RXM-GPS-R4-T Linx Technologies, RXM-GPS-R4-T Datasheet - Page 11

• Manufacturer Part Number: RXM-GPS-R4-T
• Description: GPS Modules R4 Series GPS Recvr Module Tape and Reel
• Manufacturer: Linx Technologies

Specifications of RXM-GPS-R4-T

• Rohs: yes
• Frequency Band: 1575.42 MHz
• Number Of Channels: 48
• Time To First Fix (cold Start): 32 s
• Acquisition Sensitivity: - 160 dBm
• Horizontal Position Accuracy: 2.5 m
• Operating Supply Voltage: 3.3 V
• Operating Supply Current: 56 mA
• Interface Type: Serial
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Dimensions: 15 mm x 13 mm x 2.2 mm
• Minimum Operating Temperature: - 40 C

Backup Battery
The module is designed to work with a backup battery that keeps the
SRAM memory and the RTC powered when the RF section and the main
GPS core are powered down. This enables the module to have a faster
Time To First Fix (TTFF) when the it is powered back on. The memory and
clock pull about 660µA. This means that a small lithium battery is sufficient
to power these sections. This significantly reduces the power consumption
and extends the main battery life while allowing for fast position fixes when
the module is powered back on.
The backup battery must be installed for CGEE start. If the serial command
is used to place the receiver into hibernate while keeping VCC powered,
then the battery backup current is 15µA while the current through the VCC
line is about 170µA.
Power Supply Requirements
The module requires a clean, well-regulated power source. While it is
preferable to power the unit from a battery, it can operate from a power
supply as long as noise is less than 20mV. Power supply noise can
significantly affect the receiver’s sensitivity, therefore providing clean power
to the module should be a high priority during design. Bypass capacitors
should be placed as close as possible to the module. The values should be
adjusted depending on the amount and type of noise present on the supply
line.
The 1PPS Output
The 1PPS line outputs 1 pulse per second on the rising edge of the GPS
second when the receiver has an over-solved navigation solution from
five or more satellites. The pulse has a duration of 200ms with the rising
edge on the GPS second. This line is low until the receiver acquires an
over-solved navigation solution (a lock on more than 4 satellites). The
GPS second is based on the atomic clocks in the GPS satellites, which
are monitored and set to Universal Time master clocks. This output and
the time calculated from the GPS satellite transmissions can be used as a
clock feature in an end product.
–
–
7