Specifications

Bluegiga Technologies Oy
Page 21 of 64
5 Power Control and Regulation
WT32i contains an internal battery charger and a switch mode regulator that is mainly used for internal blocks
of the module. The module can be powered from a single 3.3 V supply provided that VDD_CHG is floating.
Alternatively the module can be powered from a battery connected to VDD_BAT and using an external
regulator for VDD_IO. 1.8 V to 3.3 V supply voltage for VDD_IO can be used to give desired signal levels for
the digital interfaces of the module. USB, however, requires 3.3 V for proper operation and thus, when USB is
in use, 3.3 V for VDD_IO is required.
Battery Charger
In
Out
Switch mode
1.8V regulator
Linear 1.5V
regulator
AIO
RF
Core
Audio
Flash
PIO
USB
UART
PCM
VDD_CHG
VDD_BAT
VREG_ENA
VDD_IO
Figure 7: Power supply configuration of WT32i
VDD_ENA is software configurable enable pin for the internal regulators. Using iWRAP the enable pin can be
configured to
1. Latch on the internal regulators at the rising edge
2. Turn the regulators on at rising edge and turn off the regulators at falling edge
3. Latch the regulators on at the rising edge and turn off the regulators at the following rising edge
GPIO can be configured to control an external regulator.