The LF298-MIL devices are monolithic sample-and-hold circuits that use BI-FET technology
to obtain ultrahigh DC accuracy with fast acquisition of signal and low droop rate. Operating as a
unity-gain follower, DC gain accuracy is 0.002% typical and acquisition time is as low as 6 µs to
0.01%. A bipolar input stage is used to achieve low offset voltage and wide bandwidth. Input offset
adjust is accomplished with a single pin and does not degrade input offset drift. The wide
bandwidth allows the LF298-MIL to be included inside the feedback loop of 1-MHz operational
amplifiers without having stability problems. Input impedance of 1010 Ω
allows high-source impedances to be used without degrading accuracy.
P-channel junction FETs are combined with bipolar devices in the output amplifier to give
droop rates as low as 5 mV/min with a 1-µF hold capacitor. The JFETs have much lower noise than MOS
devices used in previous designs and do not exhibit high temperature instabilities. The overall
design ensures no feedthrough from input to output in the hold mode, even for input signals equal
to the supply voltages.
Logic inputs on the LF298-MIL are fully differential with low input current, allowing for
direct connection to TTL, PMOS, and CMOS. Differential threshold is
1.4 V. The LF298-MIL will operate from ±5-V to ±18-V supplies.
An A version is available with tightened electrical specifications.
View datasheet View product folder