Reference circuitry

To ensure good RF performance when designing PCBs, it is highly recommended to use the PCB layouts and component values provided by Nordic Semiconductor.

Documentation for the different package reference circuits, including Altium Designer files, PCB layout files, and PCB production files can be downloaded from www.nordicsemi.com.

In this section, there are reference circuits for all product variants, showing the components and component values to support on-chip features in a design.

Circuit configuration 1 for CSP98 (PAAA)

Table 1. Configuration summary for circuit configuration no. 1
Config no.Supply configurationEnabled features
VDDUSBNFC
Config. 1DCDC: supplied by battery or external supplyYesNo
Figure 1. Circuit configuration no. 1 schematic


The reference schematic shows the USB supply path, including the on-chip USB regulator and the decoupling and tuning components required at the USB pins (VBUS, DECUSB, D+, D-, and TXRTUNE). ESD and overvoltage protection components on the USB interface are not shown in this schematic. For a USB connector that may be exposed to ESD or overvoltage, the design must add appropriate protection on the VBUS and data lines in addition to the components shown here.

Note: For PCB reference layouts, see the product page for the nRF54LM20A and nRF54LM20B on www.nordicsemi.com.
Table 2. Bill of material for circuit configuration no. 1
DesignatorValueDescriptionFootprint
C1, C2, C5100 nFCapacitor, X7R, ±10%0201
C31.2 pFCapacitor, NP0, 50 V, ±0.05pF0201
C410 µFCapacitor, X6S, 6.3 V, ±20%0402
C64.7 µFCapacitor, X5R, 6.3 V, ±20%0201
C7, C13NCNot mounted0201
C81.0 pFCapacitor, C0G/NP0, 25 V0201
C10, C142.2 µFCapacitor, X6T, 2.5 V, ±20 %0201
C114.7 µFCapacitor, X5R, 10 V0402
C121.5 pFCapacitor, NP0, ±0.05 pF, 25V, High Q0201
FB1120 ΩFerrite bead, 120 Ω at 100 MHz, 200 mA, 500 mΩ max0201
L14.7 µHInductor, 120 mA, ±20%, 0.65 Ω0603
L23.6 nHInductor, 500 mA, ±0.1 nH, 170 mΩ0201
L34.7 nHInductor, 300 mA, ±3%, 250 mΩ0201
L43.3 nHInductor, 500 mA, ±0.1 nH, 170 mΩ0201
L51.0 nHInductor, 750 mA, ±0.2 nH0201
R12.2 ΩResistor, ±1%, 0.05 W0201
R2200 ΩResistor, ±1%, 0.05 W0201
U1nRF54LM20A-PAAAMultiprotocol Bluetooth® Low Energy, IEEE 802.15.4, and 2.4GHz proprietary System on ChipCSP98
X132 MHzCrystal SMD 2016, 32 MHz, Cl = 8 pF, Total Tol: ±40 ppm. For frequency tolerance requirements, see 32 MHz crystal oscillator (HFXO).XTAL_2016
X232.768 kHzCrystal SMD 2012, 32.768 kHz, Cl = 9 pF, Total tol: ±20 ppmXTAL_2012

PCB layout example

The PCB layout in the following figure is a reference layout for Circuit configuration 1 for CSP98 (PAAA).

For all available reference layouts, see the product pages for nRF54LM20A and nRF54LM20B on www.nordicsemi.com.

Figure 2. Top silk layer


Figure 3. Top layer


Figure 4. Mid layer 1


Figure 5. Mid layer 2


Figure 6. Mid layer 3


Figure 7. Mid layer 4


Figure 8. Mid layer 5


Figure 9. Mid layer 6


Figure 10. Bottom layer


PMIC support

The nRF54L Series is comprehensively supported by Nordic Semiconductor's own range of PMICs (Power Management Integrated Circuits). These PMICs are meticulously designed to enhance the performance and efficiency of the nRF54L Series devices. This integration ensures the longest battery life and the highest reliability for the end application. The synergy between the nRF54L Series and the Nordic PMICs highlights Nordic Semiconductor's commitment to providing a complete and cohesive solution for their customers' needs in wireless technology applications.