ADC1225

ADC1225: 12-Bit Plus Sign Analog-to-Digital Converter

Overview

The ADC1225 is a high-performance, CMOS-based 12-bit plus sign analog-to-digital converter (ADC) designed for precision measurement applications. It is part of the ADC1205/1225 series, offering true differential analog voltage inputs and compatibility with a wide range of microprocessors. The device operates on a single 5V supply, making it suitable for embedded systems, industrial controls, and instrumentation. With its low power consumption (25 mW max) and TTL/MOS-compatible I/O, the ADC1225 is an efficient solution for high-resolution data acquisition.

Key Features

• Microprocessor Compatibility: Works seamlessly with all major microprocessors.
• True Differential Inputs: Supports differential analog voltage inputs for noise reduction.
• Wide Input Range: 0V to 5V analog input range with a single 5V power supply.
• TTL/MOS I/O Compatibility: Ensures easy interfacing with both TTL and MOS logic families.
• Low Power Consumption: Maximum power dissipation of 25 mW, ideal for power-sensitive applications.
• TRI-STATE Outputs: Allows for bus sharing in multi-device systems.
• Standard Package Options: Available in 24-pin or 28-pin Dual-In-Line (DIP) packages.

Applications

The ADC1225 is widely used in applications requiring high-resolution analog-to-digital conversion, including:

• Industrial Automation: Process control, sensor interfacing, and data logging.
• Medical Instrumentation: Patient monitoring systems and diagnostic equipment.
• Test and Measurement: Precision voltage and current measurement devices.
• Embedded Systems: Microcontroller-based designs requiring analog signal processing.
• Military/Aerospace: High-reliability systems where specified variants are available.

Electrical Characteristics

The ADC1225 operates under the following electrical specifications:

• Resolution: 12-bit plus sign (13-bit total).
• Supply Voltage: Single 5V ±5%.
• Analog Input Range: 0V to 5V (differential or single-ended).
• Conversion Time: Typically 25 µs (varies based on clock frequency).
• Power Consumption: ≤25 mW (max).
• Operating Temperature Range: Commercial (0°C to +70°C) or Industrial (-40°C to +85°C).

Absolute Maximum Ratings

Stresses beyond these limits may cause permanent damage to the device:

• Supply Voltage (V_CC): -0.3V to +7V.
• Analog Input Voltage: -0.3V to V_CC + 0.3V.
• Digital Input Voltage: -0.3V to +7V.
• Operating Temperature: -55°C to +125°C (military-grade variants).
• Storage Temperature: -65°C to +150°C.

Note 1: Absolute maximum ratings are stress ratings only. Functional operation is not implied under these conditions.

Note 2: Military/Aerospace-specified devices may have additional or stricter ratings.

Package Information

The ADC1225 is available in two standard package configurations:

• 24-Pin DIP: Dual-In-Line Package with 0.6" row spacing.
• 28-Pin DIP: Extended pin count for additional functionality or I/O.

Both packages feature industry-standard dimensions and pin layouts, ensuring compatibility with existing PCB designs and sockets.

Functional Diagram

The ADC1225 includes the following key functional blocks:

• Differential Input Stage: Provides noise immunity and common-mode rejection.
• Successive Approximation Register (SAR): Performs the 12-bit conversion.
• Clock Oscillator: Internal or externally driven for timing control.
• TRI-STATE Output Buffer: Enables bus sharing in multi-device systems.

Ordering Information

The ADC1225 is available in multiple variants, including commercial, industrial, and military temperature grades. For specific part numbers and packaging options, refer to the manufacturer's datasheet or contact authorized distributors.

Conclusion

The ADC1225 is a versatile, high-resolution ADC suitable for a broad range of precision measurement applications. Its combination of low power consumption, microprocessor compatibility, and robust packaging makes it an excellent choice for designers seeking reliable analog-to-digital conversion. For applications requiring military or aerospace certification, consult the manufacturer for specialized variants.