Datasheet
PTH08T220W Type C Capacitors
Transient − mV/A
C − Capacitance − µF
200
300
400
500
600
700
1000
800
900
2000
3000
4000
5000
6000
7000
8000
9000
10000
V
I
= 12 V
Without TurboTrans
With TurboTrans
2
7
3
4
5
9
8
6
10
20
Transient − mV/A
C − Capacitance − µF
V
I
= 5 V
200
300
400
500
600
700
1000
800
900
2000
3000
4000
5000
6000
7000
8000
9000
10000
Without TurboTrans
With TurboTrans
2
7
3
4
5
9
8
6
10
20
R
TT
+ 40
ƪ
1 *
ǒ
C
O
ń1980
Ǔƫ
ǒ
ǒ
5 C
O
Ǔ
)880
1980
Ǔ
* 1
(
kW
)
(4)
PTH08T220W , PTH08T221W
SLTS252K – NOVEMBER 2005 – REVISED JUNE 2009 ...................................................................................................................................................
www.ti.com
12-V INPUT 5-V INPUT
Figure 17. Capacitor Type C, Figure 18. Capacitor Type C,
5000 < C( µ F) × ESR(m Ω ) ≤ 10,000(e.g. OS-CON) 5000 < C( µ F) × ESR(m Ω ) ≤ 10,000(e.g. OS-CON)
Table 6. Type C TurboTrans C
O
Values and Required R
TT
Selection Table
Transient Voltage Deviation (mV) 12 Volt Input 5 Volt Input
25% Load 50% Load 75% Load C
O
R
TT
C
O
R
TT
Step Step Step Minimum Required Required Minimum Required Required
(4 A) (8 A) (12 A) Output TurboTrans Output TurboTrans
Capacitance ( µ F) Resistor (k Ω ) Capacitance ( µ F) Resistor (k Ω )
65 125 190 220 open 220 open
50 100 150 270 274 330 121
40 80 120 330 121 550 34.8
30 60 90 470 48.7 630 26.1
25 50 75 600 28.7 800 16.2
20 40 60 800 16.2 1150 7.15
15 30 45 1300 5.11 1700 1.50
10 20 30 7500 short 10000 short
R
TT
Resistor Selection
For V
O
≤ 3.45V the TurboTrans resistor value, R
TT
can be determined from the TurboTrans programming
Equation 4 . For V
O
> 3.45 V please contact TI for C
O
and R
TT
values.
Where C
O
is the total output capacitance in µ F. C
O
values greater than or equal to 1980 µ F require R
TT
to be a
short, 0 Ω . (Equation 4 results in a negative value for R
TT
when C
O
> 1980 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 Figure 17 and
Figure 18 .
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