Quick Start Procedure; Additional Notes - Linear Technology DC1537A Demo Manual

DEMO MANUAL DC1537A
DESCRIPTION
100
95
90
85
80
75
70
65
60
0.2 0.4 0.6 0.8
LOAD CURRENT FOR BOTH CHANNELS (A)
Figure 2. Dual Channel Efficiency
at V = 24V, f = 300kHz
IN

QUICK START PROCEDURE

Demo circuit 1537A is easy to set up to evaluate the
performance of the LT3992. Refer to Figure 5 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 6 for
proper scope probe technique.
1. Place JP1 on the SINGLE position.
2. With power off, connect the input power supply to VIN1
and GND. (Connect another input power supply to VIN2
and GND if DUAL is selected.)
3. Turn on the power at the input.
NOTE. Make sure that the input voltage does not exceed
60V (Due to part selection on D3 and D4, 60V is for
transient purpose. Continuous operation can be avail-
able after D3 and D4 are replaced with higher voltage
rated schottky diodes).
2
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0.9
0.8
0.7
0.6
0.5
0.4
1.0 1.2 1.6 1.8 2.0
1.4
DC1537a F02
V = 5V/3A, V NO LOAD
OUT1 OUT2
V = 3.3V/3A, V NO LOAD
OUT2 OUT1
20 25 35
5 10 15 30
V (V)
IN
DC1537a F03
Figure 3. DC1537A T Pin Voltage
J
When Channels Running Individually
at 3A Load (T = 25°C)
A
4. Check for the proper output voltages.
NOTE. If there is no output, temporarily disconnect
the load to make sure that the load is not set too high.
5. 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.

ADDITIONAL NOTES

If an EMI filter is desirable on VIN1, it can be feasibly
installed on the back of the board in the optional circuit
area. However, a trace cut is required for the insertion of
the optional circuit. See Figure 7 for the cut line.
0.9
0.8
0.7
0.6
0.5
0.4
40 20
5 10 15
V
IN
Figure 4. DC1537A T
When Both Channels Sourcing 2A
Current at Meantime (T
25 35 40
30
(V)
DC1537a F04
Pin Voltage
J
= 25°C)
A
dc1537af