# RFD900 Holder
ADD INFORMATION ABOUT
- ONBOARD VERSION
This board is developed to directly connect RFD900 (opens new window) radio module to PC ovar USB-UART converter.
Schematic can be found in this (opens new window) repo on GitHub.
The node has connectors which are described in the table below.
|1||SBUS||Used to connect RC control|
|2||TELEM||Used to get telemetry on ttl level|
|3||PWR||Used to externaly power up modem from 2-6S battery|
|4||USB||Used to get telemetry via VCP on PC|
Here (opens new window) you can find manufacturer part number of connectors it self and its mates.
# Pin configuration and functions
|Pin N||SBUS||Pin N||TELEM|
Scheme is shown on the picture below. Model can be downloaded here (opens new window) repo on GitHub.
|Width, mm||Length, mm||Height, mm|
Total weight of device less than 50 g.
Information about case presented here.
# Absolute Maximum Ratings
|I max @ 5V||0.1||0.6||A|
*Noted Voltage should be delivered only with current limitation under 2.5 Amp.
# Recommended operating conditions
# ESD ratings
|Human-body model (HBM)||2000||V|
|Charged-device model (CDM)||500||V|
Recommended mechanical mounting
Connection example diagram
# Power Supply Recommendations
Device is designed to operate from an input voltage supply range between 4.5 V and 5.5 V over USB connector, or 5.5 - 30 V from PWR. This input supply must be able to withstand the maximum input current and maintain a stable voltage. The resistance of the input supply rail should be low enough that an input current transient does not cause a high enough drop that can cause a false UVLO fault triggering and system reset. The amount of bulk capacitance is not critical, but a 47-uF or 100-uF electrolytic capacitor is a typical choice.
# Revision history
|master (opens new window)||June 26, 2023||Variant for onboard usage|
|USB-UART (opens new window)||Sep 6, 2023||Variant for Ground station use|