TC7136CKW

ADCs/DACs - Special Purpose Overview

The TC7136CKW is a low-power, 3-1/2 digit analog-to-digital converter with integrated LCD drivers manufactured by Microchip Technology. It utilizes a dual-slope integrating architecture to achieve high resolution and noise immunity. The device operates on a single 9V supply with typical power dissipation of 500µW. Key electrical specifications include a maximum non-linearity error of ±0.2 counts, input leakage current of 1pA (typical), and internal reference temperature drift of 70ppm/°C. It features fast over-range recovery and precision null detection capabilities.

ADCs/DACs - Special Purpose Feature Summary

• Dual-slope integrating ADC with 3-1/2 digit resolution and direct LCD segment drivers
• Low power consumption: 500µW typical at 9V supply
• High input impedance: 10^12 Ω with 1pA typical leakage current
• Internal reference with 70ppm/°C typical temperature drift
• Fast over-range recovery ensuring first reading accuracy

ADCs/DACs - Special Purpose Applications

• Thermometry systems
• Bridge readouts for strain gauges and load cells
• Digital meters for voltage, current, ohms, and power
• Portable instrumentation powered by 9V batteries

ADCs/DACs - Special Purpose Procurement Notes

Verify the specific suffix 'CKW' corresponds to the 44-pin PQFP package and commercial temperature range (0°C to +70°C). Confirm that the device status is acceptable for new designs, as datasheets may indicate obsolete status for legacy components. Ensure external passive component values match the required full-scale voltage ranges.

ADCs/DACs - Special Purpose Selection Notes

Select the TC7136CKW for applications requiring low power and direct LCD driving without external multiplexing. Choose this part over the TC7136A if the standard 70ppm/°C reference drift is sufficient for the application's accuracy requirements. Ensure the oscillator frequency is set to reject line noise (e.g., 48kHz for 3 readings/sec) using appropriate ROSC and COSC values.

ADCs/DACs - Special Purpose Part Context

The TC7136CKW belongs to the TC7136 family of 3-1/2 digit ADCs. It serves as an upgrade to the TC7126 and ICL7126 families, offering improved over-range recovery and lower power consumption. The 'CKW' designation specifically identifies the 44-lead Plastic Quad Flat Package (PQFP) variant within the commercial temperature grade.

ADCs/DACs - Special Purpose Replacement Considerations

The TC7136 is documented as a drop-in replacement for the TC7126 and ICL7126. When replacing these older devices, minor changes to external passive components may be necessary to optimize noise performance and ensure compatibility with the improved integrator output zero phase.