National Semiconductor LP3982 Technical data

LP3982
Micropower, Ultra Low-Dropout, Low-Noise, 300mA
CMOS Regulator

LP3982 Micropower, Ultra Low-Dropout, Low-Noise, 300mA CMOS Regulator

March 2006

General Description

The LP3982 low-dropout (LDO) CMOS linear regulator is
available in 1.8V, 2.5V, 2.77V, 2.82V, 3.0V, 3.3V, and adjust­able versions. They deliver 300mA of output current. Pack­aged in an 8-Pin MSOP, the LP3982 is pin and package
compatible with Maxim’s MAX8860. The LM3982 is also
available in the small footprint LLP package.

The LP3982 suits battery powered applications because of
its shutdown mode (1nA typ), low quiescent current (90µA
typ), and LDO voltage (120mV typ). The low dropout voltage
allows for more utilization of a battery’s available energy by
operating closer to its end-of-life voltage. The LP3982’s
PMOS output transistor consumes relatively no drive current
compared to PNP LDO regulators.

This PMOS regulator is stable with small ceramic capacitive
loads (2.2µF typ).

These devices also include regulation fault detection, a
bandgap voltage reference, constant current limiting and
thermal overload protection.

Application Circuit

Features

n MAX8860 pin, package and spec. compatible
n LLP space saving package
n 300mA guaranteed output current
n 120mV typical dropout
n 90µA typical quiescent current
n 1nA typical shutdown mode
n 60dB typical PSRR
n 2.5V to 6V input range
n 120µs typical turn-on time
n Stable with small ceramic output capacitors
n 37µV RMS output voltage noise (10Hz to 100kHz)
n Over temperature/over current protection

±

n

2% output voltage tolerance

@

300mA

Applications

n Wireless handsets
n DSP core power
n Battery powered electronics
n Portable information appliances

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© 2006 National Semiconductor Corporation DS200369 www.national.com

Absolute Maximum Ratings (Notes 1, 2)

If Military/Aerospace specified devices are required,

LP3982

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

V

IN,VOUT,VSHDN,VSET,VCC

V

FAULT

,

−0.3V to 6.5V

ESD Rating

Human Body Model (Note 6) 2kV

Machine Model 200V

Thermal Resistance (θ

)

JA

8-Pin MSOP 223˚C/W

8-Pin LLP (Note 3)

Fault Sink Current 20mA

Power Dissipation (Note 3)

Storage Temperature Range −65˚C to 160˚C

Junction Temperature (T

) 150˚C

J

Lead Temperature (10 sec.) 260˚C

Operating Ratings(Note 1), (Note 2)

Temperature Range −40˚C to 85˚C

Supply Voltage 2.5V to 6.0V

Electrical Characteristics

Unless otherwise specified, all limits guaranteed for VIN=VO+0.5V (Note 7), V
TJ= 25˚C. Boldface limits apply for the operating temperature extremes: −40˚C and 85˚C.

Symbol Parameter Conditions Min

V

∆V

IN

O

Input Voltage 2.5 6.0 V

Output Voltage Tolerance 100µA ≤ I

V

IN=VO

≤ 300mA

OUT

+0.5V, (Note 7)
SET = OUT for the Adjust
Versions

V

I

O

I

LIMIT

I

Q

V

∆V

O

DO

O

Output Adjust Range Adjust Version Only 1.25 6 V

Maximum Output Current Average DC Current Rating 300 mA

Output Current Limit 330 770 mA

Supply Current I

Shutdown Supply Current V

Dropout Voltage
(Note 7), (Note 8)

Line Regulation I

= 0mA 90 270

OUT

I

= 300mA 225

OUT

= 0V, SHDN = GND 0.001 1 µA

O

I

= 1mA 0.4

OUT

= 200mA 80 220

OUT

I

= 300mA 120

OUT

= 1mA, (VO+ 0.5V) ≤ VI≤ 6V

OUT

(Note 7)

e

V

n

SHDN

Load Regulation 100µA ≤ I

Output Voltage Noise I

= 10mA, 10Hz ≤ f ≤ 100kHz 37 µV

OUT

Output Voltage Noise Density 10Hz ≤ f ≤ 100kHz, C

SHDN Input Threshold VIH,(VO+ 0.5V) ≤ VI≤ 6V

≤ 300mA 0.002 %/mA

OUT

= 10µF 190 nV/

OUT

(Note 7)

,(VO+ 0.5V) ≤ VI≤ 6V

V

IL

(Note 7)

I

SHDN

I

SET

SHDN Input Bias Current SHDN = GND or IN 0.1 100 nA

SET Input Leakage SET = 1.3V, Adjust Version Only

(Note 9)

V

FAULT

FAULTDetection Voltage VO≥ 2.5V, I

OUT

= 200mA

(Note 10)

I

= 2mA 0.115 0.25 V

SINK

I

FAULT

T

SD

FAULT Output Low Voltage

FAULT Off-Leakage Current FAULT = 3.6V, SHDN = 0V 0.1 100 nA

Thermal Shutdown
Temperature

Thermal Shutdown Hysteresis 10

T

ON

Start-Up Time C

= 10µF, VOat 90% of Final

OUT

Value

Note 1: Absolute Maximum ratings indicate limits beyond which damage may occur. Electrical specifications do not apply when operating the device outside of its
rated operating conditions.

=VIN,CIN=C

SHDN

(Note 5)

Typ

(Note 4)

= 2.2µF, CCC= 33nF,

OUT

Max

(Note 5)

−2 +2

−3 +3

−0.1 0.01 0.1 %/V

2

0.4

0.1 2.5 nA

120 280 mV

160

120 µs

Units

%of

V

OUT (NOM)

µA

mVI

RMS

V

˚C

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Electrical Characteristics (Continued)

Note 2: All voltages are with respect to the potential at the ground pin.

Note 3: Maximum Power dissipation for the device is calculated using the following equations:

LP3982

where T
package θ
thus below 25˚C the power dissipation figure can be increased by 4.5mW per degree, and similarity decreased by this factor for temperatures above 25˚C. The value
of the θ
resistance and power dissipation for the LLP package, refer to Application Note AN-1187.

Note 4: Typical Values represent the most likely parametric norm.

Note 5: All limits are guaranteed by testing or statistical analysis.

Note 6: Human body model: 1.5kΩ in series with 100pF.

Note 7: Condition does not apply to input voltages below 2.5V since this is the minimum input operating voltage.

Note 8: Dropout voltage is measured by reducing V

version.

Note 9: The SET pin is not externally connected for the fixed versions.

Note 10: The FAULT detection voltage is specified for the input to output voltage differential at which the FAULT pin goes active low.

is the maximum junction temperature, TAis the ambient temperature, and θJAis the junction-to-ambient thermal resistance. E.g. for the MSOP-8

J(MAX)

= 223˚C/W, T

JA

for the LLP package is specifically dependent on the PCB trace area, trace material, and the number of layers and thermal vias. For improved thermal

JA

= 150˚C and using TA= 25˚C, the maximum power dissipation is found to be 561mW. The derating factor (−1/θJA) = −4.5mW/˚C,

J(MAX)

until VOdrops 100mV from its nominal value at VIN-VO= 0.5V. Dropout Voltage does not apply to the 1.8

IN

Functional Block Diagram

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Typical Performance Characteristics Unless otherwise specified, V

2.2µF, C

LP3982

= 33nF, TJ= 25˚C, V

CC

SHDN=VIN

Dropout Voltage vs. Load Current

(For Different Output Voltages)

FAULT Detect Threshold vs. Load Current Supply Current vs. Input Voltage

.

Dropout Voltage vs. Load Current

(For Different Output Temperatures)

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IN=VO

+ 0.5V, CIN=C

OUT

=

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Supply Current vs. Load Current Power Supply Rejection Ratio vs. Frequency

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