Precision Weigh Scale Design Using the AD7190 24-Bit Sigma-Delta ADC
High-precision weigh scale reference design featuring the AD7190 24-bit sigma-delta ADC and ADP3303 regulators for low-noise, ratiometric measurement.
Overview
This circuit note (CN-0102) describes a precision weigh scale system using the AD7190, an ultralow noise 24-bit sigma-delta ADC with an internal programmable gain amplifier (PGA). The design interfaces directly with a 6-wire load cell, using a ratiometric configuration to eliminate errors from wiring resistance and power supply fluctuations. Power is managed by ADP3303 low dropout regulators to provide stable 5V and 3.3V rails. The system supports data rates from 4.7 Hz to 4.8 kHz and achieves a noise-free resolution of approximately 16.8 bits, making it suitable for high-end laboratory scales and industrial hopper scales.
Use Cases
- High-end laboratory weigh scales
- Industrial hopper scales
- Digital strain gauge measurement
- Battery-powered precision weighing systems
Topics
Referenced Parts
BMB2A1000LN2
Tyco
FB: TYCO BMB2A1000LN2
| ADP3303 | Analog Devices | ADP3303 5 V Low Dropout Linear Regulator |
| ADP3303 | Analog Devices | ADP3303 3.3 V Low Dropout Linear Regulator |
| 505H-0002-F070 | Tedea Huntleigh | LOAD CELL: TEDEA HUNTLEIGH 505H-0002-F070 |
| AD7190 | Analog Devices | AD7190 4.8 kHz, Ultralow Noise, 24-Bit, Σ-Δ ADC with PGA |
| AD7191 | Analog Devices | The AD7191 is a pin-programmable device. |
| AD7192 | Analog Devices | Other suitable ADCs are the AD7192 and AD7191. |
| AD7780 | Analog Devices | the AD7798, AD7781 and AD7780 are suitable devices. |
| AD7781 | Analog Devices | The AD7780 and AD7781 have one differential analog input |
| AD7798 | Analog Devices | for low-end weigh scales, the AD7798, AD7781 and AD7780 are suitable devices. |
| AD7799 | Analog Devices | For medium-end weigh scales, the AD7799 is a suitable device. |
| BMB2A1000LN2 | Tyco | FB: TYCO BMB2A1000LN2 |