3.1 Module Overview

The RNBD350 Bluetooth® Low Energy Module integrates the Bluetooth 5.2 baseband controller, Bluetooth stack, digital and analog I/O and RF power amplifier into one solution.

Figure 3-1. RNBD350 Module Block Diagram

Figure 3-2. Pin Diagram – RNBD350 Module

Table 3-1. Pinout and Signal Descriptions List
Pin#	RNBD350 Module Pin	RNBD350 Pin Definition	Type
1	GND	Ground	—
2	NMCLR	Reset	—
3	PA4	UART Request to Send (RTS)	O
4	VDD_A	AVDD Power Supply Input	—
5	GND	Ground	—
6	PA11/SOSCI	Reserved. No Connect	—
7	PA12/SOSCO	Reserved. No Connect	—
8	Ground	GND	—
9	PB5⁽¹⁾	Bluetooth® status LED	O
10	PA3⁽¹⁾	PTA control (BT_ACTIVE)	O
11	PB4⁽¹⁾	UART transmit indication pin	O
12	PB6	UART receive data	I
13	PB8⁽¹⁾	Bluetooth Low Energy status indication pin 2/2	O
14	PB9	UART receive indication pin/RNBD350 wake-up pin Low-power mode	I
15	PB7	Dedicated ADC pin for Host MCU to query ADC value	I
16	VDD	VDD power supply input	—
17	VDD	VDD power supply input	—
18	GND	Ground	—
19	PA5	UART transmit data	O
20	PA6	UART Clear to Send (CTS)	I
21	GND	Ground	—
22	PA9⁽¹⁾	PTA control (BT_PRIORITY)/UART mode switch	I
23	PA10⁽²⁾	Bluetooth Low Energy status indication pin 1/2	O
24	PA8⁽²⁾	PTA control (WLAN ACTIVE)	I
25	PA7	Debug UART receive data	O
26	NC	No Connect	—
27	GND	Ground	—
28	NC	No Connect	—
29	NC	No Connect	—
30	NC	No Connect	—
31	EP_PAD	Ground	—
Note: The priority of the PTA function is higher than that of the mode switch function. The priority of the PTA function is higher than that of the event indicator function. It is recommend to have a 10K pull-up resistor on the UART TXD pin (PA5). For reference, see Application Reference Schematics. For serial DFU updates, the UART pins PB6 (UART receive data) and PA5 (UART transmit data) are used.