SL876Q5-A
Product User Guide
1VV0301333 Rev. 2
Page 39 of 68
2017-06-27
Boot Select
It is not necessary to use the Boot Select pin to re-flash the receiver since SiRFlive can use
commands to perform this task. However, it is desirable to bring it out to a test point if otherwise
unconnected.
Internal / nExternal Antenna Enable
When high, the module enables RF input from the internal chip antenna and disables input
from the external antenna.
When low, the external antenna is enabled and the LNA Enable signal may then be used to
control power to the external LNA according to the power state of the receiver (operating or
low-power).
This pin has an internal pullup which makes the internal antenna the default RF input.
See
Section 8.6.3 LNA Enable.
Control Output Signals
1PPS
1PPS is a one pulse per second signal which is enabled after the receiver has achieved a 5-
satellite Kalman filter position fix. It is disabled when the position fix becomes invalid. However,
if Velocity Dead Reckoning is enabled, the pulse is continued until its timeout has expired.
The time mark is within 1
μ
s of the GPS epoch and normally within 100 ns.
Pulse width is 250 ms.
SYSTEM-ON (output)
See
Section 8.5.1 ON-OFF (input) and SYSTEM-ON (output)
LNA Enable
This signal indicates the power state of the module. It is high when the receiver is operating
and can accept an RF input. When the receiver is in a low-power state, it does not accept RF
input, therefore the LNA can be turned off to save power.
This signal controls the internal chip antenna and may also be used to control the external
antenna LNA if desired.
Summary of Contents for SL876Q5-A
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