TPS75201-EP TPS75215-EP TPS75218-EP TPS75225-EP TPS75233-EP WITH RESET
TPS75401-EP
’
75415-EP
’
75418-EP
’
75425-EP
’
75433-EP WITH POWER GOOD
FAST-TRANSIENT-RESPONSE 2-A LOW-DROPOUT VOLTAGE REGULATORS
SGLS165
–
APRIL 2003
15
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
APPLICATION INFORMATION
The TPS752xx or TPS754xx families include four fixed-output voltage regulators (1.5 V, 1.8 V, 2.5 V and 3.3 V), and
an adjustable regulator, the TPS75x01 (adjustable from 1.5 V to 5 V).
minimum load requirements
The TPS752xx and TPS754xx families are stable even at no load; no minimum load is required for operation.
pin functions
enable (EN)
The EN terminal is an input which enables or shuts down the device. If EN is a logic high, the device will be in
shutdown mode. When EN goes to logic low, then the device will be enabled.
power good (PG) (TPS752xx)
The PG terminal is an open drain, active high output that indicates the status of V
O
(output of the LDO). When V
O
reaches 83% of the regulated voltage, PG will go to a high impedance state. It will go to a low-impedance state when
V
O
falls below 83% (i.e. over load condition) of the regulated voltage. The open drain output of the PG terminal
requires a pullup resistor
.
sense (SENSE)
The SENSE terminal of the fixed-output options must be connected to the regulator output, and the connection
should be as short as possible. Internally, SENSE connects to a high-impedance wide-bandwidth amplifier through
a resistor-divider network and noise pickup feeds through to the regulator output. It is essential to route the SENSE
connection in such a way to minimize/avoid noise pickup. Adding RC networks between the SENSE terminal and
V
O
to filter noise is not recommended because it may cause the regulator to oscillate.
feedback (FB)
FB is an input terminal used for the adjustable-output options and must be connected to an external feedback
resistor divider. The FB connection should be as short as possible. It is essential to route it in such a way to
minimize/avoid noise pickup. Adding RC networks between FB terminal and V
O
to filter noise is not recommended
because it may cause the regulator to oscillate.
reset (RESET) (TPS754xx)
The RESET terminal is an open drain, active low output that indicates the status of V
O
. When V
O
reaches 95% of
the regulated voltage, RESET will go to a low-impedance state after a 100-ms delay. RESET will go to a
high-impedance state when V
O
is below 95% of the regulated voltage. The open-drain output of the RESET terminal
requires a pullup resistor.
GND/HEATSINK
All GND/HEATSINK terminals are connected directly to the mount pad for thermal-enhanced operation. These
terminals could be connected to GND or left floating.
input capacitor
For a typical application, an input bypass capacitor (0.22
μ
F
–
1
μ
F) is recommended for device stability. This
capacitor should be as close to the input pins as possible. For fast transient condition where droop at the input of
the LDO may occur due to high inrush current, it is recommended to place a larger capacitor at the input as well.
The size of this capacitor is dependant on the output current and response time of the main power supply, as well
as the distance to the load (LDO).