LF198H/883

Overview

The LF198H/883 is a monolithic sample-and-hold circuit manufactured by Texas Instruments, utilizing BI-FET technology for high accuracy and fast acquisition. It operates from ±5V to ±18V supplies with an operating temperature range of −55°C to +125°C. The device features less than 10 μs acquisition time, 0.002% typical gain accuracy, and low input offset voltage. Logic inputs are compatible with TTL, PMOS, and CMOS standards.

Feature Summary

• Monolithic design using BI-FET technology for ultra-high dc accuracy and low droop rate
• Wide bandwidth allows inclusion inside feedback loops of op amps without stability problems
• Fully differential logic inputs allow direct connection to TTL, PMOS, and CMOS
• High input impedance enables use with high source impedances without degrading accuracy

Applications

• Precision data acquisition systems
• Fast acquisition applications requiring low droop rates
• Circuits requiring wide bandwidth within operational amplifier feedback loops
• Military and defense applications certified under QML standards

Procurement Notes

Verify the specific ordering suffix against the latest Package Option Addendum to confirm package type and material specifications. Ensure compatibility with Mil-Std-883 quality conformance inspection requirements. Confirm that the selected variant meets the necessary environmental and reliability standards for the intended deployment environment.

Selection Notes

Select this component when high dc accuracy and fast signal acquisition are critical. Consider the trade-offs between hold capacitor size, acquisition time, and droop rate based on application needs. Evaluate the impact of dielectric absorption in the hold capacitor and ensure proper guarding techniques are implemented to minimize digital feedthrough errors during operation.

Part Context

This part belongs to the LF198QML family of monolithic sample-and-hold circuits. It is designed for military and defense applications, adhering to strict quality standards. The device integrates P-channel junction FETs with bipolar devices to achieve superior performance characteristics compared to previous MOS-based designs.

Replacement Considerations

Direct replacements include other variants within the LF198QML family such as LF198WG-QMLV. Verify pinout compatibility and electrical specifications before substitution. Ensure that any alternative component meets the same Mil-Std-883 certification requirements if used in qualified military or space applications.