C8051T630 Datasheet, PDF (55/221 Pages) Silicon Laboratories – Mixed-Signal Byte-Programmable EPROM MCU

C8051T630/1/2/3/4/5
10. Voltage Regulator (REG0)
C8051T630/1/2/3/4/5 devices include an internal voltage regulator (REG0) to regulate the internal core
supply to 1.8 V from a V_DD supply of 1.8 to 3.6 V. Two power-saving modes are built into the regulator to
help reduce current consumption in low-power applications. These modes are accessed through the
REG0CN register (SFR Definition 10.1). Electrical characteristics for the on-chip regulator are specified in
Table 5.5 on page 26
If an external regulator is used to power the device, the internal regulator may be put into bypass mode
using the BYPASS bit. The internal regulator should never be placed in bypass mode unless an
external 1.8 V regulator is used to supply V_DD. Doing so could cause permanent damage to the
device.
Under default conditions, when the device enters STOP mode the internal regulator will remain on. This
allows any enabled reset source to generate a reset for the device and bring the device out of STOP mode.
For additional power savings, the STOPCF bit can be used to shut down the regulator and the internal
power network of the device when the part enters STOP mode. When STOPCF is set to 1, the RST pin or
a full power cycle of the device are the only methods of generating a reset.
Rev. 1.0
55