TS2012

Application information

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4.4

Low frequency response

If a low frequency bandwidth limitation is required, it is possible to use input coupling

off frequency (see Table 5 to Table 7):

is also a tolerance around the typical value (see Table 5 to Table 7). You can also calculate

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4.5

Decoupling of the circuit

TS2012.

The TS2012 has a typical switching frequency of 280kHz and output fall and rise time about

5ns. Due to these very fast transients, careful decoupling is mandatory.

A 1µF ceramic capacitor between each PVCC and PGND and also between AVCC and

AGND is enough, but they must be located very close to the TS2012 in order to avoid any

extra parasitic inductance created by a long track wire. Parasitic loop inductance, in relation

with di/dt, introduces overvoltage that decreases the global efficiency of the device and may

cause, if this parasitic inductance is too high, a TS2012 breakdown.

In addition, even if a ceramic capacitor has an adequate high frequency ESR value, its

current capability is also important. A 0603 size is a good compromise, particularly when a

4

Ω load is used.

Another important parameter is the rated voltage of the capacitor. A 1µF/6.3V capacitor

used at 5V, loses about 50% of its value. With a power supply voltage of 5V, the decoupling

THD+N in the medium to high frequency region, this capacitor variation becomes decisive.

In addition, less decoupling means higher overshoots which can be problematic if they reach

the power supply AMR value (6V).

F

CL

1

2

π Z

in

C

in

⋅⋅

⋅

--------------------------------------------

=

C

in

1

2

π Z

in

F

CL

⋅⋅

⋅

----------------------------------------------

=

F

CLmax

1.103

F

CL

⋅

=

F

CLmin

0.915

F

CL

⋅

=