SWRS128 June   2014 CC2541-Q1

PRODUCTION DATA.  

  1. 1Device Overview
    1. 1.1 Features
    2. 1.2 Applications
    3. 1.3 Description
    4. 1.4 Functional Block Diagram
  2. 2Revision History
  3. 3Terminal Configuration and Functions
    1. 3.1 Pin Diagram
    2. 3.2 Pin Descriptions
  4. 4Specifications
    1. 4.1  Absolute Maximum Ratings
    2. 4.2  Handling Ratings
    3. 4.3  Recommended Operating Conditions
    4. 4.4  Thermal Characteristics for RHA Package
    5. 4.5  Electrical Characteristics
    6. 4.6  General Characteristics
    7. 4.7  RF Receive Section
    8. 4.8  RF Transmit Section
    9. 4.9  32-MHz Crystal Oscillator
    10. 4.10 32.768-kHz Crystal Oscillator
    11. 4.11 32-kHz RC Oscillator
    12. 4.12 16-MHz RC Oscillator
    13. 4.13 RSSI Characteristics
    14. 4.14 Frequency Synthesizer Characteristics
    15. 4.15 Analog Temperature Sensor
    16. 4.16 Comparator Characteristics
    17. 4.17 ADC Characteristics
    18. 4.18 DC Characteristics
    19. 4.19 Control Input AC Characteristics
    20. 4.20 SPI AC Characteristics
    21. 4.21 Debug Interface AC Characteristics
    22. 4.22 Timer Inputs AC Characteristics
    23. 4.23 Typical Characteristics
  5. 5Detailed Description
    1. 5.1 Functional Block Diagram
    2. 5.2 Block Descriptions
      1. 5.2.1 CPU and Memory
      2. 5.2.2 Peripherals
  6. 6Application Information
    1. 6.1 Input/Output Matching
    2. 6.2 Crystal
    3. 6.3 On-Chip 1.8-V Voltage Regulator Decoupling
    4. 6.4 Power-Supply Decoupling and Filtering
  7. 7Device and Documentation Support
    1. 7.1 Documentation Support
      1. 7.1.1 Related Documentation
        1. 7.1.1.1 Additional Information
        2. 7.1.1.2 Texas Instruments Low-Power RF Website
        3. 7.1.1.3 Texas Instruments Low-Power RF Developer Network
        4. 7.1.1.4 Low-Power RF eNewsletter
    2. 7.2 Trademarks
    3. 7.3 Electrostatic Discharge Caution
    4. 7.4 Glossary
  8. 8Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

6 Application Information

Few external components are required for the operation of the CC2541-Q1. A typical application circuit is shown in Figure 6-1.

CC2541Q1_App_Circuit_SWRS128.gif
(1) 32-kHz crystal is mandatory when running the BLE protocol stack in low-power modes, except if the link layer is in the standby state (Vol. 6 Part B Section 1.1 in [1]).
NOTE: Different antenna alternatives will be provided as reference designs.
Power supply decoupling capacitors are not shown
. Digital I/O not connected
Figure 6-1 CC2541-Q1 Application Circuit

Table 6-1 Overview of External Components (Excluding Supply Decoupling Capacitors)

Component Description Value
C401 Decoupling capacitor for the internal 1.8-V digital voltage regulator 1 µF
R301 Precision resistor ±1%, used for internal biasing 56 kΩ

6.1 Input/Output Matching

When using an unbalanced antenna such as a monopole, a balun should be used to optimize performance. The balun can be implemented using low-cost discrete inductors and capacitors. See reference design, CC2541-Q1EM, for recommended balun.

6.2 Crystal

An external 32-MHz crystal, XTAL1, with two loading capacitors (C221 and C231) is used for the 32-MHz crystal oscillator. See Section 4.9 for details. The load capacitance seen by the 32-MHz crystal is given by:

Equation 1. E001_SWRS128.gif

XTAL2 is an optional 32.768-kHz crystal, with two loading capacitors (C321 and C331) used for the 32.768-kHz crystal oscillator. The 32.768-kHz crystal oscillator is used in applications where both very low sleep-current consumption and accurate wake-up times are needed. The load capacitance seen by the 32.768-kHz crystal is given by:

Equation 2. E002_SWRS128.gif

A series resistor may be used to comply with the ESR requirement.

6.3 On-Chip 1.8-V Voltage Regulator Decoupling

The 1.8-V on-chip voltage regulator supplies the 1.8-V digital logic. This regulator requires a decoupling capacitor (C471) for stable operation.

6.4 Power-Supply Decoupling and Filtering

Proper power-supply decoupling must be used for optimum performance. The placement and size of the decoupling capacitors and the power supply filtering are very important to achieve the best performance in an application. TI provides a compact reference design that should be followed very closely.