CMX909BD5

Overview

The CMX909BD5 is a half-duplex GMSK packet data modem manufactured by CML Microcircuits. It supports data rates up to 38.4 kbits/sec and operates on 3.0V or 5.0V supplies. The device features an 8-bit parallel host processor interface, on-chip packet detection, and Mobitex compatibility including R14N short block frames. It integrates CRC generation/checking, FEC coding, interleaving, and scrambling to reduce host microcontroller processing load. The component utilizes decision feedback equalization for receiver performance enhancement. It is housed in a low-height 24-pin TSSOP package.

Feature Summary

• Integrated GMSK modulation and demodulation with on-chip packet handling
• Supports full and short data packet framing with Mobitex R14N compatibility
• Includes hardware acceleration for CRC, FEC, interleaving, and scrambling
• Features flexible operating modes and multiple power-saving options

Applications

• Mobitex terminals
• Wireless telemetry systems
• License-free radio data schemes
• ISM band radio applications

Procurement Notes

Verify the specific ordering suffix BD5 corresponds to the 24-pin TSSOP low-height package variant as defined in the official datasheet mechanical outlines. Confirm that the voltage operation requirements align with the specified 3.0V/5.0V capabilities before finalizing procurement orders.

Selection Notes

Select this model when a pin-compatible replacement for FX909A or MX909A is required with improved performance and lower voltage operation. Ensure the application design accommodates the 24-pin TSSOP footprint and provides adequate decoupling for VDD and VBIAS pins to maintain noise performance standards.

Part Context

This component belongs to the CMX909B series of communication semiconductors designed for wireless data applications. It serves as a direct backward-compatible upgrade to earlier models like the FX909A, offering enhanced data throughput and extended battery life through intelligent power management features within the same physical form factor.

Replacement Considerations

CMX909BE2 (SSOP package), CMX909BP4 (P4 package)