The TC7109 is a monolithic integrating analog-to-digital converter (ADC) designed for high-performance, low-power applications. Manufactured by TelCom Semiconductor, Inc. (later acquired by Maxim Integrated), it is commonly used in digital panel meters, data acquisition systems, and other instrumentation applications requiring precise and stable analog-to-digital conversion.

Applications

• Digital panel meters
• Data acquisition systems
• Instrumentation and measurement equipment
• Process control systems
• Digital multimeters
• Weighing scales

Features

• High accuracy: typically 1 count
• High resolution: 12-bit binary or 3½-digit BCD output
• Low power consumption
• On-chip system clock
• True differential input
• Zero drift
• Low noise
• Auto-zero phase
• Auto-polarity
• Overrange indication

Benefits

• High accuracy and resolution: Provides precise and reliable analog-to-digital conversion.
• Low power consumption: Suitable for battery-powered applications.
• Ease of use: Requires minimal external components for operation.
• On-chip system clock: Simplifies circuit design and reduces external component count.
• True differential input: Rejects common-mode noise and improves accuracy.
• Auto-zero and auto-polarity features: Eliminates offset errors and simplifies signal conditioning.
• Overrange indication: Provides a warning when the input signal exceeds the ADC's input range.

Additional Details

The TC7109 operates based on the dual-slope integration principle, providing excellent linearity and noise rejection. It integrates the input signal for a fixed period and then integrates a reference voltage until the integrator output returns to zero. The time required for the second integration is proportional to the input voltage. The device typically requires a few external components, such as capacitors and resistors, for proper operation. The TC7109 can be configured to provide either 12-bit binary or 3½-digit BCD output, depending on the application requirements. The internal clock oscillator frequency is determined by an external RC network. It is available in various package options, including DIP and SOIC. Refer to the device datasheet for detailed specifications, application circuits, and timing diagrams.