NXP Semiconductors MC145027P

Overview

MC145027P from Motorola is a CMOS 5-bit trinary address / 4-bit binary data decoder IC used in remote control encoder/decoder systems. It operates from 4.5–18 V, supports up to 243 trinary addresses or 32 binary addresses, features internal RC oscillator timing, and outputs valid transmission (VT) only after two consecutive matching address/data words - enabling secure wireless keyfob, garage door, and industrial remote applications.

For engineers reviewing the MC145027P datasheet, MC145027P pinout, MC145027P application, or MC145027P equivalent, this page delivers verified electrical specs, decoder timing behavior, address/data validation logic, VT output conditions, and real-world infrared/RF interface design constraints - all specific to the P-suffix Plastic DIP package.

Technical Context

The MC145027P implements a synchronous serial decoder architecture that validates incoming encoded data against locally configured A1–A5 address pins. It requires external R1/C1 and R2/C2 timing networks to decode pulse-width-modulated trinary symbols (0/1/open) and detect word boundaries.

Its VT output asserts only when both received address words match the local 5-bit trinary address *and* the subsequent 4-bit binary data nibbles match - enforcing dual-word verification for noise immunity. The decoder accepts CMOS-level Din input and uses internal comparators referenced to VDD/3 and 2VDD/3 thresholds on R2/C2 to distinguish end-of-word and end-of-transmission events.

Key Specifications

Pinout & Package

MC145027P is supplied in a 16-pin Plastic DIP (Dual In-line Package), Case 648, with 0.3-inch row spacing and standard through-hole mounting.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SC41343P and PT2272-M4, the MC145027P provides broader supply range, superior noise immunity via dual-word validation, and trinary address flexibility - making it the robust choice for industrial and automotive remote control receivers requiring long-term reliability.

Availability

MC145027P is available at Aetrix Electronics and suitable for garage door openers, industrial wireless sensors, automotive keyless entry receivers, and consumer IR remote control systems requiring stable component supply across extended product lifecycles.

Supply support for MC145027P 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

Motorola Semiconductor (now part of NXP Semiconductors) pioneered high-reliability analog and mixed-signal ICs for industrial, automotive, and communications markets.

The MC145027P belongs to Motorola's legacy CMOS encoder/decoder family designed specifically for secure, low-power, crystal-free remote control systems - emphasizing noise immunity, wide supply range, and minimal external component count.

FAQ

What is the minimum supply voltage required for reliable operation of the MC145027P?

The MC145027P requires a minimum supply voltage of 4.5 V to guarantee full specification compliance across temperature and process corners. Operation below 4.5 V may result in incorrect VT assertion, incomplete data latch updates, or failure to recognize valid transmissions - especially under load or at temperature extremes. This limit is defined in the Absolute Maximum Ratings table and confirmed in Electrical Characteristics testing at 5.0 V, 10 V, and 15 V.

How does the MC145027P validate incoming data to prevent false triggering?

The MC145027P prevents false triggering by requiring two consecutive, identical address/data words within a single transmission sequence. Only when both the 5-bit address (A1–A5) and 4-bit data (D6–D9) match across both words does the VT output go high. This dual-word validation, combined with internal 1/3 VDD and 2/3 VDD comparators on R2/C2 for timing integrity, rejects single-bit errors, noise spikes, and partial receptions - a core design feature confirmed in the Functional Description and Flowchart (Figure 13).

Can the MC145027P decode trinary data on its data output pins (D6–D9)?

No, the MC145027P decodes only binary data on D6–D9. While the address inputs (A1–A5) accept trinary states (low/high/open), the data portion is strictly binary: the encoder's A6/D6–A9/D9 pins must be driven low or high, and any open state on those pins is decoded as logic 1. This behavior is explicitly documented in the OPERATING CHARACTERISTICS section: "Although the address information may be encoded in trinary, the data information must be either a 1 or 0. A trinary (open) data line is decoded as a logic 1."

What external components are mandatory for MC145027P operation?

The MC145027P requires four mandatory external components: R1 and C1 (connected to Pins 6 and 7) to set symbol decoding thresholds, and R2 and C2 (connected to Pin 10) to detect word boundaries and end-of-transmission. These form timing networks with values derived from the encoder's RTC/CTC - specifically R1×C1 = 3.95×RTC×CTC and R2×C2 = 77×RTC×CTC. Omitting or mis-sizing these components causes failed decoding, as confirmed in Figures 15–16 and the Applications Information section.

Is the MC145027P pin-compatible with the SC41343P variant?

Yes, the MC145027P and SC41343P share identical pinout, package (16-pin Plastic DIP), and functional block diagram - including identical A1–A5 address inputs, D6–D9 data outputs, Din, VT, R1/C1/R2/C2 timing nodes, and VDD/VSS. However, SC41343P is rated for 2.8–10 V only, while MC145027P supports 4.5–18 V. This voltage difference is the sole functional distinction; all timing, logic, and interface behavior remain consistent between the two parts as verified in the Ordering Information and Electrical Characteristics tables.