SLUUDH6 April   2026 CC3501E , CC3551E

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Overview
  5. 2Schematic Considerations - CC35xxE IC
    1. 2.1 Schematic Reference Design
    2. 2.2 Power Supply
      1. 2.2.1 Power Input/Output Requirements
        1. 2.2.1.1 LDO Recommendations
      2. 2.2.2 Boot Sequence
        1. 2.2.2.1 Hosted Mode (Power up by reset pin)
        2. 2.2.2.2 Standalone Mode (Power up when supply above threshold)
        3. 2.2.2.3 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
        3. 2.3.2.3 Slow Clock Using an External Crystal (XTAL)
    4. 2.4 Radio Frequency (RF)
    5. 2.5 Digital Interfaces
      1. 2.5.1 xSPI
        1. 2.5.1.1 External Serial Flash
      2. 2.5.2 Serial Wire Debug (SWD)
      3. 2.5.3 Logger
      4. 2.5.4 Coexistence
    6. 2.6 Stacked PSRAM Variant
  6. 3Layout Considerations - CC35xxE IC
    1. 3.1 Layout Reference Design
      1. 3.1.1 Reference Design - CC355xE Dual Band 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 External Flash Layout

2.3.2.2 Slow Clock Using an External Oscillator

For optimal power consumption, the slow clock can be generated externally by an oscillator, XTAL, or sourced from elsewhere in the system. If using an oscialltor, the external source must meet the requirements listed below. This clock should be fed into the CC35xxE pin Slow_CLK_IN/ GPIO0 and should be stable before nReset is deasserted and device is enabled. The clock signal logic high should be the same voltage as VIO1 IO Ring.

Table 2-4 External Slow Clock Requirements
ParameterDescriptionMINTYPMAXUnit
Input slow clock frequencySquare wave32.768kHz
Frequency accuracyInital + temperature + aging±250ppm
Input Duty cycle30%50%70%
Tr/TfRise and fall time10% to 90% (rise) and 90% to 10% (fall) of digital signal level100ns
Input impedence1MΩ
Input capacitance5pF