Datasheet

Page 19 of 161
nRF8001 Product Specification
Revision 1.2
6.3 DC/DC converter
nRF8001 incorporates linear supply voltage regulators and an optional step-down DC/DC converter. The
internal linear regulators are always enabled. When enabled, the step-down DC/DC converter transforms
the battery voltage to a lower internal voltage with minimal power loss. The converted voltage is then fed to
the input of the linear regulators.
This feature is particularly useful for applications using battery technologies with higher nominal cell
voltages. The reduction in supply voltage level from a high voltage to a low voltage reduces the peak
power drain from the battery. Used with a 3 V coin cell battery, the peak current drawn from the battery is
reduced by approximately 20%.
The DC/DC converter is functional only when operating from the internal 32.768 kHz RC oscillator (see
Section 6.2.5 on page 18
) or from an external 32.768 kHz digital rail-to-rail clock (see Section 6.2.6 on
page 18).
Figure 6.
illustrates the peak current reduction in percentage (%) using the values for I
RX_DC
and I
TX_DC
in
Table 15 on page 37
.
Figure 6. Relative current consumption over supply voltage with DC/DC converter enabled
Note: Three external passive components are required in order to use the step-down converter. See
Chapter 17 on page 51
for details on schematics, layout and BOM for the two power supply
alternatives.
6.3.1 Enabling the DC/DC converter
You can enable the DC/DC converter through nRFgo Studio, see Part B, section 22.3 on page 81.
60
65
70
75
80
85
90
95
100
2,3 2,4 2,5 2,6 2,7 2,8 2,9 3,0 3,1 3,2
Supply current [%]
Supply voltage [V]
I(VDD)