SiTime extends temperature range of Endura MEMS Super-TCXO

Expanding the reach of the Endura MEMS Super-TCXO in to airborne and cold temperature terrestrial applications, SiTime announces that the TCXO now has an operating temperature range beyond its original -40 degrees C. It can now support -55 degrees C.

This enables the Endura SiT5146 to deliver best-in-class stability over -55 to +105 degrees C, says SiTime and is therefore able to be used in low earth orbiting (LEO) satellites, commercial aircraft, satellite communication systems, and rocket delivery systems as well as terrestrial systems residing in extremely cold environments

Aerospace and defence applications depend on precise and stable timing in the presence of extreme temperatures,” said Piyush Sevalia, executive vice president of marketing at SiTime. “Through our rapid-release derivatives program, we extended the operating temperature range of the SiT5146 to -55 degrees C while maintaining ±1 to ±2.5 ppm stability and excellent performance in the presence of shock and vibration,” he continued.

SiTime’s Endura SiT5146 MEMS Super-TCXO is available 0.009 ppb/g and 0.1 ppb/g acceleration sensitivity options. The ruggedised Super-TCXO can withstand high levels of shock and vibration. Frequencies are programmable with six decimals of accuracy from 1.0 to 60MHz.

The SiT5146 can be factory programmed for any combination of frequency, stability, voltage, and pull range, enabling shorter lead times. The device is available now in a 5.0 x 3.2mm package in the production quantities.

SiTime specialises in silicon MEMS timing. It offers programmable solutions that enable customers to differentiate their products with higher performance, smaller size, lower power, and better reliability.

http://www.sitime.com

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Rohde & Schwarz validates 5G RRM FR2 conformance tests

Conformance tests are vital for mobile communications technology as mobile network operators worldwide rely on conformance to the Global Certification Forum (GCF) before accepting mobile devices in their networks. Rohde & Schwarz has announced that the GCF has approved the first two radio resource management (RRM) conformance test cases for 5G FR2 frequencies, implemented on the R&S TS-RRM-NR 5G RRM conformance test system.

The test cases have been validated in seven FR2 and LTE band combinations.
The availability of validated RRM conformance tests in both FR1 and FR2 frequency bands is crucial for a successful rollout of 5G NR technology worldwide.

The GCF has officially accepted the R&S TS-RRM-NR as suitable for the 5G RRM FR2 requirements described in the 3GPP specifications. The GCF validation process requires ‘pass’ verdicts of the complete test case performed on two different end user devices. The updated version of the R&S TS-RRM family of RRM conformance test systems has accomplished this for FR2. RRM testing is a combination of several protocol and RF test methods. It is used to determine the reaction time of a mobile phone to changes in signal quality from the available sources, and the time it takes for the device to switch between different signal sources.

The new R&S CMX500 radio communication tester has added 5G NR signaling functions for both FR1 and FR2 to the updated R&S TS-RRM-NR, which now covers LTE, WCDMA, and 5G technologies. The integrated test system is operated by the sequencer software R&S CONTEST and offers high efficiency and precise, reproducible measurement results.

The 5G RRM test cases are also supported by the R&S TS8980, the integrated RF conformance test system supporting mobile technologies all the way from 2G to 5G including FR2.

Rohde & Schwarz has supplied conformance and operator acceptance testing throughout mobile radio from 2G through to LTE.

https://www.rohde-schwarz.com

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Simplified design for FemtoClock2 lowers power budget for data centres

With jitter as low as 64fs RMS, the FemtoClock2 family is available in a small 4.0 x 4.0mm2 24- and 28-pin QFN package options from Renesas Electronics. Power consumption is just 600mW.

The sub-100fs point-of-use clock is designed for data centre, server and network infrastructure markets. The FemtoClock2 family includes low jitter clock generators and jitter attenuators in a single package, enabling cost-effective and simple clock tree implementation for next generation, high speed interconnect designs.

The best-in-class jitter enables customers to easily meet next-generation PAM4 requirements on new switch or router designs, says Renesas. The form factor makes it less than one third the size of similar products available today, says the company. Designers can place the clock source at the point of use – very close to the device receiving the clock signal – for streamlined PCB layout design, reduced cross talk, and cleaner signals. The FemtoClock2 can be configured as a DCO, clock generator, or jitter attenuator.

“PAM4 technology is enabling a major leap in data transmission rates in both communications and data centre segments resulting in stringent requirement on the clock in such systems,” said Bobby Matinpour, vice president of Renesas’ timing products, data centre business division. The small size of the FemtoClock allows it to be placed anywhere on the board at the point of use. “This greatly simplifies the design by eliminating the additive jitter associated with the extensive clock routing on the board,” said Matinpour.

Customers can combine the FemtoClock2 with Renesas’ small, single-output, high-performance oscillators, or the broader ClockMatrix portfolio of timing solutions to address challenging timing needs for their high-performance server and network infrastructure designs. FemtoClock2 also works seamlessly with systems using the recently introduced PTP Clock Manager software for IEEE 1588 support, and can be combined with Renesas’ complementary power and microcontroller offerings to create comprehensive solutions for a variety of applications, such as the IEEE 1588 Winning Combination. FemtoClock2 also serves as the downstream clock capable of delivering 100fs at the pin without disrupting the synchronization.

The RC32504A and RC22504A FemtoClocks and an evaluation board are available now.

Renesas Electronics supplies microcontrollers, analogue, power, and SoC products for automotive, industrial, infrastructure and IoT applications.

http://www.renesas.com

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Liquid-cooled models extend SiC IPMs for e-mobility

Liquid-cooled SiC MOSFET intelligent power modules (IPMs) for e-mobility have been tailored for lower switching losses or for higher power. Cissoid has added the IPMs to its three-phase SiC IPM range. It has also added a module based on a lightweight AlSiC flat baseplate that meets the demand for natural convection or forced cooling in aerospace and in dedicated industrial applications. Both integrate a three-phase SiC MOSFET module with a powerful gate driver.

The IPM technology can be rapidly adapted to new voltage, power and cooling requirements, says Cissoid. They accelerate the design of SiC-based power converters enabling high efficiency and high power density. The embedded gate driver solves multiple challenges related to fast-switching SiC transistors. For example, negative drive and active miller clamping (AMC) prevent parasitic turn-on. There is also desaturation detection and soft-shut-down (SSD) to react rapidly but safely to short-circuit events. Under-voltage lockout (UVLO) functions on gate driver and DC bus voltages monitor system operation.

Two liquid-cooled power modules are based on a pin fin baseplate and rated for 1,200V blocking voltages and for 340 to 550A maximum continuous currents. The on resistance ranges from 2.53 to 4.19mOhms, depending on current rating. The total switching energies are as low as 7.48mJ (Eon) and 7.39mJ (Eoff) at 600V/300A.

Integrating the power module and the gate driver optimises the modules for lowest switching energies by tuning the dV/dt and controlling voltage overshoots which are inherent in fast switching. The reverse bias safe operating area (RBSOA) authorises peak currents up to 600A with DC bus voltages up to 880V making the power modules perfectly safe for 800V battery applications.

The air-cooled module is designed for applications where liquid cooling is not an option, for example, aerospace electromechanical actuators and power converters. This module is rated for a blocking voltage of 1,200V and a maximum continuous current of 340A. The on resistance is equal to 3.25mOms. Turn-on and turn-off switching energies are respectively 8.42mJ and 7.05mJ at 600V and 300A. The power module is cooled down through an AlSiC flat baseplate. The module is rated for 175 degrees C junction temperature and the gate driver for 125 degrees C ambient temperature.

http://www.cissoid.com

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