Datasheet

LTM8020
11
8020fd
APPLICATIONS INFORMATION
Table 1. Recommended External Component Values and Configuration
V
IN
RANGE V
OUT
C
IN
C
OUT
R
ADJ
BIAS CONNECTION
4.5V - 36V 1.25V 2.2μF 50V 1206 X7R 47μF 6.3V 1206 X5R Open >2V, < 25V
4.5V - 36V 1.5V 2.2μF 50V 1206 X7R 47μF 6.3V 1206 X5R 2.43M >2V, < 25V
4.5V - 36V 1.8V 2.2μF 50V 1206 X7R 47μF 6.3V 1206 X5R 1.1M >2V, < 25V
4.5V - 36V 2.5V 2.2μF 50V 1206 X7R 22μF 6.3V 1206 X7R 499k V
OUT
4.5V - 36V 3.3V 2.2μF 50V 1206 X7R 10μF 6.3V 1206 X7R 301k V
OUT
6.5V - 36V 5V 2.2μF 50V 1206 X7R 10μF 6.3V 1206 X7R 165k V
OUT
4.5V - 15V 1.25V 2.2μF 16V 0805 X7R 22μF 6.3V 1206 X7R Open V
IN
4.5V - 15V 1.5V 2.2μF 16V 0805 X7R 10μF 6.3V 0805 X7R 2.43M V
IN
4.5V - 15V 1.8V 2.2μF 16V 0805 X7R 10μF 6.3V 0805 X7R 1.1M V
IN
4.5V - 15V 2.5V 2.2μF 16V 0805 X7R 10μF 6.3V 0805 X7R 499k V
IN
4.5V - 15V 3.3V 2.2μF 16V 0805 X7R 10μF 6.3V 0805 X7R 301k V
OUT
6.5V - 15V 5V 2.2μF 16V 0805 X7R None 165k V
OUT
9V - 24V 1.25V 1μF 25V 0805 X7R 47μF 6.3V 0805 X5R Open V
IN
9V - 24V 1.5V 1μF 25V 0805 X7R 47μF 6.3V 0805 X7R 2.43M V
IN
9V - 24V 1.8V 1μF 25V 0805 X7R 10μF 6.3V 0805 X7R 1.1M V
IN
9V - 24V 2.5V 1μF 25V 0805 X7R 10μF 6.3V 0805 X7R 499k V
IN
9V - 24V 3.3V 1μF 25V 0805 X7R 10μF 6.3V 0805 X7R 301k V
OUT
9V - 24V 5V 4.7μF 25V 0805 X7R 10μF 6.3V 0805 X5R 165k V
OUT
18V - 36V 1.25V 2.2μF 50V 1206 X7R 47μF 6.3V 1206 X5R Open >2V, <25V
18V - 36V 1.5V 2.2μF 50V 1206 X7R 47μF 6.3V 1206 X5R 2.43M >2V, <25V
18V - 36V 1.8V 2.2μF 50V 1206 X7R 22μF 6.3V 1206 X7R 1.1M >2V, <25V
18V - 36V 2.5V 2.2μF 50V 1206 X7R 10μF 6.3V 0805 X7R 499k V
OUT
18V - 36V 3.3V 2.2μF 50V 1206 X7R 10μF 6.3V 0805 X7R 301k V
OUT
18V - 36V 5V 2.2μF 50V 1206 X7R 10μF 6.3V 0805 X7R 165k V
OUT
3.3V - 30V –3.3V 2.2μF 50V 1206 X7R 22μF 6.3V 0805 X7R 301k V
OUT
5V - 30V –5V 2.2μF 50V 1206 X7R 10μF 6.3V 0805 X7R 165k V
OUT
Minimum Input Voltage
The LTM8020 is a step-down converter, so a minimum
amount of headroom is required to keep the output in
regulation. For most applications at full load, the input
needs to be at least 1.5V above the desired output. In
addition, the input voltage required to turn on depends
upon how the SHDN pin is tied. It takes more input voltage
to turn on if SHDN is tied to V
IN
than if the turn-on is
controlled by raising SHDN when V
IN
is in the required
operating range. A graph of the input voltage required to
turn the LTM8020 on when SHDN is tied to V
IN
or when
SHDN is switched is given in the Typical Performance
Characteristics section.
Electromagnetic Compliance
The LTM8020 was evaluated by an independent nationally
recognized test lab and found to be compliant with EN55022
class B: 2006 by a wide margin. A sample graph of the
LTM8020’s radiated EMC performance is given in the
Typical Performance Characteristics section, while further
data, operating conditions and test setup are detailed in
the electromagnetic compatibility test report, available
on the Linear Technology website. Conducted emissions
requirements may be met by adding an appropriate input
power line filter. The proper implementation of this filter
depends upon the system operating and performance
conditions as a whole, of which the LTM8020 is typically
only a component, so conducted emissions are not
addressed at this level.