Datasheet
C − Capacitance − µF
Transient − mV/A
Without TurboTrans
With TurboTrans
40
30
20
4
5000
4000
3000
1000
900
300
200
500
400
700
600
800
2000
10
6
5
8
7
9
C − Capacitance − µF
Transient − mV/A
Without TurboTrans
With TurboTrans
40
30
20
4
5000
4000
3000
1000
900
300
200
500
400
700
600
800
2000
10
6
5
8
7
9
R
TT
+ 40
1 *
ǒ
C
O
ń1250
Ǔ
ǒ
C
O
ń250
Ǔ
* 1
kW
(4)
PTH04T260W , PTH04T261W
SLTS273E – SEPTEMBER 2006 – REVISED JULY 2009 ..................................................................................................................................................
www.ti.com
PTH04T260W Type C Capacitors
5-V Input 3.3-V Input
Figure 14. Capacitor Type C, 5000 < C( µ F) x ESR(m Ω ) ≤ Figure 15. Capacitor Type C, 5000 < C( µ F) x ESR(m Ω ) ≤
10,000 10,000
(e.g. OS-CON) (e.g. OS-CON)
Table 6. Type C TurboTrans C
O
Values and Required R
TT
Selection Table
Transient Voltage Deviation (mV) 5-V Input 3.3 V Input
C
O
R
TT
C
O
R
TT
25% load step 50% load step 75% load step Minimum Required Minimum Required
(0.75 A) (1.5 A) (2.25 A) Required Output TurboTrans Required Output TurboTrans
Capacitance ( µ F) Resistor (k Ω ) Capacitance ( µ F) Resistor (k Ω )
30 60 90 250 open 250 open
25 50 75 270 487 250 open
20 40 60 360 66.5 350 76.8
15 30 45 520 21.5 520 21.5
10 20 30 890 4.53 920 3.92
8 16 24 1200 0.549 1300 short
6 12 18 3050 short 3700 short
R
TT
Resistor Selection
The TurboTrans resistor value, R
TT
can be determined from the TurboTrans programming equation:
Where C
O
is the total output capacitance in µ F. C
O
values greater than or equal to 1250 µ F require R
TT
to be
a short, 0 Ω .
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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