LTM8048

11

8048fa

APPLICATIONS INFORMATION

For most applications, the design process is straight

forward, summarized as follows:

1. Look at Table 1a (or Table 1b, if the post linear regula-

tor is used) and find the row that has the desired input

range and output voltage.

3. Connect BIAS as indicated, or tie to an external source

While these component combinations have been tested for

proper operation, it is incumbent upon the user to verify

proper operation over the intended system’s line, load and

environmental conditions. Bear in mind that the maximum

output current may be limited by junction temperature,

the relationship between the input and output voltage

magnitude and polarity and other factors. Please refer

to the graphs in the Typical Performance Characteristics

section for guidance.

Capacitor Selection Considerations

the minimum recommended values for the associated op-

erating conditions. Applying capacitor values below those

indicated in Table 1 is not recommended, and may result

in undesirable operation. Using larger values is generally

acceptable, and can yield improved dynamic response, if

it is necessary. Again, it is incumbent upon the user to

verify proper operation over the intended system’s line,

load and environmental conditions.

Ceramic capacitors are small, robust and have very low

ESR. However, not all ceramic capacitors are suitable.

X5R and X7R types are stable over temperature and ap-

plied voltage and give dependable service. Other types,

including Y5V and Z5U have very large temperature and

voltage coefficients of capacitance. In an application cir-

cuit they may have only a small fraction of their nominal

capacitance resulting in much higher output voltage ripple

than expected.

A final precaution regarding ceramic capacitors concerns

the maximum input voltage rating of the LTM8048. A

ceramic input capacitor combined with trace or cable

inductance forms a high-Q (underdamped) tank circuit. If

the LTM8048 circuit is plugged into a live supply, the input

voltage can ring to much higher than its nominal value,

possibly exceeding the device’s rating. This situation is

easily avoided; see the Hot-Plugging Safely section.

3.1V to 32V

2.5V

3.1V to 15V or Open

2.2μF, 50V, 1206

100μF, 6.3V, 1210

12.4k

3.1V to 32V

3.3V

3.1V to 15V or Open

2.2μF, 50V, 1206

100μF, 6.3V, 1210

10k

3.1V to 29V

5V

3.1V to 15V or Open

2.2μF, 50V, 1206

22μF, 16V, 1210

7.15k

3.1V to 26V

8V

3.1V to 15V or Open

2.2μF, 50V, 1206

22μF, 10V, 1206

4.53k

3.1V to 24V

12V

3.1V to 15V or Open

2.2μF, 25V, 0805

10μF, 16V, 1210

3.16k

9V to 15V

2.5V

2.2μF, 50V, 1206

100μF, 6.3V, 1210

12.4k

9V to 15V

3.3V

2.2μF, 50V, 1206

47μF, 6.3V, 1210

10k

9V to 15V

5V

2.2μF, 50V, 1206

22μF, 16V, 1210

7.15k

9V to 15V

8V

2.2μF, 50V, 1206

22μF, 10V, 1206

4.53k

9V to 15V

12V

2.2μF, 25V, 0805

10μF, 16V, 1210

3.16k

18V to 32V

2.5V

3.1V to 15V or Open

2.2μF, 50V, 1206

100μF, 6.3V, 1210

12.4k

18V to 32V

3.3V

3.1V to 15V or Open

2.2μF, 50V, 1206

47μF, 6.3V, 1210

10k

18V to 29V

5V

3.1V to 15V or Open

2.2μF, 50V, 1206

22μF, 16V, 1210

7.15k

18V to 26V

8V

3.1V to 15V or Open

2.2μF, 50V, 1206

22μF, 10V, 1206

4.53k

18V to 24V

12V

3.1V to 15V or Open

2.2μF, 50V, 1206

10μF, 16V, 1210

3.16k