Stanford Research FS735 – Fourteen-channel Distribution Amplifier

The Stanford Research FS735 is a fourteen-channel distribution amplifier housed in a compact 19″ rack-mount enclosure (1U height). This dual-channel system provides seven synchronized outputs per input channel, enabling high-fidelity signal distribution across test and measurement, telecommunications, and research applications. The FS735 accommodates multiple signal types—5 MHz and 10 MHz frequency references, CMOS logic pulses, and broadband signals—with configurable input impedance (50 Ω or 1 kΩ depending on model) and AC coupling for frequency reference inputs. Each output driver operates independently, delivering low channel-to-channel timing skew and high isolation.

– Technical Specifications

Input Characteristics
• Input source impedance: 50 Ω (5 MHz/10 MHz models) or 1 kΩ (CMOS logic models)
• AC coupled inputs for frequency reference signals
• Input limiter removes amplitude modulation, fixes output amplitude, and blocks noise beyond ±50 mV from zero-crossing
• CMOS Schmitt trigger threshold: +1.3 VDC (Low to High); 0.35 V hysteresis
• Minimum CMOS pulse width: >5 ns; duty cycle near 50%

Output Characteristics
• Total outputs: 14 (7 per input channel)
• Output impedance: 50 Ω
• CMOS output levels: 0 VDC and 5.0 VDC
• 5 MHz/10 MHz output: 1 Vrms (+13 dBm) into 50 Ω load
• Output polarity: Configurable via internal jumper (non-inverting default)
• Fast transition times with very low overshoot; low channel-to-channel skew

Performance (5 MHz/10 MHz Models)
• Amplitude leveling: Yes
• Low additive phase noise and high channel-to-channel isolation
• High return loss
• Broadband models: DC–50 MHz bandwidth

Indicators
• Power LED, signal LED (100 ms flash per edge), overload LED, and fault LED for diagnostics

– Key Features

• Seven independent, isolated output drivers per channel
• Reverse termination for unterminated line applications
• Supports virtually any CMOS waveform near 50% duty cycle
• Low noise, high-isolation signal distribution
• Configurable polarity and termination for flexible integration

– Typical Applications

Frequency reference distribution, timing pulse distribution, CMOS logic signal fanout, broadband signal splitting across multiple test instruments and subsystems.

– Compatibility & Integration

19″ rack-mount form factor; 50 Ω output impedance matches standard test equipment interfaces.