LF398 Monolithic Sample-and-Hold Circuit
High-accuracy sample-and-hold circuit with fast signal acquisition and low droop rate.
- Supply Voltage: ±18V
- Power Dissipation: 500mW
- Input Voltage: ±18V
- Logic-to-Logic Reference Differential Voltage: 7-30V
- Output Short Circuit Duration: Indefinite
- Hold Capacitor Short Circuit Duration: 10 sec
- Storage Temperature: -65 to 150°C
Top Features:
- ±5V to ±18V Operating Range
- Less than 10µs Acquisition Time
- Logic Input Compatible with TTL, PMOS, CMOS
- 0.5mV Typical Hold Step at Ch = 0.01µF
The LF398 is a monolithic sample-and-hold circuit utilizing BI-FET technology for ultrahigh DC accuracy, fast signal acquisition, and low droop rate. With a DC gain accuracy of 0.002% typical and an acquisition time as low as 6µs to 0.01%, it operates as a unity-gain follower. The bipolar input stage ensures low offset voltage and wide bandwidth, allowing inclusion inside the feedback loop of 1-MHz operational amplifiers without stability issues.
Featuring an input impedance of 1010?, high-source impedances can be used without compromising accuracy. The LF398's output amplifier combines P-channel junction FETs with bipolar devices to achieve droop rates as low as 5mV/min with a 1µF hold capacitor. The design guarantees no feedthrough from input to output in hold mode, even for input signals equal to the supply voltages.
Logic inputs are fully differential with low input current, enabling direct connection to TTL, PMOS, and CMOS. The LF398 operates from ±5V to ±18V supplies, with an A version available featuring tightened electrical specifications.
*Images are for illustration only; actual product may vary.*