The 22 nm process node plays a role, but the power consumption improvements of the nRF54L Series result from a holistic and deliberate focus on system-level power consumption in the design of the wireless SoC/MCU. With low-power design expertise built up over decades, our engineers prioritize low power throughout, including ultra-low-power oscillators with fast start-up times, SRAM designed for low leakage, faster radio ramp-up and switching, and a Global RTC capable of running in System OFF, the deepest sleep mode. Our developers also focus on low-power software, including optimized drivers and wireless protocol stacks.
This blog post provides an overview to help you evaluate the nRF54L Series in terms of power consumption. Since the nRF54L Series is the next-level continuation of the nRF52 Series, we’ll compare it with the nRF52840 SoC. The improvements should be similar for other nRF52 Series SoCs, including the popular nRF52832. All wireless SoCs in the nRF54L Series have the same power consumption characteristics, with only minor differences related to how much RAM they can retain, as RAM size varies. The information should also be helpful when comparing it with other wireless SoCs/MCUs in production, sampling, or planning to be sampled.
We’ll first examine improvements related to the MCU functionality, followed by radio, Bluetooth LE, and Matter. Lastly, we’ll cover how you can easily take your own measurements.
MCU improvements
Processing efficiency
|
Scenario |
Delta |
||
|---|---|---|---|
|
CPU running CoreMark |
2.6 mA |
3.3 mA |
-21 % |
|
Processing efficiency |
20 µA/MHz (CPU running CoreMark from |
52 µA/MHz (CPU running CoreMark |
-62 % |
The nRF54L Series doubles the CPU clock speed to 128 MHz while reducing active current by 21%, from 3.3 mA to 2.6 mA. It also delivers a significant 62% improvement in processing efficiency, calculated in µA/MHz. These improvements are especially beneficial for more compute-intensive applications, where more processing can be done in less time, allowing the system to return to sleep more quickly and reducing average current consumption.
Sleep
|
Scenario |
Delta |
||
|---|---|---|---|
|
System ON, 256 KB RAM retention |
3.0 µA |
2.35 µA |
+28 % |
|
System ON, no RAM retention |
0.7 µA |
0.97 µA |
-28 % |
|
System OFF with Global RTC wakeup |
0.8 µA |
N/A* |
N/A |
|
System OFF |
0.6 µA |
0.4 µA |
+50 % |
*For nRF52840, the RTC is unavailable in System OFF, and the alternative is 1.5 µA in System ON with RTC wakeup.
While the nRF54L Series significantly reduces active and idle current in several key scenarios, some values are higher than on the nRF52840. This is primarily due to increased leakage associated with the 22 nm process node, which can result in slightly higher sleep current in specific scenarios. However, the nRF54L Series also introduces new capabilities like Global RTC in System OFF, which offers lower current than the alternatives available on nRF52840 and enables deeper sleep in more use cases.
Radio improvements
|
Scenario |
Delta |
||
|---|---|---|---|
|
Bluetooth LE TX 1 Mbps 8 dBm |
9.8 mA |
16.4 mA |
-40 % |
|
Bluetooth LE TX 1 Mbps 0 dBm |
4.8 mA |
6.4 mA |
-25 % |
|
Bluetooth LE RX 1 Mbps |
3.4 mA |
6.4 mA |
-47 % |
The nRF54L Series substantially improves radio power consumption across both transmit and receive modes. Even when transmitting at 8 dBm, current consumption is reduced by 40% compared to the nRF52840, and RX current is nearly halved. These improvements become even more significant in applications where the radio is active frequently or for extended periods.
Bluetooth LE and Matter improvements
To compare power consumption for Bluetooth LE or Matter over Thread, we recommend using the Online Power Profiler for Bluetooth LE or the Online Power Profiler for Matter. Open two browser windows of the same profiler, select nRF54L15 in one and nRF52840 in the other, set your desired parameters, and compare current consumption directly. For Bluetooth LE, we’ve included some example scenarios in the table below.
|
Scenario |
nRF54L Series |
nRF52840 |
Delta |
|---|---|---|---|
|
Unchanged advertising (TX/RX) settings |
45 µA |
94 µA |
-52 % |
|
Unchanged advertising (TX/RX) settings, |
63 µA |
129 µA |
-51 % |
|
Unchanged advertising (TX/RX) settings, |
109 µA |
204 µA |
-47 % |
|
Unchanged connection (Peripheral) settings |
26 µA |
48 µA |
-46 % |
|
Unchanged connection (Peripheral) settings, |
30 µA |
55 µA |
-46 % |
|
Unchanged connection (Peripheral) settings, |
46 µA |
81 µA |
-43 % |
These Bluetooth LE scenarios show that the nRF54L Series roughly cuts average current consumption by about half compared to the nRF52840. The more the radio is used, the greater the improvement.
Pairing an nPM Family PMIC with the nRF54L Series
For some designs, pairing the nRF54L Series with an nPM Family PMIC can further reduce system power consumption through efficient power regulation and power-saving features integrated in the PMICs, such as ship mode and hibernate mode. Check out our PMIC landing page to learn more.
Next steps
The next step is to get your hands on an nRF54L15 DK and do your measurements using a tool like Power Profiler Kit II, an affordable kit for measuring power consumption. For Bluetooth LE, we recommend starting with the Peripheral power profiling sample, which is included in the nRF Connect SDK. This sample allows you to measure power consumption when the Bluetooth LE stack is used for communication. You should see results close to the estimated results; if not, we recommend contacting technical support on DevZone.
For more power consumption–related information about Matter over Thread, we recommend our Matter over Thread: Power Consumption and Battery Life white paper, specifically the chapter Estimation of Annual Power Consumption and Battery Lifetime, as well as the Developing Low-Power Matter Devices with nRF54L Series on-demand webinar.
We hope this was a helpful overview of the nRF54L Series’ power consumption improvements and that it helps you select the right wireless SoC for your next IoT product.
