NXP Semiconductors MC145028DW

Overview

MC145028DW from ON Semiconductor (formerly Motorola) is a 9-bit trinary address decoder IC used in remote control encoder/decoder systems. It supports 19,683 unique trinary addresses or 512 binary addresses, operates from 4.5 V to 18 V, features internal RC oscillator (no crystal required), and delivers valid transmission (VT) output only after two consecutive matching address words are received. It is commonly deployed in garage door openers, wireless security sensors, and industrial remote switches.

For engineers reviewing the MC145028DW datasheet, MC145028DW pinout, MC145028DW application, or MC145028DW equivalent, key selection considerations include its 9-pin trinary address configuration, VT timing behavior requiring dual-word validation, SOG package compatibility with surface-mount assembly, and voltage range suitability for battery- or line-powered RF/IR transceivers.

Technical Context

The MC145028DW implements a synchronous serial decoder architecture that compares incoming encoded data against locally configured address pins (A1–A9). Its internal 9-bit shift register captures each trinary digit, and VT activation requires identical matches across two full transmission sequences - a security mechanism preventing false triggers from noise or partial reception.

Timing is governed by external R1/C1 and R2/C2 networks tied to pins 6–7 and 10, respectively. R1×C1 sets pulse-width discrimination (≈3.95 × RTC×CTC), while R2×C2 defines end-of-transmission detection (≈77 × RTC×CTC); both rely on the same encoder clock reference, ensuring system-level synchronization between paired MC145026 encoders and MC145028DW decoders.

Key Specifications

Pinout & Package

SOG package (Case 751G), 16-pin gull-wing surface-mount, 3.8 mm × 9.8 mm body, 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar address decoder applications.

Compared with SC41344DW and MC145027DW, the MC145028DW offers maximum address space (19,683 codes) with minimal pin count and no data output overhead - ideal for simple presence/identity verification in cost-sensitive remote control receivers.

Availability

MC145028DW is available at Aetrix Electronics and suitable for garage door openers, wireless security sensors, and industrial remote control panels requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MC145028DW 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

ON Semiconductor is a global semiconductor manufacturer specializing in power management, analog, and interface solutions for automotive, industrial, and IoT applications.

The MC145028DW belongs to Motorola's legacy CMOS encoder/decoder family, designed specifically for low-cost, crystal-free remote control systems requiring robust address validation without microcontrollers.

FAQ

What is the primary function of the MC145028DW in a remote control system?

The MC145028DW serves as a dedicated 9-bit trinary address decoder. It validates incoming serial data from an encoder (e.g., MC145026) and asserts its VT output only when two consecutive identical address words match the locally configured A1–A9 pins. This dual-word validation ensures reliable, noise-immune command recognition in RF and IR remote systems - a core function distinguishing MC145028DW from general-purpose logic ICs.

Does the MC145028DW require an external crystal or resonator?

No, the MC145028DW does not require an external crystal or resonator. It relies entirely on externally connected R1/C1 and R2/C2 networks (pins 6–7 and 10) for timing, synchronized to the encoder's RC oscillator. This eliminates BOM cost and layout complexity associated with precision timing components - a defining feature confirmed in the Motorola datasheet and central to the MC145028DW's design for low-cost remote control applications.

What supply voltage range is supported by the MC145028DW?

The MC145028DW operates over a supply voltage range of 4.5 V to 18 V, as specified in the Electrical Characteristics table for MC145027/MC145028 devices. This wide range accommodates common industrial and automotive power rails, including nominal 5 V, 9 V, 12 V, and 15 V supplies. The MC145028DW is not rated for operation below 4.5 V - low-voltage alternatives like SC41344DW must be used in sub-4.5 V designs.

How many unique addresses can the MC145028DW recognize?

The MC145028DW recognizes up to 19,683 unique addresses when configured for trinary input (low/high/open) on all nine address pins (A1–A9). If binary-only inputs (low/high) are used, it supports 512 distinct addresses. This address capacity is explicitly stated in the Motorola datasheet under "MC145028" functional description and forms the basis for interference-resistant device identification in multi-unit remote deployments.

What is the purpose of the R2/C2 network on pins 10 of the MC145028DW?

The R2/C2 network on pin 10 of the MC145028DW sets the time constant for detecting inter-word gaps and end-of-transmission (EOT). Per the datasheet, R2×C2 ≈ 77 × RTC×CTC - matching the encoder's timing base - enabling the MC145028DW to distinguish valid word boundaries and assert VT only after two complete, consecutively matched address words. Incorrect R2/C2 values cause VT misfires or failure to activate, making this network critical to reliable MC145028DW operation.