Weighing Systems

WEIGHING TECHNOLOGY

Keywords: Loadcell, strain gauge, amplifier, digital filter, microcontroller, excitation, retail scale, bench scale, conveyor scale, batching & filling systems, dosing, silo weighing, EN45501, OIML, calibration, counting scale

Weighing Companies (Manufacturers) in Turkey:

Products/Market Positions (Last Update 21 December 2001)

	Retail Scale	Bench Scale	Truck Scale	Counting Scale	Filling Automation	Material Analysis	Mono Rail Scale	Home Page
Hisar Terazi	5	1	----	2	4	2	1	www.hisarterazi.com
TESS	1	4	----	----	----	5	----	www.tessedis.com
Baster	2	5	----	1	3	3	----	www.baster.com.tr
Tunaylar	----	6	1	----	5	----	----	www.tunaylar.com
Esit	----	2	2	3	1	1	2	www.esit.com.tr
Baykon	----	3	4	----	2	4	3	www.baykon.com.tr
İhlas Tarsan	?	7	----	----	----	----	----	www.ihlastarsan.com.tr
Net Tartı	----	----	3	----	----	----	----
TEM	4	?	----	----	----	----	----
Etasis	3	?	----	----	?	----	----	www.etasis.com.tr

Mostly used ADCs in History of Electronic Weighing (December 2001) :

1- 7135 (20000 internal counts of resolution, dual slope BCD output, not suggested for new designs)

2- TC500 (16bit + sign equivalent counts, 3 pin connection to microcontroller, dual slope, not suggested for new designs)

3- CS5520 (20 bit sigma-delta converter, serial output, not suggested for new designs)

4-AD7730 (24 bit sigma-delta convertor, serial output)

1- CIRRUS LOGIC most popular Delta-Sigma ADCs

a) CS 5510/11/12/13 :

Delta-sigma (DS) analog-to-digital converter
Linearity error: 0.0015% FS
Noise-free resolution: up to 17-Bits
Differential bipolar analog inputs
V REF input range from 250 mV to 5 V
50/60 Hz simultaneous rejection (CS5510/12)
16 to 326 Hz output word rate
On-chip oscillator (CS5511/13)
Power supply configurations:
V+ = 5 V, V- = 0 V
Multiple dual supply arrangements
Low power consumption
Normal mode, 2.5 mW
Sleep mode, 10 mW
Low-cost, compact, 8-pin package

b) CS 5516/5520

On-chip instrumentation amplifier
On-chip programmable gain amplifier
On-chip 4-bit D/A for offset removal
Dynamic excitation options
Linearity error: ±0.0015% FS 20-bit no missing codes
CMRR at 50/60 Hz >200 dB
System calibration capability with calibration read/write option
3-, 4-, or 5-wire serial communications port
Low power consumption: 40 mW (10 mW standby mode for portable applications)

c) CS 5531/32/34

Chopper-stabilized PGIA (programmable gain instrumentation amplifier, 1x to 64x)
6 nV/ÖHz @ 0.1 Hz (No 1/f noise)
<500 pA input current with gains >1
Delta sigma (DS) analog-to-digital converter
Linearity error: 0.0007% FS
Noise-free resolution: Up to 23 bits
Two or four channel differential MUX
Scalable input span via calibration
5 mV to 5 V
Scalable V REF input: up to analog supply
On-chip guard drive output buffer
Simple three-wire serial interface
SPI ® and Microwire™ Compatible
Schmitt Trigger on Serial Clock (SCLK)

2- ANALOG DEVICES Delta-Sigma ADC selection guide

Table 1: Additional information on 50mW and 25mW Power Consumption ADCs

Generic Part # and Description Resolution, Bits Output Word Rate, max Number & Type of I/P Channels Analog Input Ranges Power Supplies ADC Reference

AD7710
Signal Conditioning ADC with On Chip 20 µA Current Source 24 1 kHz 2 Differential VREF/Gain or ±VREF/Gain (8 Gain Settings) 5V for positive-only inputs or ±5V for true negative inputs Internal 2.5V or External 2.5V. Differential Reference Inputs.

AD7711
Signal Conditioning ADC with Matched 200 µA RTD Excitation Current Sources 24 1 kHz 1 Differential and 1 Single-Ended fo Low-Level Signals VREF/Gain or ±VREF/Gain (8 Gain Settings) 5V for positive-only inputs or ±5V for true negative inputs Internal 2.5V or External 2.5V. Differential Reference Inputs.

AD7711A
Signal Conditioning ADC with 400 µA RTD Current Source 24 1 kHz 2 Differential VREF/Gain or ±VREF/Gain (8 Gain Settings) 5V for positive-only inputs or ±5V for true negative inputs Internal 2.5V or External 2.5V. Differential Reference Inputs.

AD7712
Signal Conditioning ADC with On Chip 20 Input Signal Attenuator 24 1 kHz 1 Differential and 1 Single-Ended for High Level Signals VREF/Gain or ±VREF/Gain, 10V or ±10V (8 Gain Settings) 5V for positive-only inputs or ±5V for true negative inputs Internal 2.5V or External 2.5V. Differential Reference Inputs.

AD7730
Bridge Transducer ADC for Load Cell Applications 24 1.2 kHz 2 Differential 10 mV/20 mV/40 mV/80 mV Analog Supply 5V Only; Digital Supply 3V or 5V External 2.5V or 5V only. Reference I/P can be tied to AVDD.

AD7730L
Bridge Transducer ADC For Low Power Applications 24 600 Hz 2 Differential 10 mV/20 mV/40 mV/80 mV Analog Supply 5V Only; Digital Supply 3V or 5V External 2.5V or 5V only. Reference I/P can be tied to AVDD.

AD7731
Low Noise, 24-Bit ADC with Fast Channel-Channel Settling time 24 6.4 kHz 3 Differential or 5 Pseudo-Differential VREF/Gain or ±VREF/Gain (7 Gain Settings) Analog Supply 5V Only; Digital Supply 3V or 5V External Only. Reference I/P can be tied to AVDD.

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Table 2: Additional information on 5mW and 1mW Power Consumption ADCs

Generic Part # and Description Resolution, Bits Output Word Rate, max Number & Type of I/P Channels Analog Input Ranges Power Supplies ADC Reference

AD7705
General Purpose ADC offering 1 mW Power Dissipation 16 500 Hz 2 Differential VREF/Gain or ±VREF/Gain (8 Gain Settings) 3V or 5V External Only. Differential Reference Inputs.

AD7706
General Purpose ADC Offering 1 mW Power Dissipation 16 500 Hz 3 Pseudo-Differential VREF/Gain or ±VREF/Gain (8 Gain Settings) 3V or 5V External Only. Differential Reference Inputs.

AD7707
General Purpose ADC offering 1 mW Power Dissipation 16 500 Hz 2 Pseudo-Differential and 1 Single-Ended for High Level Signals VREF/Gain or ±VREF/Gain (including ±100 mV), 5V, 10V, ±5V, and ±10V (8 Gain Settings) 3V or 5V. True negative inputs with positive-only supply. External Only. Differential Reference Inputs.

AD7708
Multi-channel ADC with choice of Reference Inputs. Pin-compatible with AD7718 16 1365 Hz 4 or 5 Differential or 8 or 10 Single-Ended ±VREF/Gain (8 Gain Settings) 3 V or 5 V External Only. Choice of two Differential Reference Inputs.

AD7709
Versatile ADC with Switchable Current Sources and choice of Reference Sources 16 105 Hz 2 Differential or 3 Pseudo-Differential ±VREF/Gain (8 Gain Settings) 3 V or 5 V External Only. Choice of two Differential Reference Inputs.

AD7713
Signal Conditioning ADC with Matched RTD Current Sources 24 200 Hz 2 Differential and 1 Single-Ended for High Level Signals VREF/Gain or ±VREF/Gain, 10V (8 Gain Settings) 5V Internal 2.5V or External 2.5V. Differential Reference Inputs.

AD7714
High Accuracy ADC for Low Power Applications 24 1 kHz 3 Differential or 5 Pseudo-Differential VREF/Gain or ±VREF/Gain (8 Gain Settings) Analog Supply 3V or 5V; Digital Supply 3V or 5V External Only. Differential Reference Inputs.

AD7715
General Purpose ADC for Low Power Applications 16 500 Hz 1 Differential VREF/Gain or ±VREF/Gain (4 Gain Settings) Analog Supply 3V or 5V; Digital Supply 3V or 5V External Only. Differential Reference Inputs.

AD7718
Multi-channel ADC with choice of Reference Inputs. Pin-compatible with AD7708. 24 1365 Hz 4 or 5 Differential or 8 or 10 Single-Ended ±VREF/Gain (8 Gain Settings) 3 V or 5 V External Only. Choice of two Differential Reference Inputs.

AD7719
Contains two separate ADC's with switchable current sources, low-side power switches and Factory Calibration. 24 and 16 105 Hz 2 Differential or 3 Pseudo-Differential for Main channel, 2 Single-Ended and 1 Differential or 3 Single-Ended for Secondary Channel ±REFIN1/Gain (8 Gain Settings) for Main Channel, ±REFIN2/Gain (2 Gain Settings) 3 V or 5 V External Only. Differential Reference Inputs.

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