Datasheet

C1
1 µF
NC/FB
OUT
1
3
IN
EN
GND
2
4
5
V
I
ESR = 0.2 Ω
V
O
4.7 µF
+
TPS769xx-Q1
TPS76901-Q1, TPS76912-Q1, TPS76915-Q1
TPS76918-Q1, TPS76925-Q1, TPS76927-Q1
TPS76928-Q1, TPS76930-Q1, TPS76933-Q1, TPS76950-Q1
www.ti.com SGLS118C –DECEMBER 2001–REVISED JUNE 2012
APPLICATION INFORMATION
The TPS769xx-Q1 family of low-dropout (LDO) regulators are optimized for use in battery-operated equipment
and automotive applications. They feature extremely low dropout voltages, low quiescent current (17 µA
nominally), and enable inputs to reduce supply currents to 1 µA when the regulators are turned off.
Device Operation
The TPS769xx-Q1 uses a PMOS pass element to dramatically reduce both dropout voltage and supply current
over more conventional PNP-pass-element LDO designs. The PMOS pass element is a voltage-controlled device
and, unlike a PNP transistor, it does not require increased drive current as output current increases. Supply
current in the TPS769xx-Q1 is essentially constant from no load to maximum load.
Current limiting and thermal protection prevent damage by excessive output current and/or power dissipation.
The device switches into a constant-current mode at approximately 350 mA; further load reduces the output
voltage instead of increasing the output current. The thermal protection shuts the regulator off if the junction
temperature rises above approximately 165°C. Recovery is automatic when the junction temperature drops
approximately 25°C below the high temperature trip point. The PMOS pass element includes a back gate diode
that conducts reverse current when the input voltage level drops below the output voltage level.
A voltage of 1.7 V or greater on the EN input will disable the TPS769xx-Q1 internal circuitry, reducing the supply
current to 1 µA. A voltage of less than 0.9 V on the EN input will enable the TPS769xx and will enable normal
operation to resume. The EN input does not include any deliberate hysteresis, and it exhibits an actual switching
threshold of approximately 1.5 V.
A typical application circuit is shown in Figure 21.
TPS76912-Q1, TPS76915-Q1, TPS76918-Q1, TPS76925-Q1, TPS76927-Q1, TPS76928-Q1, TPS76930-Q1,
TPS76933-Q1, TPS76950-Q1 (fixed-voltage options).
Figure 21. Typical Application Circuit
External Capacitor Requirements
Although not required, a 0.047-µF or larger ceramic input bypass capacitor, connected between IN and GND and
located close to the TPS769xx-Q1, is recommended to improve transient response and noise rejection. A higher-
value electrolytic input capacitor may be necessary if large, fast-rise-time load transients are anticipated and the
device is located several inches from the power source.
Like all low dropout regulators, the TPS769xx-Q1 requires an output capacitor connected between OUT and
GND to stabilize the internal control loop. The minimum recommended capacitance is 4.7 µF. The ESR
(equivalent series resistance) of the capacitor should be between 0.2 Ω and 10 Ω. to ensure stability. Capacitor
values larger than 4.7 µF are acceptable, and allow the use of smaller ESR values. Capacitances less than 4.7
µF are not recommended because they require careful selection of ESR to ensure stability. Solid tantalum
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Product Folder Link(s): TPS76901-Q1 TPS76912-Q1 TPS76915-Q1 TPS76918-Q1 TPS76925-Q1 TPS76927-Q1
TPS76928-Q1 TPS76930-Q1 TPS76933-Q1 TPS76950-Q1