SWRS046H – NOVEMBER 2006 – REVISED MARCH 2015
5.13 VCO and LNA Current Control
The VCO current is programmable and should be set according to operating frequency, RX/TX mode and
output power. Recommended settings for the VCO_CURRENT bits in the VCO register are shown in
and are also given by SmartRF Studio. The VCO current for frequency FREQ_A and FREQ_B
can be programmed independently.
The bias currents for the LNA, mixer and the LO and PA buffers are also programmable. The FRONTEND
and the BUFF_CURRENT registers control these currents.
5.14 Power Management
CC1020 offers great flexibility for power management in order to meet strict power consumption
requirements in battery-operated applications. Power down mode is controlled through the MAIN register.
There are separate bits to control the RX part, the TX part, the frequency synthesizer and the crystal
oscillator in the MAIN register. This individual control can be used to optimize for lowest possible current
consumption in each application.
shows a typical power-on and initializing sequence for
minimum power consumption.
shows a typical sequence for activating RX and TX mode from power down mode for
minimum power consumption.
NOTE
PSEL should be tri-stated or set to a high level during power down mode in order to prevent
a trickle current from flowing in the internal pullup resistor.
Application Note
AN023 CC1020 MCU Interfacing
) includes example source code.
TI recommends resetting the CC1020 (by clearing the RESET_N bit in the MAIN register) when the chip is
powered up initially. All registers that need to be configured should then be programmed (those which
differ from their default values). Registers can be programmed freely in any order. The CC1020 should
then be calibrated in both RX and TX mode. After this is completed, the CC1020 is ready for use. See the
detailed procedure flowcharts in
through
.
With reference to Application Note
AN023 CC1020 MCU Interfacing
), TI recommends the
following sequence:
After power up:
1. ResetCC1020
2. Initialize
3. WakeUpCC1020ToRX
4. Calibrate
5. WakeUpCC1020ToTX
6. Calibrate
After calibration is completed, enter TX mode (SetupCC1020TX), RX mode (SetupCC1020RX) or power
down mode (SetupCC1020PD).
From power-down mode to RX:
1. WakeUpCC1020ToRX
2. SetupCC1020RX
Copyright © 2006–2015, Texas Instruments Incorporated
Detailed Description
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