User manual

page 80
Analog System Lab Kit PRO
appendix A
The TPS72xx family of low-dropout (LDO) voltage
regulators oers the benets of low-dropout
voltage, micropower operation, and miniaturized
packaging. These regulators feature extremely low
dropout voltages and quiescent currents compared to
conventionalLDOregulators.Oeredinsmall-outline
integrated-circuit (SOIC) packages and 8-terminal
thin shrink small-outline (TSSOP), the TPS72xx
series devices are ideal for cost-sensitive designs
and for designs where board space is at a premium.
A combination of new circuit design and process
innovation has enabled the usual pnp pass transistor
to be replaced by a PMOS device. Because the PMOS
pass element behaves as a ue resistor, the dropout
voltage is very low – maximum of 85 mV at 100 mA
of load current (TPS7250) – and is directly proportional
to the load current. Since the PMOS pass element
is a voltage-driven device, the quiescent current is
very low (300 mA maximum) and is stable over the
entire range of output load current (0 mA to 250 mA).
Intended for use in portable systems such as laptops
and cellular phones, the low-dropout voltage and
micropoweroperationresultinasignicantincrease
in system battery operating life.
•Availablein5-V,4.85-V,3.3-V,3.0-V,and2.5-V
Fixed-Output and Adjustable Versions
•DropoutVoltage<85mVMaxatIO=100mA
(TPS7250)
•LowQuiescentCurrent,IndependentofLoad,180
mA Typ
•8-PinSOICand8-PinTSSOPPackage
•OutputRegulatedto±2%OverFullOperating
Range for Fixed-Output Versions
•ExtremelyLowSleep-StateCurrent,0.5mAMax
•Power-Good(PG)StatusOutput
•WirelessHandsets
•SmartPhones,PDAs
•MP3Players
•ZigBeeTMNetworks
•BluetoothTMDevices
•Li-IonOperatedHandheldProducts
•WLANandOtherPCAdd-onCards
http://www.ti.com/lit/gpn/tps7250
Micropower Low-Dropout (LDO) Voltage Regulator
SENSE
PG
OUT
OUT
6
5
4
IN
IN
EN
GND
3
2
1
7
8
V
I
0.1 F
PG
CSR = 1 
V
O
10 F
+
TPS7250
C
O
250 k
A.5.1 Features
A.5.3 Description
A.5.4 Download DatasheetA.5.2 Applications
TPS7250
Figure A.5: TPS7250 -Micropower Low-Dropout (LDO) Voltage Regulator