CC1070-RTR1 datasheet(33/57 Pages) TI2

33 / 57 page

CC1070

SWRS043A

Page 33 of 54

16 Power Management

CC1070 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 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. Figure 18 shows a

typical

power-on

and

initializing

sequences

for

minimum

power

consumption.

Figure 19 shows a typical sequence for

activating TX mode from power down

mode for minimum power consumption.

Note that 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 pull-up resistor.

TI recommends resetting the

CC1070 (by

clearing the RESET_N bit in the MAIN

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

CC1070 should then

be calibrated. After this is completed, the

CC1070 is ready for use. See the detailed

procedure flowcharts in Figure 17 - Figure

19.

Application Note AN023 CC1020 MCU

Interfacing provides source code for

CC1020. This source code can be used as

a starting point when writing source code

for

CC1070 .

Power Down mode

Power Off

Reset CC1070

MAIN:

PD_MODE = 1, FS_PD = 1,

XOSC_PD = 1, BIAS_PD = 1,

RESET_N = 0

Calibrate VCO and PLL

MAIN: PD_MODE = 1,

FS_PD = 1, XOSC_PD = 1,

BIAS_PD = 1

PA_POWER = 00h

MAIN: FREG = 0

Program all necessary registers

except MAIN and RESET

MAIN: RESET_N = 1

Turn on crystal oscillator, bias

generator and synthesizer

successively

Turn on power