TPS793285_技术文档

TPS79301, TPS79318

D

B

V

6

Y

E

Q

D BV 5

TPS79325, TPS79328, TPS793285

TPS79330, TPS79333, TPS793475

www.ti.com

SLVS348H–JULY 2001–REVISED OCTOBER 2004

ULTRALOW-NOISE, HIGH PSRR, FAST RF 200-mA LOW-DROPOUT LINEAR

REGULATORS IN NanoStar™ WAFER CHIP SCALE AND SOT23

FEATURES

DESCRIPTION

•

200-mA RF Low-Dropout Regulator

With Enable

The TPS793xx family of low-dropout (LDO)

low-power linear voltage regulators features high

power-supply rejection ratio (PSRR), ultralow-noise,

fast start-up, and excellent line and load transient

responses in NanoStar wafer chip scale and SOT23

packages. NanoStar packaging gives an ultrasmall

footprint as well as an ultralow profile and package

weight, making it ideal for portable applications such

as handsets and PDAs. Each device in the family is

stable, with a small 2.2-µF ceramic capacitor on the

output. The TPS793xx family uses an advanced,

proprietary BiCMOS fabrication process to yield ex-

tremely low dropout voltages (e.g., 112 mV at

200 mA, TPS79330). Each device achieves fast

start-up times (approximately 50 µs with a 0.001-µF

bypass capacitor) while consuming very low quiesc-

ent current (170 µA typical). Moreover, when the

device is placed in standby mode, the supply current

is reduced to less than 1 µA. The TPS79328 exhibits

approximately 32 µV_RMSof output voltage noise at

2.8-V output with a 0.1-µF bypass capacitor. Appli-

•

Available in 1.8-V, 2.5-V, 2.8-V, 2.85-V, 3-V,

3.3-V, 4.75-V, and Adjustable (1.22-V to 5.5-V)

•

High PSRR (70 dB at 10 kHz)

Ultralow-Noise (32 µV_RMS, TPS79328)

Fast Start-Up Time (50 µs)

Stable With a 2.2-µF Ceramic Capacitor

Excellent Load/Line Transient Response

Very Low Dropout Voltage (112 mV at Full

Load, TPS79330)

•

5- and 6-Pin SOT23 (DBV) and NanoStar Wafer

Chip Scale (YEQ) Packages

APPLICATIONS

•

RF: VCOs, Receivers, ADCs

Audio

Cellular and Cordless Telephones

Bluetooth™, Wireless LAN

Handheld Organizers, PDAs

cations with analog components

that

are

noise-sensitive, such as portable RF electronics,

benefit from the high PSRR and low-noise features

as well as the fast response time.

DBV PACKAGE

(TOP VIEW)

TPS79328

OUT

NR

IN

1

2

5

RIPPLE REJECTION

vs

OUTPUT SPECTRAL NOISE DENSITY

vs

GND

FREQUENCY

0.30

3

4

100

90

EN

V

= 3.8 V

= 2.2 µF

IN

I

= 200 mA

OUT

Fixed Option

C

OUT

= 0.1 µF

0.25

0.20

80

NR

DBV PACKAGE

(TOP VIEW)

70

IN

GND

EN

OUT

FB

1

2

6

5

60

0.15

50

40

30

I

= 1 mA

OUT

I

= 10 mA

OUT

3

4

NR

0.10

0.05

I

= 200 mA

Adjustable Option

YEQ

OUT

20

10

0

V

C

= 3.8 V

= 10 µF

IN

PACKAGE

(TOP VIEW)

OUT

= 0.01 µF

NR

0

IN

OUT

100

1 k

10 k

100 k

10

100

1 k

10 k 100 k 1 M 10 M

C3 C1

B2

A3 A1

Frequency (Hz)

NR

GND

EN

Figure 1.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas

Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

Bluetooth is a trademark of Bluetooth Sig, Inc.

NanoStar is a trademark of Texas Instruments.

UNLESS OTHERWISE NOTED this document contains PRO-

DUCTION DATA information current as of publication date. Prod-

ucts conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily

include testing of all parameters.

TPS79301, TPS79318

TPS79325, TPS79328, TPS793285

TPS79330, TPS79333, TPS793475

www.ti.com

SLVS348H–JULY 2001–REVISED OCTOBER 2004

This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated

circuits be handled with appropriate precautions. Failure to observe proper handling and installation

procedures can cause damage.

ESD damage can range from subtle performance degradation to complete device failure. Precision

integrated circuits may be more susceptible to damage because very small parametric changes could

cause the device not to meet its published specifications.

AVAILABLE OPTIONS⁽¹⁾⁽²⁾

PRODUCT

VOLTAGE

PACKAGE

SOT23 (DBV)

CSP (YEQ)

T_J

SYMBOL

PGVI

PHHI

E3

PART NUMBER

TPS79301DBVR

TPS79318DBVR

TPS79318YEQ

TPS79325DBVR

TPS79325YEQ

TPS79328DBVR

TPS79328YEQ

TPS793285DBVR

TPS793285YEQ

TPS79330DBVR

TPS79330YEQ

TPS79333DBVR

TPS793475DBVR

TPS79301

1.22 V to 5.5 V

TPS79318

TPS79325

TPS79328

TPS793285

TPS79330

1.8 V

2.5 V

2.8 V

2.85 V

3 V

SOT23 (DBV)

CSP (YEQ)

PGWI

E4

SOT23 (DBV)

CSP (YEQ)

PGXI

E2

-40°C to +125°C

SOT23 (DBV)

CSP (YEQ)

PHII

E5

SOT23 (DBV)

CSP (YEQ)

PGYI

E6

TPS79333

3.3 V

SOT23 (DBV)

PHUI

PHJI

TPS793475

4.75 V

(1) For the most current package and ordering information, see the Package Option Addendum located at the end of this data sheet.

(2) DBVR indicates tape and reel of 3000 parts. YEQR indicates tape and reel of 3000 parts. YEQT indicates tape and reel of 250 parts.

ABSOLUTE MAXIMUM RATINGS

over operating temperature range (unless otherwise noted)⁽¹⁾

UNIT

V_INrange

-0.3 V to 6 V

-0.3 V to V_IN+ 0.3 V

-0.3 V to 6 V

V_ENrange

V_OUTrange

Peak output current

Internally limited

2 kV

ESD rating, HBM

ESD rating, CDM

500 V

Continuous total power dissipation

Junction temperature range, DBV package

Junction temperature range, YEQ package

Storage temperature range, T_stg

See Dissipation Ratings Table

-40°C to 150°C

-40°C to 125°C

-65°C to 150°C

(1) Stresses beyond 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 beyond those indicated under recommended operating

conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

2

TPS79301, TPS79318

TPS79325, TPS79328, TPS793285

TPS79330, TPS79333, TPS793475

www.ti.com

SLVS348H–JULY 2001–REVISED OCTOBER 2004

DISSIPATION RATINGS TABLE

T

_A≤ 25°C

T_A= 70°C

POWER

RATING

T_A= 85°C

POWER

RATING

DERATING FACTOR

POWER

RATING

BOARD

Low-K⁽¹⁾

High-K⁽²⁾

Low-K⁽¹⁾

High-K⁽²⁾

PACKAGE

DBV

R_θJC

R_θJA

ABOVE T_A= 25°C

65°C/W

27°C/W

255°C/W

180°C/W

255°C/W

190°C/W

3.9 mW/°C

5.6 mW/°C

3.9 mW/°C

5.3 mW/°C

390 mW

560 mW

390 mW

530 mW

215 mW

310 mW

215 mW

296 mW

155 mW

225 mW

155 mW

216 mW

DBV

YEQ

(1) The JEDEC low-K (1s) board design used to derive this data was a 3-inch x 3-inch, two layer board with 2 ounce copper traces on top

of the board.

(2) The JEDEC high-K (2s2p) board design used to derive this data was a 3-inch x 3-inch, multilayer board with 1 ounce internal power and

ground planes and 2 ounce copper traces on top and bottom of the board.

ELECTRICAL CHARACTERISTICS

over recommended operating temperature range T_J= -40 to 125°C, V_EN= V_IN, V_IN= V_OUT(nom)+ 1 V⁽¹⁾, I_OUT= 1 mA,

C_OUT= 10 µF, C_NR= 0.01 µF (unless otherwise noted). Typical values are at 25°C.

PARAMETER

V_INInput voltage⁽¹⁾

TEST CONDITIONS

MIN

TYP

MAX

5.5

UNIT

V

2.7

I_OUTContinuous output current

V_FBInternal reference (TPS79301)

Output voltage range (TPS79301)

0

200

mA

V

1.201

V_FB

1.225

1.250

5.5 - V_DO

1.836

2.55

V

TPS79318

0 µA < I_OUT< 200 mA,

0 µA ≤ I_OUT< 200 mA,

0 µA < I_OUT< 200 mA,

V_OUT+ 1 V < V_IN≤ 5.5 V

0 µA < I_OUT< 200 mA,

I_OUT= 200 mA

2.8 V < V_IN< 5.5 V

3.5 V < V_IN< 5.5 V

3.8 V < V_IN< 5.5 V

3.85 V < V_IN< 5.5 V

4 V < V_IN< 5.5 V

1.764

2.45

2.744

2.793

2.94

3.234

4.655

1.8

2.5

2.8

2.85

3

V

TPS79325

TPS79328

TPS793285

TPS79330

TPS79333

V

2.856

2.907

3.06

V

Output voltage

V

4.3 V < V_IN< 5.5 V

5.25 V < V_IN< 5.5 V

3.3

4.75

0.05

5

3.366

4.845

0.12

V

TPS793475

V

(1)

Line regulation (∆V_OUT%/∆V_IN

)

%/V

mV

Load regulation (∆V_OUT%/∆I_OUT

)

T_J= 25°C

TPS79328

TPS793285

TPS79330

TPS79333

TPS793475

120

200

180

125

600

220

1

I_OUT= 200 mA

120

112

102

77

Dropout voltage⁽²⁾

(V_IN= V_OUT(nom)- 0.1V)

I_OUT= 200 mA

mV

I_OUT= 200 mA

Output current limit

GND pin current

Shutdown current⁽³⁾

FB pin current

V_OUT= 0 V

285

mA

µA

0 µA < I_OUT< 200 mA

170

V_EN= 0 V, 2.7 V < V_IN< 5.5 V

V_FB= 1.8 V

0.07

1

f = 100 Hz, T_J= 25°C,

f = 10 kHz, T_J= 25°C,

f = 100 kHz, T_J= 25°C,

I_OUT= 10 mA

70

68

70

43

I_OUT= 200 mA

C_NR= 0.001 µF

C_NR= 0.0047 µF

C_NR= 0.01 µF

C_NR= 0.1 µF

Power-supply ripple rejection TPS79328

Output noise voltage (TPS79328)

dB

55

36

33

32

BW = 200 Hz to 100 kHz,

I_OUT= 200 mA

µV_RMS

(1) Minimum V_INis 2.7 V or V_OUT+ V_DO, whichever is greater.

(2) Dropout is not measured for the TPS79318 and TPS79325 since minimum V_IN= 2.7 V.

(3) For adjustable versions, this applies only after V_INis applied; then V_ENtransitions high to low.

3

TPS79301, TPS79318

TPS79325, TPS79328, TPS793285

TPS79330, TPS79333, TPS793475

www.ti.com

SLVS348H–JULY 2001–REVISED OCTOBER 2004

ELECTRICAL CHARACTERISTICS (continued)

over recommended operating temperature range T_J= -40 to 125°C, V_EN= V_IN, V_IN= V_OUT(nom)+ 1 V, I_OUT= 1 mA,

C_OUT= 10 µF, C_NR= 0.01 µF (unless otherwise noted). Typical values are at 25°C.

PARAMETER

TEST CONDITIONS

MIN

TYP

50

MAX

UNIT

C_NR= 0.001 µF

C_NR= 0.0047 µF

C_NR= 0.01 µF

Time, start-up (TPS79328)

R_L= 14 Ω, C_OUT= 1 µF

70

µs

100

High level enable input voltage

Low level enable input voltage

EN pin current

2.7 V < V_IN< 5.5 V

V_EN= 0

1.7

0

V_IN

0.7

1

V

-1

µA

V

UVLO threshold

V_CCrising

2.25

2.65

UVLO hysteresis

100

mV

4

TPS79301, TPS79318

TPS79325, TPS79328, TPS793285

TPS79330, TPS79333, TPS793475

www.ti.com

SLVS348H–JULY 2001–REVISED OCTOBER 2004

FUNCTIONAL BLOCK DIAGRAMS

ADJUSTABLE VERSION

IN

OUT

59 k

UVLO

2.45V

Current

Sense

R1

R2

ILIM

SHUTDOWN

GND

EN

_

+

FB

UVLO

Thermal

Shutdown

External to

the Device

QuickStart

Bandgap

Reference

1.22V

250 kΩ

V

ref

IN

NR

FIXED VERSION

IN

OUT

UVLO

2.45V

Current

Sense

GND

EN

SHUTDOWN

+

ILIM

R1

R2

_

UVLO

Thermal

Shutdown

R2 = 40 kΩ

QuickStart

Bandgap

Reference

1.22V

250 kΩ

V

ref

NR

IN

Terminal Functions

TERMINAL

DESCRIPTION

SOT23 SOT23

WCSP

FIXED

NAME

NR

ADJ

FIXED

Connecting an external capacitor to this pin bypasses noise generated by the internal bandgap.

This improves power-supply rejection and reduces output noise.

4

B2

A3

Driving the enable pin (EN) high turns on the regulator. Driving this pin low puts the regulator into

shutdown mode. EN can be connected to IN if not used.

EN

3

FB

GND

IN

5

2

1

6

N/A

2

N/A

A1

This terminal is the feedback input voltage for the adjustable device.

Regulator ground

1

C3

C1

Unregulated input to the device.

OUT

5

Output of the regulator.

5

TPS79301, TPS79318

TPS79325, TPS79328, TPS793285

TPS79330, TPS79333, TPS793475

www.ti.com

SLVS348H–JULY 2001–REVISED OCTOBER 2004

TYPICAL CHARACTERISTICS (SOT23 PACKAGE)

TPS79328

OUTPUT VOLTAGE

vs

TPS79328

OUTPUT VOLTAGE

vs

TPS79328

GROUND CURRENT

vs

OUTPUT CURRENT

JUNCTION TEMPERATURE

2.805

2.804

2.803

2.802

2.801

2.800

2.799

250

200

2.805

2.800

2.795

2.790

2.785

V

= 3.8 V

= 10 µF

OUT

= 25°C

IN

V

C

= 3.8 V

IN

C

T

= 10 µF

I

= 1 mA

OUT

J

I

= 1 mA

OUT

I

= 200 mA

OUT

150

100

50

0

I

= 200 mA

OUT

2.798

2.797

2.780

2.775

V

C

= 3.8 V

= 10 µF

IN

2.796

2.795

OUT

−40 −25 −10 5 20 35 50 65 80 95 110 125

(°C)

0

50

100

(mA)

150

200

−40 −25−10 5 20 35 50 65 80 95 110 125

I

T

J

(°C)

T

J

OUT

Figure 2.

Figure 3.

Figure 4.

TPS79328 OUTPUT SPECTRAL

NOISE DENSITY

vs

NOISE DENSITY

vs

NOISE DENSITY

vs

FREQUENCY

0.30

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

0.30

V

= 3.8 V

IN

V

C

= 3.8 V

V

C

= 3.8 V

IN

= 10 µF

OUT

= 0.1 µF

NR

IN

I

= 200 mA

OUT

= 2.2 µF

OUT

= 0.1 µF

0.25

0.20

0.25

0.20

0.15

0.10

0.05

0

C

= 10 µF

OUT

= 0.001 µF

NR

C

NR

C

= 0.0047 µF

NR

C

I

= 1 mA

OUT

= 0.01 µF

NR

0.15

I

= 1 mA

OUT

C

NR

= 0.1 µF

0.10

0.05

I

= 200 mA

OUT

I

= 200 mA

OUT

0

100

1 k

10 k

100 k

100

1 k

10 k

100 k

100

1 k

10 k

100 k

Frequency (Hz)

Figure 5.

Figure 6.

Figure 7.

ROOT MEAN SQUARE OUTPUT

TPS79328

DROPOUT VOLTAGE

vs

NOISE

vs

OUTPUT IMPEDANCE

vs

C_NR

FREQUENCY

JUNCTION TEMPERATURE

2.5

180

160

140

120

100

80

60

50

40

30

20

10

V

= 3.8 V

= 10 µF

OUT

= 25° C

IN

V

= 2.7 V

IN

V

= 2.8 V

= 200 mA

= 10 µF

OUT

C

T

C

OUT

= 10 µF

I

OUT

J

C

OUT

2.0

1.5

I

= 200 mA

OUT

I

= 1 mA

OUT

1.0

0.5

I

= 100 mA

OUT

60

40

I

= 10 mA

OUT

20

BW = 100 Hz to 100 kHz

0.01

0

10

0

−40 −25−10 5 20 35 50 65 80 95 110 125

100

1 k

10 k 100 k 1 M

10 M

0.001

0.1

Frequency (Hz)

T

J

(°C)

C

NR

(µF)

Figure 8.

Figure 9.

Figure 10.

6

TPS79301, TPS79318

TPS79325, TPS79328, TPS793285

TPS79330, TPS79333, TPS793475

www.ti.com

SLVS348H–JULY 2001–REVISED OCTOBER 2004

TYPICAL CHARACTERISTICS (SOT23 PACKAGE) (continued)

TPS79328

RIPPLE REJECTION

vs

TPS79328

RIPPLE REJECTION

vs

TPS79328

RIPPLE REJECTION

vs

FREQUENCY

100

90

100

90

80

70

60

50

40

30

100

V

C

= 3.8 V

V

C

= 3.8 V

IN

= 2.2 µF

OUT

= 0.1 µF

NR

IN

90

80

70

60

50

40

= 2.2 µF

OUT

= 0.01 µF

I

= 200 mA

OUT

NR

80

I

= 200 mA

I

= 200 mA

OUT

70

60

50

40

30

I

= 10 mA

I

= 10 mA

OUT

I

= 10 mA

OUT

30

20

10

0

V

= 3.8 V

= 10 µF

IN

C

OUT

= 0.01 µF

10

0

10

0

NR

10

100

1 k

10 k 100 k 1 M 10 M

10

100

1 k

10 k 100 k 1 M 10 M

10

100

1 k

10 k 100 k 1 M 10 M

Frequency (Hz)

Figure 11.

Figure 12.

Figure 13.

TPS79328 OUTPUT VOLTAGE,

ENABLE VOLTAGE

vs

TPS79328

LINE TRANSIENT RESPONSE

TPS79328

LOAD TRANSIENT RESPONSE

TIME (START-UP)

V

C

= 3.8 V

IN

4.8

4

20

= 10 µF

OUT

V

= 3.8 V

2

0

IN

0

= 2.8 V

OUT

3.8

I

= 200 mA

−20

OUT

C

T

= 2.2 µF

= 25°C

I

C

= 200 mA

OUT

−40

300

= 2.2 µF

J

OUT

C

NR

= 0.001 µF

= 0.01 µF

dv

dt

⁰µ^.4s^V

NR

+

di

dt

0.02A

µs

20

0

3

2

1

0

+

200

100

C

= 0.0047 µF

= 0.01 µF

NR

1mA

-20

C

NR

0

50 100 150200 250 300 350 400 450 500

0

20 40 60 80 100 120 140 160 180 200

0

10 20 30 40 50 60 70 80 90 100

Time (µs)

Figure 14.

Figure 15.

Figure 16.

TPS79301

DROPOUT VOLTAGE

vs

DROPOUT VOLTAGE

vs

OUTPUT CURRENT

POWER-UP / POWER-DOWN

INPUT VOLTAGE

200

150

250

200

150

100

V

R

= 3 V

= 15 Ω

OUT

L

T

= 125°C

= 25°C

J

T

= 125°C

J

T

J

T

J

= 25°C

100

V

IN

V

OUT

T

= −55°C

50

0

J

T

= −40°C

J

50

0

I

= 200 mA

OUT

0

20 40 60 80 100 120 140 160 180 200

(mA)

5.0

2.5

3.0

3.5

4.0

4.5

1s/div

I

V

(V)

OUT

IN

Figure 17.

Figure 18.

Figure 19.

7

TPS79301, TPS79318

TPS79325, TPS79328, TPS793285

TPS79330, TPS79333, TPS793475

www.ti.com

SLVS348H–JULY 2001–REVISED OCTOBER 2004

TYPICAL CHARACTERISTICS (SOT23 PACKAGE) (continued)

TYPICAL REGIONS OF STABILITY

EQUIVALENT SERIES RESISTANCE

(ESR)

vs

OUTPUT CURRENT

(ESR)

vs

OUTPUT CURRENT

100

10

100

10

C

= 2.2 µF

OUT

C

= 10 µF

OUT

= 5.5 V

V

= 5.5 V, V

≥ 1.5 V

IN

OUT

V

IN

= −40°C to 125°C

T

J

= −40°C to 125°C

T

J

Region of Instability

1

0.1

Region of Stability

0.01

0.20

0

0.02

0.04

0.06

(A)

0.08

0.20

0

0.02

0.04

0.06

(A)

0.08

I

OUT

Figure 20.

Figure 21.

8

TPS79301, TPS79318

TPS79325, TPS79328, TPS793285

TPS79330, TPS79333, TPS793475

www.ti.com

SLVS348H–JULY 2001–REVISED OCTOBER 2004

APPLICATION INFORMATION

The TPS793xx family of low-dropout (LDO) regulators has been optimized for use in noise-sensitive

battery-operated equipment. The device features extremely low dropout voltages, high PSRR, ultralow output

noise, low quiescent current (170 µA typically), and enable-input to reduce supply currents to less than 1 µA

when the regulator is turned off.

A typical application circuit is shown in Figure 22.

V

IN

V_IN

V_OUT

IN

OUT

NR

TPS793xx

V

OUT

EN

GND

µ

F

0.1

F

2.2

µ

0.01

F

Figure 22. Typical Application Circuit

External Capacitor Requirements

A 0.1-µF or larger ceramic input bypass capacitor, connected between IN and GND and located close to the

TPS793xx, is required for stability and improves transient response, noise rejection, and ripple rejection. A

higher-value input capacitor may be necessary if large, fast-rise-time load transients are anticipated or the device

is located several inches from the power source.

Like most low dropout regulators, the TPS793xx requires an output capacitor connected between OUT and GND

to stabilize the internal control loop. The minimum recommended capacitance is 2.2 µF. Any 2.2-µF or larger

ceramic capacitor is suitable, provided the capacitance does not vary significantly over temperature. If load

current is not expected to exceed 100 mA, a 1.0-µF ceramic capacitor can be used.

The internal voltage reference is a key source of noise in an LDO regulator. The TPS793xx has an NR pin which

is connected to the voltage reference through a 250-kΩ internal resistor. The 250-kΩ internal resistor, in

conjunction with an external bypass capacitor connected to the NR pin, creates a low pass filter to reduce the

voltage reference noise and, therefore, the noise at the regulator output. In order for the regulator to operate

properly, the current flow out of the NR pin must be at a minimum, because any leakage current creates an IR

drop across the internal resistor thus creating an output error. Therefore, the bypass capacitor must have

minimal leakage current. The bypass capacitor should be no more than 0.1-µF to ensure that it is fully charged

during the quickstart time provided by the internal switch shown in the Functional Block Diagrams

As an example, the TPS79328 exhibits only 32 µV_RMSof output voltage noise using a 0.1-µF ceramic bypass

capacitor and a 2.2-µF ceramic output capacitor. Note that the output starts up slower as the bypass capacitance

increases due to the RC time constant at the NR pin that is created by the internal 250-kΩ resistor and external

capacitor.

Board Layout Recommendation to Improve PSRR and Noise Performance

To improve ac measurements like PSRR, output noise, and transient response, it is recommended that the board

be designed with separate ground planes for V_INand V_OUT, with each ground plane connected only at the GND

pin of the device. In addition, the ground connection for the bypass capacitor should connect directly to the GND

pin of the device.

9

TPS79301, TPS79318

TPS79325, TPS79328, TPS793285

TPS79330, TPS79333, TPS793475

www.ti.com

SLVS348H–JULY 2001–REVISED OCTOBER 2004

APPLICATION INFORMATION (continued)

Power Dissipation and Junction Temperature

Specified regulator operation is assured to a junction temperature of 125°C; the maximum junction temperature

should be restricted to 125°C under normal operating conditions. This restriction limits the power dissipation the

regulator can handle in any given application. To ensure the junction temperature is within acceptable limits,

calculate the maximum allowable dissipation, P_D(max), and the actual dissipation, P_D, which must be less than or

equal to P_D(max)

.

The maximum power dissipation limit is determined using Equation 1:

T_Jmax T_A

P_{D max}

+

(

)

R_QJA

(1)

Where:

•

T_Jmax is the maximum allowable junction temperature.

R_θJAis the thermal resistance junction-to-ambient for the package (see the Dissipation Ratings Table).

T_Ais the ambient temperature.

The regulator dissipation is calculated using Equation 2:

ǒ

Ǔ

P_D+ V_IN*V_OUT I_OUT

(2)

Power dissipation resulting from quiescent current is negligible. Excessive power dissipation triggers the thermal

protection circuit.

Programming the TPS79301 Adjustable LDO Regulator

The output voltage of the TPS79301 adjustable regulator is programmed using an external resistor divider as

shown in Figure 23. The output voltage is calculated using Equation 3:

R₁

R₂

ǒ_{1 )}Ǔ

V_OUT+ V_REF

(3)

Where:

•

V_REF= 1.2246 V typ (the internal reference voltage)

Resistors R1 and R2 should be chosen for approximately 50-µA divider current. Lower value resistors can be

used for improved noise performance, but the solution consumes more power. Higher resistor values should be

avoided as leakage current into/out of FB across R1/R2 creates an offset voltage that artificially in-

creases/decreases the feedback voltage and thus erroneously decreases/increases V_OUT. The recommended

design procedure is to choose R2 = 30.1 kΩ to set the divider current at 50 µA, C1 = 15 pF for stability, and then

calculate R1 using Equation 4:

V_OUT

ǒ Ǔ

R₁+

R₂

V_ref* 1

(4)

In order to improve the stability of the adjustable version, it is suggested that a small compensation capacitor be

placed between OUT and FB. For voltages <1.8 V, the value of this capacitor should be 100 pF. For voltages

>1.8 V, the approximate value of this capacitor can be calculated as shown in Equation 5:

*7

(3 x 10 ) x (R₁) R₂)

C₁

+

(R₁x R₂)

(5)

The suggested value of this capacitor for several resistor ratios is shown in the table below. If this capacitor is

not used (such as in a unity-gain configuration) or if an output voltage <1.8 V is chosen, then the minimum

recommended output capacitor is 4.7 µF instead of 2.2 µF.

10

TPS79301, TPS79318

TPS79325, TPS79328, TPS793285

TPS79330, TPS79333, TPS793475

www.ti.com

SLVS348H–JULY 2001–REVISED OCTOBER 2004

APPLICATION INFORMATION (continued)

OUTPUT VOLTAGE

PROGRAMMING GUIDE

V_IN

V_OUT

IN

OUT

FB

TPS793xx

OUTPUT

VOLTAGE

R1

R2

µ

C1

1

F

R1

R2

C1

EN

NR

µ

1

F

GND

1.22 V

2.5 V

3.3 V

3.6 V

short

31.6 k

51 k

open

0 pF

µ

0.01

F

30.1 k

22 pF

15 pF

Ω

59 k

Figure 23. TPS79301 Adjustable LDO Regulator Programming

Regulator Protection

The TPS793xx PMOS-pass transistor has a built-in back diode that conducts reverse current when the input

voltage drops below the output voltage (e.g., during power-down). Current is conducted from the output to the

input and is not internally limited. If extended reverse voltage operation is anticipated, external limiting might be

appropriate.

The TPS793xx features internal current limiting and thermal protection. During normal operation, the TPS793xx

limits output current to approximately 400 mA. When current limiting engages, the output voltage scales back

linearly until the overcurrent condition ends. While current limiting is designed to prevent gross device failure,

care should be taken not to exceed the power dissipation ratings of the package or the absolute maximum

voltage ratings of the device. If the temperature of the device exceeds approximately 165°C, thermal-protection

circuitry shuts it down. Once the device has cooled down to below approximately 140°C, regulator operation

resumes.

11

TPS79301, TPS79318

TPS79325, TPS79328, TPS793285

TPS79330, TPS79333, TPS793475

www.ti.com

SLVS348H–JULY 2001–REVISED OCTOBER 2004

TPS793xxYEQ NanoStar™ Wafer Chip Scale Information

0,79

0,84

1,30

1,34

0.625 Max

NOTES:A. All linear dimensions are in millimeters.

B. This drawing is subject to change without notice.

C. NanoStar package configuration.

D. This package is tin-lead (SnPb); consult the factory for availability of lead-free material.

NanoStar is a trademark of Texas Instruments.

Figure 24. NanoStar™ Wafer Chip Scale Package

12

PACKAGE OPTION ADDENDUM

www.ti.com

28-Feb-2005

PACKAGING INFORMATION

Orderable Device

Status ⁽¹⁾

Package Package

Pins Package Eco Plan ⁽²⁾Lead/Ball Finish MSL Peak Temp ⁽³⁾

Qty

Type

Drawing

TPS79301DBVR

ACTIVE

SOT-23

DBV

6

3000 Green (RoHS & CU NIPDAU Level-1-260C-UNLIM

no Sb/Br)

TPS79301DBVRG4

TPS79318DBVR

ACTIVE

SOT-23

DBV

6

5

3000

None

Call TI

3000 Green (RoHS & CU NIPDAU Level-1-260C-UNLIM

no Sb/Br)

TPS79318DBVRG4

TPS79318DBVT

ACTIVE

SOT-23

DBV

5

Green (RoHS & CU NIPDAU Level-1-260C-UNLIM

no Sb/Br)

250 Green (RoHS & CU NIPDAU Level-1-260C-UNLIM

no Sb/Br)

TPS79318YEQR

TPS79318YEQT

TPS79325DBVR

ACTIVE

DSBGA

SOT-23

YEQ

DBV

5

3000

250

None

Call TI

Level-1-240C-UNLIM

3000 Green (RoHS & CU NIPDAU Level-1-260C-UNLIM

no Sb/Br)

TPS79325DBVRG4

ACTIVE

SOT-23

DBV

5

3000 Green (RoHS & CU NIPDAU Level-1-260C-UNLIM

no Sb/Br)

TPS79325YEQR

TPS79325YEQT

TPS793285DBVR

ACTIVE

DSBGA

SOT-23

YEQ

DBV

5

3000

250

None

Call TI

Level-1-240C-UNLIM

3000 Green (RoHS & CU NIPDAU Level-1-260C-UNLIM

no Sb/Br)

TPS793285DBVRG4

TPS793285DBVT

ACTIVE

SOT-23

DBV

5

Green (RoHS & CU NIPDAU Level-1-260C-UNLIM

no Sb/Br)

250 Green (RoHS & CU NIPDAU Level-1-260C-UNLIM

no Sb/Br)

TPS793285YEQR

TPS793285YEQT

TPS79328DBVR

ACTIVE

DSBGA

SOT-23

YEQ

DBV

5

3000

250

None

Call TI

Level-1-240C-UNLIM

3000 Green (RoHS & CU NIPDAU Level-1-260C-UNLIM

no Sb/Br)

TPS79328DBVRG4

ACTIVE

SOT-23

DBV

5

3000 Green (RoHS & CU NIPDAU Level-1-260C-UNLIM

no Sb/Br)

TPS79328YEQR

TPS79328YEQT

TPS79330DBVR

ACTIVE

DSBGA

SOT-23

YEQ

DBV

5

3000

250

None

Call TI

Level-1-240C-UNLIM

3000 Green (RoHS & CU NIPDAU Level-1-260C-UNLIM

no Sb/Br)

TPS79330DBVRG4

ACTIVE

SOT-23

DBV

5

3000 Green (RoHS & CU NIPDAU Level-1-260C-UNLIM

no Sb/Br)

TPS79330YEQR

TPS79330YEQT

TPS79333DBVR

ACTIVE

DSBGA

SOT-23

YEQ

DBV

5

3000

250

None

Call TI

Level-1-240C-UNLIM

3000 Green (RoHS & CU NIPDAU Level-1-260C-UNLIM

no Sb/Br)

TPS79333DBVRG4

TPS793475DBVR

TPS793475DBVRG4

ACTIVE

SOT-23

DBV

5

3000 Green (RoHS & CU NIPDAU Level-1-260C-UNLIM

no Sb/Br)

3000 Green (RoHS & CU NIPDAU Level-1-260C-UNLIM

no Sb/Br)

3000 Green (RoHS & CU NIPDAU Level-1-260C-UNLIM

no Sb/Br)

⁽¹⁾The marketing status values are defined as follows:

ACTIVE: Product device recommended for new designs.

Addendum-Page 1

PACKAGE OPTION ADDENDUM

www.ti.com

28-Feb-2005

LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.

NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in

a new design.

PREVIEW: Device has been announced but is not in production. Samples may or may not be available.

OBSOLETE: TI has discontinued the production of the device.

(2)

Eco Plan - May not be currently available - please check http://www.ti.com/productcontent for the latest availability information and additional

product content details.

None: Not yet available Lead (Pb-Free).

Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements

for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered

at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.

Green (RoHS & no Sb/Br): TI defines "Green" to mean "Pb-Free" and in addition, uses package materials that do not contain halogens,

including bromine (Br) or antimony (Sb) above 0.1% of total product weight.

(3)

MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDECindustry standard classifications, and peak solder

temperature.

Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is

provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the

accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take

reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on

incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited

information may not be available for release.

In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI

to Customer on an annual basis.

Addendum-Page 2

IMPORTANT NOTICE

Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications,

enhancements, improvements, and other changes to its products and services at any time and to discontinue

any product or service without notice. Customers should obtain the latest relevant information before placing

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TI warrants performance of its hardware products to the specifications applicable at the time of sale in

accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI

deems necessary to support this warranty. Except where mandated by government requirements, testing of all

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TI assumes no liability for applications assistance or customer product design. Customers are responsible for

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型号：	TPS793285
厂家：	TEXAS INSTRUMENTS
描述：	ULTRALOW-NOISE, HIGH PSRR, FAST RF 200-mA LOW-DROPOUT LINEAR REGULATORS IN NANOSTAR? WAFER CHIP SCALE AND SOT23 超低噪声，高PSRR ，快速射频200mA的低压差线性稳压器NANOSTAR ？晶圆级和SOT23 稳压器射频
文件：	总18页 (文件大小：446K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

TPS793285 [TI]

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TPS793285DBVT

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