LIFEPAK 20/20e Defibrillator/Monitor
Device Description
Functional Description
(continued)
A05 User Interface PCB
(continued)
■
Field-Programmable Gate Array (FPGA)
— The Field-Programmable Gate
Array (FPGA) provides the interface between the CPU and all the user
interface peripherals. The FPGA works in conjunction with the CPU to
provide the 1/4 VGA signals to the A11 Display, the data and strobe signals
to the A12 Printer, and drive circuitry for the keypad LEDs. The FPGA
converts the inputs from the keypad switch matrix and W4 Selector into
digital words that can be read by the CPU.
■
Keypad
— The keypad is the primary user input control for the device. It
consists of two parts, the keypad domes, which are located on the rear side
of the A05 UI PCB, and the elastomer keypad cover that attaches to the front
case. The keypad domes protrude through holes in the front case and
enable the key covers to activate the domes when pressed by the user. The
key presses are decoded by the FPGA and sent to the CPU for processing.
The A05 UI PCB does not recognize the
ON
switch. It passes the signal to
the A04 Therapy PCB.
A06 OEM and
Mechanical
Components PCB
provides power to and collects SpO2 data from
the A10 SpO2 Module. Its primary function is to provide patient isolation between
the SpO2 module and the rest of the device design. In addition, it provides
physical mounting provisions for the SpO2 module.
(Continued on next page)
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