MC145503P - 13-Bit Mono PCM Codec-Filter | Motorola
MPN: MC145503P ✗ End of LifeMC145503P Overview
A PCM codec-filter is a signal-chain integrated circuit that converts an analog voice waveform into a digital PCM representation and reconstructs an analog signal from PCM data. Its position in the hierarchy is PCM codec-filter → audio codec interface → interface integrated circuit → semiconductor. Within a telecommunications terminal, it normally sits between microphone or line-level audio circuitry and a digital channel-processing system, reducing the number of separate analog filters and interface components required.
The MC145503P provides 13-bit PCM audio interfacing and incorporates the voice digitization and reconstruction functions required by PCM equipment. It also performs the band-limiting and smoothing functions needed to limit out-of-band energy and reduce unwanted transitions. An external precision reference may be used with this device family when tighter timing or conversion control is required. The MC145503P shares a functional relationship with the MC145500, MC145501, MC145502, MC145503, and MC145505 mono PCM codec-filter family.
The MC145503 family architecture combines transmit and receive paths with an integrated codec-filter function rather than requiring separate antialiasing and reconstruction filters. The MC145505 variant retains the same 16-pin implementation approach but introduces a common data-clock arrangement covering 64 kHz to 4.1 MHz. For the MC145503P, the architecture supports external precision referencing, while clocking, supply voltage, and conversion timing must be confirmed against the manufacturer datasheet before final schematic approval.
Typical uses include PCM voice terminals, telephone-interface equipment, digital audio transmission systems, voice-band processing modules, and legacy telecommunication line cards. Its integrated filtering makes it particularly relevant where a compact analog-to-digital and digital-to-analog voice path is required without a large collection of external filter stages. Because it is a legacy component, new designs should also evaluate currently supported audio interfaces when lifecycle continuity is more important than reproducing an older PCM architecture.
PCB design should follow the manufacturer’s application circuit for decoupling, reference connections, analog input and output routing, and clock implementation. Keep analog and digital return paths controlled, place bypass capacitors close to their associated pins, and preserve the specified external network values. Verify signal levels against the internal operational amplifiers because improper gain distribution or insufficient common-mode range can restrict usable dynamic range even when the codec itself is operating correctly.
This product page combines the manufacturer-family functional description, package and temperature information, sourcing details, and practical application guidance in one engineering-focused view. It also distinguishes a true same-package family candidate from surface-mount and PLCC variants that cannot replace the MC145503P without changing the PCB footprint.
Drop-in alternatives for MC145503P — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MC145503P (same form factor and footprint) — differing in Channel Count.
MC145505P
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →MC145503P Maximum Ratings & Electrical Characteristics
| Product Type | Mono PCM codec-filter integrated circuit |
| PCM Resolution | 13 bit |
| Signal Functions | Voice digitization, reconstruction, band limiting, and smoothing |
| Channel Count | 1 mono channel |
| Package Type | 16-PDIP |
| Terminal Count | 16 terminals |
| Package Width | 7.62 mm |
| Package Length | 19.175 mm |
| Mounting Style | Through-hole |
| Minimum Operating Temperature | -40°C |
| Maximum Operating Temperature | +85°C |
| Temperature Grade | Industrial, -40°C to +85°C |
| Precision Reference Option | External precision reference supported |
| Related Family Devices | MC145500, MC145501, MC145502, MC145503, and MC145505 |
MC145503P 19.175 mm Pin Configuration Guide
Pin configuration for MC145503P (19.175 mm package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for MC145503P.
Refer to the datasheet for full pin configuration.
Typical Applications
MC145503P is suitable for 6 applications: PCM Voice Terminal Interface, Telephone Line-Card Voice Processing, Digital Voice Transmission Module, Voice-Band Signal Conditioning, Legacy Telecommunications Equipment Repair, PCM Audio Data Interface.
PCM Voice Terminal Interface
The MC145503P fits a legacy PCM voice terminal because its 13-bit mono codec-filter function handles voice digitization, reconstruction, band limiting, and smoothing in one 16-PDIP device. Place it between the analog microphone or line interface and the system’s PCM channel-processing logic to reduce separate filtering stages. The integrated filtering path helps control out-of-band energy, while the −40°C to +85°C operating range suits industrial telecom equipment. Verify the original design’s signal levels, reference arrangement, clocking, and external component values before using the part in a new voice terminal.
Recommended
Telephone Line-Card Voice Processing
The MC145503P is appropriate for a legacy telephone line card that must condition and digitize a mono voice channel. Its integrated band-limiting and smoothing functions support the analog transmit and receive paths, allowing a compact implementation compared with separate PCM converter and filter blocks. The 13-bit resolution matches the resolution stated for this codec-filter class, while the 16-PDIP format supports repair and legacy production-line compatibility. Before insertion, compare the original clock, reference, and external filter networks because changing gain or antialiasing values can alter compliance, distortion, and signaling behavior.
Recommended
Digital Voice Transmission Module
Use the MC145503P in a digital voice transmission module when a mono analog voice signal must be encoded into PCM data and later reconstructed. The codec-filter performs digitization, reconstruction, band limiting, and smoothing within a single 16-pin circuit, simplifying signal-chain partitioning. Its −40°C to +85°C range supports industrial operating environments, while the through-hole package facilitates serviceable or legacy through-hole assemblies. Clock and reference connections are critical to correct conversion timing, so reproduce the manufacturer reference circuit and keep sensitive analog traces short and away from high-current switching paths.
Recommended
Voice-Band Signal Conditioning
The MC145503P can serve as the central voice-band conditioning element in a PCM signaling design. Its band-limiting function reduces unwanted high-frequency content before digitization, and the smoothing stage supports reconstruction of the analog receive waveform. The integrated 13-bit mono codec-filter architecture avoids several discrete signal-path stages and provides a defined function set for PCM equipment. When designing the analog front end, maintain the recommended input and output operating levels, account for the internal transmit and receive operational amplifiers, and confirm that external precision referencing is compatible with the timing architecture.
Recommended
Legacy Telecommunications Equipment Repair
The MC145503P is well suited to maintaining legacy telecommunications equipment because it reproduces the original 16-PDIP footprint and combines the PCM codec and filter functions required by established voice-channel designs. Its through-hole construction supports inspection, socket adaptation, and repair workflows common in older telecom systems. The −40°C to +85°C specification matches industrial-grade equipment conditions. During repair, inspect pin orientation carefully, compare markings and lot traceability requirements, and preserve the original reference, clock, decoupling, and analog-network configuration to avoid changing conversion timing or signal balance.
Recommended
PCM Audio Data Interface
The MC145503P can serve in a PCM audio data interface where mono voice samples must move between an analog terminal and a digital processor. It combines transmit and receive signal paths, 13-bit conversion resolution, filtering, and smoothing in one 16-pin package. This integration helps minimize component count and keeps the analog-to-digital and digital-to-analog functions close to their associated pins. The through-hole package favors maintenance of established equipment, although new products may favor a surface-mount audio codec. Any redesign should compare clocking, reference accuracy, channel latency, and digital data timing rather than treating codec functions as interchangeable by resolution alone.
Recommended
Recommended Products Summary
Engineering reference data for MC145503P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC145505P |
|---|---|---|
| Product Type | 13-bit mono PCM codec-filter | Mono PCM codec-filter |
| Brand | Motorola | Motorola |
| Package | 16-PDIP | 16-PDIP |
| Channel Count | 1 mono channel | 1 mono channel |
Key Differentiators
- Integrated mono PCM codec and filtering (vs MC145505P)
- Original 16-PDIP replacement footprint (vs MC145503DW)
- Broader package-level design flexibility (vs MC145503FN)
Design Notes
Reproduce the manufacturer application circuit, especially bypass-capacitor placement, reference routing, analog signal paths, and digital clock connections. Keep the transmit and receive analog traces short and position the codec-filter close to the associated input and output networks. Route digital clock and data signals away from sensitive analog input pins to reduce conversion error and maintain predictable signal integrity.
Do not treat MC145503DW or MC145503FN as board-level replacements. The DW version uses a 16-SOIC surface-mount package, and the FN version uses a 20-PLCC package; neither matches the MC145503P’s 16-PDIP footprint. Even when the MC145505P retains a 16-pin family implementation, verify its common 64 kHz to 4.1 MHz clock arrangement, timing, reference configuration, and external component values before approving substitution.
Preserve the manufacturer’s reference network and clock-implementation details because conversion timing can depend on reference accuracy and clock distribution. Decouple supply connections locally, maintain the recommended analog and digital grounding arrangement, and avoid long parallel routes beneath sensitive inputs. Validate the completed design for distortion, idle-channel noise, timing margin, and receive-signal stability using voice-band test levels.
Compliance Information
The MC145503P is an older industrial-temperature PCM codec-filter. No specific RoHS, REACH, halogen-free, or conflict-minerals declaration was identified for this exact MPN.
