Nellcor OxiMax N 5500 Service Manual page 93

System Processing Description
l Temperature unit : measures temperature data.
Temperature Probe
Temperature Probe
l Analog control unit: analog circuit control, PIC16C65 – selection of ECG channels
and filter, size adjustment, verification of lead off, QRS, heart rate, etc.
Asyncronous Serial Communication
with Communication UNIT
External Interface
l TCP/IP : Network connector
l Serial I/O : a female 15 pin sub-miniature D shell connector
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Patient Isolation
Isolation DC +/-5V, +/-12V
Isolation DC/DC
Constant Crrent Source
AMP &
Filter
Reference
Constant Crrent Source
AMP &
Filter
Reference
Figure 23. Temperature Unit Block Diagram
Patient Isolation
DC +5V
Isolation DC/DC
Photocoupler
Figure 24. Analog Control Unit Block Diagram
N5500 Service Manual
DC +5V
Analog to Digital PIC16C65B_P
Converter
(MCP3204)
Isolation DC +/-5V
ECG Filter Selection
ECG Gain Control
ECG Lead Off
ECG Pace Pulse Detection
Temperature 1 Input
PIC16C65B_P
Temperature 2 Input
Temperature 1 Calibration
Temperature 2 Calibration
Respiration Gain Control