JN517X Datasheet, PDF (27/100 Pages) NXP Semiconductors – Supports multiple network stacks

NXP Semiconductors
JN517x
IEEE802.15.4 Wireless Microcontroller
The JN517x radio when enabled is automatically calibrated for optimum performance. In
operating environments with a significant variation in temperature (e.g. greater than
20 C) due to diurnal or ambient temperature variation, it is recommended to recalibrate
the radio to maintain performance. Recalibration is only required on devices that never
sleep. Devices which sleep or deep sleep are automatically recalibrated when they wake.
A dedicated Application Note, Temperature Dependent Operating Guidelines JN-AN-1186
on the Wireless Connectivity area of the NXP web site Ref. 2, describes this in detail and
includes a software API function which can be used to test the temperature using the
on-chip temperature sensor and trigger a recalibration if there has been a significant
temperature change since the previous calibration.
9.7.1.1 Radio external components
In order to realize the full performance of the radio, the reference PCB layout and BOM
must be followed very closely (see Section 15.1).
The radio is powered from a number of internal 1.8 V regulators fed from the analog
supply V_DDA, in order to provide good noise isolation between the digital logic of the
JN517x and the analog blocks. These regulators are also controlled by the baseband
controller and protocol software to minimize power consumption. Decoupling for internal
regulators is required as described in Section 8.2.1.
For single-ended antennas or connectors, a balun is not required, however a matching
network is needed.
The RF matching network requires 3 external components and the IBIAS pin requires one
external component as shown in Figure 55. These components are critical and should be
placed close to the JN517x pins and analog ground as defined in Table 34. Specifically,
the output of the network comprising L2, C1 and L1 is designed to present an accurate
match to a 50  resistive network as well as provide a DC path to the final output stage or
antenna. Users wishing to match to other active devices such as amplifiers should design
their networks to match to 50  at the output of L1.
IBIAS
R1
43 kΩ
To coaxial socket
or integrated antenna
L1
50 ohms line
4.3 nH
C1
1.8 pF
L2
3 nH
C2
1.8 pF
C3
100 nF
Fig 16. External radio components
C4
47 pF
aaa-018996
JN517X
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 2.0 — 8 November 2016
© NXP Semiconductors N.V. 2016. All rights reserved.
27 of 100