Datasheet

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DEVICE INFORMATION
PIN1
)
V -0.8
O
0.8
-7.135kW
(
R =30.1
SET
x
PTV08040W
SLTS257B – SEPTEMBER 2005 – REVISED JANUARY 2008
PTV08040W
(Top View)
TERMINAL FUNCTIONS
TERMINAL
DESCRIPTION
NAME NO.
This is the common ground connection for the V
I
and V
O
power connections. It is also the 0 V
dc
GND 4, 5, 11, 12, 18, 19
reference for the control inputs.
V
I
6, 7, 13, 14, 20, 21 The positive input voltage power node to the module, which is referenced to common GND.
V
O
3, 10, 17 The regulated positive power output with respect to GND.
The Inhibit pin is an open-collector/drain negative logic input that is referenced to GND. Applying a
low-level ground signal to this input disables the module ’ s output and turns off the output voltage.
When the Inhibit control is active, the input current drawn by the regulator is significantly reduced. If
the Inhibit pin is left open-circuit, the module produces an output whenever the input voltage is above
Inhibit /
16 the UVLO threshold.
UVLO
This pin is also used for input undervoltage lockout (UVLO) programming. Connecting a resistor from
this pin to signal ground allows the ON threshold of the UVLO to be adjusted higher than the default
value. The hysterisis can also be independently reduced by connecting a second resistor from this pin
to V
I
. For further information, see the Application Information section.
A 1%, 0.05-W resistor must be connected between this pin and GND to set the output voltage higher
than the minimum value. The set-point range for the output voltage is from 0.8 V to 3.6 V. The resistor
V
O
Adjust 8 required for a given output voltage may be calculated from the following formula. If left open circuit, the
module output defaults to its lowest output voltage value. For further information on the adjustment
and/or trimming of the output voltage, see the related Application Information section.
The specification table gives the preferred resistor values for a number of standard output voltages.
The sense inputs allow the regulation circuit to compensate for voltage drop between the module and
+Sense 1 the load. For optimal voltage accuracy, +Sense should be connected to V
O
. If it is left open, a
low-value internal resistor ensures that the output remains in regulation.
For optimal voltage accuracy, – Sense should be connected to the ground return at the load. If it is left
– Sense 2
open, a low-value internal resistor ensures that the output remains in regulation.
This is an analog control input that allows the output voltage to follow another voltage during power up
and power down sequences. The pin is active from 0 V, up to the nominal set-point voltage. Within this
range, the module output follows the voltage at the Track pin on a volt-for-volt basis. When the control
Track 15
voltage is raised above this range, the module regulates at its nominal output voltage. If unused, this
input should be connected to V
I
for a faster power up. For further information, see the related
Application Information section.
N/C 9 No Connection
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