Datasheet

PTH04T241W - Type A Ceramic Capacitors
C − Capacitance − µF
Transient − mV/A
9
8
20
10
30
7
6
5
4
40
1000
500
300
200
400
700
600
800
900
3000
2000
4000
5000
PTH04T241W
Type A Ceramic Capacitors
Without TurboTrans
With TurboTrans
9
8
20
10
30
7
6
5
4
40
1000
500
300
200
400
700
600
800
900
3000
2000
4000
5000
C − Capacitance − µF
Transient − mV/A
Without TurboTrans
With TurboTrans
PTH04T241W
Type A Ceramic Capacitors
R
TT
+ 40
ƪ
1 *
ǒ
C
O
ń1500
Ǔƫ
ƪ
ǒ
5 C
O
ń1500
Ǔ
* 1
ƫ
(
kW
)
(2)
PTH04T240W , PTH04T241W
www.ti.com ...................................................................................................................................................... SLTS276D – OCTOBER 2006 – REVISED JULY 2009
5-V Input 3.3-V Input
Figure 10. Capacitor Type A, Figure 11. Capacitor Type A,
100 ≤ C( µ F) × ESR(m Ω ) ≤ 1000 100 ≤ C( µ F)xESR(m Ω ) ≤ 1000
(e.g. Ceramic) (e.g. Ceramic)
Table 4. Type A TurboTrans C
O
Values and Required R
TT
Selection Table
Transient Voltage Deviation (mV) 5-V Input 3.3-V Input
25% load step 50% load step 75% load step C
O
R
TT
C
O
R
TT
(2.5 A) (5 A) (7.5 A) Minimum Required Minimum Required
Required Output TurboTrans Required Output TurboTrans
Capacitance ( µ F) Resistor (k Ω ) Capacitance ( µ F) Resistor (k Ω )
60 120 180 300 open 300 open
50 100 150 340 232 390 97.6
40 80 120 500 40.2 550 30.1
30 60 90 770 12.4 840 9.76
25 50 75 1030 5.11 1100 4.02
20 40 60 1460 0.274 1700 short
18 36 54 2420 short 2830 short
R
TT
Resistor Selection
The TurboTrans resistor value, R
TT
can be determined from the TurboTrans programming, see Equation 2
Where C
O
is the total output capacitance in µ F. C
O
values greater than or equal to 1500 µ F require R
TT
to be a
short, 0 Ω . (R
TT
results in a negative value when C
O
> 1500 µ F).
To ensure stability, a minimum amount of output capacitance is required for a given R
TT
resistor value. The value
of R
TT
must be calculated using the minimum required output capacitance determined from the capacitor
transient response charts above.
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