Nellcor ® Circuit Board; Mp 304 Spo; Theory Of Operation - Datascope Accutorr Plus Service Manual

®
2.2.9 Nellcor

MP 304 SpO

The MP 304 is a complete SpO
®
Nellcor Puritan Bennett.
The MP 304 is centralized around a Motorola MC68HC16 micro processor (U-4), driven
by a 32.76 Khz. Oscillator. (Y-2) The processor is supported by a 32K x 8 static RAM
(U-3) and a SpO program boot EPROM (U-6).
2
Patient information is initially processed in a patented ASIC (U-1) (Application Specific
Integrated Circuit). Clock pulses are provided by Y-1, a 10 MHZ oscillator. The resulting
analog data is then routed into separate Red and Infra Red ADC's (Analog to Digital
Converters) (U-5 and U-7) The resulting digital data is clocked into the microprocessor
and is transmitted serially to the Nellcor
processing and display.
NELLCOR
Sensor
Input
U-1
P-1
A S I C
Y-1
10 Mhz
Accutorr Plus Service Manual
Chapter 2 - Theory of Operation
Circuit Board Theory of Operation
2
detection and determination circuit, proprietary of
2
Interface Board (0670-00-0675) for further
®
U-3
Static
RAM
32x8
SERIAL
RED_ADC
DATA
U-5
ADC
U-7
IR_ADC
ADC
RX
TX
RST*
Connector to
NELLCOR Interface
Board
DATA BUS
U-6
EPROM
ADDRESS BUS
U-4
MC68HC16
Y-2
32.768 Khz
NELLCOR MP304
Block Diagram
0671-00-0162
Revised 12/20/00
Figure 2-10
Nellcor MP304
Block Diagram
2-29