Linear Technology DC1928A Demo Manual page 3

QUICK START PROCEDURE
RAIL TRACKING
Demonstration circuit 1928A is configured for an onboard
soft-start circuit. The soft-start ramp rate can be adjusted
by changing the value of C24. Demonstration circuit 1928A
CONFIGURATION
Soft-Start without Tracking (Default)
V Equals External Ramp
OUT
V Tracking Scaled External Ramp
OUT
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Figure 2. Measuring Input or Output Ripple Across Terminals or Directly Across Bulk Capacitor
100
95
90
85
80
75
70
65
60
0
R32
0Ω
0Ω
DEMO MANUAL DC1928A
PULSE-SKIPPING
FCM
BURST
1 2 3 4 5 6 7 8 9 10 11
I (A)
LOAD
Figure 3. Measured Efficiency
can also be modified to track an external reference. Refer
to Table 1 for tracking options and to the data sheet for
more details.
TRK/SS RESISTORS AND CAPACITOR
R35
Open
Open
Resistor Divider
12
RAIL TRACKING
C24 TRK/SS PIN
0.1µF OPEN
Open External Reference Applied
Open External Reference Applied
dc1928af
3