Datasheet RN4678 (Microchip) - 6

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RN4678 2.0 APPLICATION INFORMATION
the RN4678, the CTS (RN4678 input pin) must be pulled high. The RN4678 pul s the RTS pin (output pin)
2.1 Module Configuration
low to indicate that it can accept data. For the I/O pins, P2_0, P2_4 and EAN, place the
2.3 Control and Indication I/O Pins
RN4678 into Operating mode. Each of these pins have internal pull-up and allow configuration settings and The GPIO pins of the RN4678 module can be firmware to be updated from UART. Table 2-1 provides configured to different functions using the ASCII system configuration details. command interface. Table 2-2 shows the various pins in the RN4678 module that are available for
2.2 Flow Control
configuration and their default configuration settings. Table 2-3 provides details on each of the functions Flow control is enabled by default on the RN4678 available. module. With the flow control enabled, the RTS and CTS lines need to be connected to the corresponding lines for the module to operate. To pause data flow from
TABLE 2-1: SYSTEM CONFIGURATION SETTINGS P2_0 P2_4 EAN Operational Mode
Low Low High Write FLASH Low High Low Write EEPROM and Test mode High High Low Normal Operational/Application mode
TABLE 2-2: CONTROL AND INDICATION I/O PIN ASSIGNMENTS

PIN Symbol Default Configuration
P0_0 UART_RTS
(1,2 )
P0_5 N/C P1_7 UART_CTS
(1 ,2 )
P3_1 INQUIRY CONTROL P3_2 LINK_DROP_CONTROL (DISCONNECT) P3_3 UART_RX_IND P3_4 PAIRING_KEY P3_7 LOW_BATTERY_IND
Note 1:
The RTS pin can only be assigned to P0_0 and the CTS pin can only be assigned to P1_7.
2:
The RTS and CTS pins can be configured as GPIOs if flow control is disabled.
TABLE 2-3: CONFIGURABLE FUNCTIONS AND DESCRIPTIONS Function Name Description
Low Battery Indication Pin output goes low when the battery level is below a specified level. Default battery low indication voltage level is 3.4V RSSI Indication Use this pin to indicate the quality of the link based on the RSSI level. If the RSSI level is lower than the specified values, then the RSSI indication pin goes low. Link Drop Control Use this pin to force the module to drop the current BLE link with a peer device. Pulling the Link Drop pin low forces to disconnect. The pin must be pulled low for at least 10 ms.  2016-2020 Microchip Technology Inc. DS50002519E-page 6 Document Outline RN4678 Features RF/Analog Data Throughput Operating Conditions MAC/Baseband/Higher Layer Features Applications Description Table of Contents Most Current Data Sheet Errata Customer Notification System 1.0 Device Overview FIGURE 1-1: RN4678 Internal Block Diagram TABLE 1-1: PIN Description FIGURE 1-2: RN4678 PIN DIAGRAM 2.0 Application Information 2.1 Module Configuration 2.2 Flow Control 2.3 Control and Indication I/O Pins 2.4 Power Tree FIGURE 2-1: Power Tree Diagram 2.5 Software Button (SW_BTN) FIGURE 2-2: SW_BTN TIME (HIGH) AT APP MODE(1,2) FIGURE 2-3: SW_BTN TIME (LOW) AT ACCESS STATES(1) FIGURE 2-4: SW_BTN TIME (LOW) AT LINK STATES(1,2) 2.6 WAKE-UP FIGURE 2-5: WAKE-UP TIME(1) 2.7 External Reset FIGURE 2-6: TIMING WAVEFORMS ON RESET (1,2) 2.8 LED Driver FIGURE 2-7: LED Driver 2.9 Host MCU Interface over UART FIGURE 2-8: Power and MCU Interface Example for Rn4678 2.10 Reference Circuit FIGURE 2-9: RN4678 Reference Circuit 3.0 Electrical Characteristics Absolute Maximum Ratings TABLE 3-1: Recommended Operating Conditions TABLE 3-2: 3.3V LDO Electrical Parameters (1,2) TABLE 3-3: PMU LDO(1,2) TABLE 3-4: SAR-ADC AND Battery Voltage Detector TABLE 3-5: Intensity Controllable LED Driver TABLE 3-6: Power Consumption-Classic(1) TABLE 3-7: Power Consumption-Low Energy(1,2) 4.0 Radio Characteristics TABLE 4-1: Transmitter Performance (1,2) TABLE 4-2: Receiver Performance(1) 5.0 Physical Dimensions FIGURE 5-1: RN4678 Module Dimensions FIGURE 5-2: RN4678 Recommended PCB Footprint FIGURE 5-3: RN4678 Host PCB Mounting Suggestion 6.0 Reflow profile FIGURE 6-1: Reflow Profile 7.0 Module Placement FIGURE 7-1: Module Placement Examples TABLE 7-1: Recommended Antenna FIGURE 7-2: Keep Out Area Recommended for Antenna 7.1 RN4678 Ceramic Chip Antenna FIGURE 7-3: RN4678 Antenna Radiation Pattern 8.0 Ordering Information TABLE 8-1: Ordering Information 9.0 Regulatory Approval 9.1 United States 9.2 Canada 9.3 Europe TABLE 9-1: EUROPEAN COMPLIANCE TESTING 9.4 Japan 9.5 Korea 9.6 Taiwan 9.7 China 9.8 Other Regulatory Information Appendix A: Revision History The Microchip WebSite Product Identification System Trademarks Worldwide Sales