Datasheet
ELECTRICAL CHARACTERISTICS
PTN78000W , PTN78000H
SLTS230C – NOVEMBER 2004 – REVISED SEPTEMBER 2008 ......................................................................................................................................
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operating at 25 ° C free-air temperature, V
I
= 24 V, V
O
= 12 V, I
O
= I
O
(max), C
I
= 2 × 4.7 µ F, C
O
= 100 µ F (unless otherwise
noted)
PTN78000H
PARAMETER TEST CONDITIONS
MIN TYP MAX UNIT
V
O
= 12 V 0.1 1.5
I
O
Output current T
A
= 85 ° C, natural convection airflow V
O
= 15 V 0.1 1.5
(1)
A
V
O
= 22 V 0.1 1
(1)
V
I
Input voltage range Over I
O
range 15
(2)
36 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
± 3%
(3)
variation
– 40 ° C < T
A
< 85 ° C
V
I
< 19 V 11.85 V
I
– 3
Output voltage adjust
19 V ≤ V
I
≤ 25 V 11.85 V
I
– 4
V
O
Adj V
range
V
I
> 25 V 11.85 22
V
I
= 24 V, R
SET
= 383 k Ω , V
O
= 12 V 91%
η Efficiency V
I
= 24 V, R
SET
= 15 k Ω , V
O
= 15 V 93%
V
I
= 32 V, R
SET
= 95.3 Ω , V
O
= 22 V 94%
Output voltage ripple 20 MHz bandwith 1% V
O
V
(PP)
I
O (LIM)
Current limit threshold Δ V
O
= – 50 mV, minimum V
I
2 × I
O(max)
A
1 A/ µ s load step from 50% to 100% I
O
max
Transient response Recovery time 200 µ s
V
O
over/undershoot 1 %V
O
V
I
increasing 12.2
UVLO Undervoltage lockout V
V
I
decreasing 12
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 9.4
(5)
µ F
Nonceramic 100
(6)
µ F
External output
C
O
Ceramic 200
capacitance
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) The maximum output current is 1.5 A or the maximum output power is 22.5 W, whichever is less.
(2) For output voltages less than 19 V, the minimum input voltage is 15 V or (V
O
+ 3) V, whichever is greater. For output voltages of 19 V
and higher, the minimum input voltage is (V
O
+ 4) V. 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 small, low-leakage ( < 100 nA) MOSFET is recommended for control. See the Application Information section for
further guidance.
(5) Two external 4.7- µ F ceramic capacitors are 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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