NXP Semiconductors MPC850SRZQ50BU

Overview

MPC850SRZQ50BU from NXP Semiconductors (formerly Freescale) is a PowerQUICC™ integrated communications processor combining a 32-bit MPC8xx core with a dedicated RISC communications processor (CP), dual-port RAM, Ethernet MAC, USB controller, and serial interface peripherals. It operates at 50 MHz, supports 3.3 V I/O with 5 V tolerance, and targets cost-sensitive remote-access and telecom edge devices requiring embedded protocol offload.

For engineers reviewing the MPC850SRZQ50BU datasheet, MPC850SRZQ50BU pinout, MPC850SRZQ50BU application, or MPC850SRZQ50BU equivalent, key selection criteria include its dual SCC support for Ethernet/HDLC, USB 1.1 host/slave capability, CPM-based serial channel offload, and BGA-352 package thermal performance under industrial temperature range.

Technical Context

The MPC850SRZQ50BU integrates a statically designed MPC8xx core (PowerPC architecture) with Harvard instruction/data caches (2 KB I-cache, 1 KB D-cache), MMU with 8-entry TLBs, and a separate 32-bit RISC communications processor (CP) managing up to seven serial channels-including two SCCs, one USB, two SMCs, one I²C, and one SPI. Its CPM executes protocol-specific microcode for HDLC, Ethernet, and transparent modes without burdening the main core.

It features a programmable memory controller supporting DRAM, SDRAM, SRAM, and flash; four 16-bit timers (or two 32-bit); IEEE 1149.1 JTAG debug interface; and low-power stop/sleep/deep-sleep modes. The device uses a 3.3 V core supply with 5 V-tolerant I/O pins and supports dynamic voltage scaling between 2.2 V (≤25 MHz) and 3.3 V operation.

Key Specifications

Pinout & Package

Package: 352-ball PBGA (Plastic Ball Grid Array), 27 mm × 27 mm, 1.27 mm pitch, RoHS-compliant. Thermal pad on underside requires solder paste stencil opening and thermal via array per AN-1231/D guidelines.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar integrated communications processor applications.

Compared with MPC850DEZQ50B and MPC852TVR50B, the MPC850SRZQ50BU uniquely combines ATM support, UTOPIA ports, and PCMCIA-ATA in a 352-ball BGA - making it the sole option for legacy DSLAM line cards requiring both ATM segmentation and removable storage.

Availability

MPC850SRZQ50BU is available at Aetrix Electronics and suitable for DSL access multiplexers, industrial Ethernet gateways, and remote terminal units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MPC850SRZQ50BU 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

NXP Semiconductors acquired Freescale in 2015 and maintains full technical support, documentation, and long-term supply for the PowerQUICC family.

The MPC850SRZQ50BU belongs to the PowerQUICC™ communications processor line, engineered for cost-sensitive networking edge devices where protocol offload, multi-interface integration, and industrial reliability are mandatory.

FAQ

What is the maximum bus speed supported by the MPC850SRZQ50BU?

The MPC850SRZQ50BU supports a maximum bus speed of 50 MHz in full-speed mode. Higher-frequency variants (e.g., 66 MHz or 80 MHz parts) must be operated in half-speed bus mode - meaning an MPC850SRZQ50BU running at 50 MHz uses native full-speed timing, with CLKOUT period of 20 ns and setup/hold margins validated per Table 6 in the hardware specifications.

Does the MPC850SRZQ50BU support USB host mode?

Yes, the MPC850SRZQ50BU includes a full-featured USB 1.1 controller supporting both host and peripheral modes at 1.5 Mbps (low-speed) and 12 Mbps (full-speed). Its USB port integrates internal pull-up resistors and complies with USB specification timing requirements, enabling direct connection to USB modems, flash drives, or HID devices without external transceivers.

What is the role of the Communications Processor Module (CPM) in the MPC850SRZQ50BU?

The CPM in the MPC850SRZQ50BU is a dedicated 32-bit RISC processor that handles serial communication protocols independently of the main MPC8xx core. It manages up to seven serial channels - including two SCCs for Ethernet/HDLC, one USB, two SMCs, one SPI, and one I²C - executing protocol-specific microcode to offload tasks like frame assembly, CRC generation, and buffer management.

Is the MPC850SRZQ50BU pin-compatible with other MPC850 family members?

No, the MPC850SRZQ50BU is not universally pin-compatible across the MPC850 family. While it shares the 352-ball PBGA footprint with MPC850SR and MPC850DSL variants, differences in signal mapping (e.g., UTOPIA port pins on MPC850SRZQ50BU versus ATM-specific pins on MPC850DSL) and power sequencing requirements mean PCB layout must be verified per each variant's mechanical drawing and pin list.

What thermal design guidance applies to the MPC850SRZQ50BU?

The MPC850SRZQ50BU requires careful thermal management due to its BGA-352 package. Freescale recommends a multilayer PCB with thermal vias under the thermal pad, achieving θJA = 31 °C/W. For 50 MHz operation at 700 mW typical dissipation, board temperature rise must stay below 20 °C above ambient to maintain junction temperature ≤95 °C - necessitating ≥4 thermal vias and 1 oz copper planes per AN-1231/D.