HYT TC-610P Service Manual page 20

To detect VOX ON level;
To detect low voltage alarm;
To detect and determine external earpiece.
3） Data Transmission and Processing:
To initialize EEPROM data;
To transfer programming data;
To process the code of Channel Selector Knob.
To encode and decode signaling;
To transfer data of baseband processing chip (PLL).
7. Power Management Circuit
The block diagram is shown in the figure below:
After power-on, one flow of battery voltage is filtered by L604 and C682, and then goes to the RF power
amplifer and audio power amplifer for amplification. Another flow goes to the 5V regulator (U606). After
regulated, the VCC_5V voltage is output for use by MCU and baseband processing chip. As the radio
operates at half-duplex mode, the Tx and Rx power supplies need to be controlled alternately. In addition,
to meet requirements of battery save mode, MCU needs to output a pulse signal (SAVE control signal)
with fixed duty ratio. If the SAVE control signal is at high level, Q610 becomes conductive and provides
the 5V voltage (V_SAVE) for the operating circuit (PLL and Rx circuit). If the SAVE control signal is a
pulse signal, the radio will enter Battery Save Mode. During transmission, CPU control signal (TXC) is at
Figure 9
18
TC-610P Service Manual