Datasheet

RN4678
DS50002519D-page 8  2016-2019 Microchip Technology Inc.
2.4 Power Tree
Figure 2-1 illustrates the power tree diagram of the RN4678.
FIGURE 2-1: POWER TREE DIAGRAM
UART RX Indication Use this pin to enable communication with the UART when the module is in
Low-Power mode. When not in Low-Power mode, the module runs on a 16
MHz clock. If Low-Power mode is enabled on the module by using
command SO,1, the module runs on a 32 kHz clock thus reducing power
consumption. However, in Low-Power mode, the host MCU cannot
communicate with the module via the UART since the UART is not
operational. If the user intends to provide data or commands via UART in
the Low-Power mode, then the UART_RX_IND pin must be pulled low and
the user needs to wait for at least five milliseconds before sending the data.
Pulling the UART_RX_IND pin low allows the module to operate the 16
MHz clock and to enable UART.
Pairing Key Use this pin to force the module to enter Standby mode. The pin must be
pulled down for at least 160 ms.
Inquiry Control This pin forces the module enter Inquiry mode (BT Classic). The pin must
be pulled low for at least 240 ms for the device to enter Inquiry mode.
Profile_IND This pin is used to indicate whether current connection is in BR/EDR (BT
Classic), or in Bluetooth Low Energy (BLE). If the Profile_IND pin is high,
then the current connection is BR/EDR connection. If low, then the current
connection is a BLE connection. This pin is valid only for Link State.
Function Name Description
BAT_IN
3.3v˜4.2v
LDO33
PMU Logic
VCC_RF
AVDD_SAR
VDD_XO
VDD_IO
LED
EEPROM
LDO18
PMULDO
o
LDO33_EN
LDO18_EN 1v8
3v3
SW_BTN