NOTE: xx indicates output voltages
Available Output Voltages: 2.5, 2.8, 3.0, 3.3, 5.0.
Otheroutputvoltagesareavailable.Please contactMicrochip
T echnology Inc. for details.
Junction
Temp. Range
General Description
The TC1108 is a fixed output, high accuracy (typically
±0.5%) CMOS low dropout regulator. Total supply
current is typically 50µA at full load (20 to 60 times
lower than in bipolar regulators).
TC1108 key features include ultra low noise operation,
very low dropout voltage (typically 240mV at full load),
and f ast response to step changes in load.
The TC1108 incorporates both over temperature and
over current protection. The TC1108 is stable with an
output capacitor of only 1µF and has a maximum
output current of 300mA. I t is available in a SOT-223
package.
Typical Application
1
V
IN
V
IN
TC1108
2
GND
V
OUT
3
+
C1
1µF
V
OUT
Package Type
SOT-223
TC1108VDB
321
V
GNDV
IN
2002 Microchip TechnologyInc.DS21357B-page 1
OUT
TC1108
1.0ELECTRICAL
CHARACTERISTICS
Absolute Maximum Ratings*
Input Voltage .........................................................6.5V
Output Voltage..................(V
– 0.3V) to (VIN+0.3V)
SS
Stresses above those listed under "Absolute Maximum
Ratings" may cause permanent damage to the device. These
are stress ratings only and functional operation of the device
at these or any other conditions above those indicated in the
operation sections of the specifications is not implied.
Exposure to Absolute Maximum Rating conditions for
extended periods may affectdevice reliability.
Power Dissipation................Internally Limited (Note 6)
Maximum Voltage on Any Pin ........V
Operating Temperature Range......-40°C < T
+0.3V to -0.3V
IN
<125°C
J
Storage Temperature..........................-65°C to +150°C
TC1108 ELECTRICAL SPECIFICATIONS
Electrical Characteristics: VIN=V
specifications apply for junction temperatures of -40°C to +125°C.
SymbolParameterMinTypMaxUnitsTest Conditions
V
IN
I
OUTMAX
V
OUT
/∆TV
∆V
OUT
/∆VINLine Regulation—0.050.35%(VR+1V)≤ VIN ≤ 6V
∆V
OUT
∆V
OUT/VOUT
V
IN-VOUT
I
DD
InputOperating Voltage2.7—6.0VNote 7
Maximum Output Current300——mA
Output Voltage—
Temperature Coefficient—40—ppm/°CNote 2
OUT
Load Regulation—0.52.0%IL= 0.1mA to I
DropoutVoltage—
Supply Current—5090µA
PSRRPower Supply Rejection Ratio—60—dBF
I
OUTSC
/∆PDThermal Regulation—0.04—V/WNote 5
∆V
OUT
Output ShortCircuit Current—550650mAV
eNOutput Noise—260—nV/√Hz
Note 1: VRis the regulator output voltage setting.
2:
TC V
=(V
OUT
OUTMAX–VOUTMIN
V
3: Regulation is measured at a constant junction temperature using low duty cycle pulse testing. Load regulation is tested over a load range
from 0.1mA to the maximum specified output current. Changes in output voltage due to heating effects are covered by the thermal
regulation specification.
4: Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at a
1V differential.
5: Thermal Regulation is defined as the change in output voltage at a time T after a change in power dissipation is applied, excluding load or
line regulation effects. Specifications are for a current pulse equal to I
6: The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable junction temperature and the
thermal resistance from junction-to-air (i.e., T
thermal shutdown. Please see Section 4.0 Thermal Considerations for more details.
7: The minimum V
OUT
has to justify the conditions: VIN≥ VR+V
IN
+1V,IL=100µA, CL=3.3µF, TA= 25°C, unless otherwise noted. Boldface type
OUT
V
R
–2.5%
—
—
V
±0.5%
R
240
—
20
80
V
R
—
+2.5%
30
160
480
VNote 1
mVI
=0.1mA
L
I
= 100mA
L
I
= 300mA (Note 4)
L
RE
OUT
F=10kHz,C
R
LOAD
6
)x10
x ∆T
at VIN= 6V for T = 10 msec.
LMAX
, θJA). Exceeding the maximum allowable power dissipation causes the device to initiate
A,TJ
and VIN≥ 2.7V for IL= 0.1mA to I
DROPOUT
OUTMAX
OUTMAX
≤ 1kHz
=0V
OUT
=50Ω
.
(Note 3)
=1µF,
DS21357B-page 2
2002 Microchip TechnologyInc.
2.0PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 2-1.
TABLE 2-1:PIN FUNCTION TABLE
TC1108
Pin No.
(3-PinSOT-223)
1V
2GNDGroundterminal.
3V
SymbolDescription
IN
OUT
Unregulated supply input.
Regulated voltage output.
3.0DETAILED DESCRIPTION
The TC1108 is a precision, fixed output LDO. Unlike
bipolar regulators, the TC1108’s supply current does
not increase with load current. In addition, V
remains stable and within regulation over the entire
0mA to I
OUTMAX
operating l oad current range, (an
important consideration in RTC and CMOS RAM
battery back-up applications).
Figure 3-1 shows a typical application circuit.
FIGURE 3-1:TYPICAL AP P LICATION
CIRCUIT
V
OUT
3
+
C2
1µF
Battery
1
V
C1
1µF
2
GND
IN
TC1108
+
+
–
V
OUT
OUT
3.1Output Capacitor
A1µF (min) capacitorfrom V
The output capacitor should have an effective series
resistance greaterthan0.1Ω andlessthan5.0Ω.A1µF
capacitorshould be connected from V
is m ore than 10 inches of wire between the regulator
and the AC filter capacitor, or if a battery is used as the
power source. Aluminum electrolytic or tantalum
capacitor types can be used. (Since many al uminum
electrolytic capacitors freeze at approximately -30°C,
solid tantalums are recommended for applications
operating below -25°C.) When operating from sources
other than batteries, supply-noise rejection and
transient response can be improved by increasing the
value of the input and output capacitors and employing
passive filtering techniques.
to ground is required.
OUT
to GND if there
IN
2002 Microchip TechnologyInc.DS21357B-page 3
TC1108
4.0THERMAL CONSIDERATIONS
4.1Thermal Shutdown
Integrated thermal protection circuitry shuts the
regulator off when die temperature exceeds 150°C.
The regulator remains off until the die temperature
drops to approximately 140°C.
4.2Power Dissipation
The amount of power the regulator dissipates is
primarily a function of input and output voltage, and
output current. The following equation is used to
calculate worst case actual power dissipation:
EQUATION 4-1:
≈ (V
P
D
INMAX–VOUTMIN)ILOADMAX
Where:
= Worst case actual power dissipation
P
D
= Maximum voltage on V
V
INMAX
V
I
LOADMAX
= Minimum regulator output voltage
OUTMIN
= Maximum output (load) current
The maximum allowable power dissipation (Equation
4-2) is a function of t he maximum ambient temperature
(T
), the maximum allowable die temperature
AMAX
(T
) and the thermal resistance from junction-to-air
JMAX
(θ
).
JA
EQUATION 4-2:
P
=(T
DMAX
Where all terms are previously defined.
JMAX–TAMAX
θ
JA
IN
)
Equation 4-1 can be used in conjunction with Equation
4-2 to ensure regulator thermal operation is within
limits. For example:
2. Maximum allowable dissipation
Actual power dissipation:
P
≈ (V
D
INMAX–VOUTMIN)ILOADMAX
= [(3.3 x 1.1) – (2.7 x .995)]275 x 10
–3
= 260mW
Maximum allowable power dissipation:
P
DMAX
=(T
JMAX–TAMAX
θ
)
JA
= (125 – 95)
59
= 508mW
In this example, the TC1108 dissipates a maximum of
260mW; below the allowable limit of 508mW. In a
similar manner, Equation 4-1 and Equation 4-2 can be
used to calculate maximum current and/or input
voltage limits. For example, the maximum allowable
V
, is found by sustituting the maximum allowable
IN
power dissipation of 508mW into Equation 4-1, from
which V
INMAX
=4.6V.
Table 4-1 shows various values of θJAfor the TC1108
versus board copper area.
TABLE 4-1:THERMAL RESISTANCE
GUIDELINES FOR TC1108
Copper
Area
(Topside)*
2500 sq mm 2500sq mm 2500 sq mm45°C/W
1000 sq mm 2500sq mm 2500 sq mm45°C/W
225 sq mm 2500 sq mm 2500 sq mm53°C/W
100 sq mm 2500 sq mm 2500 sq mm59°C/W
1000 sq mm 1000sq mm 1000 sq mm52°C/W
1000 sq mm0 sq mm1000sq mm55°C/W
Copper
Area
(Backside)
Board
Area
NOTE: *Tab of device attached to topside copper
DS21357B-page 4
Thermal
Resistance
(θ
)
JA
2002 Microchip TechnologyInc.
TC1108
5.0TYPICAL CHARACTERISTICS
Note:The gr aphs and tables provided following this note are a statistical summary based on a limited number of
samplesandareprovidedforinformationalpurposesonly.Theperformancecharacteristicslisted hereinare
not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore outside t he warranted r ange.
0.012
0.010
0.008
0.006
0.004
0.002
0.000
LINE REGULATION (%)
-0.002
-0.004
-40° -20°
0° 20° 40° 60° 80° 100° 120°
TEMPERATURE (
Supply Current
100.0
90.0
80.0
70.0
60.0
SUPPLY CURRENT (µA)
50.0
40.0
-40° -20°
0° 20° 40° 60° 80° 100° 120°
TEMPERATURE (°C)
Line Regulation
°C)
Output Noise
NOISE (µV/√HZ)
10.0
1.0
0.1
0.0
0.01
0.011
FREQUENCY (kHz)
R
LOAD
C
OUT
10
DropoutVoltagevs.LoadCurrent
0.40
0.35
0.30
0.25
0.20
0.15
0.10
DROPOUT VOLTAGE (V)
0.05
0.00
0
50
150
100
LOAD CURRENT (mA)
200 250 300
= 50Ω
= 1µF
1001000
2.00
Load Regulation
1.80
1.60
1.40
1.20
1.00
0.80
0.60
LOAD REGULATION (%)
0.40
0.20
0.00
-40° -20° 0° 20° 40° 60° 80° 100° 120°
1 to 300mA
1 to 100mA
TEMPERATURE (
1 to 50mA
°C)
2002 Microchip TechnologyInc.DS21357B-page 5
TC1108
6.0PACKAGING INFORMATION
6.1Package Marking Information
“1” = partnumber code
“2” = represents temperature + date code + lot identity
Component Taping Orientation for 3-Pin SOT-223 Devices
Carrier Tape, Number of Components Per Reel and Reel Size
Package Carrier Width (W) Pitch (P) Part Per Full Reel Reel Size
3-Pin SOT-223 12 mm 8 mm 4000 13 in
PIN 1
User Direction of Feed
Device
Marking
W
P
Standard Reel Component Orientation
for TR Suffix Device
(Mark Right Side Up)
DS21357B-page 6
2002 Microchip TechnologyInc.
6.3Package Dimensions
3-Pin SOT-223
TC1108
.264 (6.70)
.248 (6.30)
.122 (3.10)
.114 (2.90)
.287 (7.30)
.264 (6.70)
.071
(1.80)
MAX.
.146 (3.70)
.130 (3.30)
PIN 1
.004 (0.10)
.001 (0.02)
.091 (2.30) TYP.
.031 (0.80)
.024 (0.60)
.181 (4.60) TYP.
.041 (1.04)
.033 (0.84)
10° MAX.
.013 (0.33)
.009 (0.24)
.036 (0.91) MIN.
Dimensions: inches (mm)
2002 Microchip TechnologyInc.DS21357B-page 7
TC1108
NOTES:
DS21357B-page 8
2002 Microchip TechnologyInc.
TC1108
SALES AND SUPPORT
Data Sheets
Products supportedby a preliminary DataSheetmayhave an erratasheetdescribingminor operationaldifferences and recommendedworkarounds.To determine if an errata sheetexists for a particular device,please contact one of the following:
1.Your local Microchip sales office
2.The Microchip Corporate Literature Center U.S. FAX: (480) 792-7277
3.The Microchip Worldwide Site (www.microchip.com)
Pleasespecify which device, revision of silicon and Data Sheet (includeLiterature #) you are using.
New Customer Notification System
Register on our web site (www.microchip.com/cn)to receive the most currentinformationon our products.
2002 Microchip Technology Inc.DS21357B-page 9
TC1108
NOTES:
DS21357B-page 10 2002 Microchip Technology Inc.
TC1108
Information contained in this publication regarding device
applications and the like is intended through suggestion only
and may be superseded by updates. It is your responsibility to
ensure that your application meets with your specifications.
No representation or warranty is given and no liability is
assumed by Microchip Technology Incorporated with respect
to the accuracy or use of such information, or infringement of
patents or other intellectual property rights arising from such
use or otherwise. Use of Microchip’s products as critical components in life support systems is not authorized except with
express written approval by Microchip. No licenses are conveyed, implicitly or otherwise, under any intellectual property
rights.
Trademarks
The Microchip name and logo, the Micr ochip logo, Filter Lab,
K
EELOQ,microID,MPLAB,PIC,PICmicro,PICMASTER,
PICSTART, PRO MA TE, SEEVAL and The Embedded Control
SolutionsCompany areregiste red trademarksof MicrochipTechnologyIncorp or ated in the U.S.A. and other countries .
dsPIC, ECONOMONI TOR, FanSense, FlexROM, fuzzyLAB,
In-Circuit Serial Programming, ICSP, ICEPIC, microPort,
Migratable Memory, MPASM, MPLIB, MPLINK, MPSIM,
MXDEV,MXLAB, PICC, PICDEM, PICDEM.net, rfPIC, Select
Mode and Total Endurance are trademarks of Microchip
TechnologyIncorporated in the U.S.A.
Serialized Quick Turn Programming (SQTP) is a service mark
of Microchip TechnologyIncorporated in t he U.S.A.
All other trademarks mentioned herein are property of their
respective companies.
Microchip received QS-9000 quality system
certification for its worldwide headquarters,
design and wafer fabrication facilities in
Chandler and Tempe, Arizona in July 1999
and Mountain View, California in March 2002.
The Company’s quality system processes and
procedures are QS-9000 compliant for its
®
PICmicro
devices, Serial EEPROMs, microperipherals,
non-volatile memory and analog products. In
addition, Microchip’s quality system for the
design and manufacture of development
systemsisISO 9001certified.
2002 Microchip TechnologyInc.DS21357B-page 11
8-bit MCUs, KEELOQ®code hopping
WORLDWIDE SALESAND SERVICE
AMERICAS
Corporate Office
2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: 480-792-7200 Fax: 480-792-7277
Technical Support: 480-792-7627
Web Address: http://www.microchip.com
Rocky Mountain
2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: 480-792-7966 Fax: 480-792-7456
Atlanta
500 Sugar Mill Road, Suite 200B
Atlanta, GA 30350
Tel: 770-640-0034 Fax: 770-640-0307
Boston
2 Lan Drive, Suite 120
Westford, MA 01886
Tel: 978-692-3848 Fax: 978-692-3821
Chicago
333 Pierce Road, Suite 180
Itasca, IL 60143
Tel: 630-285-0071 Fax: 630-285-0075
Microchip Technology Australia Pty Ltd
Suite 22, 41 Rawson Street
Epping 2121, NSW
Australia
Tel: 61-2-9868-6733 Fax: 61-2-9868-6755
China - Beijing
Microchip Technology Consulting (Shanghai)
Co., Ltd., Beijing Liaison Office
Unit 915
Bei Hai Wan Tai Bldg.
No. 6 Chaoyangmen Beidajie
Beijing, 100027, No. China
Tel: 86-10-85282100 Fax: 86-10-85282104
China - Chengdu
Microchip Technology Consulting (Shanghai)
Co., Ltd., Chengdu Liaison Office
Rm. 2401, 24th Floor,
Ming Xing Financial Tower
No. 88 TIDU Street
Chengdu 610016, China
Tel: 86-28-86766200 Fax: 86-28-86766599
China - Fuzhou
Microchip Technology Consulting (Shanghai)
Co., Ltd., Fuzhou Liaison Office
Unit 28F, World Trade Plaza
No. 71 Wusi Road
Fuzhou 350001, China
Tel: 86-591-7503506 Fax: 86-591-7503521
China - Shanghai
Microchip Technology Consulting (Shanghai)
Co., Ltd.
Room 701, Bldg. B
Far East International Plaza
No. 317 Xian Xia Road
Shanghai, 200051
Tel: 86-21-6275-5700 Fax: 86-21-6275-5060
China - Shenzhen
Microchip Technology Consulting (Shanghai)
Co., Ltd., Shenzhen Liaison Office
Rm. 1315, 13/F , Shenzhen Kerry Centre,
Renminnan Lu
Shenzhen 518001, China
Tel: 86-755-2350361 Fax: 86-755-2366086
China - Hong Kong SAR
Microchip Technology Hongkong Ltd.
Unit 901-6, Tower2, Metroplaza
223 Hing Fong Road
Kwai Fong, N.T., Hong Kong
Tel: 852-2401-1200 Fax: 852-2401-3431
India
Microchip Technology Inc.
India Liaison Office
Divyasree Chambers
1 Floor, Wing A (A3/A4)
No. 11, O’Shaugnessey Road
Bangalore, 560 025, India
Tel: 91-80-2290061 Fax: 91-80-2290062
Japan
Microchip Technology Japan K.K.
Benex S-1 6F
3-18-20, Shinyokohama
Kohoku-Ku, Yokohama-shi
Kanagawa, 222-0033, Japan
Tel: 81-45-471- 6166 Fax: 81-45-471-6122
Korea
Microchip Technology Korea
168-1, Youngbo Bldg. 3 Floor
Samsung-Dong, Kangnam-Ku
Seoul, Korea 135-882
Tel: 82-2-554-7200 Fax: 82-2-558-5934
Singapore
Microchip Technology Singapore Pte Ltd.
200 Middle Road
#07-02 Prime Centre
Singapore, 188980
Tel: 65-6334-8870 Fax: 65-6334-8850
Microchip Technology SARL
Parc d’Activite du Moulin de Massy
43 Rue du Saule Trapu
Batiment A - ler Etage
91300 Massy, France
Tel: 33-1-69-53-63-20 Fax: 33-1-69-30-90-79