Mitel GPS Orion-S/-HD Receiver User Manual

Page 10

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Document Title:

6

User’s Manual for the GPS Orion-S/-HD Receiver

Document No.

Issue 1.0

GTN-MAN-0110

June 22, 2003

DLR/GSOCNo part of this document shall be reproduced in any form or disclosed to third parties without prior authorization.

RAM memory. The EPROM is arranged into two 16 bit wide chips (256 kB total), while RAM
is partitioned into four 8 bit wide memory chips with a total size 512 kB. The RAM memory
contents can be maintained by a dedicated backup power supply line with a current of ap-
proximately 0.1 mA.

The main board offers an SMA (or MCX) connector for the GPS antenna. It is connected to
the interface board via a 9-pin header that provides two bi-directional serial lines, the main
and backup power supply, an input discrete and a reset line. Optionally, a tenth pin is made
available for the pulse-per-second signal. A summary of the pin assignment is provided in
Table 2.1.

Table 2.1 Pin assignment for GPS Orion interface connector

Pin

Function

1

Ground

2

Vdr (memory backup positive supply)

3

RX B serial input

4

RX A serial input

5

TX B serial output

6

TX A serial output

7

Discrete input line (used as a “lift-off” signal)

8

Vdd level sense circuit output (used as a “reset” if connected to GND)

9

Vdd (+5V prime power supply input)

10

PPS output (optional)

General physical and electrical parameters of the Orion main board are summarized in Table
2.2. The GPS Orion receiver and its components have not been validated for space applica-
tions. Nevertheless, limited information on the radiation hardness of the core chipset sug-
gests it’s suitability up to a total dose of about 15 krad [11]. However, no latch-up protection
is presently provided to safeguard against destruction of CMOS circuits under the action of
heavy ions. Other than the standard Orion receiver, the main boards of the Orion-S and -HD
receivers are not equipped with a “supercap” capacitor, since this is not considered vacuum-
proof. This means that the non-volatile memory and real-time clock is lost whenever the main
board is disconnected from the backup power supply (pin 2).

Table 2.2 Physical and electrical parameters of GPS Orion main board

Parameter

Value

Dimension

95mm x 50mm x ~10m m

Weight

ca. 50g

Operations Temperature

-40°C to +85°C (as per [1])

Storage Temperature

-50°C to +110°C (as per[1])

Main power supply

+5V DC (+/- 10%), 400 mA (2W)

Backup power supply

>+2.2V DC, ca. 100

µ

A

Data I/O levels

CMOS TTL (0V, +5V)

RF input

Connector

SMA (or MCX)

Active antenna power supply

+5V DC, 50 mA

Impedance

50




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