SWRU612 December   2023 CC3300 , CC3301 , CC3301MOD , CC3351

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Overview
  5. 2Schematic Considerations
    1. 2.1 Schematic Reference Design
    2. 2.2 Power Supply
      1. 2.2.1 Power Input/Output Requirements
      2. 2.2.2 Power-Up Sequence
        1. 2.2.2.1 SOP Modes
    3. 2.3 Clock Source
      1. 2.3.1 Fast Clock
      2. 2.3.2 Slow Clock
        1. 2.3.2.1 Slow Clock Generated Internally
        2. 2.3.2.2 Slow Clock Using an External Oscillator
    4. 2.4 Radio Frequency (RF)
    5. 2.5 Digital Interfaces
      1. 2.5.1 Reset
      2. 2.5.2 Secure Digital Input Output (SDIO)
        1. 2.5.2.1 SDIO Timing Diagram - Default Speed
        2. 2.5.2.2 SDIO Timing Diagram - High Speed
      3. 2.5.3 Serial Peripheral Interface (SPI)
        1. 2.5.3.1 SPI Timing Diagram
      4. 2.5.4 Universal Asynchronous Receiver-Transmitter (UART)
      5. 2.5.5 Serial Wire Debug (SWD)
      6. 2.5.6 Coexistence
  6. 3Layout Considerations
    1. 3.1 Layout Reference Design
      1. 3.1.1 Reference Design Layout
      2. 3.1.2 BP-CC3301 Design Layout
      3. 3.1.3 M2-CC3301 Design Layout
    2. 3.2 IC Thermal Pad
    3. 3.3 Radio Frequency (RF)
    4. 3.4 XTAL
    5. 3.5 Power Supplies
    6. 3.6 SDIO

2.3.2.2 Slow Clock Using an External Oscillator

For optimal power consumption, the slow clock can be generated externally by an oscillator or sourced from elsewhere in the system. The external source must meet the requirements shown in Table 2-4. This clock should be fed into the CC330x pin Slow_CLK_IN and should be stable before nReset is deasserted and device is enabled.

Table 2-4 External Slow Clock Requirements
Parameter Description MIN TYP MAX Unit
Input slow clock frequency Square wave 32768 Hz
Frequency accuracy Inital + temperature + aging ±250 ppm
Input Duty cycle 30 50 70 %
Tr/Tf Rise and fall time 10% to 90% (rise) and 90% to 10% (fall) of digital signal level 100 ns
VIL Input low level 0 0.35 x VIO V
VIH Input high level 0.65 x VIO 1.95 V
Input impedence 1 MΩ
Input capacitance 5 pF