Product overview
Shenzhen JND Technology Co., Ltd’s JND ST-91-U7L is a single-frequency, single-mode GPS/GNSS receiver module for positioning, tracking and navigation. Its physical architecture uses single-sided surface mounting and a secondary SMT assembly approach for incorporation into host electronics. The module combines a U-blox7 chipset, a KDS 0.5 PPM TCXO, an RTC crystal, and an integrated low-noise amplifier and SAW filter. It uses lead-free manufacturing and meets RoHS requirements. It also supports positioning with a passive antenna.
Integration options include UART/TTL output and optional USB 2.0 output. Serial communication defaults to 9600 bps, with selectable rates extending from 1200 to 921600 bps; navigation updates are adjustable from 1 to 10 Hz. Integrators can configure NMEA sentence combinations, satellite quality controls, drift-reduction settings and operating modes, including airborne operation and 2D or 3D positioning. Built-in SPI flash for retaining configuration through power loss is optional. The receiver also supports AssistNow assistance services and a positioning PPS indicator whose behavior changes after a position fix.
Specifications
| Specification | Value & conditions |
|---|---|
| Receiver architecture | Single-frequency, single-mode ST-91-U7L receiver module. |
| Chipset | U-blox7 chipset. |
| Intended functions | Positioning, tracking and navigation. |
| Module characteristics | GPS/GNSS receiver module described as having ultra-low power consumption, ultra-high sensitivity and an ultra-small form factor. |
| Mounting architecture | Single-sided surface mounting with a secondary SMT assembly approach. |
| Manufacturing | Lead-free manufacturing; RoHS compliant. |
| Output interfaces | UART/TTL output; optional USB 2.0 output.USB 2.0 output is optional. |
| Reference oscillator | KDS high-precision 0.5 PPM TCXO. |
| RF front end | Built-in low-noise amplifier and SAW filter. |
| Passive-antenna operation | Supports rapid positioning with a passive antenna.With a passive antenna. |
| Configuration retention | Optional built-in SPI flash retains configuration commands after power loss.With optional built-in SPI flash fitted. |
| Serial data rates | 9600 bps default; selectable 1200, 2400, 4800, 19200, 38400, 57600, 115200, 230400, 460800 and 921600 bps.9600 bps is the default. |
| Output protocol | NMEA 0183 V3.0: GGA, GSA, GSV, RMC, VTG and GLL.Output sentence combinations are configurable. |
| RTC | Built-in RTC crystal. |
| Data refresh rate | 1 Hz–10 Hz.Adjustable. |
| Satellite quality controls | Configurable satellite quality controls and software settings to reduce position drift. |
| Operating and positioning modes | Pedestrian, vehicle, static, portable and airborne modes; 2D and 3D positioning.User-selectable modes. |
| Positioning PPS indicator support | Supports a positioning PPS indicator.Before a position fix, the indicator can remain steadily lit or off; after a fix, it flashes. |
| Assisted GPS services | Supports A-GPS services including AssistNow Online and AssistNow Offline. |
| Navigation engine | Combined GPS, Galileo and SBAS engine, including WAAS, EGNOS, MSAS and GAGAN. |
