The MC145500, MC145501, MC145502, MC145503, and MC145505 are all per channel PCM Codec–Filter mono–circuits. These devices perform the voice digitization and reconstruction as well as the band limiting and smoothing required for PCM systems.

MC145500 (This Device is Not Recommended for New Designs)
• 16–Pin Package
• Transmit Bandpass and Receive Low–Pass Filter On–Chip
• Pin Selectable Mu–Law/A–Law Companding with Corresponding Data Format
• On–Chip Precision Reference Voltage (3.15 V)
• Power Dissipation of 50 mW, Power–Down of 0.1 mW at ± 5 V
• Automatic Prescaler Accepts 128 kHz, 1.536, 1.544, 2.048, and 2.56 MHz for Internal Sequencing
MC145501 — All of the Above Plus:
(This Device is Not Recommended for New Designs)
• 18–Pin Package
• Selectable Peak Overload Voltages (2.5, 3.15, 3.78 V)
• Access to the Inverting Input of the TxI Input Operational Amplifier MC145502 — All of the Above Plus:
• 22–Pin and 28–Pin Packages
• Variable Data Clock Rates (64 kHz to 4.1 MHz)
• Complete Access to the Three Terminal Transmit Input Operational Amplifiers
• An External Precision Reference May Be Used MC145503 — All of the Above Features of the MC145500 Plus:
• 16–Pin Package
• Complete Access to the Three Terminal Transmit Input Operational Amplifiers
MC145505 — Same as MC145503 Except:
• 16–Pin Package
• Common 64 kHz to 4.1 MHz Transmit/Receive Data Clock