Application information L6935
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6 Application information
L6935 is the best choice in smart linear regulator applications, due to its own small size,
high power delivered and high regulation accuracy. Furthermore thermal shut-down and
OCP guarantee the highest reliability for each application.
V
IN
can be separated by V
BIAS
: in this way the device can regulate the output voltage even if
V
IN
< V
BIAS
, resulting in a better performance. In fact, the power dissipated decreases as
V
IN
get lower, according to the relationship P
DISS
= (V
IN
- V
OUT
) x I
OUT
.
6.1 Components selection
6.1.1 Input capacitor
The choice of the input capacitor value depends on the several factor such as load transient
requirements, input source (battery or DC/DC converter) and its distance from the input
capacitor. Generally speaking, a capacitor with the lowest ESR possible should be chosen:
a value within the range [10 µF; 100 µF] can be sufficient in many cases.
6.1.2 Output capacitor
The choice of the output capacitor value basically depends on the load transient
requirement. Output capacitor must be sized according to the dynamic requests of the load.
A too small capacitor may exhibit huge voltage drop after a load transient is applied: a value
greater than 10 µF should be used.
In order to guarantee a good reliability, at least X5R type should be used as I/O capacitors.
Different kinds of input/output capacitors can be used: Table 6. shows a few tested
examples.
Table 6. Input/output capacitor selection guide
Manufacturer Type I/O cap. value Rated voltage
Murata - GRM31CR61ExxxK
(1)
1. xxx in the part numbers stands for 106 (10 µF), 226 (22 µF)... 105 (100 µF)
MLCC, SMD1206, X5R 10...100 µF 6.3 - 25 V
Panasonic - ECJ3YB1AxxxM MLCC, SMD1206, X5R 10...100 µF 10 - 25 V
Panasonic - EEFFD0HxxxR
SPCap - SMD7343
28 mΩ ESR
10...100 µF4 - 8 V
Sanyo - 8TPE100MPC2
POSCAP, SMD6032
25 mΩ ESR
10...100 µF 6.3 - 25 V
TDK - C3216X5R0JxxxMT MLCC, SMD1210, X5R 10...100 µF 6.3 V
