2
dc1559af
DEMO MANUAL DC1559 A
QUICK START PROCEDURE
Demo circuit 1559A is an easy way to evaluate the per-
formance of the LTM8046. Refer to Figure 3 for proper
measurement equipment setup and follow the procedure
below:
Note: When measuring the input or output voltage ripple,
care must be taken to avoid a long ground lead on the
oscilloscope probe. Measure the input or output voltage
ripple by touching the probe tip directly across the VIN or
VOUT and GND terminals. See Figure 4 for proper scope
probe technique.
1. With power off, connect the input power supply to VIN
and GND.
2. Turn on the power at the input.
Note: Make sure that the input voltage does not exceed 26V.
3. Check for the proper output voltage between VOUT and
VOUT-.
Note: If there is no output, temporarily disconnect the load
to make sure that the load is not set too high.
4. Once the proper output voltage is established, adjust
the load within the operating range and observe the output
voltage regulation, ripple voltage, efficiency and other
parameters.
V
IN
(V)
4
0
OUTPUT CURRENT (mA)
100
300
400
500
700
6
14
18
200
600
12
22
26
24
8 10
16
20
FREQUENCY (MHz)
–120
INTENSITY (dBm) –80
–40
0
–100
–60
–20
1
2
3
4
5
0.5
0
1.5
2.5
3.5
4.5
Figure 1. V
OUT
Maximum Output Current vs V
IN
Figure 2. V
OUT
Output Noise Spectrum with I
OUT
at 300mA
and V
IN
at 12V
