MCZ33990EF

Specialized Overview

The MCZ33990EF is an enhanced Class B serial transceiver designed for bi-directional half-duplex communication meeting the SAE J-1850 standard. It operates from a vehicle's 12 V battery system (7.0 V to 16 V) and interfaces directly with 5.0 V CMOS microcontrollers. The device transmits data on a single-wire bus at rates up to 10.4 kbps using Variable Pulse Width Modulation. Key electrical parameters include a maximum VBAT of 40 V, an operating temperature range of -40°C to 125°C, and sleep state current below 65 µA. It features short-circuit protection, thermal shutdown, and loss-of-ground detection.

Specialized Feature Summary

• Interfaces directly with standard 5.0 V CMOS microcontrollers without level shifting
• Provides internal reverse battery protection and robust short-circuit current limiting
• Includes loss of ground protection to prevent bus corruption during assembly faults
• Supports diagnostic loopback mode and 4X transmission modes via tristate control

Specialized Applications

• Automotive SAE J-1850 Class B Data Communication Network Interface
• Primary node implementation in Class B bus architectures
• Secondary node implementation in Class B bus architectures
• Vehicle body control modules requiring low-power standby states

Specialized Procurement Notes

Verify the component origin as NXP Semiconductors or Freescale Semiconductor, noting that NXP acquired Freescale. Confirm the EF suffix indicates Pb-free packaging compliant with JEDEC standards. Ensure the datasheet revision matches Rev 4.0 or later for final technical data specifications. Cross-reference the ordering information to confirm the 8-pin SOICN package availability.

Specialized Selection Notes

Select this component when designing systems requiring strict compliance with SAE J-1850 Class B protocols. It is suitable for applications needing direct 5.0 V logic interfacing and operation across wide automotive voltage fluctuations. Consider the 8-pin SOICN package constraints for PCB layout. Evaluate the need for external pull-down resistors on the LOAD pin for proper ground loss functionality.

Specialized Part Context

The MCZ33990EF belongs to the MC33990 family of analog integrated circuits built on SMARTMOS technology. This process combines CMOS logic, bipolar/MOS analog circuitry, and DMOS power FETs to ensure robustness against extreme temperatures and voltages. The device serves as a critical interface between digital microcontrollers and the analog requirements of automotive serial buses.

Specialized Replacement Considerations

The MC33390DDR2 is a similar Class B Serial Transceiver from Freescale. Verify compatibility regarding pinout and electrical characteristics before substitution. Note that the MCZ33990EF specifically denotes the Pb-free variant with the EF suffix.

Specialized FAQ

How does the device handle loss of assembly ground?

When assembly ground is lost, the LOAD output transistor self-biases off, limiting leakage current to less than 100 µA. This prevents the BUS pin from sourcing current and corrupting the bus while allowing other nodes to function normally.

What is the purpose of the 4X/LOOP pin?

The 4X/LOOP pin controls the transmit mode. A logic 0 enables normal waveshaping, a logic 1 disables waveshaping for faster 4X transmitting, and a high-impedance state activates loopback mode for system diagnostics.

Can the receiver wake the device from sleep mode automatically?

No, the device does not automatically wake from sleep upon bus activity. The microcontroller must explicitly toggle the SLEEP pin high to enable the transmitter after detecting activity on the RX line.