Overview
The ADS7138IRTER, produced by Texas Instruments, is a compact, 8-channel, 12-bit analog-to-digital converter (ADC) with an I2C-compatible serial interface. This device is designed for versatility, allowing each of its eight channels to be configured as either analog inputs, digital inputs, or digital outputs. It features an internal oscillator for ADC conversion processes and supports various I2C modes, including standard, fast, fast-mode plus, and high-speed modes. The ADS7138IRTER also includes a digital comparator with a dedicated alert pin for interrupting the host when predefined thresholds are crossed, and it supports a programmable averaging filter for enhanced resolution.
Key Specifications
| Parameter | Min | Max | Unit | |
|---|---|---|---|---|
| Analog Supply Voltage (AVDD) | 2.35 | 3.3 | 5.5 | V |
| Digital Supply Voltage (DVDD) | 1.65 | 3.3 | 5.5 | V |
| Ambient Temperature (TA) | -40 | 25 | 125 | °C |
| Resolution | 12 bits (no missing codes) | |||
| Differential Nonlinearity (DNL) | -0.75 | ±0.2 | 0.75 | LSB |
| Integral Nonlinearity (INL) | -1.5 | ±0.45 | 1.5 | LSB |
| Input Offset Error (V(OS)) | -2 | ±0.4 | 2 | LSB |
| Gain Error | -0.065 | ±0.025 | 0.065 | %FSR |
| ADC Conversion Time | 600 ns (autonomous mode) | |||
| Analog Supply Current (IAVDD) | 150 | 210 | µA (I2C high-speed mode, AVDD = 5 V) | |
Key Features
- 8-channel, multiplexed, 12-bit successive approximation register (SAR) ADC.
- Channels can be configured as analog inputs, digital inputs, or digital outputs.
- Internal oscillator for ADC conversion processes.
- I2C-compatible serial interface supporting standard, fast, fast-mode plus, and high-speed modes.
- Digital comparator with programmable high and low thresholds, hysteresis, and an event counter.
- Dedicated alert pin for interrupting the host when predefined thresholds are crossed.
- Programmable averaging filter for enhanced resolution.
- 8-bit cyclic redundancy check (CRC) for serial communication interface.
- Autonomous and single-shot conversion modes.
Applications
The ADS7138IRTER is suitable for a variety of applications, including industrial automation, medical devices, and automotive systems. Its versatility in channel configuration and robust I2C interface make it ideal for monitoring multiple analog inputs in real-time. It is also useful in applications requiring precise analog-to-digital conversion with low power consumption and high accuracy.
Q & A
- What is the resolution of the ADS7138IRTER ADC?
The ADS7138IRTER has a 12-bit resolution with no missing codes. - What are the operating voltage ranges for AVDD and DVDD?
The analog supply voltage (AVDD) ranges from 2.35 V to 5.5 V, and the digital supply voltage (DVDD) ranges from 1.65 V to 5.5 V. - What are the supported I2C modes?
The device supports standard, fast, fast-mode plus, and high-speed I2C modes. - Can the channels be configured differently?
Yes, each of the eight channels can be configured as either an analog input, digital input, or digital output. - What is the purpose of the dedicated alert pin?
The dedicated alert pin is used to interrupt the host when predefined high or low thresholds are crossed on any input channel. - Does the device have any power-saving features?
Yes, the device has various power-saving modes, including a low power consumption state when no conversion is active. - What is the typical ADC conversion time in autonomous mode?
The typical ADC conversion time in autonomous mode is 600 ns. - Does the device support any data integrity checks?
Yes, the device supports an 8-bit cyclic redundancy check (CRC) for serial communication. - What is the ambient temperature range for the device?
The device operates within an ambient temperature range of -40°C to 125°C. - What is the recommended decoupling capacitor for AVDD and GND pins?
Texas Instruments recommends connecting a 1-µF, low-equivalent series resistance (ESR) ceramic decoupling capacitor between the AVDD and GND pins.
