LP3988 datasheet(5/11 Pages) NSC

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Electrical Characteristics (Continued)

Unless otherwise specified: V

EN = 1.8V, VIN =VOUT + 0.5V, CIN = 1 µF, IOUT = 1mA, COUT = 1 µF. Typical values and limits

appearing in standard typeface are for T

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

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

Symbol

Parameter

Conditions

Typ

Limit

Units

Min

Max

Logic Low Input threshold

IN = 2.5V to 6.0V

0.5

Logic High Input threshold

IN = 2.5V to 6.0V

1.2

Power Good

THL

THH

Power Good

Low threshold

High Threshold

%ofV

OUT (PG ON) Figure 2

%ofV

OUT (PG OFF) Figure 2 (Note

14)

PG Output Logic Low Voltage

PULL-UP = 100µA, fault condition

0.02

0.1

PGL

PG Output Leakage Current

PG Off, V

PG = 6V

0.02

µA

Power Good Turn On time,

(Note 9)

IN = 4.2V

µs

OFF

Power Good Turn Off time,

(Note 9)

IN = 4.2V

µs

Note 1: Absolute Maximum Ratings are limits beyond which damage to the device may 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: The Absolute Maximum power dissipation depends on the ambient temperature and can be calculated using the formula:

D =(TJ -TA)/

where TJ is the junction temperature, TA is the ambient temperature, and θ JA is the junction-to-ambient thermal resistance. The 364mW rating appearing under

Absolute Maximum Ratings for the SOT23-5 package results from substituting the Absolute Maximum junction temperature, 150˚C, for TJ, 70˚C for TA, and 220˚C/W

for

θJA. More power can be dissipated safely at ambient temperatures below 70˚C . Less power can be dissipated safely at ambient temperatures above 70˚C. The

Absolute Maximum power dissipation can be increased by 4.5mW for each degree below 70˚C, and it must be derated by 4.5mW for each degree above 70˚C. Same

principle applies to the micro SMD package.

Note 4: The human body model is 100pF discharged through 1.5k

Ω resistor into each pin. The machine model is a 200 pF capacitor discharged directly into each

pin.

Note 5: Like the Absolute Maximum power dissipation, the maximum power dissipation for operation depends on the ambient temperature. The 250mW rating

appearing under Operating Ratings for the SOT23-5 package results from substituting the maximum junction temperature for operation, 125˚C, for TJ, 70˚C for TA,

and 220˚C/W for

θJA into (Note 3) above. More power can be dissipated at ambient temperatures below 70˚C . Less power can be dissipated at ambient

temperatures above 70˚C. The maximum power dissipation for operation can be increased by 4.5mW for each degree below 70˚C, and it must be derated by 4.5mW

for each degree above 70˚C. Same principle applies to the micro SMD package.

Note 6: All limits are guaranteed. All electrical characteristics having room-temperature limits are tested during production with TJ = 25˚C or correlated using

Statistical Quality Control (SQC) methods. All hot and cold limits are guaranteed by correlating the electrical characteristics to process and temperature variations

and applying statistical process control.

Note 7: The target output voltage, which is labeled VOUT(nom), is the desired voltage option.

Note 8: An increase in the load current results in a slight decrease in the output voltage and vice versa.

Note 9: Dropout voltage is the input-to-output voltage difference at which the output voltage is 100mV below its nominal value.

Note 10: Short circuit current is measured on input supply line after pulling down VOUT to 95% VOUT(nom).

Note 11: Guaranteed by design. The capacitor tolerance should be ±30% or better over the full temperature range. The full range of operating conditions such as

temperature, DC bias and even capacitor case size for the capacitor in the application should be considered during device selection to ensure this minimum

capacitance specification is met. X7R capacitor types are recommended to meet the full device temperature range.

Note 12: Turn-on time is time measured between the enable input just exceeding VIH and the output voltage just reaching 95% of its nominal value.

Note 13: 100V machine model for Power-good flag, pin 4.

Note 14: The low and high thresholds are generated together. Typically a 2.6% difference is seen between these thresholds.

Note 15: The minimum VIN is dependant on the device output option.

For Vout(NOM) < 2.5V, VIN(MIN) will equal 2.5V. For Vout(NOM) >= 2.5V, VIN(MIN) will equal Vout(NOM) + 200mV.

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