Datasheet

ELECTRICAL CHARACTERISTICS
PTN78000W , PTN78000H
www.ti.com ...................................................................................................................................... SLTS230C – NOVEMBER 2004 – REVISED SEPTEMBER 2008
operating at 25 ° C free-air temperature, V
I
= 20 V, V
O
= 5 V, I
O
= I
O
(max), C
I
= 2.2 µ F, C
O
= 100 µ F (unless otherwise noted)
PTN78000W
PARAMETER TEST CONDITIONS
MIN TYP MAX UNIT
I
O
Output current T
A
= 85 ° C, natural convection airflow 0 1.5 A
V
I
Input voltage range Over I
O
range 7
(1)
36
(2)
V
Set-point voltage tolerance T
A
= 25 ° C ± 2%
(3)
Temperature variation – 40 ° C to +85 ° C ± 0.5%
Line regulation Over V
I
range ± 10 mV
V
O
Load regulation Over I
O
range ± 10 mV
Includes set point, line, load
Total output voltage variation ± 3%
(3)
– 40 ° C < T
A
< 85 ° C
V
I
< 12 V 2.5 V
I
– 2
12 V ≤ V
I
≤ 15.1 V 2.5 V
I
– 2.5
V
O
Adj Output voltage adjust range V
15.1 V < V
I
≤ 25 V 2.5 12.6
V
I
> 25 V 0.1 x V
I
12.6
V
I
= 24 V, R
SET
= 732 Ω , V
O
= 12 V 91%
η Efficiency V
I
= 15 V, R
SET
= 21 k Ω , V
O
= 5 V 86%
V
I
= 15 V, R
SET
= 78.7 k Ω , V
O
= 3.3 V 82%
Output voltage ripple 20 MHz bandwith 1% V
O
V
(PP)
I
O (LIM)
Current limit threshold Δ V
O
= – 50 mV 3.2 A
1 A/ µ s load step from 50% to 100% I
O
max
Transient response Recovery time 100 µ s
V
O
over/undershoot 2.5 %V
O
V
I
increasing 5.5
UVLO Undervoltage lockout V
V
I
decreasing 5.2
Input high voltage (V
IH
) 1 Open
(4)
V
Inhibit control (pin 3) Input low voltage (V
IL
) – 0.1 0.3
Input low current (I
IL
) 0.25 mA
I
I (STBY)
Input standby current Pin 3 connected to GND 17 mA
F
S
Switching frequency Over V
I
and I
O
ranges 440 550 660 kHz
C
I
External input capacitance Ceramic 2.2
(5)
µ F
Nonceramic 100
(6)
µ F
C
O
External output capacitance Ceramic 200
Equiv. series resistance (nonceramic) 10
(7)
m Ω
Per Telcordia SR-332, 50% stress,
MTBF Calculated reliability 8.9
10
6
Hr
T
A
= 40 ° C, ground benign
(1) For output voltages less than 10 V, the minimum input voltage is 7 V or (V
O
+ 2) V, whichever is greater. For output voltages of 10 V
and higher, the minimum input voltage is (V
O
+ 2.5) V. See the Application Information section for further guidance.
(2) For output voltages less than 3.6 V, the maximum input voltage is 10 × V
O
. See the Application Information section for further guidance.
(3) 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 with 100 ppm/ ° C or better temperature stability.
(4) This control pin has an internal pullup, and if left open circuit, the module operates when input power is applied. The open-circuit voltage
is typically 1.5 V. A smal,l low-leakage ( < 100 nA) MOSFET is recommended for control. See the Application Information section for
further guidance.
(5) An external 2.2- µ F ceramic capacitor is required across the input (V
I
and GND) for proper operation. Locate the capacitor close to the
module.
(6) 100 µ F of output capacitance is required for proper operation. See the Application Information section for further guidance.
(7) This is the typical ESR for all the electrolytic (nonceramic) capacitance. Use 17 m Ω as the minimum when using maximum ESR values
to calculate.
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