Table Of Contents - Novametrix Medical Systems MARS PO2 TECH 2001 Service Manual

Rev. 01
Contents
Patient Safety ................................................................................................................1
Warnings .....................................................................................................................1
Cautions ......................................................................................................................2
Introduction ...................................................................................................................5
SpO2 Principles of Operation ......................................................................................5
Indications and Usage .................................................................................................6
Symbols .......................................................................................................................6
Illustrations ...................................................................................................................7
Front Panel ..................................................................................................................7
Rear and Top Panel ....................................................................................................8
Theory of Operation ....................................................................................................9
2726 Power Supply Board ...........................................................................................9
AC Mains and Battery Operation Overview .......................................................9
AC Mains Operation ........................................................................................10
Battery Operation .............................................................................................10
2775 Main Board .......................................................................................................10
Power On/Off Control Circuitry ........................................................................11
Power Supplies ................................................................................................11
Voltage References .........................................................................................12
Preserving RAM and Real Time Clock Data ....................................................12
Low Battery Voltage Shutdown ........................................................................13
Timing Sequencer ............................................................................................13
Data Sampling Controller .................................................................................13
Sensor LED Drive Circuits ...............................................................................14
Sensor Photodiode Return Path ......................................................................15
Calibrating the 20-Bit Analog-to-Digital Converters .........................................15
20-Bit Analog-to-Digital Conversion .................................................................16
Sensor Status Decoding and Conversion ........................................................17
Sensor Status Parameters ...............................................................................17
Microprocessor ................................................................................................18
Memory ............................................................................................................18
Real Time Clock (RTC) ....................................................................................19
Sound generator ..............................................................................................19
Keypanel Interface ...........................................................................................19
Display Interface ..............................................................................................20
I/O Device Controller .......................................................................................20
Watchdog Timer ..............................................................................................21
Serial I/O Controller .........................................................................................21
RS232 Serial Communication ..........................................................................22
2776 DSP Module .....................................................................................................23
Power Supply & Supervisory Circuits ..............................................................23
UART and Level Shifting Circuitry ...................................................................23
DSP Processor ................................................................................................24
Memory and Programmable Logic Device (PLD) ............................................24
Model 2001 Service Manual
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