TC835CBU

ADCs/DACs - Special Purpose Overview

The TC835CBU is a low-power, 4-1/2 digit (0.005% resolution) Binary Coded Decimal (BCD) analog-to-digital converter manufactured by Microchip Technology. Characterized for 200 kHz clock rate operation, it achieves a conversion rate of five per second, which is nearly twice as fast as the ICL7135 or TC7135. The device operates on a single +5V supply when used with an external charge pump like the TC7660, or standard ±5V supplies. It features multiplexed BCD data outputs and control signals including BUSY, STROBE, OVERRANGE, and UNDERRANGE, facilitating direct interfacing with microprocessors and UARTs without requiring external sample-and-hold circuits.

ADCs/DACs - Special Purpose Feature Summary

• Dual-slope integrating architecture with system zero and integrator output zero phases for enhanced accuracy
• Multiplexed BCD data output compatible with LCD and LED display decoder/drivers
• High input sensitivity of 100 µV with differential inputs and 86 dB typical common-mode rejection ratio
• Integrated control outputs for auto-ranging, busy status, and polarity indication

ADCs/DACs - Special Purpose Applications

• Personal computer data acquisition systems
• Electronic scales and panel meters
• Process control instrumentation
• HP-IL bus instrumentation

ADCs/DACs - Special Purpose Procurement Notes

Verify that the ordering suffix 'CBU' corresponds to the 64-pin MQFP package variant as specified in the datasheet pinout diagrams. Confirm that the application environment remains within the specified operating temperature range of 0°C to +70°C. Ensure power supply voltages do not exceed the absolute maximum ratings of +6V for V+ and -9V for V-. Check for compliance with RoHS standards if required by the end product specifications.

ADCs/DACs - Special Purpose Selection Notes

Select the TC835CBU when a high-resolution 4-1/2 digit ADC is needed with direct microprocessor interface capabilities. This component is suitable for applications requiring low power consumption and immunity to line noise at 200 kHz clock frequencies. Consider the 64-pin MQFP package constraints for PCB layout. Ensure the design can accommodate the necessary external integrating components, such as polypropylene capacitors for low dielectric absorption, to maintain specified linearity and accuracy.

ADCs/DACs - Special Purpose Part Context

The TC835 serves as an upgraded, pin-compatible successor to the TC7135 and ICL7135 models. It retains the dual-slope integration principle but offers improved speed and simplified calibration requirements by eliminating the need for external diode resistor rollover error compensation circuits. The device is part of Microchip's legacy analog-to-digital converter portfolio designed for precision measurement applications.

ADCs/DACs - Special Purpose Replacement Considerations

The TC835 is explicitly documented as a pin-compatible upgrade for the TC7135 and ICL7135. Designers replacing these older components should verify that the board layout supports the specific pin configuration of the TC835CBU (64-pin MQFP) versus the original packages. No other cross-model substitutes are verified in the provided documentation.