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dc1533af

DEMO MANUAL DC1533A

QUICK START PROCEDURE

Figure 1. Proper Measurement Equipment Setup

Demo circuit DC1533A is an easy way to evaluate the

performance of the LTM8045. Refer to Figure 1 for the

proper measurement equipment setup and Figure 2 for

the maximum output current versus input voltage, then

follow the procedure below:

NOTE: Do not hot-plug the VIN terminal at high input volt-

ages. Hot-plugging a power supply through wire leads

to the demonstration circuit can cause the voltage on

the extremely low ESR ceramic input capacitor to ring to

twice its DC value. In order to protect the LTM8045, an

aluminum electrolytic capacitor with higher ESR is placed

at the input terminals. This may protect against some, but

not all, input transients due to a hot-plugged power supply.

See Application Note 88 for more details.

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 3 for proper scope

probe technique.

1. Place JP1 in the ON position.

2. Connect the power supply (with power off), load, and

meters as shown in Figure 1.

3. After all connections are made, turn on the input power

and verify that the output voltage is –5V.

NOTE: If the output voltage is too low, temporarily discon-

nect 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.

NOTE: See the section that follows for instructions to

convert DC1533A to a 5VOUT SEPIC with a positive VOUT.