LT1568IGN#TRPBF

Overview

The LT1568IGN#TRPBF is a high-frequency active RC filter building block manufactured by Analog Devices Inc. It integrates two matched second-order Butterworth lowpass filters with unity gain in a single 16-lead SSOP package. The device operates on a single supply voltage ranging from 2.7V to 11V, or dual supplies up to ±5V. Internal capacitors are trimmed to –0.75% tolerance, and the cutoff frequency is programmable from 200kHz to 10MHz using external resistors. Key electrical parameters include a signal-to-noise ratio of 92dB at 2MHz, total harmonic distortion of –84dB, and a shutdown mode reducing supply current to approximately 0.5mA.

Feature Summary

• Integrates two matched second-order filter sections for precise amplitude and phase matching suitable for I/Q channels.
• Features rail-to-rail input and output capabilities allowing operation across wide supply voltage ranges.
• Includes a dedicated enable pin that activates a low-power shutdown state to minimize current consumption.
• Supports flexible configurations including cascaded fourth-order filtering and single-ended to differential conversion.

Applications

• Antialiasing and reconstruction filters for high-speed data communications systems
• Dual or independent I-and-Q channel processing requiring matched filter responses
• Single-ended to differential signal conversion for driving high-speed analog-to-digital converters

Procurement Notes

Verify the specific suffix TRPBF indicates tape and reel packaging when sourcing components. Confirm the operating temperature range corresponds to the 'I' grade specification. Ensure the ordering information matches the manufacturer's official documentation to avoid discrepancies in package type or performance guarantees.

Selection Notes

Select this component when designing circuits requiring matched dual filter stages without discrete component mismatch. Consider the internal capacitor trimming for applications demanding consistent frequency response. Evaluate the shutdown functionality if power management during idle states is required for the system architecture.

Part Context

This part belongs to the LT1568 family of active RC filter building blocks. It replaces discrete RC active filters and LC modules by providing integrated amplifiers and precision capacitors. The device simplifies design by allowing cutoff frequency adjustment via a single resistor value per section.

Replacement Considerations

LT1568CGN#TRPBF

FAQ

How is the cutoff frequency determined for the LT1568?

The cutoff frequency is set by a single external resistor value connected to each filter section. Equal resistor values create matched lowpass filters, while unequal values allow for different gains or frequency responses.

What is the function of the EN pin?

The EN pin controls the shutdown mode. When driven high or left open, it reduces supply current to approximately 0.5mA. To enable normal operation, the pin must be pulled low relative to the positive supply voltage.

Can the LT1568 operate with a single supply?

Yes, the device operates from a single supply as low as 2.7V up to 11V, or dual supplies up to ±5V. In single-supply mode, the GNDA and GNDB pins establish the common mode reference.