Picostrain Strain Gage Circuits


System-on-Chip for Strain Gauge Applications

The PS081 is a system-on-chip for ultra low power and high resolution strain gauge applications.

As a PS08 derivative, the PS081 also combines an ultra low power 24-Bit microprocessor with a high resolution T/D-converter (TDC) according to the known PICOSTRAIN measuring principle. An LCD controller and an EEPROM makes it a full featured System on Chip. Equipped with an extended memory range, enlarged ROM routines, enhanced IO-capabilities and an optional interface for external LCD driver control, the PS081 fulfills all requirements of coming generations of weigh scales, force sensors, pressure sensors or torque measurement systems in the consumer and the industrial market.

PicoStrain: Strain Gauge / Load Cells

The Most Powerful Combination of Low Power and Highest Accuracy.

The unique combination of a low power microprocessor with the PICOSTRAIN measuring unit shows impressive performance. The device reaches more than 28-Bit rms resolution and its excellent linearity and drift numbers are only comparable to absolute high-end Sigma-Delta A/D-converters. On the resolution side the PS081 makes it possible to get up to150,000 stable peak to peak divisions (at 2mV/V)! On the other hand a sophisticated power management together with the special features of the PICOSTRAIN method can reduce the total system current down to 15 µA, including the sensor current. Since the device is specified down to 2.2V it can be driven by a single lithium coin cell for a very long time. This will save costs and offers great advantages for wireless and battery driven systems.

Further features like the software adjustment of the offset and gain compensation or the possibility to operate with only one halfbridge opens the door to new and innovative solutions.

Get into the technology of the PS081 and save your competitive advantage with the worlds most innovative technology for strain gauges!

General Circuit Features

  • PICOSTRAIN Front-End with up to 19.5 Bit resolution (@2mV/V)
  • Capability to measure half-bridges, full-bridges, quattro-bridges and Wheatstone-bridges
  • Microprocessor with 24-Bit data structure
  • 2 k x 8-Bit EEprom progam memory including charge pump (no need of an additional programming voltage)
  • 3 k ROM powerful program code like
  • 48 Bit multiplication and division or binary to 7-segment conversion
  • 8-layer hardware stack
    Embedded very low current 10 kHz oscillator (300 nA)
  • Driver for external 4 MHz ceramic oscillator
  • Operating current 0.7 µA with timer active
  • up to 18 programmable I/O-ports
  • 4 x 14, 3 x 15, 2 x 16 LCD driver, optional SPI to external LCD driver support
  • Embedded charge pump for driving the LCD at 2.0 V, 2.5 V and 3.0 V
  • Embedded bandgap voltage reference for low battery detection and LCD voltage stabilization
  • Ports for temperature measurement with low-cost external carbon resistors
  • Watchdog timer
  • Serial SPI interface for EEPROM programming or operation with an external microprocessor
  • Supply voltage 2.2 to 3.6 V at full functionality, down to 1.5 V without
  • EEPROM reprogramming and voltage measurement
  • System operational current down to 17 µA at 3 Hz and 2000 divisions
  • As dice (115 µm pitch) or packaged (QFN56)



Additional Information

Documentation & Downloads

PICOSTRAIN PS081 Advantages

Advantage 1:
Extremely low current consumption for your complete bridge sensor system

The combination of an ultra-low power microcontroller with the PICOSTRAIN measuring principle shows an extremely low overall current consumption of the total system. It is possible to reduce the power consumption by a factor 10 to 20 compared to conventional AD-Converter solutions.

General Circuit Features

Advantage 2:
One solution suits to (nearly) all applications, from low cost up to highest precision
PS081 allows to build systems with 1.500 … 150,000 peak to peak divisions (at 2mV/V strain) and update rates up to 1 kHz. One and the same chip covers the requirements of many applications, just by variation of your software.

Advantage 3:
Reduced overall system costs
PS081 reduces or saves battery costs. In many applications a single coin cell battery may last for 10 years under normal operation. The number of external components is far below the usual.

Advantage 4:
New products that could not be done up to now
There are new product options mainly due to the low current consumption and low operating voltage. First to mention are solar driven applications. Also 1.55 V silver-oxide batteries are possible although with some restrictions (e.g. re-programming). The measurement quality is impressive even at those low voltages and it might be difficult to find something comparable in the market.

Advantage 5:
Improve your Quality and lower your production cost
PS081 offers unique possibilities to simplify the production of your bridge sensor and to improve its quality. The bridge offset can be simply adjusted by setting a register, gain drift can be reduced through software correction of Rspan. This method is more precise than with standard solutions. At the same time costly mechanical trimming, wich is still common practice, becomes redundant

PS081 – PicoStrain

PICOSTRAIN Comparison PS08 vs. PS081


PS08 PS081
EEPROM: 1K x 8-BIt 2K x 8-Bit
User-EEPROM 2 x 24-BIt 16 x 24-BIt
Inputs: max. 5 max. 21
External LCD support no yes
Enlarged ROM routines
– Anti vibration filter
– Unit conversion
– SPI to LCD support
– and more…
no yes
Packaged version QFN56 QFN56
Dice version 2770 x 2520 µm²
Pad: 116 µ x 90 µm
Wafer thickness: 725 µm
2370 x 3470
Pad: 116 µm x 90 µm
Wafer thickness: 725 µm
  • Extended user-EEPROM in PS081 for general use
  • QFN versions are pin compatible
  • Register adaptions are necessary

Battery Lifetime

PS081 – PicoStrain

PICOSTRAIN PS081 Evaluation System

The PS081-EVA evaluation system provides a complete weighing system made of a mainboard with LCD and solar panel, up to three plug-in modules, a 10kg load cell platform and windows-based evaluation and assembler software. It offers extensive and user-friendly configuration and evaluation of the PS081 single-chip solution for weigh scales.
The PS081-EVAL system is connected to the PC’s USB interface through the PICOPROG programming device. For a proper use of the evaluation system it is strongly recommended to refer to the current PS081 datasheet.

General Circuit Features

  • PS081-EVAL-MB main board
    • LCD display 22 x 51mm²
    • Optional interface to external LCD controller
      • Power select by 3 jumpers:
      • Solar panel 55 x 20 mm²
      • Battery holder for CR2032
      • Wall power supply, Voltage selectable by on-boardjumpers
    • 10Push buttons
    • Serial interface to PICOPROG programmer
    • Optional buzzer
  • PS081-EVA-HR high resolution module
    • For up to 150,000 stable scale divisions & solar applications
    • 4 halfbridges
    • 4 layer PCB
  • PS081-EVA-STD standard module
    • For up to 60,000 stable scale divisions
    • 4 halfbridges
    • 2 layer PCB
  • PS081-EVA-WB Wheatstone module
    • For up to 60.000 stable scale divisions with classical load cells
    • 1 Wheatstone bridge
    • 4 layer PCB
  • PICOPROG Programmer
    • 10kg load cell
    • 350 Ohm sensors
    • Mounted on platform
    • Wired as 2 half bridges with 1 span compensation resistor

Eval Kit

PS081 – PicoStrain

Ordering Numbers

Part Number
RoHS Compl.
Shipping Package
PS09 MNR 1783 Dice Yes Waffle pack
PS09FN MNR 1840 QFN40 Yes
PS081 MNR 1615 Dice Yes Waffle pack
PS081FN MNR 1612 QFN56 Yes
PS081-EVA-KIT MNR 1525 PCB Yes
PicoProg Uni System V2.0 MNR 1723 PCB Yes

Ordering Numbers

Part Number
RoHS Compl.
Shipping Package
PS09 MNR 1783 Dice Yes Waffle pack
PS09FN MNR 1840 QFN40 Yes
PS081 MNR 1615 Dice Yes Waffle pack
PS081FN MNR 1612 QFN56 Yes
PS081-EVA-KIT MNR 1525 PCB Yes
PicoProg Uni System V2.0 MNR 1723 PCB Yes