MC68334GCEH20 - 32-Bit CPU32 MCU 20MHz ROMless 132-PQFP
MPN: MC68334GCEH20 ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $42.5 | $42.50 |
| 10 | $38.25 | $382.50 |
| 100 | $34 | $3,400.00 |
| 500 | $30.5 | $15,250.00 |
| 1,000 | $27.95 | $27,950.00 |
MC68334GCEH20 Overview
The MC68334 belongs to the M68300 family of microcontrollers, which pioneered the integration of microcontroller peripherals with a 32-bit CPU32 processing core. An MCU (microcontroller unit) is a single-chip computer containing a processor core, on-chip memory, and programmable peripherals; the M68300 family extends this concept by integrating a Time Processing Unit (TPU) - a dedicated microcoded engine optimised for high-speed digital I/O tasks such as PWM, period capture, and stepper motor control. Within the broader hierarchy, MCUs sit below microprocessors in integration level: MCU -> embedded microcontroller -> 32-bit microcontroller -> M68300 family -> semiconductor.
Key features of the MC68334GCEH20 include 1 Kbyte of standby RAM, a CPU32 core with 32-bit internal architecture, a System Integration Module providing chip-select and bus arbitration logic, a Time Processing Unit for autonomous I/O timing, and a 20 MHz maximum operating frequency. The 132-pin PQFP package supports surface-mount assembly and provides ample I/O for industrial control applications.
Architecturally, the CPU32 core executes the M68000 instruction set with 32-bit internal registers, providing code density and deterministic interrupt response. The TPU executes microcoded routines in parallel with the CPU, offloading time-critical tasks such as crank-angle tracking, PWM generation, and quadrature decoding. External memory interfaces support 8/16-bit ROM, SRAM, and peripheral chips via programmable chip-select outputs.
Typical applications for the MC68334GCEH20 include automotive engine management (cam/crank timing), industrial motor control (variable-frequency drives), robotics (multi-axis motion control), process control instrumentation, and aerospace flight control subsystems. The 20 MHz clock and TPU make it particularly suited to real-time control loops where deterministic response is required.
When designing with this part, engineers should note that the 132-PQFP package requires multilayer PCB layout care and adequate thermal relief on the GND pins. The ROMless architecture mandates external flash or EPROM for code storage and an external watchdog for unattended operation.
This page synthesises distributor pricing, lifecycle status, and drop-in compatible alternatives for the MC68334GCEH20, providing design engineers with practical decision support not found in the manufacturer datasheet alone.
Drop-in alternatives for MC68334GCEH20 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MC68334GCEH20 (same form factor and footprint) — differing in Data Bus Width, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC68334GCEH16
✅ Drop-In📋 Reference alternative (not in catalog)
MC68334GEM16
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC68334GEM20
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC68332ACEH25
✅ Drop-In✓ In Stock
$35.54 / Unit
View Datasheet →MC68334GCEH20 Maximum Ratings & Electrical Characteristics
| Manufacturer | NXP Semiconductors (formerly Freescale / Motorola) |
| Product Type | 32-bit Microcontroller (MCU) |
| Core Architecture | CPU32 (M68300 / 68k family) |
| Instruction Set | M68000 compatible |
| Operating Frequency (Max) | 20 MHz |
| Data Bus Width | 32-bit (internal) / 16-bit (external) |
| Program Memory | ROMless (external memory required) |
| RAM Size | 1 Kbyte (1024 bytes) standby RAM |
| Package | 132-pin PQFP (Plastic Quad Flat Pack), 24.13 x 24.13 mm |
| Integrated Peripherals | System Integration Module (SIM), Time Processing Unit (TPU) |
| Mounting Type | Surface Mount |
MC68334GCEH20 132-pin pqfp (plastic quad flat pack), 24.13 x 24.13 mm Pin Configuration Guide
Pin configuration for MC68334GCEH20 (132-pin pqfp (plastic quad flat pack), 24.13 x 24.13 mm package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for MC68334GCEH20.
Refer to the datasheet for full pin configuration.
Typical Applications
MC68334GCEH20 is suitable for 6 applications: Automotive Engine Management (ECU), Industrial Motor Control (VFD / Servo Drive), Robotics and Multi-Axis Motion Control, Process Control Instrumentation, Aerospace Flight Control Subsystems, Printer and Industrial Imaging Controllers.
Automotive Engine Management (ECU)
The MC68334GCEH20's 20 MHz CPU32 core and integrated Time Processing Unit make it well suited to engine control units (ECUs) in legacy automotive platforms. The TPU offloads crankshaft position decoding, fuel-injector pulse-width modulation, and camshaft timing events from the main CPU, delivering deterministic sub-microsecond event response required for sequential fuel injection. According to the NXP/Freescale datasheet, the TPU executes microcoded timing routines in parallel with the CPU32, freeing the processor for closed-loop lambda and torque calculations. The 132-PQFP package provides ample I/O for ignition drivers, knock-sensor conditioning, and CAN/LIN transceivers. Note: this legacy part predates AEC-Q100 obligations and is now obsolete; consider NXP's MPC5121VY400 for new automotive designs.
Recommended
Industrial Motor Control (VFD / Servo Drive)
Industrial variable-frequency drives and servo-motor controllers benefit from the MC68334GCEH20's combination of 32-bit arithmetic, TPU-driven PWM generation, and SIM chip-select logic. The TPU can produce up to 16 channels of PWM with programmable duty cycle and dead-time insertion, enabling three-phase inverter control for AC induction, BLDC, and switched-reluctance motors. According to the NXP datasheet, the CPU32 core executes vector-control and PI-loop code with deterministic interrupt response. The 1 Kbyte internal RAM supports small lookup tables and runtime variables, while external ROM holds the modulation firmware. The 132-PQFP package provides sufficient I/O for analog feedback, gate-driver interfacing, and incremental encoder inputs through the TPU.
Recommended
Robotics and Multi-Axis Motion Control
Multi-axis robotics controllers can leverage the MC68334GCEH20's Time Processing Unit for parallel management of joint servo loops. Each TPU channel can be assigned to quadrature-encoder pulse counting, step/direction generation, or PWM output, allowing up to 16 axes of coordinated motion from a single MCU. According to the manufacturer datasheet, the TPU handles all time-critical events autonomously so the CPU32 can run trajectory-planning and inverse-kinematics algorithms. The 32-bit internal registers give wide dynamic range for position counters and PID integrators. The 132-PQFP surface-mount package suits densely-populated robot-controller PCBs. Designers should pair the part with external RAM/flash and dual-port memory for multi-axis state exchange.
Recommended
Process Control Instrumentation
Distributed control systems (DCS) and process instrumentation benefit from the MC68334GCEH20's combination of 32-bit arithmetic, deterministic interrupt response, and flexible chip-select output for peripheral expansion. According to the NXP/Freescale datasheet MC68334GCEH20, the System Integration Module provides up to 12 programmable chip-select outputs that can address external ADC/DAC chips, EEPROM, and serial communication peripherals. The CPU32 core runs PID loops and Modbus / Hart protocol stacks at 20 MHz. The 1 Kbyte internal standby RAM retains calibration constants and run-time variables when main power is removed, supporting remote instrumentation in hazardous-location applications. Pair with 4-20 mA loop interfaces and isolated serial links for full process-control front ends.
Recommended
Aerospace Flight Control Subsystems
Legacy aerospace flight-control subsystems and avionics computers were early adopters of the MC68334GCEH20's deterministic CPU32+TPU architecture. The TPU executes redundant-channel voting and actuator-command refresh at sub-100 microsecond intervals, providing the deterministic I/O response required for primary flight-control surfaces. According to the manufacturer documentation, the M683xx family was specified across the full military temperature range and used in DO-178B-certified systems. The 132-PQFP package supports high-density PCB layouts typical of flight-control computers. Aerospace programs should use Rochester Electronics to source last-time-buy inventory; new flight-control designs should migrate to active alternatives like the MPC5121VY400 or modern Kinetis / S32K parts.
Recommended
Printer and Industrial Imaging Controllers
Laser printer engines and industrial imaging controllers benefit from the MC68334GCEH20's high-speed TPU for managing stepper motors, scan-line timing, and charge-control loops. According to the NXP/Freescale datasheet, the TPU can produce precisely timed pulses for laser-diode modulation, polygon-mirror phase-lock, and paper-feed stepper commutation. The CPU32 core processes image-rendering pipelines and high-speed data paths. The 132-PQFP package supports dense printer-engine PCBs with on-board RAM for image buffers. While new designs use 32-bit ARM Cortex-M controllers, the MC68334GCEH20 remains in service-pools for legacy enterprise printers, with Rochester Electronics providing factory-traceable replacements.
Recommended
Recommended Products Summary
Engineering reference data for MC68334GCEH20 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC68334GCEH16 | MC68334GEM16 | MC68334GEM20 | MC68332ACEH25 |
|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 132-PQFP (24.13x24.13 mm) | 132-PQFP (24.13x24.13 mm) - same | 132-PQFP (24.13x24.13 mm) - same | 132-PQFP (24.13x24.13 mm) - same | 132-PQFP (24.13x24.13 mm) - same |
| Core Architecture | CPU32 (M68300 / 68k) | CPU32 (M68300) | CPU32 (M68300) | CPU32 (M68300) | CPU32 (M68300) |
| Maximum Clock Frequency | 20 MHz | 16 MHz (-20%) | 16 MHz (-20%) | 20 MHz (same) | 25 MHz (+25%) |
| On-chip RAM | 1 Kbyte | 1 Kbyte (same) | 1 Kbyte (same) | 1 Kbyte (same) | 1 Kbyte (same) |
| Time Processing Unit (TPU) | Yes | Yes | Yes | Yes | No (SIM only) |
| Program Memory | ROMless (external) | ROMless (same) | ROMless (same) | ROMless (same) | ROMless (same) |
| Lifecycle Status | Obsolete (EOL) | Obsolete (EOL) | Obsolete (EOL) | Obsolete (EOL) | Obsolete (EOL) |
| Datasheet Source | NXP / Freescale | NXP / Freescale | NXP / Freescale | NXP / Freescale | NXP / Freescale |
Key Differentiators
- Faster 20 MHz clock versus 16 MHz variants (vs MC68334GCEH16)
- Integrated Time Processing Unit (TPU) versus SIM-only alternative (vs MC68332ACEH25)
- Pin-to-pin compatible across the MC68334G family (vs MC68334GEM20)
Design Notes
The 132-PQFP package requires careful PCB layout to maintain signal integrity on the 16-bit external data bus and TPU I/O. Estimated: at 20 MHz CPU clock, the 5 V address/data signals have edge rates of approximately 1 ns - route the D0-D15, A0-A23, and control lines (AS, DS, R/W) over a continuous ground plane to keep impedance below 50 ohms. Place bypass capacitors (0.1 microfarad ceramic + 10 microfarad tantalum) within 5 mm of every VDD/VSS pair. The 132-PQFP gull-wing leads at 0.635 mm pitch demand reflow profile compliance with JEDEC J-STD-020 and footprint tolerance per IPC-7351.
The MC68334GCEH20 consumes approximately 600 mW at 20 MHz when all peripherals are active. With a theta_JA estimated between 35-45 C/W (132-PQFP package, JEDEC EIA/JESD51 test board), the junction temperature rise above ambient would be 21-27 C - acceptable for industrial-temperature applications. Estimated: this calculation assumes all 132 pins soldered to a 4-layer JEDEC test board; actual theta_JA in production boards may differ by 10-20%. For high ambient-temperature enclosures (>70 C), provide forced-air cooling or a copper heatsink bonded to the PQFP top surface.
Estimated common pitfall: the ROMless MC68334GCEH20 requires external program memory - never assume internal flash is present; missing external ROM/flash will manifest as address-error exceptions on the first instruction fetch. To mitigate, design the board with at least one 32-pin EPROM/flash footprint AND one 32-pin SRAM footprint, even if RAM is internal. Also: the 132-PQFP footprint is NOT pin-compatible with later LQFP variants - if you intend to migrate to a ColdFire upgrade, allocate PCB space for a daughter-card adapter rather than drop-in.
The MC68334GCEH20 requires a clean 5 V supply; tolerance is typically 4.75 V to 5.25 V according to legacy M68000-family specifications. Use a low-dropout regulator with at least 1 A peak current capability to handle the CPU32 core's dynamic switching transients (estimated peak delta_I/dt 100 mA/us). Add a 100 ohm ferrite-bead in series with the VDD pin and bulk decoupling caps at the regulator output. For battery-backed systems, route the VSTBY pin to a 3-5 V standby supply to retain the on-chip RAM during main-power loss.
Compliance Information
RoHS and lead-free status cannot be confirmed from the verified web data for this obsolete legacy part. AEC-Q100 not applicable - part predates automotive qualification requirements. Engineers should request compliance documentation from Rochester Electronics or select a ColdFire V1 replacement for new designs.
