Datasheet
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PTH08T250W
Texas
Instruments
PTH08T250W
www.ti.com
SLTS278G –NOVEMBER 2010–REVISED MARCH 2009
ELECTRICAL CHARACTERISTICS
PTH08T250W
(continued)
T
A
= 25°C, V
I
= 12 V, V
O
= 3.3 V, C
I
= 1000 µF, C
O
= 660 µF, and I
O
= I
O
max (unless otherwise stated)
PARAMETER TEST CONDITIONS PTH08T250W UNIT
MIN TYP MAX
Nonceramic 1000
(6)
C
I
External input capacitance µF
Ceramic 22
Capacitance Value Non-ceramic 660
(7)
8000
(8)
µF
w/o TurboTrans Ceramic 1000
(9)
Equivalent series resistance (non-ceramic) 3 mΩ
Non-ceramic 660
(7)
C
O
External output capacitance
(10)
Capacitance Value µF
w/ TurboTrans Ceramic 1000
(9)
10000
Capacitance × ESR product (C
O
× ESR) 1000 µF×mΩ
(10)
Per Telcordia SR-332, 50% stress,
MTBF Reliability 2.79
10
6
Hr
T
A
= 40°C, ground benign
(6) A 1000 µF electrolytic input capacitor is required for proper operation. When operating at an input voltage greater than 8V the minimum
required input capacitance may be reduced to 560mF. The input capacitor must be rated for a minimum of 600 mA rms of ripple current.
(7) 660 µF of external non-ceramic output capacitance is required for basic operation. Adding additional capacitance at the load further
improves transient response. See the Capacitor Application Information section and the TuboTrans Technology section for more
guidance.
(8) This is the calculated maximum when not using TurboTrans™ technology. This value includes both ceramic and non-ceramic
capacitors. The minimum ESR requirement often results in a lower value of output capacitance. See the Capacitor Application
Information section for more guidance.
(9) Ceramic output capacitance may be added in addition to the required non-ceramic output capacitance. The amount of ceramic
capacitance must be less than the non-ceramic capacitance, not to exceed 1000 µF.
(10) When using TurboTrans™ technology, a minimum value of output capacitance is required for proper operation. Additionally, low ESR
capacitors are required for proper operation. See the TurboTrans Technology section for further guidance.
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