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dc2518af
DEMO MANUAL DC2518A
COMMON BOARD OPERATIONS
Each channel has an LED which visually indicates if the
channel has power. When the CONTROL pin is switched
on and off, you will observe the relative on/off timing of
the four channels. The timings are intentionally skewed
to show the rails ramp times more clearly.
For the LTC2975, the TON_DELAY and TOFF_DELAY
values extend to 655ms, providing a reasonable range
for sequencing power supply rails on and off.
Figure 6. Sequencing Output Channels On/Off
Figure 7. TON_DELAY and TOFF_DELAY Settings
Margin All Rails
The LTC2975 Power System Manageron the DC2518A
not only monitors each of the four outputs but can margin
the outputs either high or low. Margining is the operation
that moves a rail up or down for testing purposes. It al-
lows a system to be fully characterized over supply limits
without the use of external hardware or resources. The
GUI provides an easy way to margin all rails high or all low
by clicking one of four buttons. To invoke the margining
dialog, click the GroupOp icon in the toolbar. The buttons
labeled “ignore faults” will margin without creating a fault
even if the fault limits are exceeded.
A look at the telemetry window shows the effect of the
margin high and margin low operations. This screen shot
is a telemetry plot of READ_VOUT_PERCENT showing all
rails going from nominal set-points to margin high, margin
low, and back to nominal voltages.
