NXP Semiconductors K22F series, Reference Manual, Page: 859 / 1407

• Bandgap enabled/standby (output buffer disabled)
• Low power buffer mode (output buffer enabled)
• High power buffer mode (output buffer enabled)
• 1.2 V output at room temperature
• Dedicated output pin, VREF_OUT
37.1.3 Modes of Operation
The Voltage Reference continues normal operation in Run, Wait, and Stop modes. The
Voltage Reference can also run in Very Low Power Run (VLPR), Very Low Power Wait
(VLPW) and Very Low Power Stop (VLPS). If it is desired to use the VREF regulator
and/or the chop oscillator in the very low power modes, the system reference voltage
(also referred to as the bandgap voltage reference) must be enabled in these modes. Refer
to the chip configuration details for information on enabling this mode of operation.
Having the VREF regulator enabled does increase current consumption. In very low
power modes it may be desirable to disable the VREF regulator to minimize current
consumption. Note however that the accuracy of the output voltage will be reduced (by as
much as several mVs) when the VREF regulator is not used.
NOTE
The assignment of module modes to core modes is chip-
specific. For module-to-core mode assignments, see the chapter
that describes how modules are configured.
37.1.4 VREF Signal Descriptions
The following table shows the Voltage Reference signals properties.
Table 37-1. VREF Signal Descriptions
Signal Description I/O
VREF_OUT Internally-generated Voltage Reference output O
NOTE
When the VREF output buffer is disabled, the status of the
VREF_OUT signal is high-impedence.
Chapter 37 Voltage Reference (VREFV1)
K22F Sub-Family Reference Manual, Rev. 4, 08/2016
NXP Semiconductors 859