• Precision Measurement Technologies
  • Technology Center for

PICOSTRAIN PS021

ACAM PS021 Chip

Digital Amplifier for Strain Gauges

General Circuit Features

The PICOSTRAIN integrated circuits are realized without any analog component. Again, acam uses its TDC technology to set new standards in circuit design and takes the advantages of this principle like:

  • Up to 2 full- or 4 halfbridges
  • Up to 2 Wheatstone bridges
  • Capable of driving only a halfbridge without any loss in precision
  • For compensated or non-compensated bridges
  • Adaptation of compensation resistor's Tk by software
  • Offset and span compensation internally separated (mathematically), therefore no need to trim the bridge offset
  • Resistance strain gauge: 350 Ohm to 10 kOhm
  • Programmable resolution: Up to 19 Bit (20nV rms or 500,000 scale div) @ 2 mV/V strain and 5 Hz update rate
  • High Measurement rate: Up to 50 kHz with high resolution (12.4 ENOB @ 4 kHz and 2 mV/V max. strain)
  • Extremely low current consumption possible: Down to
  • 15 µA (incl. SG) at 1 Hz and 10 ENOB with 1 kOhm SG and 1000 µ strain
  • High stability with temperature, low gain error (< 1 ppm/K)
  • No need for a pre-amplifier
  • No separate supply of SG
  • No separate reference voltage
  • Optional Single-conversion mode
  • Separate temperature measurement
  • Optional capacity measurement
  • Serial interface (SPI compatible)
  • Supply voltage I/O and SG: 1.8 ... 5.5 V
  • Separate Supply for interface I/Os
  • Supply voltage PS021: 1.8 ... 3.6 V
  • Op. temperature range -40°C ... +120°C
  • QFN48 / QFP48 package (body size 7 x 7 mm²)

Schematic Diagram

(Click to enlarge)

Applications

  • Metal strain gages
  • Scales and load cells
  • Force sensors
  • Pressure sensors (also 4 - 20 mA)
  • SG-amplifiers in general
  • Solar cell driven devices
  • Battery driven devices