IN Brief:
- RHFLVDS42 provides four LVDS receiver channels with data rates up to 600Mbit/s and a common-mode input range from -4V to +5V.
- ST reports QML-V qualification and radiation hardness up to 300krad total ionising dose, with separate heavy-ion test limits.
- Manufacturing takes place in Rennes, France, using 130nm CMOS technology; the exact qualified ordering configuration must be confirmed.
STMicroelectronics has announced QML-V qualification for its RHFLVDS42 quad low-voltage differential signalling receiver, extending its offering of radiation-resistant components for spacecraft and other aerospace electronics. The device combines four receiver channels with data rates up to 600Mbit/s, operation from a 2.3V to 3.6V supply and protection against specified radiation effects.
The qualification announcement, issued on 19 October, concerns a receiver manufactured in Rennes, France, using ST’s 130nm CMOS technology. The component is intended for high-speed point-to-point data connections between electronic subsystems, with differential signalling used to maintain signal integrity across printed circuit board traces, backplanes and cables.
Electrical interfaces in spacecraft must continue operating despite temperature variation, radiation exposure and differences in the electrical conditions of interconnected equipment. Failures in a communications path can interrupt the transfer of sensor measurements, control instructions or system status information, making interface behaviour and component assurance important parts of the design.
Low-voltage differential signalling transfers information using the difference between two signal conductors. A receiver determines the transmitted logic state from that differential voltage rather than relying solely on the voltage of one conductor relative to ground. Interference affecting both conductors similarly can therefore be rejected, within the limits of the receiver’s common-mode capability.
ST specifies an input common-mode voltage range extending from -4V to +5V for the RHFLVDS42. This allows it to operate across defined differences between the reference potentials of connected equipment. The transmission medium is designed around a controlled impedance of 100 ohms, helping limit reflections that could otherwise distort high-speed signalling.
Signal integrity also depends on the physical arrangement of the interconnection. Poorly matched impedance, inappropriate termination, excessive discontinuities and crosstalk can distort the receiver input even where the nominal data rate remains within the device specification. ST uses a flow-through pin arrangement intended to simplify routing and reduce coupling between adjacent signals.
The four-channel receiver provides outputs compatible with specified low-voltage CMOS logic conventions. ST also incorporates fail-safe behaviour intended to produce a defined output under particular invalid or floating input conditions, while cold-spare capability allows the device to be considered for redundant architectures in which an inactive subsystem may share electrical connections with operational equipment.
Redundancy introduces its own constraints. An inactive receiver must not place an unacceptable load on the active interface, and the switching arrangements between primary and backup equipment must preserve the electrical conditions required by the communication link. The presence of cold-spare functionality provides a component capability, but does not constitute qualification of an entire redundant spacecraft system.
Radiation resistance is a separate part of the device specification. ST reports total ionising dose tolerance up to 300krad in silicon, describing accumulated exposure that can affect semiconductor materials and circuit characteristics over a mission’s operational life. The radiation assurance requirements for a particular spacecraft depend on the expected environment, shielding, mission duration and acceptable component margins.
Single-event effects arise through a different mechanism, when an energetic particle deposits charge within semiconductor structures. Depending on the circuit and operating conditions, an event may cause a transient disturbance, an incorrect logic state or a potentially destructive latch-up condition. These effects cannot be represented by a total dose figure alone.
For the RHFLVDS42, ST reports no single-event latch-up at a linear energy transfer of 122.6MeV cm²/mg, and no observed single-event transient or upset at 61.3MeV cm²/mg under the specified tests. Those values are test conditions and observed limits, not a guarantee that the receiver cannot experience a radiation-induced failure in every possible environment.
The device operates over a specified temperature range from -55°C to +125°C and is housed in a grounded-lid hermetic ceramic Flat-16 package. ST also lists electrostatic discharge robustness and a 4.8V absolute maximum voltage rating. The absolute maximum rating describes an electrical stress boundary and must not be confused with the normal 2.3V to 3.6V operating supply.
The October announcement identifies the receiver as QML-V qualified, referencing a quality and reliability qualification framework for space-grade semiconductor components. Such qualification relates to controlled manufacture, assurance and screening requirements in addition to the electrical performance of the underlying silicon.
ST’s product catalogue separately identifies the RHFLVDS42 as active and in volume production, while its publicly listed engineering and ordering information does not establish that every available configuration carries identical screening documentation. Customers specifying QML-V procurement should therefore confirm the exact orderable part, applicable qualification evidence and lot documentation with ST.
Manufacture in Rennes gives the device a European production base, while ST’s documentation identifies EAR99 export classification for the product. Export classification does not eliminate the need to assess the destination, end user and transaction-specific rules applicable to a particular shipment.
The supplier also provides product documentation and modelling resources for integration work. Electrical design still requires checking the loading, transmission medium, timing margins, common-mode conditions and any relevant failure behaviour of the complete link, rather than assuming that qualification of the receiver independently qualifies the interface assembly.
The RHFLVDS42 is available through ST’s product portfolio, with its space-grade qualification forming the new October development. Procurement and design verification will determine how the qualified configuration is incorporated into systems requiring controlled component traceability, radiation assurance and reliable high-speed communications.
