4
SkyTraq Technology, Inc.
Preliminary Draft www.skytraq.com.tw
PINOUT DESCRIPTION
Pin No.
Name
Description
1
GND
Ground
2
TXD
UART serial data output, 3.3V LVTTL.
One full-duplex asynchronous serial UART port is implemented. This UART
output is normally used for sending position, time and velocity information
from the receiver in NMEA-0183 format. When idle, this pin output HIGH.
3
RXD
UART serial data input, 3.3V LVTTL.
One full-duplex asynchronous serial UART port is implemented. This UART input
is normally for sending commands or information to the receiver in SkyTraq
binary protocol. In the idle condition, this pin should be driven HIGH. If the
driving circuitry is powered independently of PX1100S, ensure that this pin is
not driven to HIGH when primary power to PX1100S is removed, or a 10K-ohm
series resistor can be added to minimize leakage current from application to
the powered off module.
4
1PPS
One-pulse-per-second (1PPS) time mark output, 3.3V LVTTL. The rising edge
synchronized to UTC second when getting 3D position fix. The pulse duration is
about 100msec at rate of 1 Hz.
5
NC
No connection, empty pin
6
V_BCKP
Backup supply voltage for internal RTC and backup SRAM, 1.3V ~ 3.6V. V_BCKP
must be applied whenever VCC is applied. This pin should be powered
continuously to minimize the startup time. If VCC and V_BCKP are both
removed, the receiver will be in factory default mode upon power up, all user
configuration set is lost. For applications the does not care cold starting every
time, this pin can be connect to VCC.
7
NC
No connection, empty pin
8
VCC
Main power supply, 3.3V +/- 10%
9
RSTN
External active-low reset input to the baseband.
Only needed when power supply rise time is very slow or software controlled
reset is desired.