Overview
The ADS1251U/2K5, produced by Texas Instruments, is a precision, wide dynamic range, delta-sigma Analog-to-Digital (A/D) converter. It operates with a 24-bit resolution from a single +5V supply and is designed for high-resolution measurement applications. The delta-sigma architecture ensures 24 bits of no missing codes performance and achieves an effective resolution of 19 bits with 1.5ppm of rms noise at conversion rates up to 20kHz. This converter is particularly suited for applications requiring high accuracy and low noise, such as cardiac diagnostics, smart transmitters, industrial process control, weight scales, and chromatography.
Key Specifications
| Parameter | Conditions | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| Data Rate | 20.8 | kHz | |||
| Resolution | 24 bits | ||||
| Effective Resolution | Up to 20kHz | 19 bits | |||
| Noise | CLK = 8MHz, VREF = 4.096V | 1.5 | 2.5 | ppm of FS | |
| Integral Nonlinearity (INL) | 15 | ppm of FSR | |||
| Differential Input Impedance | CLK = 8MHz | 210 kΩ | Ω | ||
| Input Capacitance | 6 | pF | |||
| Power Supply Voltage | +4.75 | +5 | +5.25 | VDC | |
| Operating Power | VDD = +5VDC | 7.5 | 10 | mW | |
| Power-Down Current | 0.4 | 1 | µA | ||
| Operating Temperature Range | –40 | +85 | °C |
Key Features
- 24-bit resolution with no missing codes
- Effective resolution of 19 bits up to 20kHz data rate
- Low noise: 1.5ppm of rms noise
- Differential inputs
- Integral Nonlinearity (INL): 15ppm (max)
- External reference input (0.5V to 5V)
- Power-down mode and sync mode
- Low power consumption: 8mW at 20kHz and 5mW at 10kHz
- Flexible 2-wire synchronous serial interface
Applications
- Cardiac diagnostics
- Smart transmitters
- Industrial process control
- Weight scales
- Chromatography
- Portable instrumentation
- Direct thermocouple interfaces
- Blood analysis
- Infrared pyrometers
- Liquid/gas chromatography
Q & A
- What is the resolution of the ADS1251U/2K5? The ADS1251U/2K5 has a 24-bit resolution with no missing codes.
- What is the effective resolution at 20kHz data rate? The effective resolution is 19 bits up to 20kHz data rate.
- What is the noise level of the ADS1251U/2K5? The noise level is 1.5ppm of rms noise.
- What type of inputs does the ADS1251U/2K5 have? The ADS1251U/2K5 has differential inputs.
- What is the power consumption at 20kHz and 10kHz data rates? The power consumption is 8mW at 20kHz and 5mW at 10kHz.
- Does the ADS1251U/2K5 have a power-down mode? Yes, the ADS1251U/2K5 has a power-down mode.
- What is the operating temperature range of the ADS1251U/2K5? The operating temperature range is –40°C to +85°C.
- What is the typical application of the ADS1251U/2K5? Typical applications include cardiac diagnostics, smart transmitters, industrial process control, and chromatography.
- How does the serial interface of the ADS1251U/2K5 work? The ADS1251U/2K5 includes a flexible 2-wire synchronous serial interface for data communication.
- What is the package type of the ADS1251U/2K5? The ADS1251U/2K5 is offered in an SO-8 package.
