6
Power Supply 5V and 10V Regulators
Transformer
From
To 3.3 V
Regulator
10V
This potential is used to power the headphone amplifier and signal that the system is not in stand-by operation.
When installed on the I/O assembly, this potential will drive the primary circuit TRAIC. The GREEN LED on the
control module is driven by this potential. Q30, Q31 and associated components for an enable circuit for the
linear regulator U20. These components permit U20 to be disconnected from Vsnub during stand-by operation,
thus avoiding the quiescent dissipation of U20 during these conditions.
5V
The only internal power requirement for 5 volts are the CODEC, U4000, power supply and the current source for
the ramp circuit formed by Q6201 and R6207. The source for the +5V linear regulator, U11, is Vraw. +5V is
provided only when Vraw is enabled.