AN725
Rev. 0.1
5
4.6. DC-DC Load and Power Efficiency
The DCDC0 module on SiM3L1xx devices is a dc-dc buck converter with an input range of 1.8 to 3.8 V and an
output range of 1.25 to 3.8 V. The efficiency of this regulator changes based on load and the converter
configuration, as shown in Figure 4. The converter configuration can be changed dynamically or bypassed
according to the anticipated demands of the application to maintain the highest power efficiency and reduce power
consumption.
Figure 4. Reducing Power Consumption with the DC-DC Buck Converter
There are three ranges of operation for the dc-dc converter corresponding to three different load sizes:
1. Loads less than 5 mA
2. Loads between 5 and 15 mA
3. Loads greater than 15 mA
When operating with loads less than 5 mA, the dc-dc converter is most efficient when configured for light loads:
1. Power switch size set to 0 (PSMD = 0)
2. Asynchronous mode enabled (ASYNCEN = 1)
3. Minimum pulse width set to 40 ns (MINPWSEL = 3)
For loads between 5 and 15 mA, the converter should be set in a middle configuration:
1. Power switch size set to 0 (PSMD = 0)
2. Synchronous mode enabled (ASYNCEN = 0)
3. Minimum pulse width disabled (MINPWSEL = 0)
Current (mA)
P
o
w
er Efficienc
y
(%)
50%
55%
60%
65%
70%
75%
85%
80%
0
10
20
30
40
50
90%
100
90
80
70
60
Configured for Low Loads
Configured for High Loads
