Microcircuit provides metal strain gage measurement.
Press Release Summary:
ACAM Picostrain PS01 utilizes time-to-digital converter technology, eliminating analog circuitry. It determines resistor ratio from time interval measurement, done with resolution of 14 psec, which corresponds to 70 GHz for counter. Chip offers programmable update rates up to 65kHz. Digital design provides output stability over operating temperature of -40 to 120°C. Unit has 48 TQFP enclosure and 8-bit or SPI serial interfaces. It supports temperature measurement of up to 4 sensors.
Original Press Release:
New Compact Chip for Precision Strain Gage Measurement Provides Lower Current and Faster Update Times, Eliminates Analog Circuitry for Longer Battery Life
Time-to-digital converter technology makes PS01 chip ideal for metal strain gage measurement on a variety consumer and industrial products like scales and pressure transducers, but also for temperature measurement
December 2002 - The new purely digital ACAM Picostrain PS01 chip for strain gage measurement capitalizes on proven time-to-digital converter (TDC) technology to offer product designers a more flexible "alternative to analog" for measuring metal strain gages or temperature. The PS01's ground-breaking measuring principle determines resistor ratio from a highly precise time interval measurement, done with a resolution of 14 ps, which corresponds to a respectable 70 GHz for a counter. This provides advantages of faster updates and lower total current requirements, while eliminating complex analog circuitry to simplify integration. Measuring only 9 mm-square, the compact PS01 is ideal for consumer and industrial products, such as weight scales, postage scales, pressure transducers and load cells. The ACAM PS01 is available exclusively in the U.S. through Transducers Direct, experts in signal time-of-flight technology for pressure, position and magnetostrictive transducers.
Strain gages used with the PS01 require no separate power supply or reference voltage, and connect directly to the chip. The chip can work with a full bridge or half bridges, and the user determines how much current is supplied to the strain gage. Depending on the application, the total current of the system can be reduced down to only 5 mA. Battery-powered devices, such as those using 3V lithium coin cells, can experience extended battery life of up to 10 times, depending on the application, due to lower current draw versus analog circuitry.
The PS01 offers programmable update rates up to 65kHz. Digital design provides excellent output stability over a wide operating temperature range of -40 to 120°C. The PS01 has a 48 TQFP enclosure and 8-bit or SPI serial interfaces. It supports temperature measurement of up to four sensors.
The optional PSA1 setup and evaluation shortens development time for boards using the PS01 chip by allowing all of the chip's setup parameters to be quickly configured and checked via a graphical PC interface. The PSA1 connects to a PC via RS232 cable and operates in a Windows® environment. It can also be used as a stand-alone unit with 0 to 10 VDC analog output. Several settings for core and I/O supply voltage can be selected with jumpers. Additional jumpers allow current measurement, and two clocks with 32,768 Hz (low power mode) or 10 MHz (high power mode) are available to provide a reference frequency.
Transducers Direct has the PS01 chip available for immediate shipping with a price of $7.50 each @ 1,000 pieces, but offers significant discounts for larger-volume OEM orders.
For more information on the PS01 strain gage TDC, contact: Rob Matthes, President, Transducers Direct; 1120 Cottonwood Dr.; Cincinnati, OH 45140.
Tel: 513-583-9491. Fax: 513-583-9476. Email: rmatthes@transducersdirect.com. Internet: www.transducersdirect.com.
