LF347DR

Overview

The LF347DR is a quad JFET-input operational amplifier manufactured by Texas Instruments. It integrates four high-speed amplifiers in a single monolithic integrated circuit, utilizing well-matched JFET and bipolar transistors. The device features a gain-bandwidth product of 3 MHz and a typical slew rate of 16 V/µs. It operates within a supply voltage range of ±3.5 V to ±18 V (7 V to 36 V total). Key electrical characteristics include an input bias current of 200 pA, an input offset voltage of 10 mV, and a common-mode rejection ratio of 100 dB. The component is housed in a 14-pin SOIC package with a surface-mount installation style.

Feature Summary

• High-speed JFET input stage providing low input bias and offset currents
• Wide common-mode and differential voltage range extending up to the positive supply rail
• Internal frequency compensation eliminates the need for external components
• Output short-circuit protection ensures robust operation under fault conditions

Applications

• Audio preamplifier circuits requiring low noise and high impedance
• Active filter designs utilizing wide bandwidth capabilities
• Voltage follower and buffer applications in signal conditioning chains
• Integrator and differentiator circuits in analog computing systems

Procurement Notes

Verify the specific datasheet revision corresponding to the LF347DR part number before finalizing design integration. Confirm that the SOIC-14 package dimensions and thermal characteristics align with the target PCB layout requirements. Ensure that the operating temperature range meets the environmental specifications of the intended application environment. Cross-reference the manufacturer's latest documentation for any updates regarding pinout configurations or recommended operating conditions.

Selection Notes

Select this component when designing circuits that require high input impedance combined with moderate speed performance. The JFET input stage makes it suitable for applications involving high-source-impedance sensors where bias current errors must be minimized. Compare against bipolar-input op-amps if lower offset voltage is critical, as JFET inputs typically exhibit higher offset voltages. Consider the power supply constraints, as the device requires a minimum total supply voltage of 7 V for proper operation.

Part Context

The LF347 belongs to the LF34x family of quad operational amplifiers from Texas Instruments. This series is designed to provide cost-effective solutions for multi-channel analog signal processing. The 'DR' suffix specifically denotes the surface-mount SOIC-14 package variant, distinguishing it from through-hole DIP versions like the LF347N. This family shares core architectural similarities but varies in packaging and minor electrical parameter tolerances based on the specific suffix designation.

Replacement Considerations

The LF347M-NOPB is a documented equivalent offering similar quad JFET-input specifications in a narrow SOIC package. Verify compatibility regarding package width and thermal dissipation characteristics when substituting. Other members of the LF34x family may serve as functional alternatives if pinout and electrical parameters match the design requirements.