DA14580
FINAL
Bluetooth Low Energy 4.2 SoC
DC‐DC Efficiency vs Voltage
95%
90%
85%
80%
75%
70%
65%
60%
55%
50%
0.9
1.8
2.35
0
0.5
1
1.5
2
2.5
3
3.5
Buck
Boost
Boost (Vout > 1.4 V)
Figure 10: DC-DC Efficiency in Buck/Boost Mode at
Various Voltage Levels
The X axis represents the supply voltage. BOOST
mode should be used when voltage ranges from 0.9 V
to 2.0 V to sustain a decent efficiency over 70 %. From
that point on, the power dissipation becomes quite
large.
BUCK mode can operate correctly with voltages in the
range of 2.35 V to 3.3 V.
There are two voltage areas in Figure 10 designated by
dashed lines. The first one (0 V to 0.9 V) indicates that
the DA14580 is not operational when the voltage is
below 0.9 V. This is the absolute threshold for the DC-
DC converter Boost mode.
The second area (1.8 V to 2.2 V) indicates that Deep
Sleep mode is not allowed when the DC-DC converter
is configured in BUCK mode and the voltage is within
this range, because the OTP will not be readable any
more. However, this part of the voltage range can be
covered by the BOOST mode. Furthermore, when
BUCK mode is mandatory, Extended Sleep mode can
be activated instead of Deep Sleep mode, thus not
using the OTP for the code mirroring but retain the
code in SysRAM.
Note: The system should never be cold booted when
the supply voltage is less than 2.5 V. A manual power
up with a power supply less than 2.5 V in buck mode
might create instability.
Datasheet
Revision 3.4
09-Nov-2016
CFR0011-120-00-FM
17 of 155
© 2014 Dialog Semiconductor
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