AN2653

Snubber network compensation method

17/22

In fact, this compensation introduces a zero and an additional pole into the loop gain:

always the best case.

5.2

Application on the TS507

For the TS507, according to the abacus in Figure 27 and Figure 28, this compensation

method in the case of a voltage follower configuration, works only if the capacitive load is

less than 1 nF, in order to obtain (at least) a phase margin of 20°.

Figure 29 and Figure 30 are the same abacus in case of a gain of either -10 or +11.

V

r

V

s

------

–

A

ω

()

1jR

+

()

⋅

1

Z

o

R

L

-------

jZ

C

SN

+

()ω j1

Z

o

R

L

-------

+

⎝⎠

⎛⎞ R

Z

2

–

++

+

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

=

Figure 27.

Gain margin abacus in a voltage

follower configuration

Figure 28.

Phase margin abacus in a voltage

follower configuration

Voltage Follower Configuration - Load Abacus

Gain Margin

1.E-12

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

RL (Ω)

0 dB

10 dB

20 dB

30 dB

TS507 :

Vcc = 5 V

Vicm = 2,5 V

T = 25 °C

STABLE

UNSTABLE

Voltage Follower Configuration - Load Abacus

Phase Margin

1.E-12

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

RL (Ω)

0 °

C1 (10 °)

20 °

C1 (30 °)

40 °

TS507 :

Vcc = 5 V

Vicm = 2,5 V

T = 25 °C

STABLE

UNSTABLE

Figure 29.

Gain margin abacus in a gain

configuration of either -10 or +11

Figure 30.

Phase margin abacus in a gain

configuration of either -10 or +11

Gain Configuration of either -10 or +11 - Load Abacus

Gain Margin

1.E-12

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

RL (Ω)

0 dB

10 dB

20 dB

30 dB

40 dB

50 dB

TS507 :

Vcc = 5 V

Vicm = 2,5 V

T = 25 °C

STABLE

UNSTABLE

Gain Configuration of either -10 or +11 - Load Abacus

Phase Margin

1.E-12

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

RL (Ω)

0 °

20 °

40 °

60 °

80 °

TS507 :

Vcc = 5 V

Vicm = 2,5 V

T = 25 °C

STABLE

UNSTABLE