SkyTraq PX1120S - User Manual

To Next Page

SkyTraq Technology, Inc. Preliminary Draft www.skytraq.com.tw

Features

⚫ 230 acquisition/tracking channels

⚫ Support global GPS, Beidou, Galileo, GLONASS

⚫ Supports regional QZSS, SBAS

⚫ 16 million time-frequency hypothesis testing

per sec

⚫ -148dBm cold start sensitivity

⚫ -165dBm tracking sensitivity

⚫ 29 second cold start TTFF

⚫ 3.5 second TTFF with AGPS

⚫ 1 second hot start

⚫ 2.0m CEP accuracy

⚫ Multipath detection and suppression

⚫ Jamming detection and mitigation

⚫ AGPS Support

⚫ Contains LNA, SAW Filter, TCXO, RTC Xtal

⚫ Works with active and passive antenna

⚫ On board active antenna short protection

⚫ On board active antenna detection

⚫ Complete receiver in 12.2mm x 16.0mm size

⚫ Operating temperature -40 ~ +85ºC

⚫ Pb-free RoHS compliant

Applications

⚫ Navigation and asset tracking

⚫ Timing reference

L1 Quad Constellation

GNSS Receiver Module

The PX1120S is a satellite navigation receiver capable of

using GPS, Beidou, Galileo, GLONASS, QZSS, SBAS signal to

provide 3D navigation in a single compact SMD module. The

PX1120S can track all in-view GPS, Beidou, Galileo,

GLONASS, QZSS satellites. It is fully autonomous such that

once power is applied, the receiver automatically searches,

acquires and tracks satellite signals. When a sufficient

number of satellites are tracked with valid measurements,

the receiver produces 3D position and velocity outputs.

Global quad-constellation signal receiving capability enables

using greater number of satellite signal than GPS/GLONASS

dual-constellation receivers. The increased satellite number

offers superior performance in challenging urban canyon

and multipath environments.

Single-chip Phoenix positioning engine is inside the receiver

module. It features high sensitivity and fast TTFF. PX1120S

can acquire, track, and get position fix autonomously in

difficult weak signal environment. Its high sensitivity allows

continuous position coverage in nearly all outdoor

application environments. The high performance signal

parameter search engine is capable of testing 16 million

time-frequency hypotheses per second, offering superior

signal acquisition and TTFF speed.

The receiver module contains SAW filter and a notch filter

to remove out-band interference and LTE B13 signal at the

RF input prior to the first stage LNA. This configuration

allows normal operation even under strong RF interference

when cellular modem is near the PX1120S.

PX1120S is backward pin-to-pin compatible with earlier

SkyTraq 12mm x 16mm form factor GNSS module, allowing

very easy migration.

Main Page

Need help?

Do you have a question about the SkyTraq PX1120S and is the answer not in the manual?

The SkyTraq PX1120S is a high-performance L1 quad-constellation GNSS receiver module designed for satellite navigation applications. This compact surface-mount device is capable of providing 3D navigation by utilizing signals from GPS, BeiDou, Galileo, GLONASS, QZSS, and SBAS satellites. The module operates autonomously, meaning that once power is supplied, it automatically searches for, acquires, and tracks satellite signals. When a sufficient number of satellites are tracked and valid measurements are obtained, the receiver outputs 3D position and velocity data.

Function Description

At its core, the PX1120S integrates a single-chip Phoenix positioning engine, which is responsible for its high sensitivity and fast Time-To-First-Fix (TTFF). This engine allows the module to acquire, track, and achieve a position fix even in challenging weak signal environments. Its high sensitivity ensures continuous position coverage in nearly all outdoor applications. The module's advanced signal parameter search engine can test up to 16 million time-frequency hypotheses per second, contributing to its rapid signal acquisition and TTFF speed.

The global quad-constellation signal receiving capability is a key feature, enabling the use of a greater number of satellite signals compared to dual-constellation GPS/GLONASS receivers. This increased satellite count translates to superior performance in difficult environments such as urban canyons and areas with significant multipath interference.

The PX1120S module incorporates a SAW filter and a notch filter at the RF input. These filters are designed to remove out-of-band interference, including LTE B13 signals, before the signal reaches the first stage LNA (Low Noise Amplifier). This pre-filtering allows the module to operate normally even when subjected to strong RF interference, such as from a nearby cellular modem.

The module provides position, time, and velocity information through a simple UART serial interface, using the standard NMEA-0183 protocol. This straightforward interface makes integration and usage very easy. The PX1120S handles all necessary system initialization, signal acquisition, signal tracking, data demodulation, and navigation solution calculations autonomously.

Usage Features

The PX1120S offers a wide range of features that enhance its usability and performance in various applications:

Comprehensive Satellite Support: It supports a broad array of global and regional satellite systems, including GPS, BeiDou, Galileo, GLONASS, QZSS, and SBAS, ensuring robust positioning worldwide.
Fast Startup Times: The module boasts quick startup times, with a 1-second hot start, 3.5-second TTFF with AGPS, and a 29-second cold start TTFF. This rapid acquisition of a position fix is crucial for applications requiring immediate location data.
High Sensitivity: With a cold start sensitivity of -148dBm and tracking sensitivity of -165dBm, the PX1120S can maintain signal lock and provide positioning even in very weak signal conditions.
Accuracy: It delivers a 2.0m CEP (Circular Error Probable) accuracy for position and 0.1m/sec for velocity, along with a 10ns time accuracy, making it suitable for applications requiring precise measurements.
Multipath and Jamming Mitigation: The module includes advanced features for multipath detection and suppression, as well as jamming detection and mitigation, improving performance in challenging RF environments.
AGPS Support: Assisted GPS (AGPS) is supported, which can further reduce TTFF by providing satellite ephemeris data through an external source.
Flexible Antenna Options: The PX1120S can operate with both active and passive antennas. It includes on-board active antenna short protection and detection, adding to its versatility.
Integrated Components: The module contains an LNA, SAW Filter, TCXO (Temperature Compensated Crystal Oscillator), and RTC Xtal (Real-Time Clock Crystal), minimizing the need for external components.
Compact Size: With dimensions of 12.2mm x 16.0mm, the PX1120S is a complete receiver in a very small form factor, ideal for space-constrained applications.
Wide Operating Temperature Range: It operates reliably across a wide temperature range from -40°C to +85°C, making it suitable for harsh industrial and automotive environments.
RoHS Compliant: The module is Pb-free and RoHS compliant, adhering to environmental standards.
Backward Compatibility: The PX1120S is pin-to-pin compatible with earlier SkyTraq 12mm x 16mm form factor GNSS modules, simplifying migration for existing designs.
Update Rates: The module supports various update rates, from 1 Hz (default) up to 25 Hz, with special versions supporting 50 Hz and 100 Hz for high-dynamic applications.
NMEA Output: It outputs standard NMEA-0183 messages, including GGA, GLL, GSA, GSV, VTG, RMC, and ZDA, providing comprehensive navigation data.

Maintenance Features

While the PX1120S is a module designed for integration, certain considerations relate to its maintenance and handling:

Power Supply Stability: The module requires a stable power supply with minimal ripple (<50mVpp) on the VCC pin to ensure optimal receiver sensitivity. Bypass capacitors (10uF and 0.1uF) are recommended near the VCC pin to filter noise.
Backup Supply (V_BCKP): The V_BCKP pin is crucial for maintaining the internal SRAM memory and RTC when the module is powered down. This enables a faster time-to-first-fix upon power-up. If V_BCKP is not continuously powered, the receiver will revert to factory default settings upon each cold start. For applications where fast startup is not critical, V_BCKP can be connected to VCC.
Reflow Profile: Adhering to the recommended reflow profile is essential during SMT mounting to prevent damage to the module from excessive temperatures or prolonged exposure. The cooling temperature fall rate should not exceed 3°C/sec.
ESD Sensitivity: The PX1120S is an ESD sensitive device and must be handled with care to prevent electrostatic discharge damage.
Moisture Sensitivity Level (MSL): The modules are rated MSL4. They must be used for SMT reflow mounting within 72 hours of being removed from their vacuum-sealed ESD-protective moisture barrier bag under factory conditions (<30°C / 60% RH). If this floor life is exceeded or the bag is not vacuumed, the device requires pre-baking at 85°C for 8 to 12 hours before reflow. Parts should be placed individually on an oven tray for baking, not in tape-on-reel form.
Layout Guidelines: Proper PCB layout is critical for optimal performance. This includes separating RF and digital circuits, maintaining 50-ohm impedance for the RF signal path, keeping RF traces short, avoiding noisy sources, and ensuring proper grounding with short traces to the ground plane. Bypass capacitors should be low ESR ceramic types and placed adjacent to their respective pins.

In summary, the SkyTraq PX1120S is a robust and versatile GNSS receiver module, offering high performance and ease of integration for a wide array of navigation and asset tracking applications, as well as for providing precise timing references.

SkyTraq PX1120S Specifications

General

Type	GNSS Receiver
Channels	72
Sensitivity (Tracking)	-165 dBm
Sensitivity (Acquisition)	-148 dBm
Position Accuracy	2.5m CEP
Update Rate	10 Hz
Operating Temperature	-40°C to +85°C
Acquisition (Hot Start)	1 s
Operating Current	25 mA
Storage Temperature	-40°C to +85°C
GNSS	GPS, GLONASS, BeiDou, QZSS
Frequency	L1
Interface	UART, I2C
Supply Voltage	3.0 V to 3.6 V
Protocol	NMEA 0183
Antenna Type	Active or Passive
Power Consumption (Tracking)	25mA @ 3.3V
Baud Rate	9600 bps