LTM8047 LINER [Linear Technology], LTM8047 Datasheet - Page 11

• Manufacturer Part Number: LTM8047
• Description: 3.1VIN to 32VIN Isolated ?Module DC/DC Converter
• Manufacturer: LINER [Linear Technology]

LTM8048 Table 1a. Recommended Component Values and Configuration for Specific V
Note: Do not allow BIAS to exceed V
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-
2. Apply the recommended C
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 C
the minimum recommended values for the associated op-
erating conditions. Applying capacitor values below those
tor is used) and find the row that has the desired input
range and output voltage.
R
up to 15V or V
ADJ2
3.1V to 32V
3.1V to 32V
3.1V to 29V
3.1V to 26V
3.1V to 24V
18V to 32V
18V to 32V
18V to 29V
18V to 26V
18V to 24V
IN
9V to 15V
9V to 15V
9V to 15V
9V to 15V
9V to 15V
, C
V
and C
IN
OUT1
BYP
and C
IN
if required.
, whichever is less.
OUT2
capacitor values in Table 1 are
V
IN
2.5V
3.3V
2.5V
3.3V
2.5V
3.3V
12V
12V
12V
OUT1
5V
8V
5V
8V
5V
8V
, a bulk input capacitor is required.
IN
, C
OUT1
, C
3.1V to 15V or Open
3.1V to 15V or Open
3.1V to 15V or Open
3.1V to 15V or Open
3.1V to 15V or Open
3.1V to 15V or Open
3.1V to 15V or Open
3.1V to 15V or Open
3.1V to 15V or Open
3.1V to 15V or Open
OUT2
V
V
V
V
V
V
BIAS
, R
IN
IN
IN
IN
IN
ADJ1
,
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.
2.2μF , 50V, 1206
2.2μF , 50V, 1206
2.2μF , 50V, 1206
2.2μF , 50V, 1206
2.2μF , 25V, 0805
2.2μF , 50V, 1206
2.2μF , 50V, 1206
2.2μF , 50V, 1206
2.2μF , 50V, 1206
2.2μF , 25V, 0805
2.2μF , 50V, 1206
2.2μF , 50V, 1206
2.2μF , 50V, 1206
2.2μF , 50V, 1206
2.2μF , 50V, 1206
C
IN
OUT1
Voltages (T
100μF , 6.3V, 1210
100μF , 6.3V, 1210
100μF , 6.3V, 1210
100μF , 6.3V, 1210
47μF , 6.3V, 1210
47μF , 6.3V, 1210
22μF , 16V, 1210
22μF , 10V, 1206
10μF , 16V, 1210
22μF , 16V, 1210
22μF , 10V, 1206
10μF , 16V, 1210
22μF , 16V, 1210
22μF , 10V, 1206
10μF , 16V, 1210
C
OUT1
A
= 25°C)
LTM8048
R
12.4k
7.15k
4.53k
3.16k
12.4k
7.15k
4.53k
3.16k
12.4k
7.15k
4.53k
3.16k
10k
10k
10k
ADJ1
11
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