LP2985 Datasheet, PDF(8/21 Page) National Semiconductor (TI) – Micropower 150 mA Low-Noise Ultra Low-Dropout Regulator Designed for Use with Very Low ESR Output Capacitors

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LP2985 Datasheet, PDF (8/21 Pages) National Semiconductor (TI) – Micropower 150 mA Low-Noise Ultra Low-Dropout Regulator Designed for Use with Very Low ESR Output Capacitors

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Electrical Characteristics (Note 10) (Continued)

Limits in standard typeface are for TJ = 25ËC. and limits in boldface type apply over the full operating temperature range. Un-

less otherwise specified: VIN = VO(NOM) + 1V, IL = 1 mA, CIN = 1 ÂµF, COUT = 4.7 ÂµF, VON/OFF = 2V.

LP2985AI-X.X

LP2985I-X.X

Symbol

Parameter

Conditions

Typ

(Note 6)

Units

Min

Max

Min

Max

Output Noise

BW = 300 Hz to 50 kHz,

Voltage (RMS)

COUT = 10 ÂµF

ÂµV

CBYPASS = 10 nF

Ripple Rejection

f = 1 kHz, CBYPASS = 10 nF

COUT = 10 ÂµF

IO(SC)

Short Circuit Current RL = 0 (Steady State)

400

(Note 9)

IO(PK)

Peak Output Current VOUT â¥ Vo(NOM) â5%

350

Note 1: âAbsolute Maximum Ratingsâ indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating the

device outside of its rated operating conditions.

Note 2: The ESD rating of pins 3 and 4 for the SOT-23 package, or pins 5 and 2 for the micro SMD package, is 1 kV.

Note 3: The maximum allowable power dissipation is a function of the maximum junction temperature, TJ(MAX), the junction-to-ambient thermal resistance, Î¸J-A,

and the ambient temperature, TA. The maximum allowable power dissipation at any ambient temperture is calculated using:

Where the value of Î¸J-A for the SOT-23 package is 220ËC/W in a typical PC board mounting and the micro SMD package is 225ËC/W. Exceeding the maximum

allowable dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown.

Note 4: For 12V option, output voltage survival: -0.3 to +16V. If used in a dual-supply system where the regulator load is returned to a negative supply, the LP2985

output must be diode-clamped to ground.

Note 5: The output PNP structure contains a diode between the VIN to VOUT terminals that is normally reverse-biased. Reversing the polarity from VIN to VOUT will

turn on this diode.

Note 6: Limits are 100% production tested at 25ËC. Limits over the operating temperature range are guaranteed through correlation using Statistical Quality Control

(SQC) methods. The limits are used to calculate Nationalâs Average Outgoing Quality Level (AOQL).

Note 7: Dropout voltage is defined as the input to output differential at which the output voltage drops 100 mV below the value measured with a 1V differential.

Note 8: The ON/OFF input must be properly driven to prevent possible misoperation. For details, refer to Application Hints.

Note 9: The LP2985 has foldback current limiting which allows a high peak current when VOUT > 0.5V, and then reduces the maximum output current as VOUT is

forced to ground (see Typical Performance Characteristics curves).

Note 10: Exposing the micro SMD device to direct sunlight will cause misoperation. See Application Hints for additional information.

Note 11: For 12V option, add 50 ÂµA to all ON state quiescent current values.

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