LP3990SDX-0.8/NOPB - Texas Instruments High-Performance Analog

October 16, 2006

LP3990

150mA Linear Voltage Regulator for Digital Applications

General Description

The LP3990 regulator is designed to meet the requirements

of portable, battery-powered systems providing an accurate

output voltage, low noise, and low quiescent current. The

LP3990 will provide a 0.8V output from the low input voltage

of 2V at up to 150mA load current. When switched into shut-

down mode via a logic signal at the enable pin, the power

consumption is reduced to virtually zero.

The LP3990 is designed to be stable with space saving ce-

ramic capacitors as small as 1.0µF.

Performance is specified for a -40°C to 125°C junction tem-

perature range.

For output voltages other than 0.8V, 1.2, 1.35V, 1.5V, 1.8V,

2.5V, 2.8V, or 3.3V please contact your local NSC sales of-

fice.

Features

■1% Voltage Accuracy at Room Temperature

■Stable with Ceramic Capacitor

■Logic Controlled Enable

■No Noise Bypass Capacitor Required

■Thermal-Overload and Short-Circuit Protection

Key Specifications

■Input Voltage Range 2.0 to 6.0V

■Output Voltage Range 0.8 to 3.3V

■Output Current 150mA

■Output Stable - Capacitors 1.0uF

■Virtually Zero IQ (Disabled) <10nA

■Very Low IQ (Enabled) 43uA

■Low Output Noise 150uVRMS

■PSRR 55dB at 1kHz

■Fast Start Up 105us

Package

All available in Lead Free option.

4 Pin micro SMD 1 mm x 1.3 mm

6 pin LLP (SOT23 footprint)

SOT23 - 5

For other package options contact your NSC sales office.

Applications

■Cellular Handsets

■Hand-Held Information Appliances

Typical Application Circuit

20076801

LP3990 150mA Linear Voltage Regulator for Digital Applications

Pin Descriptions

Packages

Pin No Symbol Name and Function

LLP micro

SMD

SOT23-5

5 A2 3 VEN Enable Input; Enables the Regulator when ≥ 0.95V.

Disables the Regulator when ≤ 0.4V.

Enable Input has 1MΩ pulldown resistor to GND.

2 A1 2 GND Common Ground. Connect to Pad.

1 B1 5 VOUT Voltage output. A 1.0µF Low ESR Capacitor should be connected

to this Pin. Connect this output to the load circuit.

6 B2 1 VIN Voltage Supply Input. A 1.0µF capacitor should be connected at

this input.

3 4 N/C No Connection. Do not connect to any other pin.

4 N/C No Connection. Do not connect to any other pin.

Pad GND Common Ground. Connect to Pin 2.

Connection Diagrams

Micro SMD, 4 Bump Package

20076803

See NS package number TLA04

LLP-6 Package

20076806

See NS package number SDE06A

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LP3990

SOT23 - 5 Package (MF)

20076808

See NS package number MF05A

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LP3990

Ordering Information

For micro SMD Package

Output Voltage

(V) Grade LP3990 Supplied as 250 Units,

Tape and Reel

LP3990 Supplied as 3000 Units,

Tape and Reel Package Marking

0.8 STD LP3990TL-0.8 LP3990TLX-0.8

1.2 STD LP3990TL-1.2 LP3990TLX-1.2

1.35 STD LP3990TL-1.35 LP3990TLX-1.35

1.5 STD LP3990TL-1.5 LP3990TLX-1.5

1.8 STD LP3990TL-1.8 LP3990TLX-1.8

2.5 STD LP3990TL-2.5 LP3990TLX-2.5

2.8 STD LP3990TL-2.8 LP3990TLX-2.8

For LLP-6 Package

Output Voltage

(V) Grade LP3990 Supplied as 1000 Units,

Tape and Reel

LP3990 Supplied as 3000 Units,

Tape and Reel

Package Marking

0.8 STD LP3990SD-0.8 LP3990SDX-0.8 L085B

1.2 STD LP3990SD-1.2 LP3990SDX-1.2 L086B

1.35 STD LP3990SD-1.35 LP3990SDX-1.35 L150B

1.5 STD LP3990SD-1.5 LP3990SDX-1.5 L087B

1.8 STD LP3990SD-1.8 LP3990SDX-1.8 L088B

2.5 STD LP3990SD-2.5 LP3990SDX-2.5 L090B

2.8 STD LP3990SD-2.8 LP3990SDX-2.8 L091B

For SOT23 - 5 Package

Output Voltage

(V) Grade LP3990 Supplied as 1000 Units,

Tape and Reel

LP3990 Supplied as 3000 Units,

Tape and Reel

Package Marking

1.2 STD LP3990MF-1.2 LP3990MFX-1.2 SCDB

1.5 STD LP3990MF-1.5 LP3990MFX-1.5 SCEB

1.8 STD LP3990MF-1.8 LP3990MFX-1.8 SCFB

2.5 STD LP3990MF-2.5 LP3990MFX-2.5 SCJB

2.8 STD LP3990MF-2.8 LP3990MFX-2.8 SCKB

3.3 STD LP3990MF-3.3 LP3990MFX-3.3 SCLB

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LP3990

Absolute Maximum Ratings

(Notes 1, 2)

If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales Office/

Distributors for availability and specifications.

Input Voltage -0.3 to 6.5V

Output Voltage -0.3 to (VIN + 0.3V) with

6.5V (max)

Enable Input Voltage -0.3 to (VIN + 0.3V) with

6.5V (max)

Junction Temperature 150°C

Lead/Pad Temp. (Note 3)

LLP/SOT23 235°C

micro SMD 260°C

Storage Temperature -65 to 150°C

Continuous Power Dissipation

Internally Limited(Note 4)

ESD (Note 5)

Human Body Model 2KV

Machine Model 200V

Operating Ratings (Note 1)

Input Voltage 2V to 6V

Enable Input Voltage 0 to (VIN + 0.3V) with

6.0V (max)

Junction Temperature -40°C to 125°C

Ambient Temperature TARange

(Note 6)

-40°C to 85°C

Thermal Properties (Note 1)

Junction To Ambient Thermal

Resistance(Note 8)

θJA(LLP-6) 88°C/W

θJA(microSMD) 220°C/W

θJASOT23-5 220°C/W

Electrical Characteristics

Unless otherwise noted, VEN =950mV, VIN = VOUT + 1.0V, or 2.0V, whichever is higher. CIN = 1 µF, IOUT = 1 mA, COUT =0.47 µF.

Typical values and limits appearing in normal type apply for TJ = 27°C. Limits appearing in boldface type apply over the full junction

temperature range for operation, −40 to +125°C. (Note 13)

Symbol Parameter Conditions Typ Limit Units

Min Max

VIN Input Voltage (Note 14) 2 6 V

ΔVOUT Output Voltage Tolerance ILOAD = 1 mA Micro SMD -1 +1

LLP -1.5 +1.5

SOT-23 -1.5 +1.5

Over full line and

load regulation.

Micro SMD -2.5 +2.5

LLP -3 +3

SOT-23 -4 +4

Line Regulation Error VIN = (VOUT(NOM) + 1.0V) to 6.0V, 0.02 -0.1 0.1 %/V

Load Regulation Error IOUT = 1mA

to 150mA

VOUT = 0.8 to 1.95V

MicroSMD

0.002 -0.005 0.005

%/mA

VOUT = 0.8 to 1.95V

LLP, SOT-23

0.003 -0.008 0.008

VOUT = 2.0 to 3.3V

MicroSMD

0.0005 -0.002 0.002

VOUT = 2.0 to 3.3V

LLP, SOT-23

0.002 -0.005 0.005

VDO Dropout Voltage IOUT = 150mA

(Notes 7, 10)

120 200 mV

ILOAD Load Current (Notes 9, 10) 0 µA

IQQuiescent Current VEN = 950mV, IOUT = 0mA 43 80

µA

VEN = 950mV, IOUT = 150mA 65 120

VEN = 0.4V 0.002 0.2

ISC Short Circuit Current Limit (Note 11) 550 1000 mA

IOUT Maximum Output Current 150 mA

PSRR Power Supply Rejection Ratio f = 1kHz, IOUT = 1mA to 150mA 55 dB

f = 10kHz, IOUT = 150mA 35

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LP3990

Symbol Parameter Conditions Typ Limit Units

Min Max

enOutput noise Voltage (Note 10) BW = 10Hz to

100kHz,

VOUT = 0.8 60

µVRMS

VOUT = 1.5 125

VOUT = 3.3 180

TSHUTDOWN Thermal Shutdown Temperature 155 °C

Hysteresis 15

Enable Control Characteristics

IEN

(Note 12)

Maximum Input Current at

VEN Input

VEN = 0.0V 0.001 0.1 µA

VEN = 6V 6 2.5 10

VIL Low Input Threshold VIN = 2V to 6V 0.4 V

VIH High Input Threshold VIN = 2V to 6V 0.95 V

Timing Characteristics

TON Turn On Time (Note 10) To 95% Level

VIN(MIN) to 6.0V

VOUT = 0.8 80 150

µs

VOUT = 1.5 105 200

VOUT = 3.3 175 250

Transient

Response

Line Transient Response |δVOUT|Trise = Tfall = 30µs (Note 10)

δVIN = 600mV 8 16 mV

(pk - pk)

Load Transient Response |δVOUT|Trise = Tfall = 1µs (Note 10)IOUT = 1mA to

150mA

COUT = 1µF

100 mV

Note 1: Absolute Maximum Ratings are limits beyond which damage can occur. Operating Ratings are conditions under which operation of the device is

guaranteed. Operating Ratings do not imply guaranteed performance limits. For guaranteed performance limits and associated test conditions, see the Electrical

Characteristics tables.

Note 2: All Voltages are with respect to the potential at the GND pin.

Note 3: For further information on these packages please refer to the following application notes;AN-1112 Micro SMD Package Wafer Level Chip Scale

Package,AN-1187 Leadless Leadframe Package.

Note 4: Internal thermal shutdown circuitry protects the device from permanent damage.

Note 5: The human body model is 100pF discharged through a 1.5kΩ resistor into each pin. The machine model is a 200pF capacitor discharged directly into

each pin.

Note 6: The maximum ambient temperature (TA(max)) is dependant on the maximum operating junction temperature (TJ(max-op) = 125°C), the maximum power

dissipation of the device in the application (PD(max)), and the junction to ambient thermal resistance of the part/package in the application (θJA), as given by the

following equation: TA(max) = TJ(max-op) - (θJA × PD(max)).

Note 7: Dropout voltage is voltage difference between input and output at which the output voltage drops to 100mV below its nominal value. This parameter only

for output voltages above 2.0V.

Note 8: Junction to ambient thermal resistance is dependant on the application and board layout. In applications where high maximum power dissipation is

possible, special care must be paid to thermal dissipation issues in board design.

Note 9: The device maintains the regulated output voltage without the load.

Note 10: This electrical specification is guaranteed by design.

Note 11: Short circuit current is measured with VOUT pulled to 0V and VIN worst case = 6.0V.

Note 12: Enable Pin has 1MΩ typical, resistor connected to GND.

Note 13: All limits are guaranteed. All electrical characteristics having room-temperature limits are tested during production at TJ = 25°C or correlated using

Statistical Quality Control methods. Operation over the temperature specification is guaranteed by correlating the electrical characteristics to process and

temperature variations and applying statistical process control.

Note 14: VIN(MIN) = VOUT(NOM) + 0.5V, or 2.0V, whichever is higher.

Output Capacitor, Recommended Specifications

Symbol Parameter Conditions Nom Limit Units

Min Max

COUT Output Capacitance Capacitance

(Note 15)

1.0 0.7 µF

ESR 5 500 mΩ

Note 15: The full operating conditions for the application should be considered when selecting a suitable capacitor to ensure that the minimum value of capacitance

is always met. Recommended capacitor type is X7R. However, dependent on application, X5R, Y5V, and Z5U can also be used. (See capacitor section in

Applications Hints)

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LP3990

Typical Performance Characteristics. Unless otherwise specified, CIN = 1.0µF Ceramic, COUT = 0.47

µF Ceramic, VIN = VOUT(NOM) + 1.0V, TA = 25°C, VOUT(NOM) = 1.5V , Shutdown pin is tied to VIN.

Output Voltage Change vs Temperature

20076810

Ground Current vs Load Current

20076831

Ground Current vs VIN. ILOAD = 0mA

20076812

Ground Current vs VIN. ILOAD = 1mA

20076813

Ground Current vs VIN. ILOAD = 150mA

20076814

Short Circuit Current

20076815

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LP3990

Short Circuit Current

20076816

Line transient

20076817

Power Supply Rejection Ratio

20076819

Power Supply Rejection Ratio

20076820

Enable Start-up Time

20076821

Enable Start-up Time

20076822

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LP3990

Load Transient

20076825

Noise Density

20076828

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LP3990

Application Hints

EXTERNAL CAPACITORS

In common with most regulators, the LP3990 requires exter-

nal capacitors for regulator stability. The LP3990 is specifi-

cally designed for portable applications requiring minimum

board space and smallest components. These capacitors

must be correctly selected for good performance.

INPUT CAPACITOR

An input capacitor is required for stability. It is recommended

that a 1.0µF capacitor be connected between the LP3990 in-

put pin and ground (this capacitance value may be increased

without limit).

This capacitor must be located a distance of not more than

1cm from the input pin and returned to a clean analogue

ground. Any good quality ceramic, tantalum, or film capacitor

may be used at the input.

Important: To ensure stable operation it is essential that

good PCB design practices are employed to minimize ground

impedance and keep input inductance low. If these conditions

cannot be met, or if long leads are used to connect the battery

or other power sorce to the LP3990, then it is recommended

that the input capacitor is increased. Also, tantalum capaci-

tors can suffer catastrophic failures due to surge current when

connected to a low-impedance source of power (like a battery

or a very large capacitor). If a tantalum capacitor is used at

the input, it must be guaranteed by the manufacturer to have

a surge current rating sufficient for the application.

There are no requirements for the ESR (Equivalent Series

Resistance) on the input capacitor, but tolerance and tem-

perature coefficient must be considered when selecting the

capacitor to ensure the capacitance will remain approximately

1.0µF over the entire operating temperature range.

OUTPUT CAPACITOR

The LP3990 is designed specifically to work with very small

ceramic output capacitors. A 1.0µF ceramic capacitor (tem-

perature types Z5U, Y5V or X7R) with ESR between 5mΩ to

500mΩ, is suitable in the LP3990 application circuit.

For this device the output capacitor should be connected be-

tween the VOUT pin and ground.

It is also possible to use tantalum or film capacitors at the

device output, COUT (or VOUT), but these are not as attractive

for reasons of size and cost (see the section Capacitor Char-

acteristics).

The output capacitor must meet the requirement for the min-

imum value of capacitance and also have an ESR value that

is within the range 5mΩ to 500mΩ for stability.

NO-LOAD STABILITY

The LP3990 will remain stable and in regulation with no ex-

ternal load. This is an important consideration in some cir-

cuits, for example CMOS RAM keep-alive applications.

CAPACITOR CHARACTERISTICS

The LP3990 is designed to work with ceramic capacitors on

the output to take advantage of the benefits they offer. For

capacitance values in the range of 0.47µF to 4.7µF, ceramic

capacitors are the smallest, least expensive and have the

lowest ESR values, thus making them best for eliminating

high frequency noise. The ESR of a typical 1.0µF ceramic

capacitor is in the range of 20mΩ to 40mΩ, which easily

meets the ESR requirement for stability for the LP3990.

For both input and output capacitors, careful interpretation of

the capacitor specification is required to ensure correct device

operation. The capacitor value can change greatly, depend-

ing on the operating conditions and capacitor type.

In particular, the output capacitor selection should take ac-

count of all the capacitor parameters, to ensure that the

specification is met within the application. The capacitance

can vary with DC bias conditions as well as temperature and

frequency of operation. Capacitor values will also show some

decrease over time due to aging. The capacitor parameters

are also dependant on the particular case size, with smaller

sizes giving poorer performance figures in general. As an ex-

ample, Figure 1 shows a typical graph comparing different

capacitor case sizes in a Capacitance vs. DC Bias plot. As

shown in the graph, increasing the DC Bias condition can re-

sult in the capacitance value falling below the minimum value

given in the recommended capacitor specifications table

(0.7µF in this case). Note that the graph shows the capaci-

tance out of spec for the 0402 case size capacitor at higher

bias voltages. It is therefore recommended that the capacitor

manufacturers’ specifications for the nominal value capacitor

are consulted for all conditions, as some capacitor sizes (e.g.

0402) may not be suitable in the actual application.

20076840

FIGURE 1. Graph Showing a Typical Variation in

Capacitance vs DC Bias

The ceramic capacitor’s capacitance can vary with tempera-

ture. The capacitor type X7R, which operates over a temper-

ature range of -55°C to +125°C, will only vary the capacitance

to within ±15%. The capacitor type X5R has a similar toler-

ance over a reduced temperature range of -55°C to +85°C.

Many large value ceramic capacitors, larger than 1µF are

manufactured with Z5U or Y5V temperature characteristics.

Their capacitance can drop by more than 50% as the tem-

perature varies from 25°C to 85°C. Therefore X7R is recom-

mended over Z5U and Y5V in applications where the ambient

temperature will change significantly above or below 25°C.

Tantalum capacitors are less desirable than ceramic for use

as output capacitors because they are more expensive when

comparing equivalent capacitance and voltage ratings in the

0.47µF to 4.7µF range.

Another important consideration is that tantalum capacitors

have higher ESR values than equivalent size ceramics. This

means that while it may be possible to find a tantalum capac-

itor with an ESR value within the stable range, it would have

to be larger in capacitance (which means bigger and more

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LP3990

costly) than a ceramic capacitor with the same ESR value. It

should also be noted that the ESR of a typical tantalum will

increase about 2:1 as the temperature goes from 25°C down

to -40°C, so some guard band must be allowed.

ENABLE CONTROL

The LP3990 features an active high Enable pin, VEN, which

turns the device on when pulled high. When not enabled the

regulator output is off and the device typically consumes 2nA.

If the application does not require the Enable switching fea-

ture, the VEN pin should be tied to VIN to keep the regulator

output permanently on.

To ensure proper operation, the signal source used to drive

the VEN input must be able to swing above and below the

specified turn-on/off voltage thresholds listed in the Electrical

Characteristics section under VIL and VIH.

Micro SMD MOUNTING

The micro SMD package requires specific mounting tech-

niques, which are detailed in National Semiconductor Appli-

cation Note AN-1112.

For best results during assembly, alignment ordinals on the

PC board may be used to facilitate placement of the micro

SMD device.

Micro SMD LIGHT SENSITIVITY

Exposing the micro SMD device to direct light may affect the

operation of the device. Light sources, such as halogen

lamps, can affect electrical performance, if placed in close

proximity to the device.

Light with wavelengths in the infra-red portion of the spectrum

is the most detrimental, and so, fluorescent lighting used in-

side most buildings, has little or no effect on performance.

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LP3990

Physical Dimensions inches (millimeters) unless otherwise noted

micro SMD, 4 Bump, Package (TLA04)

NS Package Number TLA04AMA

The dimensions for X1, X2 and X3 are given as:

X1 = 1.014 +/− 0.03mm

X2 = 1.294 +/− 0.03mm

X3 = 0.600 +/− 0.075mm

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LP3990

LLP, 6 Lead, Package (SOT23 Land)

NS Package Number SDE06A

SOT23 - 5 Package

NS Package Number MF05A

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LP3990

Notes

LP3990 150mA Linear Voltage Regulator for Digital Applications

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