Working Domain Voltages; Vcc12; Vcc3; Vcc5 - Micros Systems Workstation 5 Service Manual

Workstation 5 System Board Technical Descriptions
System Board Power Distribution

Working Domain Voltages

The following describes the Working Domain Voltages.
In response to the user pressing the power button or connecting the AC power
cable, the PMC in the CS5536 Companion Device issues the
to enable the following voltages.

VCC12

The 'Always ON'
Q25 (Sht24) to produce the
domain, see below) goes active, this turns on Q25, which in turn enables
Q22, switching on
VCC12
amp, LCD Panel and Backlight Inverter, Memory Voltage Regulator U43
(Sht25), and the RS232 Line Drivers/Receivers.
VCC12
Interface for more information about

VCC3

VCC3
SS_STBY2
Q16 inverts this signal to the active low
signal to the active high
Output switching is handled by Q19 and Q20 through inductor L4 and
EC28. The over current trip point is determined by R293/C298 connected
across the

VCC5

VCC5
SS_STBY3
Q16 inverts this signal to the active low
signal to the active high
Output switching is handled by Q18 and Q17 through inductor L5 and
EC27. The over current trip point is determined by R297/C302 across the
TRIP3
VCC12-
VCC12-
of D24, D26, and EC25.
Drivers/Receivers.
2-36
output is fed to a switch consisting of U22 and
+12V
VCC12
.
VCC12
powers many system board components including the audio power
is used on Sheet 30 to generate
is produced by U38 REG#2. The SoftStart input to this regulator,
, is enabled by the
STBY_3V
input.
TRIP2
is produced by U38 REG#3. The SoftStart input to this regulator,
, is enabled by the
STBY_5V
input.
is derived from the
SW_3
VCC12-
output. When
VCC5
VCC24V . See the Cash Drawer
.
VCC24V
output of the Companion chip.
WORKING
PS_ON# and Q13 inverts the
.
output of the Companion chip.
WORKING
PS_ON# and Q12 inverts the
.
output of U38, through a combination
is used only by the RS232 Line
Workstation 5 Field Service Guide
WORKING signal
(also the working