Overview
The ADS7818EB, produced by Texas Instruments, is a 12-bit sampling analog-to-digital converter (A/D) that includes a sample/hold circuit, an internal 2.5V reference, and a synchronous serial interface. This device is designed for high-speed, low-power applications and is particularly suited for battery-operated systems such as wireless communication devices, portable multi-channel data loggers, and spectrum analyzers. The ADS7818EB operates over a temperature range of –40°C to +85°C and is available in plastic mini-DIP-8 or MSOP-8 packages.
Key Specifications
| Parameter | Min | Typ | Max | Units |
|---|---|---|---|---|
| Resolution | 12 | 12 | 12 | Bits |
| Integral Linearity Error | ±0.5 | ±1 | ±2 | LSB |
| Differential Linearity Error | ±0.5 | ±0.8 | ±1 | LSB |
| Offset Error | ±1 | ±2 | ±5 | LSB |
| Gain Error (25°C) | ±7 | ±12 | ±15 | LSB |
| Conversion Time | 1.625 | µs | ||
| Acquisition Time | 0.350 | µs | ||
| Throughput Rate | 500 | kHz | ||
| Power Supply Voltage | 4.75 | 5.0 | 5.25 | V |
| Quiescent Current (fSAMPLE = 500kHz) | 2.2 | mA | ||
| Power Dissipation (fSAMPLE = 500kHz) | 11 | mW | ||
| Power Down Current | 0.5 | mA | ||
| Operating Temperature Range | –40 | +85 | °C |
Key Features
- High-Speed Conversion: The ADS7818EB supports a throughput rate of up to 500 kHz, making it suitable for high-speed data acquisition applications.
- Low Power Consumption: The device operates at a low power dissipation of 11 mW at a 500 kHz throughput rate and can be placed into a power-down mode to reduce dissipation to 2.5 mW.
- Internal Reference: It includes an internal 2.5V reference voltage that can be overdriven by an external reference voltage for greater stability or different input ranges.
- Synchronous Serial Interface: The device provides a synchronous serial interface for data transfer, which is useful for low-cost isolation in remote data acquisition.
- Small Package Options: Available in plastic mini-DIP-8 or MSOP-8 packages, making it ideal for space-constrained applications.
- High Input Impedance: The input impedance of the analog input is greater than 1 GΩ during the hold mode, ensuring minimal loading on the input signal.
Applications
- Wireless Communication Devices: Suitable for battery-operated wireless communication devices due to its low power consumption and high-speed conversion capabilities.
- Portable Multi-Channel Data Loggers: Ideal for portable data loggers that require high-speed and low-power analog-to-digital conversion.
- Spectrum Analyzers: Used in spectrum analyzers where high-speed data acquisition and low power consumption are critical.
- Remote Data Acquisition: The synchronous serial interface provides low-cost isolation for remote data acquisition applications.
Q & A
- What is the resolution of the ADS7818EB?
The ADS7818EB has a resolution of 12 bits.
- What is the typical power dissipation of the ADS7818EB at a 500 kHz throughput rate?
The typical power dissipation is 11 mW at a 500 kHz throughput rate.
- Can the internal reference voltage be overdriven by an external voltage?
Yes, the internal reference voltage can be overdriven by an external voltage in the range of 2.0V to 2.55V.
- What is the operating temperature range of the ADS7818EB?
The operating temperature range is –40°C to +85°C.
- How is the data output formatted from the ADS7818EB?
The data output is in straight binary format.
- What is the minimum clock frequency required for the ADS7818EB?
The minimum clock frequency is set by the leakage on the internal capacitors, but it can vary between 200 kHz and 8 MHz.
- Can the ADS7818EB be placed into a power-down mode?
Yes, the device can be placed into a power-down mode by keeping the CONV input low during the conversion and at the start of the 13th clock cycle.
- What is the input impedance of the analog input during the hold mode?
The input impedance of the analog input is greater than 1 GΩ during the hold mode.
- What are the package options available for the ADS7818EB?
The device is available in plastic mini-DIP-8 or MSOP-8 packages.
- What are some typical applications of the ADS7818EB?
Typical applications include wireless communication devices, portable multi-channel data loggers, and spectrum analyzers.
