Lassen SQ GPS Receiver 2 5
Hardware Integration 2
2.3
Power Requirements
The Lassen SQ GPS module re3.3 VDC ±0.3 VDC at 33 mA,
typical excluding the antenna. The on-board capacitance is 10 µF. An
important design consideration for power is the module's internal
clock frequency at 12.504 MHz ± 3 KHz. Interference spurs on prime
power in this narrow frequency band should be kept to less than 1mV.
The receiver does not require any special power up or down
sequencing. The receiver power is supplied through pin 7 of the I/O
connector. See Table 2.2 for the +3.3 VDC power specifications.
Warning – The Lassen SQ GPS receiver is ready to accept TSIP
commands approximately 2.1 seconds after power -up. If a command is
sent to the receiver within this 2.1 second window, the receiver will ignore
the command. The Lassen SQ GPS receiver will not respond to
commands sent within the 2.1 second window and will discard any
associated command data.
Battery Back-up
The Lassen SQ GPS receiver provides an input for battery back-up
(BBU) power to keep the module's RAM memory alive and to power
the real-time clock when the receiver's prime power is turned off.
RAM memory is used to store the GPS almanac, ephemeris, and last
position. User configuration data, including port parameters and
receiver processing options can be stored in non-volatile Flash which
does not require back-up power. By using battery back-up, time to first
fix is reduced to 20 seconds (typical). Though not required, providing
BBU power can reduce time to first fix. A 3.6 volt lithium battery used
for back-up power can last up to five years.
Содержание SQ
Страница 1: ...F Part Number 47838 00 Revision A June 2002 Lassen SQ GPS Receiver System Designer Reference Manual...
Страница 4: ......
Страница 11: ...Contents Lassen SQ GPS Receiver xi General 163 Mechanical 164 Compact Unpackaged Antenna 166 Glossary...
Страница 12: ...Contents xii Lassen SQ GPS Receiver...
Страница 14: ...About this Manual xiv Lassen SQ GPS Receiver...
Страница 46: ...2 Hardware Integration 32 Lassen SQ GPS Receiver...
Страница 150: ...B TSIP Tool kit User s Guide 136 Lassen SQ GPS Receiver...
Страница 166: ...C NMEA 0183 152 Lassen SQ GPS Receiver...
Страница 171: ...Lassen SQ GPS Receiver 157 Specifications and Mechanical Drawings D...
Страница 175: ...Lassen SQ GPS Receiver 161 Specifications and Mechanical Drawings D...
Страница 179: ...Lassen SQ GPS Receiver 165 Specifications and Mechanical Drawings D...
Страница 181: ...Lassen SQ GPS Receiver 167 Specifications and Mechanical Drawings D...
Страница 182: ...D Specifications and Mechanical Drawings 168 Lassen SQ GPS Receiver...
Страница 196: ...Glossary 182 Lassen SQ GPS Receiver...