PTH04T261WAD Datasheet, PDF (20/36 Pages) Texas Instruments – 3-A, 2.2-V to 5.5-V INPUT, NON-ISOLATED,

PTH04T260W, PTH04T261W
SLTS273E – SEPTEMBER 2006 – REVISED JULY 2009.................................................................................................................................................. www.ti.com
PTH04T260W Type C Capacitors
5-V Input
40
3.3-V Input
40
30
Without TurboTrans
30
20
20
Without TurboTrans
10
10
9
9
8
8
7
With TurboTrans
7
6
6
5
5
4
4
With TurboTrans
C − Capacitance − µF
Figure 14. Capacitor Type C, 5000 < C(µF) x ESR(mΩ) ≤
10,000
(e.g. OS-CON)
C − Capacitance − µF
Figure 15. Capacitor Type C, 5000 < C(µF) x ESR(mΩ) ≤
10,000
(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
25% load step
(0.75 A)
50% load step
(1.5 A)
75% load step
(2.25 A)
C_O
Minimum
Required Output
Capacitance (µF)
R_TT
Required
TurboTrans
Resistor (kΩ)
C_O
Minimum
Required Output
Capacitance (µF)
R_TT
Required
TurboTrans
Resistor (kΩ)
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:
R_TT + 40
1 * ^ǒC_O ń1250^Ǔ _kW
ǒ_{CO ń250}Ǔ _{* 1}
(4)
Where C_O is the total output capacitance in µF. C_O values greater than or equal to 1250 µF 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.
20
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