PS081 datasheet(38/155 Pages) AMSCO

38 / 155 page

acam-messelectronic gmbh - Friedrich-List-Str.4 - D-76297 Stutensee-Blankenloch - Germany - www.acam.de

3-15

PSØ81

instead of 2mV/V. Then this corresponds to a reduction by factor 2, which is 1-bit, so the ENOB is

17.7 bit in this case.

The effective resolution (ENOB) is also reduced when Wheatstone connection is used instead of

PICOSTRAIN connection. The reason for that is the reduction of the strain by 1/3 because when

discharging over 1 strain gage of the bridge the other 3 strain gages are in parallel and lower the

extension/strain of the gage to measure. Expressed in ENOB the reduction is -0.6 bit.

3.5

Modes and Timings

The PS081 has 3 basic operating modes as well as combinations of them. They are related to the

sampling frequency and the active time of the 4 MHz oscillator. Therefore, the selection has influence

on the stability of the result and the current consumption.

The basic modes are:

Continuous Mode

Single Conversion Mode

Stretched Mode

3.5.1

Continuous Mode

Figure 3.16 Continuous mode

The chip is making continuously discharge time measurements. The oscillator is on all the time.This

mode is the choice for applications targeting highest resolution. It is the standard mode for all appli-

cations that allow a current consumption > 500 µA.

3.5.2

Single Conversion Mode

Figure 3.17 Single conversion mode

The chip makes a complete measurement sequence and then goes to sleep mode. The oscillator is

Member of the ams Group

PS081 Datasheet(PDF) 38 Page - ams AG