23
iO1000 Detailed Service Manual - THEORY OF OPERATION
¥
8-channel, 8-bit A/D conversion
¥
PA high-end regulation
¥
Real-time clock (RTC)
DC Voltage Distribution
The iO1000 unit operates with a low-level supply voltage of 3.0Vdc, nominal-
level voltage of 3.6Vdc, and high-level voltage of 4.2Vdc
The DC voltage distribution of the iO1000 radio is supported by the GCAP II IC
(Figure 11 on page 24). This IC supplies regulated power to the radio using its lin-
ear requlators, V1, V2, and V3.
A discrete regulator on the RF board supplies 2.775Vdc to both the receive and
transmit circuitry, while V2 GCAP II linear regulator supplies 2.775Vdc to the
clock buffers and low-voltage sense comparator. V1 GCAPII linear regulator sup-
plies 2.775Vdc to the memories and V3 linear regulator supplies 1.875Vdc to the
DSP and MCU cores. Additionally, an external 3.0Vdc linear regulator on the
logic board supplies power to the accessories. Several sections of the radio are
connected directly to the external power supply, which supplies Raw_B+ and
.
The external power supply is connected to the accessory connector J4 pins 19
through 23 (+) and 26 through 30 (-). These pins supply the Raw_B+ to the RF
TX power amplifier. The Optional B+ output of the U005 regulator supplies 3.0V
to the accessories through the accessory connector. Raw_B+ is routed through
F001 (Fuse) becoming , which provides power to the GCAP II IC..
The battery is connected to the J9003 pins 1 (+) and 2 (-). These pins supply the
Raw_B+ to the RF TX power amplifier. The Optional B+ output of the U005 reg-
ulator supplies the accessories through the bottom connector. Raw_B+ is routed
through F001 (Fuse) becoming , which goes through the main FET and
provides power to the GCAP II IC.