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L6932
Multilayer ceramic caps have the lowest ESR and can be required for particular applications. Nevertheless in
several applications they are ok, the loop stability issue has to be considered (see loop stability section).
Below a list of some suggested capacitor manufacturers.
Loop Stability
The stability of the loop is affected by the zero introduced by the output capacitor.
The time constant of the zero is given by:
This zero helps to increase the phase margin of the loop until the time constant is higher than some hundreds
of nsec, depending also on the output voltage and current.
So, using very low ESR ceramic capacitors could produce oscillations at the output, in particular when regulating
high output voltages (adjustable version).
To solve this issue is sufficient to add a small capacitor (e.g. 1nF to 10nF) in parallel to the high side resistor of
the external divider, as shown in figure 9.
Figure 9. Compensation Network
Thermal Considerations
Since the device is housed in a small SO(4+2+2) package the thermal issue can be the bottleneck of many ap-
plications. The power dissipated by the device is given by:
P
DISS
= (V
IN
- V
OUT
) · I
OUT
Manufacturer Type Cap Value (µF) Rated Voltage (V)
PANASONIC CERAMIC 1 to 47 4 to 16
TAYO YUDEN CERAMIC 1 to 47 4 to 16
TDK CERAMIC 1 to 47 4 to 16
TOKIN CERAMIC 1 to 47 4 to 16
SANYO POSCAP 1 to 47 4 to 16
PANASONIC SP 1 to 47 4 to 16
KEMET TANTALUM 1 to 47 4 to 16
TESRC
OUT
⋅= F
ZERO
1
2π ESR C
OUT
⋅⋅
------- ---- --------------- ----- -------------=
VOUT=1.2V TO 5V UP to 2A
VIN=2V TO 14V
C1
OUT
1
3
7
5
6
4
8
2
L6932D1.2
GND
C2
IN
EN
ADJ
R1
R2
C3
