LTC1065ISW#PBF

Overview

The LTC1065ISW#PBF is a monolithic, clock-tunable, linear phase 5th order Bessel lowpass filter with high DC accuracy. It operates from ±2.375V to ±8V power supplies and features an internal or external clock input. The cutoff frequency is controlled by a clock signal with a fixed 100:1 ratio. Key electrical parameters include a typical output DC offset of 1mV at ±5V supply, 80µVRMS wideband noise, and 50µVRMS clock feedthrough. The device provides a maximum cutoff frequency of 50kHz and supports cascading for steeper roll-off. It is housed in a 16-lead SO-Wide (SW) package.

Feature Summary

• Provides a 5th order Bessel polynomial frequency response with linear phase characteristics.
• Features clock-tunable cutoff frequency using either an internal oscillator or external clock source.
• Delivers high DC accuracy with typically 1mV output offset voltage over a wide range of clock frequencies.
• Supports single-ended operation with low distortion and high common-mode rejection.

Applications

• Anti-aliasing filters in data acquisition systems
• Strain gauge amplifier signal conditioning
• Low-level filtering and smoothing applications
• Reconstruction filters in digital-to-analog conversion

Procurement Notes

Verify the specific suffix #PBF indicates lead-free compliance when sourcing. Confirm the ISW designation matches the required industrial temperature range of -40°C to +85°C. Ensure the 16-pin SW package footprint aligns with the PCB layout specifications provided in the datasheet. Cross-reference the manufacturer part number directly with Analog Devices documentation to avoid counterfeit components.

Selection Notes

Select this component when a precise Bessel response is required for minimal transient overshoot. The internal clock simplifies design by requiring only one external RC network for frequencies below 500kHz. Consider the 100:1 clock-to-cutoff ratio when determining available clock frequencies. Verify that the input signal levels remain within the specified dynamic range to maintain low total harmonic distortion.

Part Context

This part belongs to the LTC1065 family of active filters, which also includes variants like the LTC1063 offering Butterworth responses. The ISW variant specifically denotes the industrial temperature grade and surface-mount packaging. It serves as a direct replacement for legacy discrete filter designs requiring tunable cutoff frequencies without sacrificing DC precision.

Replacement Considerations

The LTC1063 is pin-compatible but offers a Butterworth response instead of Bessel. For higher-order filtering, consider cascading multiple LTC1065 units or selecting the LTC1064 series for elliptic or Cauer responses. Ensure any substitute maintains the 16-pin SW package dimensions if board space is constrained.