The Keithley 4225-RPM Remote Preamplifier/Switch Module is an expansion unit for the 4200A-SCS Parameter Analyzer that extends low-current measurement capabilities and enables automatic switching between DC SMUs, C-V, and ultra-fast pulsed I-V instruments without re-cabling. This remote amplifier and multiplexer eliminates the need for manual reconfiguration when transitioning between measurement types, reducing test setup complexity and cycle time.
## Technical Specifications
The 4225-RPM adds six current measurement ranges to the 4225-PMU Ultra-Fast Pulsed I-V Instrument Module: 100 nA, 1 μA, 10 μA, 100 μA, 1 mA, and 10 mA. Current measurement resolution reaches <200 pA without averaging, with a noise floor of approximately 10 pA. Noise performance varies by range: 200 pA (100 nA range), 2 nA (1 μA), 5 nA (10 μA), 50 nA (100 μA), 300 nA (1 mA), and 1.5 μA (10 mA).
Output resistance typically ranges from 20 Ω to 50 Ω. The 4225-RPM-LR variant reduces this to 2 Ω to 3 Ω and supports capacitive loads up to 75 pF, with correspondingly reduced load-line effects.
Autoranging functionality enables automatic range selection during pulsed I-V sweeps, optimizing current measurement across different signal levels. Recommended minimum pulse widths scale from 134 μs (100 nA range) to 160 ns (10 mA range). Minimum measure windows range from 10 μs (100 nA) down to 20 ns (10 mA).
## Key Features
• Automatic instrument switching—no re-cabling required
• Extends 4225-PMU measurement range into the nanoampere regime
• Autoranging across six current decades
• Compact remote amplifier design
• Two variants: standard (20–50 Ω output) and low-resistance (2–3 Ω output)
## Typical Applications
Characterization of low-current devices including diodes, transistors, and other semiconductor components requiring I-V curves across multiple decades of current.
## Compatibility & Integration
Designed for integration with Keithley 4200A-SCS Parameter Analyzer mainframes.
