CC1000
SWRS048A Page 28 of 55
18. 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 CURRENT
register are shown in the tables on page
41.
The bias current for the LNA, and the LO
and PA buffers are also programmable.
Table 10 shows the current consumption
and receiver sensitivity for different
settings (2.4 kBaud Manchester encoded
data).
CURRENT register FRONT_END register RF freq-
uency
[MHz]
Current
consumption
[mA]
Sensitivity
[dBm]
VCO_
CURRENT
[3:0]
LO_DRIVE
[1:0]
PA_DRIVE
[1:0]
BUF_CUR
RENT
LNA_CUR
RENT[1:0]
433 9.3 -110 0100 01 00 0 10
433 7.4 -109 0100 00 00 0 00
868 11.8 -107 1000 11 00 1 10
868 9.6 -105 1000 10 00 0 00
Note: Current consumption and sensitivity are typical figures at 2.4 kBaud Manchester encoded data, BER 10
-3
Table 10. Receiver sensitivity as function of current consumption
19. Power management
CC1000
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
synthesiser and the crystal oscillator (see
page 39). This individual control can be
used to optimise for lowest possible
current consumption in a certain
application.
A typical power-on and initialising
sequence for minimum power
consumption is shown in Figure 18 and
Figure 19.
PALE 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.
PA_POW should be set to 00h before
power down mode to ensure lowest
possible leakage current.
