PTH04T261WAD Datasheet, PDF (8/36 Pages) Texas Instruments – 3-A, 2.2-V to 5.5-V INPUT, NON-ISOLATED,

PTH04T260W, PTH04T261W
SLTS273E – SEPTEMBER 2006 – REVISED JULY 2009.................................................................................................................................................. www.ti.com
PTH04T260/261W
(TOP VIEW)
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TERMINAL FUNCTIONS
TERMINAL
DESCRIPTION
NAME
NO.
V_I
V_O
GND
2 The positive input voltage power node to the module, which is referenced to common GND.
4 The regulated positive power output with respect to the GND.
3
This is the common ground connection for the V_I and V_O power connections. It is also the 0 Vdc reference for
the control inputs.
Inhibit and
UVLO ⁽¹⁾
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
10 ^{module produces an output whenever a valid input source is applied.}
This pin is also used for input undervoltage lockout (UVLO) programming. Connecting a resistor from this pin to
GND (pin 3) allows the ON threshold of the UVLO to be adjusted higher than the default value. For more
information, see the Application Information section.
V_O Adjust
A 0.05 W 1% resistor must be directly connected between this pin and pin 6 (– Sense), close to the module to
set the output voltage to a value higher than 0.69 V. The temperature stability of the resistor should be 100
ppm/°C (or better). The setpoint range for the output voltage is from 0.69 V to 3.6 V. If left open circuit, the
7 _{output voltage defaults to its lowest value. For further information, on output voltage adjustment see the related}
application note.
The specification table gives the preferred resistor values for a number of standard output voltages.
+ Sense
– Sense
5
The sense input allows the regulation circuit to compensate for voltage drop between the module and the load.
For optimal voltage accuracy, +Sense must be connected to V_O, close to the load.
The sense input allows the regulation circuit to compensate for voltage drop between the module and the load.
6 For optimal voltage accuracy, –Sense must be connected to GND (pin 3), very close to the module (within 10
cm).
Track
This is an analog control input that enables the output voltage to follow an external voltage. This pin becomes
active typically 20 ms after the input voltage has been applied, and allows direct control of the output voltage
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from 0 V up to the nominal set-point voltage. Within this range the module's output voltage follows the voltage at
the Track pin on a volt-for-volt basis. When the control voltage is raised above this range, the module regulates
at its set-point voltage. The feature allows the output voltage to rise simultaneously with other modules powered
from the same input bus. If unused, this input should be connected to V_I.
NOTE: Due to the undervoltage lockout feature, the output of the module cannot follow its own input voltage
during power up. For more information, see the related application note.
TurboTrans™
This input pin adjusts the transient response of the regulator. To activate the TurboTrans feature, a 1%, 0.05 W
resistor must be connected between this pin and pin 5 (+Sense) very close to the module. For a given value of
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output capacitance, a reduction in peak output voltage deviation is achieved by using this feature. If unused, this
pin must be left open-circuit. The resistance requirement can be selected from the TurboTrans resistor table in
the Application Information section. External capacitance must never be connected to this pin unless the
TurboTrans resistor is a short, 0Ω.
SmartSync
This input pin sychronizes the switching frequency of the module to an external clock frequency. The SmartSync
1
feature can be used to sychronize the switching fequency of multiple PTH04T260/261W modules, aiding EMI
noise suppression efforts. If unused, this pin should be connected to GND (pin 3). For more information, please
review the Application Information section.
(1) Denotes negative logic: Open = Normal operation, Ground = Function active
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