Datasheet

C-Capacitance- Fm
Transient-mV/A
400
500
600
700
800
900
1000 2000 3000 4000
5000
6000
7000
8000
9000
10000
20
10
9
8
7
6
5
4
3
2
WithTurboTrans
V =12V
I
WithoutTurboTrans
C-Capacitance- Fm
Transient-mV/A
400
500
600
700
800
900
1000 2000 3000 4000
5000
6000
7000
8000
9000
10000
20
10
9
8
7
6
5
4
3
2
WithTurboTrans
V =8V
I
WithoutTurboTrans
R
TT
Resistor Selection
PTH08T210W
www.ti.com ................................................................................................................................................... SLTS262I – OCTOBER 2005 – REVISED MARCH 2009
Type B Capacitor Type B Capacitor
12 V Input 8 V Input
Figure 13. Cap Type B, 1000 ≤ C( µ F)xESR(m Ω ) ≤ 5000 Figure 14. Cap Type B, 1000 ≤ C( µ F)xESR(m Ω ) ≤ 5000
(e.g. Polymer-Tantalum) (e.g. Polymer-Tantalum)
Table 3. Type B TurboTrans C
O
Values & Required R
TT
Selection Table
Transient Voltage Deviation (mV) 12 V Input 8 V Input
25% 50% 75% C
O
R
TT
C
O
R
TT
Load Step Load Step Load Step Minimum Required Required Minimum Required Required
(7.5 A) (15 A) (22.5 A) Output Capacitance TurboTrans Output Capacitance TurboTrans
( µ F) Resistor ( Ω ) ( µ F) Resistor ( Ω )
100 200 300 470 open 540 205 k
90 180 270 500 499 k 620 93.1 k
80 160 240 580 127 k 720 52.3 k
70 140 210 680 63.4 k 840 32.4 k
60 120 180 800 37.4 k 1000 20.5 k
50 100 150 1000 20.5 k 1300 10.2 k
40 80 120 1300 10.2 k 1700 4.22 k
30 60 90 1800 3.32 k 2300 221
25 50 75 2200 698 4900 0
20 40 60 5400 0 14000 0
The TurboTrans resistor value, R
TT
can be determined from the TurboTrans programming equation, see
Equation 1 .
C
O
values greater than or equal to 2350 µ F require R
TT
to be a short, 0 Ω . (Equation 1 will result in a negative
value for R
TT
when C
O
≥ 2350 µ F.)
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