NXP Semiconductors MC705B16NCFNER

Overview

MC705B16NCFNER from NXP Semiconductors (formerly Motorola/Freescale) is an 8-bit HCMOS microcontroller featuring a 16 KB on-chip ROM, 256 bytes RAM, 128 bytes EEPROM, 8-channel 8-bit ADC, dual 8-bit pulse-length modulation (PLM) outputs, and a serial communications interface (SCI). It operates at up to 4 MHz with 5 V supply and targets embedded control in automotive body electronics, industrial sensors, and appliance motor control.

For engineers reviewing the MC705B16NCFNER datasheet, MC705B16NCFNER pinout, MC705B16NCFNER application, or MC705B16NCFNER equivalent, this page delivers verified functional identity, validated package mapping (52-pin PLCC), confirmed pin roles, real-world use cases, and two technically documented alternative parts for design continuity.

Technical Context

The MC705B16NCFNER implements the M68HC05 CPU core with 32 instruction mnemonics, supports single-chip and bootstrap modes, and integrates a programmable timer with input capture, output compare, and free-running counter functions. Its SCI operates in asynchronous mode with idle-line and address-mark wake-up support.

It includes dedicated analog front-end circuitry: a 12-input multiplexed 8-bit ADC with conversion time of 25 µs (max), and two independent PLM channels with programmable clock prescaling and duty-cycle resolution down to 1%. The device supports STOP, WAIT, and SLOW low-power modes with defined current consumption profiles.

Key Specifications

Pinout & Package

MC705B16NCFNER is housed in a 52-pin Plastic Leaded Chip Carrier (PLCC) package with J-lead configuration, lead pitch of 0.05 inches (1.27 mm), and body size 19.05 mm × 19.05 mm. The package is RoHS-compliant and designed for reflow soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC705B16NCFNER, MC68HC908JK3 offers field-upgradable FLASH but sacrifices ROM-based security, while MC9RS08KA2 trades PLM hardware for higher-resolution ADC-making the former better for firmware-secure appliances and the latter for metrology-critical instruments.

Availability

MC705B16NCFNER is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor nodes, and home appliance motor control requiring stable component supply across extended product lifecycles.

Supply support for MC705B16NCFNER 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

NXP Semiconductors is a global semiconductor leader specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with roots in Motorola's semiconductor division.

The MC705B16NCFNER belongs to the legacy M68HC05 microcontroller family, designed for cost-sensitive, high-reliability embedded control in environments where long-term availability and deterministic real-time behavior are prioritized over raw performance.

FAQ

What is the maximum operating frequency of the MC705B16NCFNER?

The MC705B16NCFNER supports a maximum external clock frequency of 4 MHz, achievable using a quartz crystal, ceramic resonator, or external clock source connected to OSC1/OSC2. At this frequency, instruction execution time is 1 µs per cycle for most instructions, enabling deterministic timing for real-time control tasks such as motor commutation or sensor sampling. The device also supports lower frequencies for reduced power consumption in battery-operated applications.

Does the MC705B16NCFNER include an internal voltage regulator?

No, the MC705B16NCFNER does not include an internal voltage regulator. It requires a clean, well-decoupled 5 V ±5% supply applied directly to the VDD pin, with a 0.1 µF ceramic capacitor placed as close as possible to the VDD–VSS pair. External regulation must be provided upstream, and the device draws up to 20 mA typical in active mode at 4 MHz - confirming its design for direct integration into 5 V system rails without LDO overhead.

Can the MC705B16NCFNER perform analog-to-digital conversion while in WAIT mode?

Yes, the MC705B16NCFNER supports ADC operation during WAIT mode. According to the official Freescale technical data, the A/D converter remains functional and can complete conversions initiated before entering WAIT, with results stored in ADDATA. This enables low-power sensor polling strategies - for example, waking briefly to sample temperature, then returning to WAIT - reducing average system current while maintaining responsiveness.

What programming options are available for the MC705B16NCFNER?

The MC705B16NCFNER features mask-programmed ROM, meaning its firmware is permanently embedded during silicon fabrication and cannot be reprogrammed in the field. Programming occurs at the wafer level by NXP; users receive fully functional, production-ready devices. This ensures immunity to accidental overwrite, strong IP protection, and guaranteed code integrity - ideal for high-volume, fixed-function applications like automotive modules or white-goods controllers where firmware stability is critical.

Is the MC705B16NCFNER pin-compatible with other members of the M68HC05 family?

The MC705B16NCFNER uses a 52-pin PLCC package and shares identical pinout with the MC68HC705B16 and MC68HC05B16 variants in the same package option. Pin functions - including VDD, RESET, IRQ, PLMA, PLMB, RDI, TDO, and all port I/O - match across these part numbers. However, differences in memory size, peripheral enablement, or factory fuse settings mean that while PCB layout is reusable, firmware and initialization routines may require validation for full functional equivalence.