The ADS1232 and ADS1234 (ADS123x) are precision, 24-bit, analog-to-digital converters (ADCs). With a low-noise programmable gain amplifier (PGA), a precision delta-sigma ADC, and internal oscillator, the ADS123x provide a complete front-end solution for bridge sensor applications including weigh scales, strain gauges, and pressure sensors.
An input multiplexer (MUX) accepts either two (ADS1232) or four (ADS1234) differential inputs. The ADS1232 also includes a temperature sensor to monitor ambient temperature. The low-noise PGA has a selectable gain of 1, 2, 64, or 128, supporting a full-scale differential input of ±2.5 V, ±1.25 V, ±39 mV, or ±19.5 mV.
The delta-sigma ADC provides a maximum of 23.5-bits effective resolution, and supports two data rates: 10 SPS (providing 50-Hz and 60-Hz rejection) and 80 SPS. The ADS123x can be clocked externally using an oscillator or a crystal, or by the internal oscillator.
Offset calibration is performed on-demand, and the ADS123x can be put in a low-power standby mode or shut off completely in power-down mode. The ADS123x are operated through simple pin-driven control—there are no digital registers to program.
Data are output over a two-wire serial interface that connects directly to the MSP430 and other microcontrollers.
PART NUMBER | PACKAGE | BODY SIZE (NOM) |
---|---|---|
ADS1232 | TSSOP (24) | 7.80 mm × 4.40 mm |
ADS1234 | TSSOP (28) | 9.70 mm × 4.40 mm |
Changes from Revision F (February 2008) to Revision G (January 2021)
Changes from Revision E (October 2007) to Revision F (February 2008)
Changes from Revision D (September 2007) to Revision E (October 2007)
Changes from Revision C (June 2006) to Revision D (September 2007)
Changes from Revision B (September 2005) to Revision C (June 2006)
PIN | TYPE | DESCRIPTION | ||||||
---|---|---|---|---|---|---|---|---|
NAME | ADS1232 | ADS1234 | ||||||
A0 | 8 | 8 | Digital input | Input MUX select pins. See Table 8-1 and Table 8-2 for more information. | ||||
A1 | — | 7 | Digital input | Input MUX select pins. See Table 8-1 and Table 8-2 for more information. | ||||
AGND | 17 | 21 | Analog | Analog ground | ||||
AINN1 | 12 | 12 | Analog input | Negative analog input channel 1 | ||||
AINN2 | 13 | 17 | Analog input | Negative analog input channel 2 | ||||
AINN3 | — | 14 | Analog input | Negative analog input channel 3 | ||||
AINN4 | — | 15 | Analog input | Negative analog input channel 4 | ||||
AINP1 | 11 | 11 | Analog input | Positive analog input channel 1 | ||||
AINP2 | 14 | 18 | Analog input | Positive analog input channel 2 | ||||
AINP3 | — | 13 | Analog input | Positive analog input channel 3 | ||||
AINP4 | — | 16 | Analog input | Positive analog input channel 4 | ||||
AVDD | 18 | 22 | Analog | Analog power supply: 2.7 V to 5.3 V | ||||
CAP | 9, 10 | 9, 10 | Analog | PGA bypass, connect a 0.1-µF capacitor to pins 9 and 10 | ||||
CLKIN/XTAL1 | 3 | 3 | Digital input | External crystal connection 1, or external clock input, or tie low to activate internal oscillator. See the Section 8.3.5 section for more information. | ||||
DGND | 2, 5, 6 | 2, 5, 6 | Digital | Digital ground | ||||
DRDY/DOUT | 24 | 28 | Digital output | Dual-purpose output: Data ready indicates valid data by going low. Data output outputs data, MSB first, on the first rising edge of SCLK. |
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DVDD | 1 | 1 | Digital | Digital power supply: 2.7 V to 5.3 V | ||||
GAIN0 | 19 | 23 | Digital input | Gain select pins. See the Section 8.3.3 section for more information. | ||||
GAIN1 | 20 | 24 | Digital input | Gain select pins. See the Low-Noise PGA section for more information. | ||||
REFN | 15 | 19 | Analog input | Negative reference input | ||||
REFP | 16 | 20 | Analog input | Positive reference input | ||||
PDWN | 22 | 26 | Digital input | Power-down: hold this pin low to power down and reset the ADC. Toggle the pin at device power-up. See the Section 8.4.5 section for more information. | ||||
SCLK | 23 | 27 | Digital input | Serial clock: clock out data on the rising edge. Also used to initiate offset calibration and standby modes. See the Section 8.4.1 and Section 8.4.3 sections for more information. | ||||
SPEED | 21 | 25 | Digital input | Data rate select. See the Section 8.3.8 section for more information. | ||||
TEMP | 7 | — | Digital input | Temperature sensor select. See Table 8-1 for more information. | ||||
XTAL2 | 4 | 4 | Digital | External crystal connection 2 |