LTC1062CN8#PBF

Overview

The LTC1062CN8#PBF is a 5th order all-pole maximally flat lowpass filter with no DC error, manufactured by Analog Devices Inc. It operates on a single 5V supply or up to ±8V, with a total supply voltage range of ±2.5V to ±9V. The device features an internal clock that can be externally driven, with a typical clock-to-cutoff frequency ratio of 100:1. Key electrical parameters include a power supply current of 4.5 mA (typical) and an input frequency range of 0 to 20 kHz. The cutoff frequency is set by an external RC network and the internal oscillator, which defaults to approximately 140 kHz with ±5V supplies when COSC is floating.

Feature Summary

• Eliminates DC offset and low-frequency noise problems by placing the filter outside the DC path.
• Provides a 5th order rolloff at the output through coupling via an external capacitor and resistor.
• Supports operation with single or dual supplies ranging from ±2.5V to ±9V.
• Allows for cascading two devices to form a 10th order quasi-maximally flat lowpass filter.

Applications

• Antialiasing filters
• Digital voltmeters
• Strain gauges

Procurement Notes

Verify the specific package type N8 (PDIP-8) and temperature grade C (-40°C to +85°C) against design requirements. Confirm pinout compatibility for the 8-lead PDIP footprint during PCB layout. Ensure supply voltages remain within the specified ±2.5V to ±9V range to maintain performance specifications.

Selection Notes

Select this component for applications requiring high DC accuracy and low passband noise without external components for filter shaping. Consider the internal buffer if a buffered output is needed, noting its millivolt-level DC offset. Evaluate the need for external clock driving versus using the internal oscillator based on required cutoff frequency precision and ripple rejection.

Part Context

The LTC1062 belongs to a family of switched-capacitor filters designed for DC-accurate signal processing. It is distinct from continuous-time active filters due to its reliance on an internal clocked switched-capacitor network. The CN8 suffix indicates a commercial temperature range and plastic DIP packaging, differentiating it from military or ceramic variants like the MJ8 or CS.

Replacement Considerations

LTC1063 offers similar 5th order Butterworth filtering but requires no external components for cutoff setting. LTC1065 provides a Bessel response variant. For higher order requirements, LTC1569-6 or LTC1569-7 provide 10th order options without external clocks.