JN516X Datasheet, PDF (12/94 Pages) NXP Semiconductors – IEEE802.15.4 Wireless Microcontroller

2.2 Pin Descriptions
2.2.1 Power Supplies
The device is powered from the VDD1 and VDD2 pins, each being decoupled with a 100nF ceramic capacitor. VDD1
is the power supply to the analogue circuitry; it should be decoupled to ground. VDD2 is the power supply for the
digital circuitry; and should also be decoupled to ground. In addition, a common 10µF tantalum capacitor is required
for low frequencies. Decoupling pins for the internal 1.8V regulators are provided which each require a100nF
capacitor located as close to the device as practical. VB_SYNTH, VB_RAM and VB_DIG require only a 100nF
capacitor. VB_RF and VB_RF2 should be connected together as close to the device as practical, and require one
100nF capacitor and one 47pF capacitor. The pin VB_VCO requires a 10nF capacitor. Refer to B.4.1 for schematic
diagram.
VSSA (paddle), VSS1, VSS2 are the ground pins.
Users are strongly discouraged from connecting their own circuits to the 1.8v regulated supply pins, as the regulators
have been optimised to supply only enough current for the internal circuits.
2.2.2 Reset
RESETN is an active low reset input pin that is connected to a 500kΩ internal pull-up resistor. It may be pulled low
by an external circuit. Refer to Section 6.2 for more details.
2.2.3 32MHz Oscillator
A crystal is connected between XTAL_IN and XTAL_OUT to form the reference oscillator, which drives the system
clock. A capacitor to analogue ground is required on each of these pins. Refer to Section 5.1 for more details. The
32MHz reference frequency is divided down to 16MHz and this is used as the system clock throughout the device.
2.2.4 Radio
The radio is a single ended design, requiring a capacitor and just two inductors to match to 50Ω microstrip line to the
RF_IN pin.
An external resistor (43kΩ) is required between IBIAS and analogue ground (paddle) to set various bias currents and
references within the radio.
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JN-DS-JN516x v1.1 Production
© NXP Laboratories UK 2013