NXP Semiconductors MPC745BVT300LE

Overview

MPC745BVT300LE from Freescale Semiconductor is a 300 MHz PowerPC™ RISC microprocessor implementing the 60x bus architecture, featuring a 32 KB instruction cache, 32 KB data cache, and no L2 cache interface - distinguishing it from the MPC755. It operates at 2.0 V core voltage with 2.5 V or 3.3 V I/O support and targets low-power embedded control in networking edge devices, industrial controllers, and telecom line cards.

For engineers reviewing the MPC745BVT300LE datasheet, MPC745BVT300LE pinout, MPC745BVT300LE application, or MPC745BVT300LE equivalent, key selection criteria include its lack of L2 cache interface, PBGA-255 package, 300 MHz core frequency with 25–100 MHz SYSCLK range, thermal management assist unit (TAU), and support for doze/nap/sleep power states - all critical for thermally constrained, cost-sensitive PowerPC-based designs.

Technical Context

The MPC745BVT300LE implements the PowerPC instruction set architecture with a dual-integer-unit (FXU1/FXU2) and IEEE 754-compliant floating-point unit, supporting single- and double-precision arithmetic. Its memory management includes 128-entry two-way set-associative TLBs and eight BATs per domain, enabling up to 4 GB physical addressing.

It integrates a JTAG/COP debug interface, time base counter/decrementer, clock multiplier, and hardware performance monitor. Unlike the MPC755, it omits the L2 cache controller, L2 tags, and L2 bus interface - confirmed by Freescale documentation stating "MPC745 is identical to the MPC755 except it does not support the L2 cache interface."

Key Specifications

Pinout & Package

The MPC745BVT300LE is housed in a surface-mount 255-ball plastic ball grid array (PBGA) package with 1.27 mm pitch, optimized for thermal dissipation and board-level reliability in industrial environments.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RISC microprocessor applications.

Compared with MPC745BVT300LE, the MPC745BVT350LE offers higher deterministic throughput within identical thermal and layout constraints, while the MPC7447A delivers architectural upgrades at the cost of redesign effort - making the MPC745BVT300LE optimal for stable, cost-sensitive, long-lifecycle deployments where 300 MHz suffices.

Availability

MPC745BVT300LE is available at Aetrix Electronics and suitable for industrial PLC controllers, telecom line cards, and network edge routers requiring stable component supply, long-term obsolescence management, and traceable sourcing for safety-critical firmware validation.

Supply support for MPC745BVT300LE 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 connectivity solutions for automotive, industrial, and networking markets.

The MPC745 belongs to Freescale's PowerPC 7xx family, designed specifically for cost-optimized, low-power embedded control applications where deterministic real-time performance and thermal resilience outweigh raw compute density.

FAQ

What is the maximum operating temperature for the MPC745BVT300LE?

The MPC745BVT300LE has a maximum junction temperature (Tj) of 105°C under recommended operating conditions. Its thermal management assist unit (TAU) provides real-time die temperature monitoring via dedicated SPRs (THRM0–THRM3), enabling software-initiated throttling or shutdown before exceeding this limit. The PBGA-255 package exhibits a junction-to-ambient thermal resistance (RθJA) of 34°C/W under natural convection, requiring appropriate heatsinking or airflow in enclosed systems to sustain full 300 MHz operation.

Does the MPC745BVT300LE support L2 cache?

No, the MPC745BVT300LE does not support an L2 cache interface. As explicitly stated in Freescale's MPC755 hardware specifications document: "The MPC745 is identical to the MPC755 except it does not support the L2 cache interface." This omission removes the L2 controller, L2 tags, and associated 17-bit L2 address / 64-bit L2 data bus signals - simplifying board design and reducing system cost, but limiting sustained bandwidth for large working sets compared to L2-equipped variants like the MPC755.

What are the valid SYSCLK frequency ranges for the MPC745BVT300LE?

The MPC745BVT300LE accepts SYSCLK frequencies from 25 MHz to 100 MHz, as specified in Table 8 of the Freescale MPC755 hardware specifications. This range supports bus-to-core frequency multipliers of 2x through 8x and 10x, yielding the rated 300 MHz core frequency (e.g., 75 MHz SYSCLK × 4). SYSCLK jitter must remain within ±150 ps (total), and duty cycle must be 40–60% at OVDD/2 to ensure reliable PLL lock and internal timing margin across voltage and temperature extremes.

How is I/O voltage selected on the MPC745BVT300LE?

I/O voltage selection on the MPC745BVT300LE is controlled by the BVSEL pin, sampled during power-on reset. When BVSEL = 0, the processor bus interface defaults to 2.5 V operation; when BVSEL = 1, it defaults to 3.3 V. The actual OVDD supply must match this selection - applying 3.3 V OVDD while BVSEL = 0 violates the absolute maximum ratings and may cause functional failure. Input thresholds (VIH/VIL) and output drive strength are configured accordingly, and BVSEL must remain stable during operation per Freescale's specification.

Is the MPC745BVT300LE pin-compatible with the MPC755?

No, the MPC745BVT300LE is not pin-compatible with the MPC755. The MPC745 uses a 255-ball PBGA package, whereas the MPC755 is offered in 360-ball CBGA or PBGA packages. More critically, the MPC745 omits all L2-related pins (e.g., L2AVDD, L2OVDD, L2AD[16:0], L2D[63:0]), resulting in fundamentally different ball maps and incompatible PCB footprints. Interchangeability is precluded by both mechanical and electrical incompatibility - only the MPC745BVT350LE shares the same PBGA-255 package and pinout.