National Semiconductor LP3988 Technical data

August 2004

LP3988
Micropower, 150mA Ultra Low-Dropout CMOS Voltage
Regulator With Power Good

General Description

The LP3988 is a 150mA low dropout regulator designed
specially to meet requirements of Portable battery­applications. The LP3988 is designed to work with a space
saving, small 1µF ceramic capacitor. The LP3988 features
an Error Flag output that indicates a faulty output condition.

The LP3988’s performance is optimized for battery powered
systems to deliver low noise, extremely low dropout voltage
and low quiescent current. Regulator ground current in­creases only slightly in dropout, further prolonging the bat­tery life.

Power supply rejection is better than 60 dB at low frequen­cies and starts to roll off at 10 kHz. High power supply
rejection is maintained down to lower input voltage levels
common to battery operated circuits.

The device is ideal for mobile phone and similar battery
powered wireless applications. It provides up to 150 mA,
from a 2.5V to 6V input, consuming less than 1 µA in disable
mode and has fast turn-on time less than 200µs.

The LP3988 is available 5 pin SOT-23 package and 5 bump
thin micro SMD package. Performance is specified for −40˚C
to +125˚C temperature range and is available in 1.85, 2.5,

2.6, 2.85, 3.0 and 3.3V output voltages.

n 40dB PSRR at 10kHz
n ≤1 µA quiescent current when shut down
n Fast Turn-On time: 100 µs (typ.)
n 80 mV typ dropout with 150mA load
n −40 to +125˚C junction temperature range for operation
n 1.85V, 2.5V, 2.6V, 2.85V, 3.0V, and 3.3V

Features

n 5 bump thin micro SMD package
n SOT-23-5 package
n Power-good flag output
n Logic controlled enable
n Stable with ceramic and high quality tantalum capacitors
n Fast turn-on
n Thermal shutdown and short-circuit current limit

Applications

n CDMA cellular handsets
n Wideband CDMA cellular handsets
n GSM cellular handsets
n Portable information appliances
n Tiny 3.3V

±

5% to 2.85V, 150mA converter

LP3988 Micropower, 150mA Ultra Low-Dropout CMOS Voltage Regulator With Power Good

Key Specifications

n 2.5 to 6.0V input range
n 150mA guaranteed output

Typical Application Circuit

20020502

© 2004 National Semiconductor Corporation DS200205 www.national.com

Block Diagram

LP3988

Pin Descriptions

Name micro SMD SOT Function

V

EN

A1 3 Enable Input Logic, Enable High

GND B2 2 Common Ground

V

OUT

V

IN

C1 5 Output Voltage of the LDO

C3 1 Input Voltage of the LDO

Power Good A3 4 Power Good Flag (output):

open-drain output, connected to
an external pull-up resistor.
Active low indicates an output
voltage out of tolerance
condition.

20020501

Connection Diagrams

SOT-23-5 Package (MF) 5 Bump micro SMD Package (TLA)

Top View

See NS Package Number MF05A

20020507

20020530

Top View

See NS Package Number TLA05

www.national.com 2

Ordering Information

SOT23-5 Package

Output

Voltage (V)

2.5 STD LP3988IMF-2.5 LP3988IMFX-2.5 LFSB

2.6 STD LP3988IMF-2.6 LP3988IMFX-2.6 LDJB

2.85 STD LP3988IMF-2.85 LP3988IMFX-2.85 LDLB

3.0 STD LP3988IMF-3.0 LP3988IMFX-3.0 LFAB

3.3 STD LP3988IMF-3.3 LP3988IMFX-3.3 LH5B

Grade

Output

Voltage (V)

1.85 STD LP3988ITL-1.85 LP3988ITLX-1.85

2.6 STD LP3988ITL-2.6 LP3988ITLX-2.6

2.85 STD LP3988ITL-2.85 LP3988ITLX-2.85

LP3988 Supplied as 1000

Units, Tape and Reel

5 Bump Thin Micro SMD Package

Grade LP3988 Supplied as 250

Units, Tape and Reel

LP3988 Supplied as 3000

Units, Tape and Reel

LP3988 Supplied as 3000

Units, Tape and Reel

LP3988

Package Marking

www.national.com3

Absolute Maximum Ratings (Notes 1, 2)

If Military/Aerospace specified devices are required,

LP3988

please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.

V

IN

V

OUT,VEN

only to micro SMD)

Junction Temperature 150˚C

Storage Temperature −65˚C to +150˚C

Lead Temp, Pad Temp. 235˚C

Power Dissipation (Note 3)

SOT23-5
micro SMD

, PowerGood(applies

−0.3V to (VIN+0.3V),

−0.3 to 6.5V

with 6V max

364mW
355mW

ESD Rating (Note 4)

Human Body Model 2kV

Machine Model

SOT23-5 (Note 13) 150V

micro SMD 200V

Operating Ratings (Notes 1, 2)

V

(Note 15) 2.5V to 6V

IN

V

OUT,VEN

Junction Temperature −40˚C to +125˚C

Junction-to-Ambient Thermal
Resistance (θ
SOT23-5
micro SMD

Maximum Power Dissipation (Note 5)

SOT23-5

micro SMD

Electrical Characteristics

Unless otherwise specified: VEN= 1.8V, VIN=V
appearing in standard typeface are for T

= 25˚C. Limits appearing in boldface type apply over the entire junction temperature

J

range for operation, −40˚C to +125˚C. (Note 6) (Note 7)

Symbol Parameter Conditions Typ

Output Voltage
Tolerance −20˚C % T

∆V

OUT

Line Regulation Error

Load Regulation Error
(Note 8)

PSRR Power Supply Rejection Ratio

I

Q

Quiescent Current VEN= 1.4V, I

Dropout Voltage (Note 9) I

I

SC

e

n

C

OUT

TSD

Short Circuit Current Limit (Note 10) 600 mA

Output Noise Voltage BW = 10 Hz to 100 kHz,

Output Capacitor Capacitance (Note 11) 120µF

Thermal Shutdown Temperature 160 ˚C

Thermal Shutdown Hysteresis 20 ˚C

Enable Control Characteristics (Note 12)

I

EN

Maximum Input Current at EN VEN= 0 and VIN= 6.0V 0.1 µA

+ 0.5V, CIN= 1 µF, I

OUT

J

−40˚C % T

J

% 125˚C, SOT23-5
% 125˚C, SOT23-5

OUT

= 1mA, C

−40˚C % TJ% 125˚C, micro SMD -3 3

V

IN=VOUT (NOM)

I

= 1 mA to 150 mA 0.005

OUT

VIN=V

OUT(nom)

+ 0.5V to 6.0V

+ 1V,

f = 1 kHz,

=50mA(Figure 3)

I

OUT

V

IN=VOUT(nom)

+ 1V,

f = 10 kHz,

=50mA(Figure 3)

I

OUT

= 0 mA 85 120

OUT

= 1.4V, I

EN

V

= 0.4V 0.003 1.0

EN

=1mA 1 5

OUT

I

= 150 mA 80 115

OUT

= 1µF

C

OUT

= 0 to 150 mA 140 200

OUT

ESR (Note 11) 5 500 mΩ

0toV

IN

)

JA

220
255

o

C/W

o

C/W

250mW
244mW

= 1 µF. Typical values and limits

OUT

Limit

Min Max

−2

−3

−3.5

−0.15

0.15

−0.2

0.007

2

3

3.5

0.2

Units

%of

V

OUT(nom)

%/V

%/mA

65

45

dB

µAV

mV

150

220

µVrms

www.national.com 4