Choose the right quartz crystal for your energy saving MCU with THIS simple test

Next generation MCUs and RF chipsets, commonly used in IoT, wearable, and battery powered applications, have presented a problem frequently ignored by many designers across all industries. Lower power consumption requires next generation crystals to optimize for a weaker gain and drive from the Pierce analyzer. The ability to sustain oscillation for a given quartz crystal oscillator design depends heavily on the crystal’s motional parameters, board parasitics, and oscillator circuit characteristics. Yet, as MCUs are upgraded to lower power models, their crystal counterparts have stayed the same. The Pierce oscillator circuit, a closed loop system most commonly integrated into low power ICs, sustains oscillation at an operating point, depending on the crystal plating capacitance (CL), crystal equivalent series resistance (ESR), and oscillator amplifier’s gain and phase response associated with the oscillator’s transconductance (gm). But, how do you know if your crystal’s parameters match your system?

Abracon’s Pierce analyzer system (PAS) was designed by our engineers to help you make the right choice for your industry leading designs. The PAS test validates quartz crystal performance in-circuit and simultaneously measures the crystal, crystal oscillator, and printed circuit board parasitics. Testing in-system accounts for all variables and enables ideal matching of crystal parameters to the board and oscillator in the MCU or RF chipset. This is especially critical for applications using next generation, energy saving technologies requiring optimal gm factors.

Lower CL and lower ESR increase operating gain margin of the loop, ensuring sustained oscillations across all variables including variation in bias, loading, temperature, and over time. Gm_critical is the critical transconductance value that a crystal must achieve in order to remain in the safe zone of loop operation. Crystals that do not meet gm_critical are not well matched to the Pierce oscillator and may cause long term reliability issues associated with startup. Since lower power consumption decreases gm and gm_crictical for a given Pierce oscillator, energy saving designs deployed in IoT and wearables applications are the most at risk of failure. Conducting a PAS test reduces risk and improves the reliability of your system.

“Semiconductor technology strives to wring all the power consumption out of the latest generation of MCUs and RF chipsets,” commented Syed Raza, VP of Engineering with Abracon “the on-chip Pierce oscillator is starved of much needed gain negatively impacting the gm_critical metric. The PAS test is the surest way to diagnose preventable problems.”

“As The Heartbeat of the IoT™, we strive to provide customers with as many tools and services as possible that will take their designs to the next low power plateau. The PAS test service enables validation of a critical subsystem in the design given that nothing will operate if the oscillator fails to run.” commented Juan Conchas, Director of Marketing with Abracon.

The service provides a comprehensive report outlining the functional parameters of the oscillator circuit and recommends changes when necessary. This service is conducted by Abracon and can be ordered through any franchised distributor, with multiple turn-around times from 2-weeks to 4-weeks.

Learn more about the Pierce Oscillator here.
Find more information on the PAS test, here.

Check inventory for the PAS here: PAS-BC1WK/ PAS-BC2WK/ PAS-BC3WK

About Abracon, LLC
Founded in 1992, and headquartered in Spicewood, Texas, Abracon is a leading global manufacturer of passive and electromechanical timing, synchronization, power, connectivity and RF solutions. Abracon offers a wide selection of quartz timing crystals and oscillators, MEMS oscillators, real time clocks (RTC), Bluetooth modules, ceramic resonators, SAW filters and resonators, power and RF inductors, transformers, circuit protection components and RF antennas and wireless charging coils. The company is ISO9001-2008 certified with design & application engineering resources in Texas and sales offices in Texas, California, China, Taiwan, Singapore, Scotland, Israel, Hungary, UK, and Germany. Abracon’s products are offered through its global distribution network. For more information about Abracon, visit www.abracon.com.

Abracon Pierce Analyzer System (PAS) validates quartz crystals in-circuit

PAS-BC1WK/ PAS-BC2WK/ PAS-BC3WK

(Austin, TX) Abracon, LLC (Abracon), a leading global manufacturer of passive & electromechanical timing, synchronization, power, connectivity and RF components announces the availability of an advanced proprietary Pierce analyzer system that validates quartz crystal performance in-circuit. The ability to sustain oscillation for a given quartz crystal oscillator design depends heavily on crystal’s motional parameters, board parasitics and oscillator circuit characteristics. The oscillator circuit is a closed loop system that sustains oscillation at an operating frequency, depending on the crystal plating capacitance (CL), crystal equivalent series resistance (ESR) and Oscillator Amplifier’s gain & phase response. Lower CL and lower ESR at the crystal level, enables the circuit to operate with adequate gain margin and improves the closed-loop stability; ensuring sustained oscillations across all variables, including variation in bias, loading, temperature and over time. Integrated circuits that use external quartz crystals do not always account for these key limiting factors. For instance, estimating or simulating the effect of board parasitics is not always possible. In-circuit testing of the quartz crystal while connected to the oscillator IC and attached to the board reveals design errors and inaccuracies that may cause over-drive, under-drive or center frequency deviations; or even the ability to sustain oscillations.

“Overdrive on the crystal causes long term reliability concerns due to microfractures within the crystal lattice. Under-drive may lead to complete oscillator loop failure, and center frequency errors as high as +/-500 parts per million may be completely out of range of acceptable frequency drift for a given application,” says Syed Raza, VP of Engineering with Abracon. “To conserve power, next generation IC’s must lower the gain in the oscillator loop requiring quartz crystals with much lower ESR at lower plating load. With next generation ultra-low power circuits used in the Internet of Things (IoT) and wearables, fabricated in <14 nanometer geometry; it’s no longer safe to assume that the oscillator will operate with sufficient gain margin, especially over temperature and time.

“The quartz crystal oscillator,” says Juan Conchas, Director of Marketing with Abracon, “sets the beat of the entire system. As oscillators are starved of power, failure to operate or operation off-center frequency is much more likely and more challenging to correct. For this reason, the ability to verify the performance of the crystal oscillator loop in-circuit, has become a necessary step in validating the overall system design.”

The service provides a comprehensive report outlining the functional parameters of the oscillator circuit and recommends changes when necessary. This service is conducted by Abracon and can be ordered through any franchised distributor, with multiple turn-around times from 2-week to 4-weeks.

About Abracon, LLC
Founded in 1992, and headquartered in Irvine, California, Abracon is a leading global manufacturer of passive and electromechanical timing, synchronization, power, connectivity and RF solutions. Abracon offers a wide selection of quartz timing crystals and oscillators, MEMS oscillators, real time tlocks (RTC), Bluetooth modules, ceramic resonators, SAW filters and resonators, power and RF inductors, transformers, circuit protection components and RF antennas and wireless charging coils. The company is ISO9001-2008 certified with design & application engineering resources in California and Texas and sales offices in Texas, California, China, Taiwan, Singapore, Scotland, and Germany. Abracon’s products are offered through its global distribution network.

Abracon Media Contact
PR@abracon.com