4-4 Controller Board
ModB/Vstby Supply
Under various conditions, the supply to the ModB/Vstby would vary. Table 4-1 shows these
conditions and circuits in operation.
Table 4-1: ModB/Vstby Supply Modes
Condition Circuit Operation
Radio On Vdd supply voltage via CR411
Radio Off • Vdd turned off
• Q416 gate is pulled low by R462
• Q416 is switched on
• U410 supplies 3.2V to ModB/Vstby
Primary battery removed • Vdd turned off
• Q416 gate is pulled low by R462
• Q416 is switched on
• LiO battery provides 3.2V to ModB/Vstby
Flash Mode • Boot_Ctrl line pull low
• ModA & ModB goes low
• Processor in boot-strap mode
• Flashing enabled
To Next Page
Loading...
