Microchip Technology TC1264-3.3VDBTR, TC1264-3.3VAB, TC1264-3.0VEBTR, TC1264-3.0VDBTR, TC1264-2.5VEBTR Datasheet

TC1264

W

W

3

D

C1264

64

3

0

D

3

3

K

3

800mA Fixed Output CMOS LDO

Features

• Very Low Dr opout Voltage

• 800mA Output Current

• High Output Voltage Accuracy

• Standard or Custom Output Voltages

• Over Current and O ver Temperature Protection

Applications

• Battery Operated Systems

• PortableComputers

• Medical Instruments

• Instrumentation

• Cellular/GSM/PHSPhones

• Linear Post-Regulators for SMPS

• Pagers

Device Selection Table

Part Number Package

TC1264-xxVDB 3-Pin SOT-223 -40°C to +125°C
TC1264-xxVAB 3-Pin TO-220 -40°C to +125°C
TC1264-xxVEB 3-Pin DDPAK -40°C to +125°C

NOTE: xx indicates output voltages.
Available Output Voltages: 1.8, 2.5, 3.0, 3.3.
Otheroutputvoltagesareavailable.Please contactMicrochip

T echnology Inc. for details.

Junction

Temp. Range

Package Type

-Pin TO-22

TC12

ND

TAB IS GN

T

TAB IS GND

-Pin SOT-22

FRONT VIE

TC1264

3-Pin DDPA

FRONT VIE

T

ND

V

3

OUT

GND

2

1

V

IN

TAB IS GN

T

General Description

The TC1264 is a fixed output, high accuracy (typically
±0.5%) CMOS low dropout regulator. Designed
specificallyforbattery-operatedsystems,the TC1264’s
CMOS construction eliminates wasted ground current,
significantly extending battery life. Total supply current
is typically 80µA at full load (20 to 60 times lower than
in bipolar regulators).

TC1264 key features include ultra low noise operation,
very low dropout voltage (typically 450mV at full load),
and f ast response to step changes in load.

The TC1264 incorporates both over temperature and
over current protection. The TC1264 is stable with an
output capacitor of only 1µF and has a maximum
output current of 800mA. It is available in 3-Pin
SOT-223, 3-Pin TO-220 and 3-Pin DDPAK packages.

Typical Application

V



2002 Microchip TechnologyInc. DS21375B-page 1

V

IN

IN

GND

V

TC1264

OUT

C1
1µF

V

OUT

TC1264

1.0 ELECTRICAL
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 8)

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

TC1264 ELECTR ICAL SPECI FICATIONS

Electrical Characteristics: VIN=VR+1.5V,(Note 1),IL=100µA, CL=3.3µF, TA= 25°C, unless otherwise noted. Boldface type

specifications apply for junction temperatures of -40°C to +125°C.

Symbol Parameter Min Typ Max Units Test Conditions

V

IN

I

OUTMAX

V

OUT

/∆TV

∆V

OUT

/∆V

∆V

OUT

∆V

OUT/VOUT

V

IN-VOUT

I

DD

PSRR Power Supply Rejection Ratio — 64 — dB F ≤ 1kHz
I

OUTSC

/∆P

∆V

OUT

eN Output Noise — 260 — nV/√Hz

Note 1: VRis the regulator output voltage setting.

2: The minimum V
3: This accuracy represents the worst case over the entire output current and temperature range.
4:

5: Regulation is measured at a constant junction temperature using low duty cycle pulse testing. Load regulation is tested over a load range

6: Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at a
7: 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
8: The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable junction temperature and the

Input Operating Voltage 2.7 — 6.0 V Note 2
Maximum Output Current 800 ——mA
Output Voltage VR–2.5%

V

–2%

R

–7% — VR+3% VIL= 0.1mA to 800mA (Note 3)

V

R

Temperature Coefficient — 40 — ppm/°C Note 4

OUT

Line Regulation — 0.007 0.35 %(VR+1V)≤ VIN ≤ 6V

IN

Load Regulation -0.01 0.002 0 %/mA IL=0.1mAtoI
Dropout Voltage —

—
—
—
—
—
—

V

R

V

R

±0.5%
±0.5%

20

50
150
260
450
700
890

V

R

V

+2.5%

+3%

R

30
160
480
800

1300
1000
1400

VV

R

V

R

mV V

R

V

R

≥ 2.5V
=1.8V

OUTMAX

≥ 2.5V, IL=100µA

I

=100mA

L

I

=300mA

L

I

=500mA

L

I

=800mA

L

=1.8V,IL=500mA

I

=800mA

L

(Note 6)

SupplyCurrent — 80 130 µAIL=0

Output Short Circuit Current — 1200 — mA V
ThermalRegulation — 0.04 — V/W Note 7

D

has to justify the conditions: VIN≥ VR+V

IN

TC V

=(V

OUT

OUTMAX–VOUTMIN

V

x ∆T

OUT

from 0.1mA to the maximum specified output current. Changes in output voltage due to heating effects are covered by the thermal
regulation specification.

1.5V differential.
line regulation effects. Specifications are for a current pulse equal to I
thermal resistance from junction-to-air (i.e., T

thermal shutdown. Please see Section 4.0 Thermal Considerations for more details.

)x10

6

, θJA). Exceeding the maximum allowable power dissipation causes the device to initiate

A,TJ

andVIN≥ 2.7V for IL= 0.1mA to I

DROPOUT

at VIN= 6V for T = 10 msec.

LMAX

OUT

IL=I

OUTMAX

=0V

OUTMAX

.

,F=10kHz

(Note 5)

DS21375B-page 2



2002 Microchip TechnologyInc.

2.0 PIN DESCRIPTIONS

The descriptions of the pins are listed in Table 2-1.

TABLE 2-1: PIN FUNCTION TABLE

Pin No.

(3-PinSOT-223)

(3-Pin TO-220)
(3-Pin DDPAK)

1V
2 GND Ground terminal.
3V

Symbol Description

IN

OUT

Unregulated supply input.

Regulated voltage output.

TC1264

3.0 DETAILED DESCRIPTION

The TC1264 is a precision, fixed output LDO. Unlike
bipolar regulators, the TC1264’s supply current does
not increase with load current. In addition, V
remains stable and within regulation over the entire
0mA to I

LOADMAX

load current range (an important
consideration in RTC and CMOS RAM battery back-up
applications).

Figure 3-1 shows a typical applicationcircuit.

FIGURE 3-1: TYPICAL APP LICATION

CIRCUIT

Battery

C1
1µF

V

GND

+

+

–

IN

TC1264

V

OUT

+

C2
1µF

V

OUT

OUT

3.1 Output Capacitor

A1µF (min) capacitorfrom V
The output capacitor should have an effective series
resistance greater than 0.1Ω and less than 5Ω.A1µF
capacitorshould be connected from V
is more 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 aluminum
electrolytic capacitors freeze at approximately -30°C,
solid tantalums are recommended for applications
operatingbelow -25°C.) When operating from sources
other than batteries, supply-noise rejection and
transient response can be i mproved by increasing the
value of the input and outputcapacitorsand employing
passive filtering techniques.

to groundis required.

OUT

to GND if there

IN



2002 Microchip TechnologyInc. DS21375B-page 3

TC1264

4.0 THERMAL CONSIDERATIONS

4.1 Thermal Shutdown

Integrated thermal protection circuitry shuts the
regulator off when die temperature exceeds 160°C.
The regulator remains off until the die temperature
drops to approximately 150°C.

4.2 Power 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:

P

≈ (V

D

INMAX–VOUTMIN)ILOADMAX

Where:

P

= Worst case actual power dissipation

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 the maximum ambient temperature
(T

), the maximum allowable die temperature

AMAX

(T

) and t he thermal resistance from j unction-to-air

JMAX

(θ

).

JA

EQUATION 4-2:

P

=(T

DMAX

JMAX–TAMAX

θ

Where all terms ar e previously defined.

Table 4-1 and Table 4-2 show various values of θJAfor
the TC1264 packages.

TABLE 4-1: THERMAL RESISTANCE

GUIDELINES FOR TC1264 IN
SOT-223 PACKA GE

Copper

Area

(Tops ide)*

2500 sq mm 2500sq mm 2500 sq mm 45°C/W
1000 sq mm 2500sq mm 2500 sq mm 45°C/W

225 sq mm 2500 sq mm 2500 sq mm 53°C/W

100 sq mm 2500 sq mm 2500 sq mm 59°C/W
1000 sq mm 1000sq mm 1000 sq mm 52°C/W
1000 sq mm 0 sq mm 1000 sq mm 55°C/W

Copper

Area

(Backside)

JA

Board

Area

IN

)

Thermal

Resistance

(θ

)

JA

TABLE 4-2: THERMAL RESISTANCE

GUIDELINES FOR TC1264 IN
3-PIN DDPAK/TO-220
PACKAGE

Copper

Area

(Tops ide)*

2500 sq mm 2500 sq mm 2500 sq mm 25°C/W
1000 sq mm 2500 sq mm 2500 sq mm 27°C/W

125 sq mm 2500 sq mm 2500 sq mm 35°C/W

Copper

Area

(Backside)

Board

Area

*Tab of device attached t o topside copper
Equation 4-1 can be used in conjunction with Equation

4-2 to ensure regulator thermal operation is within
limits. For example:

Given:

V

INMAX

V

OUTMIN

I

LOADMAX

T

JMAX

T

AMAX
JA = 59°C/W (SOT-223)

θ

= 3.3V ± 10%
= 2.7V ± 0.5%
= 275mA
= 125°C
=95°C

Find: 1. Actual power dissipation

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
= 260mW

Maximum allowable power dissipation:

P

DMAX

=(T

JMAX–TAMAX

θ

)

JA

= (125 – 95)

59

= 508mW

In this example, the TC1264 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 substituting the maximum allowable

IN

power dissipation of 508mW into Equation 4-1, from
which V

INMAX

=4.6V.

Thermal

Resistance

(θ

–3

JA

)

*Tab of device attached t o topside copper

DS21375B-page 4



2002 Microchip TechnologyInc.