LTC1569IS8-6#PBF

Overview

The LTC1569IS8-6#PBF is a 10th order lowpass filter featuring linear phase and a root raised cosine amplitude response. It operates from single supplies of 3V to 5V or dual supplies including -5V, consuming 3mA at 3V. The cutoff frequency is programmable via a single external resistor (RX) with an internal oscillator, supporting divider settings of 1, 4, or 16 for a range up to 64kHz. Alternatively, an external clock can be applied to the DIV/CLK pin with a fixed 64:1 ratio. Key electrical characteristics include a maximum DC offset of 5mV, 80dB common-mode rejection ratio at DC, and 82dB signal-to-noise ratio at 5V supply.

Feature Summary

• Provides linear phase and root raised cosine amplitude response suitable for pulse shaping in data communications.
• Features high DC accuracy with a maximum output DC offset of 5mV and 80dB CMRR.
• Allows cutoff frequency programming using a single external resistor without requiring an external clock.
• Supports differential or single-ended inputs with low power consumption modes.

Applications

• Data communication filters for 3V operation
• Linear phase and phase matched filters for I/Q signal processing
• Pin programmable cutoff frequency lowpass filters

Procurement Notes

Verify the component authenticity by checking the manufacturer markings against the datasheet specifications. Confirm the package type is SO-8 and the suffix indicates industrial temperature range. Ensure the ordering information matches the specific part number requirements for your design implementation.

Selection Notes

Select this component when a 10th order lowpass filter with linear phase is required. It is suitable for applications needing a cutoff frequency up to 64kHz on a single 3V supply. Consider the internal oscillator flexibility if an external clock source is unavailable. Verify that the input impedance and output swing requirements align with the system voltage levels.

Part Context

This device belongs to the LTC1569 family of sampled data filters. It shares the same core architecture as other variants like the LTC1569C and LTC1569I, differing primarily in temperature range and packaging. The IS8-6 designation specifies the industrial temperature grade and surface mount SO-8 package configuration.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Designers should consult Analog Devices for potential alternatives within the active product portfolio.

FAQ

How is the cutoff frequency determined?

The cutoff frequency is set by a single external resistor connected between the RX pin and V+. The internal oscillator frequency is divided by 1, 4, or 16 based on the state of the DIV/CLK pin.

What is the maximum recommended value for the external resistor?

The maximum recommended resistor value for the RX pin is 40kΩ. Values less than 10kΩ can only be used in the divide-by-16 mode.

Can the filter operate with an external clock?

Yes, the internal oscillator can be disabled by shorting the RX pin to V-, allowing an external clock signal to be applied directly to the DIV/CLK pin.