2
dc2358af
DEMO MANUAL DC2358A
PERFORMANCE SUMMARY
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Minimum Input Voltage
4.5
V
Maximum Input Voltage
40
V
Output Voltage V
OUT1
V
IN
= 4.5V to 40V
5.3
5.6
5.9
V
Output Voltage V
OUT2
V
IN
= 4.5V to 40V
4.85
5
5.15
V
Voltage Ripple V
OUT1
V
IN
= 12V, I
OUT1
= 200mA, I
OUT2
= 0mA
25
mV
Voltage Ripple V
OUT2
V
IN
= 12V, I
OUT1
= 0mA, I
OUT2
= 200mA
1
mV
Demo circuit 2358A is easy to set up to evaluate the per-
formance of the LTM8068. Refer to Figure 4 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 V
IN
and GND or V
OUT
and V
OUTN
terminals. See Figure 5 for
proper scope probe technique.
1. With power off, connect the input power supply to V
IN
and GND.
2. Turn on the power at the input.
NOTE. Make sure that the input voltage does not
exceed 40V.
3. Check for the proper output voltages. (For OUT1, check
the voltage between V
OUT1
and V
OUTN
. For OUT2, check
the voltage between V
OUT2
and V
OUTN
.)
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 voltages are established, adjust
the load within the operating range and observe the
output voltage regulation, ripple voltage, efficiency and
other parameters.
QUICK START PROCEDURE
Specifications are at T
A
= 25°C
Figure 1. Maximum Output Current vs
V
IN
: 5.6V
OUT1
Flyback Output with V
OUT2
Unloaded; 5V
OUT2
LDO output with
V
OUT1
Unloaded
Figure 2. V
OUT1
Output Noise Spectrum
with I
OUT1
at 200mA and V
IN
at 12V
(V
OUT2
Has No Extra Load)
Figure 3. V
OUT2
Output Noise Spectrum
with I
OUT2
at 200mA and V
IN
at 12V
(V
OUT1
Has No Extra Load)
V
IN
(V)
0
MAXIMUM LOAD CURRENT (mA)
500
100
300
400
200
0
dc2358 F01
40
20
10
30
5.6V
OUT1
5V
OUT2
FREQUENCY (MHz)
0
INTENSIT
Y (dBm)
0
–80
–40
–20
–60
–100
2.5
4.5
1.5
3.5
dc2358 F02
5.0
2.0
4.0
1.0
3.0
0.5
FREQUENCY (MHz)
0
INTENSIT
Y (dBm)
0
–80
–40
–20
–60
–100
2.5
4.5
1.5
3.5
dc2358 F03
5.0
2.0
4.0
1.0
3.0
0.5
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