User's Manual

eUniStone
PBA 31309
Basic Operating Information
User’s Manual Intel Public 15
Hardware Description Revision 1.0, 1-Feb-2013
2.0 Basic Operating Information
2.1 Power Supply
eUniStone is supplied from a single supply voltage VSUPPLY. This supply voltage must
always be present. The Bluetooth chip is supplied from an internally generated 2.5 V
supply voltage. This voltage can be accessed from the VREG pin. This voltage shall not
be used for supplying other components in the host system but can be used for
referencing the host interfaces.
The GPIO’s and the UART interface are supplied with dedicated, independent, reference
levels via the VDD1 and VDDUART pins. All other digital I/O pins are supplied internally
by either 2.5 V (Internal2) or 1.5 V (Internal1). Section 1.4 provides a mapping
between pins and supply voltages.
The I/O power domains (VDD1 and VDDUART) are completely separated from the other
power domains and can stay present also in low power modes.
2.2 Clocking
eUniStone contains a crystal from which the internal 26 MHz system clock is generated.
Also, the low power mode clock of 32.768 kHz is generated internally, which means
that no external clock is needed.
2.3 Low Power Modes
To minimize current consumption, eUniStone automatically switches between different
low power modes. The major modes are described below.
2.3.1 Low Power Mode
In Low Power Mode (LPM) most parts of eUniStone are powered down. This is done
automatically in idle mode or if the link is in Sniff mode and the host allows LPM with
the pin P0.14.
2.3.2 Complete Power Down
If Bluetooth functionality is not needed at all, VSUPPLY should be grounded to minimize
power consumption. In this state there is no activity in eUniStone and the Bluetooth
state (native clock, etc.) is not updated.
2.3.3 ON/OFF
eUniStone provides an alternative way to power down using the ONOFF logic input.
When the ONOFF is low, the internal regulator on the module is turned OFF. The
intention with the signal is to have the possibility to turn off the module without having
to turn off the supply voltage. In the OFF state, the module will consume less than 1
mA excluding the interface currents that is mainly set by the external load.
If this signal isn’t used then it should be connected to VSUPPLY on the host PCB.