LTC1068CG#PBF

Overview

The LTC1068CG#PBF is a clock-tunable, quad second-order switched-capacitor filter building block housed in a 28-lead plastic SSOP package. It contains four matched, low-noise filter sections with a nominal clock-to-center frequency ratio of 100:1. The device operates on a single 5V supply (3.14V to 5.5V) or dual ±5V supplies, drawing approximately 6.5mA at 4.75V. Key electrical parameters include a typical center frequency error of ±0.3%, a GBW product of 6MHz, and a slew rate of 10V/µs. It supports lowpass, highpass, bandpass, and notch configurations via external resistor networks.

Feature Summary

• Integrates four identical second-order switched-capaculator filter sections within a single surface-mount package.
• Provides precise center frequency tuning through an external clock signal with minimal inherent frequency error.
• Supports multiple filter topologies including lowpass, highpass, bandpass, and notch functions using configurable operating modes.
• Operates efficiently with low power supply current requirements across standard single and dual voltage rails.

Applications

• Dual matched fourth-order Butterworth lowpass filters
• Clock-tunable bandpass filter banks
• Notch filters for interference rejection

Procurement Notes

Verify the specific suffix CG indicates the commercial temperature range of 0°C to 70°C. Confirm the PBF designation ensures lead-free compliance per RoHS standards. Ensure the SSOP package footprint matches the PCB layout specifications provided in the datasheet pin configuration diagrams before finalizing procurement orders.

Selection Notes

Select this variant when a 100:1 clock-to-center frequency ratio is required. Compare against LTC1068-200, LTC1068-50, and LTC1068-25 if different tuning ratios are needed. Consider the I-grade version for industrial temperature ranges. Use FilterCAD software to determine optimal external resistor values for desired Q factors and cutoff frequencies.

Part Context

This component belongs to the LTC1068 series of monolithic switched-capacitor filters. The family includes variants with different fixed clock-to-center frequency ratios: 200:1, 100:1, 50:1, and 25:1. All members share similar internal architectures and packaging options, differing primarily in their default tuning characteristics and maximum achievable center frequencies for a given clock input.

Replacement Considerations

Direct substitutes within the same family include LTC1068IG#PBF for extended temperature operation. Other ratio-specific alternatives are LTC1068-200CG#PBF, LTC1068-50CG#PBF, and LTC1068-25CG#PBF. Verify that the replacement part maintains the required clock-to-center frequency ratio for the specific application design.