Hytera PD502, Service Manual, Page: 83 / 136

UHF1(400-470MHz) Circuit Description
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On-Off/Volume Control knob is on, SW- and SW+ are at high level, and the radio powers up. After
power-on, Pwr_Hold goes to high level, and Pwr_Key_Det goes to low level.
During power-off, SW- is at low level, while Pwr_Key_Det is at high level. The system detects power-off
procedure via Pwr_Key_Det and implements the power-off procedure. Then Pwr_Hold and SW+ go to
low level, and the power is cut off.
Power Protection
Power protection includes over-current, reverse-voltage and ESD protection.
Power Consumption Control
OMAP can control and configure the power supply and working mode of the peripheral modules (RF
section and baseband section) via the I/O interface and serial bus, so as to reduce power consumption.
5.1.2
Control Module
OMAP5912 Dual-core Processor
The radio uses the dual-core processor OMAP5912, which is mainly composed of ARM926EJ-S and
TMS320C55xx. ARM926EJ-S is the main controller, while TMS320C55xx is used for
modulation/demodulation and voice encoding/decoding.