Datasheet

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ELECTRICAL CHARACTERISTICS
PTH08000W
SLTS248B – JUNE 2005 – REVISED FEBRUARY 2008
at 25 ° C free-air temperature, V
I
= 12 V, V
O
= 3.3 V, I
O
= I
O
max, C
I
= 100 µF (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
I
O
Output current T
A
= 85 ° C, natural convection airflow 0 2.25 A
V
I
Input voltage range Over I
O
range 4.5
(1)
14 V
Set-point voltage tolerance T
A
= 25 ° C 2
(2)
%
Temperature variation -40 ° C ≤ T
A
≤ 85 ° C 0.5 %V
O
V
O
Line regulation Over V
I
range 7 mV
Load regulation Over I
O
range 0.13 %V
O
Total output voltage variation Includes set-point, line, load, -40 ° C ≤ T
A
≤ 85 ° C 3
(2)
%V
O
V
(ADJ)
Output Voltage Adjust Range Over I
O
range 0.9 5.5 V
R
SET
= 346 Ω , V
O
= 5 V 93.5%
R
SET
= 1.87 k Ω , V
O
= 3.3 V 92%
R
SET
= 3.74 k Ω , V
O
= 2.5 V 90.5%
T
A
= 25 °C,
η Efficiency R
SET
= 6.19 k Ω , V
O
= 2 V 89.5%
I
O
= 2 A
R
SET
= 8.06 k Ω , V
O
= 1.8 V 88%
R
SET
= 13 k Ω , V
O
= 1.5 V 86.5%
R
SET
= 27.4 k Ω , V
O
= 1.2 V 84.5%
Output voltage ripple 20-MHz bandwidth 40 mV
PP
Overcurrent threshold Reset, followed by autorecovery 3.5 A
C
O
= 100 µF, 1 A/µs Recovery time 50 µs
Transient response load step from 50% to
V
O
over/undershoot 100 mV
100% I
O
max
I
IL
track Track input current (pin 2) Pin to GND – 130 µA
dV
track
/dt Track slew rate capability C
O
≤ C
O
(max) 1 V/ms
V
I
= increasing 4.35 4.5
UVLO Undervoltage lockout V
V
I
= decreasing 3.6 4
Input high voltage (V
IH
) Open
(3)
V
Inhibit control (pin 4) Input low voltage (V
IL
) – 0.2 0.5
Input low current (I
IL
) – 5 µA
I
I
(stby) Input standby current Pins 5 and 2 connected 1 mA
f
S
Switching frequency Over V
I
and I
O
ranges 300 kHz
External input capacitance Electrolytic type (C
I
) 100
(4)
µF
Ceramic type (C
O
) 220
µF
External output capacitance Nonceramic type (C
O
) 100
(5)
330
(6)
Equivalent series resistance (nonceramic) 10
(7)
m Ω
Per Telcordia SR-332, 50% stress,
MTBF Calculated reliability 10.3
10
6
Hr
T
A
= 40 ° C, ground benign
(1) The minimum input voltage is 4.5 V or (V
O
+ 1.1) V, whichever is greater.
(2) The set-point voltage tolerance is affected by the tolerance and stability of R
SET
. The stated limit is unconditionally met if R
SET
has a
tolerance of 1% with 100 ppm/ ° C or better temperature stability.
(3) This control pin has an internal pull-up to 3 V (TYP). Do not place an external pull-up on this pin. If it is left open-circuit, the module
operates when input power is applied. A small, low-leakage (< 100 nA) MOSFET is recommended for control. See the Application
section for further guidance.
(4) An external 100-µF electrolytic capacitor is required across the input (V
I
and GND) for proper operation. Locate the capacitor close to
the module.
(5) An external output capacitor is not required for proper operation. Adding 100 µF of distributed capacitance at the load improves the
transient response.
(6) This is the calculated maximum capacitance. The minimum ESR limitation often results in a lower value. See the capacitor application
information for further guidance.
(7) This is the minimum ESR for all the electrolytic (nonceramic) capacitance. Use 14 m Ω as the minimum when calculating the total
equivalent series resistance (ESR) using the maximum ESR values specified by the capacitor manufacturer.
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