MC145557P - 13-Bit A-Law PCM Codec-Filter | Motorola
MPN： MC145557P ✓ 啟用中MC145557P 概覽
A PCM codec-filter is an interface integrated circuit that processes pulse-code-modulated audio or voice signals between an analog system and a digital PCM channel. Within the broader semiconductor hierarchy, it is a codec and signal-conditioning device within interface ICs, with a more specialized function than a general-purpose audio codec. The MC145557P specifically combines 13-bit PCM processing with A-law encoding in a single 16-lead PDIP package.
The principal identified specifications are 13-bit PCM resolution, A-law operation, one codec-filter function, and a 16-pin PDIP package. Its single-function organization makes it suitable for designs that require dedicated per-channel voice conversion rather than a multi-channel codec with additional control and routing functions. The through-hole PDIP format also supports conventional PCB assembly, prototyping, repair, and communication equipment with larger component packages.
In a PCM system, the codec-filter provides the conversion and filtering functions needed to digitize voice information, reconstruct received PCM information, and limit the signal band before transmission or processing. Devices in the MC145554, MC145557, MC145564, and MC145567 family perform these per-channel functions and can operate in synchronous or asynchronous systems. The MC145557P is differentiated within that family by its A-law configuration and 13-bit PCM resolution.
Typical implementation areas include telephony and voice communication equipment, PCM interface modules, digital voice processing systems, telecommunications line interfaces, and legacy PCM test equipment. Its 16-lead PDIP package may be especially useful where a through-hole footprint is preferred over a surface-mount package, or where the original circuit design already uses this package style.
Circuit implementation should follow the Motorola manufacturer datasheet for pin assignment, external component selection, clocking, and signal-path layout. Verify the required A-law system configuration, 13-bit PCM word format, synchronous or asynchronous timing mode, and grounding arrangement before finalizing the PCB. The PDIP footprint also requires adequate lead spacing and clearance from adjacent components.
This product overview consolidates the confirmed codec type, PCM resolution, A-law configuration, package format, sourcing context, and functional relationships into an engineering-focused reference. It also provides application guidance, design cautions, package information, and links to the manufacturer documentation needed for an informed design decision.
直接替換替代品，適用於 MC145557P — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此產品無可直接替換的替代品。
申請替代品MC145557P 最大額定值與電氣特性
| Product Type | PCM codec-filter integrated circuit |
| PCM Resolution | 13 bits |
| Encoding Format | A-law |
| Functions per Package | 1 codec-filter function |
| Package Type | 16-lead PDIP |
| Package Pitch | 7.62 mm |
| Package Body Width | 0.300 in |
| 腳位數 | 16 pins |
| 安裝類型 | Through-hole |
| Signal Processing Role | Voice digitization and reconstruction with band limiting and smoothing |
| PCM System Timing | Synchronous and asynchronous operation |
| 生命週期狀態 | Active |
| RoHS 狀態 | Non-compliant |
MC145557P 0.300 in 腳位配置指南
MC145557P（0.300 in 封裝）的腳位配置。 腳位編號、功能與連接圖定義於製造商資料手冊中。請參閱該手冊以取得確切的封裝尺寸與焊接指引。
無詳細腳位定義資料： MC145557P.
請參閱 資料表 以查看完整腳位配置。
典型應用
MC145557P 適用於 6 應用s: Legacy PCM Voice Interface, Telecommunications Line Equipment, Asynchronous PCM Test Module, PCM Voice Processor, Digital Voice Recording Front End, Equipment Repair andobsolescence Recovery.
Legacy PCM Voice Interface
The MC145557P fits a legacy per-channel PCM voice interface because it combines 13-bit digitizing and reconstruction functions with A-law processing in one 16-lead PDIP device. It can be placed where an analog voice node must become a 13-bit PCM stream or where a received PCM signal must return to an analog voice path. The device also performs the band-limiting and smoothing role associated with PCM codec-filters. Designers should confirm clocking mode, signal levels, and analog external-component requirements against the Motorola datasheet before laying out the circuit.
推薦
Telecommunications Line Equipment
The MC145557P is applicable in telecommunications line equipment that processes one voice channel per codec-filter location. Its 13-bit PCM resolution and A-law format provide defined digital conversion characteristics, while the single-function 16-lead PDIP package supports straightforward through-hole insertion. The part can serve in channel modules where analog speech is digitized or reconstructed before entering a larger PCM transport system. Designers must verify supply voltage, clock frequency, synchronization mode, and external filtering values before incorporating the IC into legacy line-card hardware.
推薦
Asynchronous PCM Test Module
The MC145557P can support an asynchronous PCM test module because its codec-filter family is documented for synchronous and asynchronous operation. A test fixture may use the 13-bit A-law conversion function to generate or analyze individual voice channels while exercising timing and signal-conditioning behavior. Its 16-lead PDIP package makes it straightforward to prototype on a through-hole fixture or replacement board. The implementation should follow the manufacturer timing diagrams and must account for the specified clock relationship, analog impedance, and filtering network.
推薦
PCM Voice Processor
The MC145557P is suited to a dedicated PCM voice-processing block where one analog voice channel must be digitized to 13-bit A-law PCM or reconstructed from that format. Its single-function organization makes it useful when the surrounding processor already handles channel routing and system control. The codec-filter also supplies the band-limiting and smoothing stage expected within a PCM voice path. Keep analog traces short, observe the datasheet grounding arrangement, and validate the complete clocking and filtering behavior at the system level.
推薦
Digital Voice Recording Front End
The MC145557P can form part of a digital voice recording front end where a channel-level analog signal is converted into a 13-bit A-law PCM representation. The codec-filter role combines conversion with signal conditioning, reducing the number of separate blocks required for a conventional PCM recording path. Its PDIP format is practical for prototype instruments, educational equipment, and repair platforms that prefer soldered through-hole assembly. Confirm input range, sampling clock, synchronization mode, and external filter components before recording begins.
推薦
Equipment Repair andobsolescence Recovery
The MC145557P is useful for equipment repair or obsolescence recovery when an existing 16-lead PDIP footprint and 13-bit A-law PCM behavior must be preserved. Direct replacement of the original device is preferable because changing resolution, companding, timing, or lead arrangement can disrupt the surrounding channel circuitry. Use the Request a Quote form for current sourcing and include the target quantity, original equipment, and required inspection documentation. Any alternate proposal should undergo complete pin, clock, analog-signal, and system-level compatibility checks.
推薦
推薦產品摘要
工程參考資料，適用於 MC145557P — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 |
|---|---|
| Product Type | PCM codec-filter |
| PCM Resolution | 13 bits |
| Encoding Format | A-law |
| Functions per Package | 1 function |
| Package | 16-lead PDIP |
| Package Pitch | 7.62 mm |
| Mounting Type | Through-hole |
| System Timing Support | Synchronous and asynchronous operation |
| Signal Processing | Voice digitization and reconstruction with band limiting and smoothing |
| RoHS Status | Non-compliant |
設計說明
Assign every connection from the 16-lead PDIP pin-description table in the Motorola manufacturer datasheet. In particular, separate analog voice paths from digital clock and data routing, keep the analog input or output network close to the associated pins, and route the 7.62 mm-pitch footprint without crossing sensitive analog traces beneath switching or high-speed digital nets. Confirm whether the exposed connections require a specific analog ground or digital ground arrangement.
Establish the clocking architecture before routing the PCB because MC145557P family devices support synchronous and asynchronous PCM operation. Propagate the selected timing source to every associated channel and use the manufacturer timing diagrams to preserve required setup, hold, and bit-period relationships. Keep clock traces short and isolated from analog voice lines, and test the completed board for timing margin across minimum and maximum supply conditions.
Do not treat a shared family identifier as proof of interchangeability. A replacement for MC145557P must preserve the 13-bit PCM format, A-law operation, clock characteristics, electrical limits, analog interface behavior, and 16-lead PDIP pinout. Use the complete datasheet comparison checklist before approval, and validate any substitute for signal level, timing, distortion, and channel noise rather than checking only nominal functionality.
Plan the through-hole footprint for a 16-lead PDIP body with 7.62 mm lead pitch and 0.300 in body width. Maintain adequate spacing around the IC for soldering access and avoid placing tall components where they interfere with lead formation or socket clearance. Provide unobstructed access to all pins, use a consistent ground-plane strategy, and keep external filtering components close to their corresponding signal pins.
合規資訊
The MC145557P is listed as RoHS non-compliant. No additional compliance declarations are established by the available product information.
