Overview
The ADS7861E/2K5G4 from Texas Instruments is a high-speed, low-power, dual 12-bit analog-to-digital converter (ADC) designed for simultaneous sampling of four fully differential input channels grouped into two pairs. This device operates from a single +5V supply and features an internal +2.5V reference voltage, which can also be configured to use an external reference in the range of 1.2V to 2.6V. The ADS7861E/2K5G4 is capable of converting at a rate of 500kSPS and includes dual successive approximation ADCs, two differential sample-and-hold amplifiers, and a high-speed parallel interface. It is particularly suited for applications requiring high-speed data acquisition with low power consumption and high accuracy.
Key Specifications
| Parameter | Value | Conditions |
|---|---|---|
| Resolution | 12 bits | |
| Sampling Rate | 500 kSPS | |
| Input Channels | 4 (grouped into 2 pairs) | |
| Input Type | Fully differential | |
| Reference Voltage | Internal: +2.5V, External: 1.2V to 2.6V | |
| Supply Voltage | +5V | |
| Operating Temperature Range | -40°C to +125°C | |
| Common-Mode Rejection | Typically 80 dB | |
| Sample-and-Hold Bandwidth | Greater than Nyquist rate, typical small-signal bandwidth: 40 MHz | |
| Aperture Delay Time | Typically 50 ps (aperture jitter) | |
| Package Type | 24-QSOP |
Key Features
- Dual 12-bit successive approximation ADCs with simultaneous sampling capability.
- Four fully differential input channels grouped into two pairs.
- Internal +2.5V reference voltage with the option to use an external reference.
- High-speed parallel interface with data output on both Serial A and Serial B lines.
- Low power consumption and high-speed operation up to 500 kSPS.
- Typical common-mode rejection of 80 dB.
- Sample-and-hold amplifiers with a typical small-signal bandwidth of 40 MHz.
- Low aperture jitter of typically 50 ps.
- Configurable operation modes using M0, M1, and A0 pins.
Applications
- High-speed data acquisition systems.
- Medical imaging and diagnostic equipment.
- Aerospace and defense systems requiring high accuracy and speed.
- Industrial automation and control systems.
- Test and measurement instruments.
- Audio and video processing systems.
Q & A
- What is the resolution and sampling rate of the ADS7861E/2K5G4?
The ADS7861E/2K5G4 has a resolution of 12 bits and a sampling rate of up to 500 kSPS.
- How many input channels does the ADS7861E/2K5G4 have, and what type are they?
The device has four fully differential input channels grouped into two pairs.
- What is the operating supply voltage for the ADS7861E/2K5G4?
The device operates from a single +5V supply.
- Can the ADS7861E/2K5G4 use an external reference voltage?
- What is the typical common-mode rejection ratio of the ADS7861E/2K5G4?
The typical common-mode rejection ratio is 80 dB.
- How does the sample-and-hold section of the ADS7861E/2K5G4 perform?
The sample-and-hold amplifiers have a typical small-signal bandwidth of 40 MHz and an aperture jitter of typically 50 ps.
- What are the different operation modes of the ADS7861E/2K5G4?
The device can operate in four different modes controlled by the M0, M1, and A0 pins, allowing for two-channel or four-channel operation and different serial output configurations.
- How is the conversion process initiated on the ADS7861E/2K5G4?
The conversion process is initiated by bringing the CONVST pin HIGH for a minimum of 15 ns.
- What are the recommendations for the physical layout of the ADS7861E/2K5G4 circuitry?
For optimum performance, care should be taken to ensure clean power supply, reference, and ground connections. Bypass capacitors should be used, and the layout should avoid glitches or sudden changes near the device.
- What is the package type of the ADS7861E/2K5G4?
The device is packaged in a 24-QSOP package.
