NXP Semiconductors MC145483ENR2

Overview

MC145483ENR2 from Freescale Semiconductor is a 13-bit linear PCM codec-filter IC performing voice digitization and reconstruction with on-chip transmit band-pass (200 Hz–3.4 kHz) and receive low-pass (≤3.4 kHz) filtering, 2's complement data format, and integrated precision 0.886 V reference voltage. It operates from a single 3 V supply and supports both synchronous and asynchronous clocking for telephony-grade voice coding in digital communication systems.

For engineers reviewing the MC145483ENR2 datasheet, MC145483ENR2 pinout, MC145483ENR2 application, or MC145483ENR2 equivalent, key selection criteria include its fully differential analog signal path, 8 mW typical power dissipation, 300 Ω push-pull power drivers with external gain adjust, and support for Long/Short Frame Sync, sign-bit extended, and receive gain-adjust digital interface modes.

Technical Context

The MC145483ENR2 implements a differential switched-capacitor architecture with active R-C pre- and post-filtering, autozeroed sample-and-hold, and shared 13-bit DAC-based successive-approximation ADC. Its analog signal path is fully differential from the TI+/TI– inputs through the 5-pole transmit band-pass filter and 3-pole high-pass filter (bypassable via HB pin) to the 13-bit linear A/D converter.

Digital reconstruction uses the same 13-bit DAC structure, followed by sinX/X-compensated 5-pole switched-capacitor low-pass filtering and active R-C smoothing. The device supports four distinct PCM interface modes-Long Frame Sync, Short Frame Sync, sign-bit extended (16-bit transfers), and receive gain-adjust (13+3-bit)-all synchronized to MCLK frequencies from 256 kHz to 4.096 MHz.

Key Specifications

Pinout & Package

MC145483ENR2 is packaged in a 20-pin SOG (Small Outline Gull-wing) package per Case 751D. Pin assignments are identical across SOG, SSOP, and TSSOP variants. The ENR2 suffix corresponds to the SOG package with DW ordering code.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PCM codec applications.

Compared with TLV320AIC10IPFB and CS44600-CQZ, the MC145483ENR2 delivers purpose-built telephony performance-including integrated 200 Hz–3.4 kHz filtering, –5 dBm TLP calibration, and 300 Ω line drivers-in a lower-pin-count, lower-power SOG package optimized for fixed-function voice infrastructure.

Availability

MC145483ENR2 is available at Aetrix Electronics and suitable for VoIP gateways, digital PBX line cards, and wireless base station modems requiring stable component supply, long-term lifecycle support, and consistent analog performance across production batches.

Supply support for MC145483ENR2 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

Freescale Semiconductor (now part of NXP Semiconductors) is a fabless semiconductor company specializing in embedded processing, analog, and mixed-signal solutions for automotive, industrial, and communications markets.

The MC145483ENR2 belongs to Freescale's legacy telephony analog front-end product line, designed specifically for carrier-grade voice digitization in TDM and early VoIP infrastructure where deterministic latency, low idle noise, and ITU-T G.711 compliance were critical.

FAQ

What is the function of the HB pin on the MC145483ENR2?

The HB (High-Pass Filter Bypass) pin on the MC145483ENR2 controls whether the internal third-order 50/60 Hz rejection filter is active in the transmit path. When HB is logic low, the filter is enabled to attenuate power-line interference; when logic high, it is bypassed, allowing dc-coupled input signals. This feature is essential for applications requiring tone generation or dc-level monitoring alongside voice coding, and is confirmed in the Pin Descriptions section of the official Freescale MC145483 datasheet.

Does the MC145483ENR2 support both Long and Short Frame Sync protocols?

Yes, the MC145483ENR2 supports both Long Frame Sync and Short Frame Sync timing protocols on its FST and FSR pins. The device automatically detects and adapts to either format without configuration, enabling interoperability with legacy T1/E1 framers and modern DSPs. This dual compatibility is explicitly stated in the Device Description and Digital I/O sections of the Freescale MC145483 datasheet and verified across all package variants including MC145483ENR2.

What is the significance of the VAG and VAG Ref pins on the MC145483ENR2?

The VAG pin on the MC145483ENR2 provides a mid-supply (1.5 V) analog ground reference for all internal analog circuitry, while VAG Ref is its dedicated bypass node requiring a 0.1 µF capacitor to VSS. This separation decouples clock noise from the analog core, improving PSRR by >60 dB. Both pins are high-impedance in power-down mode. Their behavior and decoupling requirements are fully documented in the Pin Descriptions and PCB Layout sections of the Freescale MC145483 datasheet.

Can the MC145483ENR2 drive a 600 Ω telephone line directly?

No, the MC145483ENR2 cannot drive a 600 Ω telephone line directly. Its PO+/PO– outputs are specified for 300 Ω loads delivering 3.544 Vpp, and its RO– output drives only 2 kΩ. Driving 600 Ω requires an external line transformer or buffer amplifier. This limitation is confirmed by the "Power Amplifier Output" and "Receive Analog Output" specifications in the Freescale MC145483 datasheet, which define load conditions and voltage swing limits.

What master clock frequencies are supported by the MC145483ENR2?

The MC145483ENR2 supports MCLK frequencies of 256 kHz, 512 kHz, 1.536 MHz, 1.544 MHz, 2.048 MHz, 2.56 MHz, and 4.096 MHz. An internal prescaler automatically selects the correct divide ratio to generate the required 256 kHz internal sequencing clock. Synchronization requirements vary by frequency: 256/512 kHz require rising-edge alignment with FST, while ≥1.536 MHz require alignment for optimum performance. This is detailed in the Master Clock section of the Freescale MC145483 datasheet.