HT78XX Series
500mA TinyPower TM LDO
Selection Table
Part No.Output Voltage
Tolerance
s.h.e mv
Package
HT7818  1.8V ±2%
SOT-89TO-92
HT7825  2.5V HT7827  2.7V HT7830  3.0V HT7833  3.3V HT7850
5.0V
Block Diagram
Rev.1.001March 2,2007
Features
·Output voltage ranges:Fixed range of 1.8V,2.5V,
2.7V,
3.0V,3.3V,5.0V type.
·Highly accuracy:±2%
·Low voltage drop:360mV (typ.),
V OUT =5.0V at 500mA
·Guaranteed output current:500mA
·Low quiescent current:5m A (typ.)·Current limiting
·Over-temperature shutdown ·SOT-89,TO-92Packages
Applications
·Battery powered systems ·Personal Digital Assistants ·Peripheral cards
·PCMCIA cards
·Personal Communication Equipment
General Description
The HT78XX series of positive,linear regulators fea-tures low quiescent current (5m A typ.)with low d
ropout voltage,making them ideal for battery applications.The devices are capable of supplying 500mA of output cur-rent continuously.
They are available with several fixed output voltages ranging from 1.8V to 5.0V.Although designed primarily
as fixed voltage regulators,these devices can be used with external components to obtain variable voltages and currents.
These rugged devices have Thermal Shutdown and Current Limiting to prevent device failure under the ²Worst ²of operating
conditions.
Pin Assignment
Absolute Maximum Ratings*
Maximum Supply Voltage ............................up to 8.5V Storage Temperature ..........................-50°C to 125°C
Operating Temperature .........................-40°C to 85°C
Note:These are stress ratings only.Stresses exceeding the range specified under ²Absolute Maximum Ratings ²may
cause substantial damage to the device.Functional operation of this device at other conditions beyond those listed in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability.
²*²Absolute maximum ratings indicate limits beyond which damage to the device may occur.Operating Ratings in-dicate conditions for which the device is intended to be functional,but do not guarantee specific performance limits.The guaranteed specifications apply only for the test conditions listed.
Thermal Information
Symbol
Parameter
Package Max.Unit q JA
Thermal Resistance (Junction to Ambient)
(Assume no ambient airflow,no heat sink)SOT-89200°C/W TO-92200°C/W P D
Power Dissipation
SOT-890.50W TO-92
0.50
W
Note:P D is measured at Ta=25°C
Rev.1.002March 2,2007
Electrical Characteristics T
j=25°C,V IN=V OUT+1.0V,I O=1mA,unless otherwise specified Symbol Parameter Test Conditions Min.Typ.Max.Unit
V IN Input Voltage¾¾¾8V
D V OUT Output Voltage Tolerance¾-2¾2%
I SS Quiescent Current I O=0mA¾57m A
D V LOAD Load Regulation(Note1)1mA£I OUT£500mA¾0.0040.008%/mA
V DROP Dropout Voltage(Note2)D V OUT=2%
I OUT=500mA
V O£1.8V¾8001200
mV
2.5V£V O£2.7V¾500650
3.0V£V O£5.0V¾360500
D V LIN
E Line Regulation V OUT+1.0V£V IN£8.0V¾0.20.3%/V
I LIM Current Limit(Note3)D V OUT=10%500¾¾mA
Temperature Coefficient-40°C<Ta<85°C¾±0.8¾mV/°C Note:  1.Load regulation is measured at a constant junction temperature,using pulse testing with a low ON time and is guaranteed up to the maximum power dissipation.Power dissipation is determined by the input/output
differential voltage and the output current.Guaranteed maximum power dissipation will not be available over the full input/output range.The maximum allowable power dissipation at any ambient temperature is
P D=(T J(MAX)-Ta)/q JA.
2.Dropout voltage is defined as the input voltage minus the output voltage that produces a2%change in the
output voltage from the value at V IN=V OUT+1V with a fixed load.
3.Current limit is measured by pulsing for a short time.
Application Circuits
Basic Circuits
Typical Application Circuits
·High output current positive voltage regulator
Rev.1.003March2,2007
·Increased Output voltage Circuit
V=V(1+R2
R1
)+I R2
OUT XX SS ·Dual Supply Circuit
V=V+V
OUT1XX2XX1
V=V
OUT2XX2·Tracking Voltage Regulator
-V=V x R R
O O A B
Rev.1.004March2,2007
Package Information
3-Pin SOT-89Outline Dimensions
Symbol
Dimensions in mil
Min.Nom.Max.
A173¾181
B64¾72
C90¾102
D35¾47
E155¾167
F14¾19
G17¾22
H¾59¾
I55¾63
J14¾17
Rev.1.005March2,2007