
Philips Electronics
DESCRIPTION
The LF198/LF298/LF398 are monolithic sample-and-hold circuits which utilize high-voltage ion-implant JFET technology to obtain ultra-high 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 6µs 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 LF198 to be included inside the feedback loop of 1MHz op amps without having stability problems. Input impedance of 10‛°Ω allows high source impedances to be used without degrading accuracy.
FEATURES
• Operates from ±5V to ±18V supplies
• Less than 10µs acquisition time
• TTL, PMOS, CMOS compatible logic input
• 0.5mV typical hold step at CH=0.01µF
• Low input offset
• 0.002% gain accuracy
• Low output noise in hold mode
• Input characteristics do not change during hold mode
• High supply rejection ratio in sample or hold
• Wide bandwidth
APPLICATION
• The LF198/LF298/LF398 are ideally suited for a wide variety of sample-and-hold applications, including data acquisition, analog-to-digital conversion, synchronous demodulation, and automatic test setup