Philip Avalon FM20/FM30 Interface Board (P/N: M2703-26420 / M2703-66420)

1. Basic Information

• Official Part Number: M2703-26420 (also referenced as M2703-66420)
• Compatible Devices: Philip Avalon FM20 (M2702A), FM30 (M2703A) Fetal Monitors
• Function: Front-end I/O interface & signal switching board; routes transducer signals to mainboard
• Board Dimensions: ~190 mm × 85 mm
• PCB Layers: 4-layer, medical-grade FR-4

2. External Connectors (Front Panel)

3. Internal Interfaces (to Mainboard)

• Mainboard Connector: 50-pin flat cable (to M2703-66450 Main CPU Board)
• Power Input: 24 VDC ±10%, 5 VDC ±5% (from Bus Master Board)
• Signal Lines: Analog (US/TOCO/MECG) + digital (ID/control) + power
• Isolation: Medical-grade isolation (2500 Vrms) between patient & system circuits

4. Electrical Specifications

• Ultrasound (US) Input:
  • Frequency: 1 MHz pulsed Doppler
  • Input Sensitivity: 10 µVpp – 500 mVpp
  • Gain: Software-adjustable 0–60 dB
• TOCO Input:
  • Bridge amplifier, 0–5 V analog range
  • Sensitivity: 2 mV/TOCO unit
  • Filter: 0.05–10 Hz bandpass
• MECG Input:
  • 3-lead, 0.05–100 Hz bandwidth
  • 50/60 Hz notch filter
  • Input impedance: >10 MΩ

5. Environmental & Reliability

• Operating Temp: +5°C to +45°C
• Storage Temp: -20°C to +60°C
• Humidity: 10–95% RH (non-condensing)
• Compliance: IEC 60601-1, IEC 60601-2-37 (medical device safety)
• Lifetime: ≥5 years (24/7 clinical use)
• ESD Protection: ±15 kV (air), ±8 kV (contact)

6. Key Features

• Smart Transducer Auto-Recognition: Detects connected transducer type (US/TOCO/MECG)
• Signal Multiplexing: Switches between twin US signals & routes to DSP
• Overvoltage/Overcurrent Protection: safeguards mainboard from transducer faults
• LED Status Indicators: Power, signal lock, transducer detect