Datasheet RN4678 (Microchip) - 11

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RN4678 2.8 LED Driver
The following are the LED status indications. Each indi- cation is a configurable flashing sequence: The RN4678 has a dedicated LED driver and the LED can be connected directly to this pin, as shown in • Standby Figure 2-7. • Link Back The maximum current sourcing for the LED is 5 mA. • Low Battery The brightness of this LED can be configured via an • Inquiry ASCII command. • Link
FIGURE 2-7: LED DRIVER 2.9 Host MCU Interface over UART
Figure 2-8 illustrates an example of UART interface with host MCU and power scheme using 3.3V to the LDO33_O VDD. From the LDO33_O pin, voltage can be routed to the VDD_IO pin and the external circuitry including the MCU. This power scheme ensures that the RN4678 RN4678518 and the MCU I/O voltages are compatible. Module LED1
Note:
The internal 3.3V LDO current source must not exceed 50 mA (maximum).
FIGURE 2-8: POWER AND MCU INTERFACE EXAMPLE FOR RN4678
3.3V (3.3V to 4.2V) BAT_IN P1_5/STATUS_IND_1 I/O VDD P0_4/UART_TX_IND/STATUS_IND_2 I/O 10uF SW_BTN I/O LDO33_O
RN4678
WAKE_UP I/O
MODULE
RST_N I/O I/O LDO18_O P3_7
HOST
P3_4 I/O
MCU
P3_3 I/O Note:2 P3_2 I/O VDD_IO P3_1 I/O (Note:1) P0_5 I/O P0_0/RTS CTS P1_7/CTS RTS LED TXD RX RXD TX P2_0 P2_4 EAN System Configuration
Note 1:
Ensure that VDD_IO and MCU VDD voltages are compatible.
2:
The control and indication ports are configurable.  2016-2020 Microchip Technology Inc. DS50002519E-page 11 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