JN516X Datasheet, PDF (54/94 Pages) NXP Semiconductors – IEEE802.15.4 Wireless Microcontroller

17 Analogue Peripherals
The JN516X contains a number of analogue peripherals allowing the direct connection of a wide range of external
sensors and switches.
Chip Boundary
ADC1
VREF/ADC2
ADC3 (DIO0)
ADC4 (DIO1)
Temp
Sensor
ADC
Supply Voltage
(VDD1)
Vref
Internal Reference
Vref Select
COMP1P (DIO16)
COMP1M (DIO17)
Comparator 1
Figure 37: Analogue Peripherals
In order to provide good isolation from digital noise, the analogue peripherals and radio are powered by the radio
regulator, which is supplied from the analogue supply VDD1 and referenced to analogue ground VSSA.
A reference signal Vref for the ADC can be selected between an internal bandgap reference or an external voltage
reference supplied to the VREF pin. ADC input 2 cannot be used if an external reference is required, as this uses the
same pin as VREF. Note also that ADC3 and ADC4 use the same pins as DIO0 and DIO1 respectively. These pins
can only be used for the ADC if they are not required for any of their alternative functions. Similarly, the comparator
inputs are shared with DIO16 and DIO17. If used for their analogue functions, these DIOs must be put into a passive
state by setting them to Inputs with their pull-ups disabled.
The ADC is clocked from a common clock source derived from the 16MHz clock
17.1 Analogue to Digital Converter
The 10-bit analogue to digital converter (ADC) uses a successive approximation design to perform high accuracy
conversions as typically required in wireless sensor network applications. It has six multiplexed single-ended input
channels: four available externally, one connected to an internal temperature sensor, and one connected to an
internal supply monitoring circuit.
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JN-DS-JN516x v1.1 Production
© NXP Laboratories UK 2013