Stanford Research SIM910 – JFET Preamplifier

The Stanford Research SIM910 is a JFET voltage preamplifier engineered for low-noise amplification of small signals from DC to 1 MHz. Built on the modular SIM platform, it integrates into the SIM900 mainframe or operates standalone with external DC supplies. The JFET front-end delivers exceptional performance with high input impedance (100 MΩ) and minimal bias current, making it ideal for high-impedance source measurements where noise and loading effects must be minimized.

Technical Specifications

• Input noise voltage (RTI, gain ≥ 10): 4 nV/√Hz @ 1 kHz (typical)


• Input noise voltage (RTI, gain 1): 12 nV/√Hz @ 1 kHz (typical)


• Input current noise: <10 fA/√Hz (typical) Frequency Response & Bandwidth


• Bandwidth: DC to 1 MHz


• -3 dB point: 1.9 MHz (typical)


• AC coupling: 16 mHz -3 dB frequency Gain & Accuracy


• Selectable gain: 1 to 100 (1-2-5 sequence)


• Gain accuracy: ±0.5% (DC to 100 kHz); ±5% @ 1 MHz (typical)


• Gain stability: 200 ppm/°C Input & Output Characteristics


• Input impedance: 100 MΩ || ~35 pF


• Common-mode rejection ratio: 85 dB


• Output voltage limits: ±10 V


• Dual parallel outputs (front and rear panel)

Key Features

• Programmable gain adjustable via front panel or remote interface


• AC or DC coupling selectable


• Differential (A-B) or single-ended (A) input configuration


• BNC input connectors with floatable or grounded shields


• External power requirements: +5 VDC (100 mA max.), ±15 VDC (300 mA max.)

Typical Applications

• Lock-in detection systems


• Piezoelectric and capacitive sensor readout


• Photocurrent amplification


• Low-level signal conditioning

Compatibility & Integration Connects to SIM900 mainframe via DB-15 rear panel connector. Operates standalone with external ±15 VDC and +5 VDC supplies.