin assignment and electrical characteristics with the MC9RS08KA2CDB in the 6-pin DFN package (98ASA00735D). Both use the same VDD, VSS, PTA2/KBIP2/TCLK/RESET/VPP, PTA3/ACMPO/BKGD/MS, PTA0/KBI0, and PTA1/KBI1 pin definitions - enabling direct hardware reuse when upgrading firmware capacity.