LTC1569CS8-7#PBF

Overview

The Analog Devices LTC1569CS8-7#PBF is a 10th-order lowpass filter featuring linear phase and a root raised cosine amplitude response. It operates from single 3V to dual ±5V supplies, achieving up to 300kHz cutoff on a 5V supply. The device utilizes a single external resistor to set the cutoff frequency via an internal oscillator or accepts an external clock with a 32:1 ratio. Key electrical parameters include a maximum DC offset of 5mV, 80dB CMRR at DC, and 80dB signal-to-noise ratio at 5V. It supports differential or single-ended inputs in an 8-lead SOIC package.

Feature Summary

• Integrates a 10th-order linear phase filter network with a root raised cosine amplitude response for optimal pulse shaping.
• Enables precise cutoff frequency programming using only one external resistor or an external clock source.
• Provides high DC accuracy with a maximum output DC offset of 5mV and 80dB common-mode rejection ratio.
• Offers configurable power savings modes through internal divide-by-4 and divide-by-16 clock dividers.

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 specific suffix #PBF indicates lead-free compliance when sourcing this component. Confirm the operating temperature range matches the 'C' grade specification (0°C to 70°C) required for your application environment. Ensure the SO-8 package dimensions align with your PCB footprint requirements before finalizing procurement.

Selection Notes

Select the LTC1569CS8-7#PBF when a 10th-order linear phase response is necessary for data acquisition systems. Choose this part if the design requires cutoff frequencies up to 300kHz with a single 5V supply. Consider the internal oscillator feature if minimizing external clock generation components is a priority for the circuit design.

Part Context

This component belongs to the LTC1569 family of sampled data filters. It is distinguished by its ability to achieve high selectivity without requiring an external clock generator. The device integrates precision oscillators and divider logic within the SO-8 package to simplify implementation in space-constrained designs.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Verify compatibility with alternative devices based on pinout and electrical specifications rather than direct substitution.

FAQ

How is the cutoff frequency determined?

The cutoff frequency is set by a single external resistor connected between the RX pin and V+ when using the internal oscillator, or by an external clock signal applied to the DIV/CLK pin with a 32:1 clock-to-cutoff ratio.

What is the function of the GND pin?

The GND pin serves as the reference voltage for the filter. For single supply operation, it must be externally biased to 2V (for 5V supply) or 1.11V (for 3V supply) to maximize dynamic range.

Does the device support differential inputs?

Yes, the LTC1569-7 supports both differential and single-ended inputs. When driven differentially, the voltage between IN+ and IN– is filtered with a DC gain of 1.