LP2950/2951

Micrel

3

February 1999

3-39

Parameter

Condition

Min

Typ

Max

Units

Shutdown Input Current

V

30

50

µA

100

µA

V

450

600

µA

750

µA

Regulator Output Current

Note 11

3

10

µA

in Shutdown

20

µA

Note 1:

Boldface limits apply at temperature extremes.

Note 2:

Unless otherwise specified all limits guaranteed for T

are Feedback tied to 5V Tap and Output tied to Output Sense (V

Note 3:

Guaranteed and 100% production tested.

Note 4:

Guaranteed but not 100% production tested. These limits are not used to calculate outgoing AQL levels.

Note 5:

Dropout voltage is defined as the input to output differential at which the output voltage drops 100mV below its nominal value measured at 1V

differential. At very low values of programmed output voltage, the minimum input supply voltage of 2V (2.3V over temperature) must be taken

into account.

Note 6:

Comparator thresholds are expressed in terms of a voltage differential at the Feedback terminal below the nominal reference voltage

measured at 6V input. To express these thresholds in terms of output voltage change, multiply by the error amplifier gain = V

(R1 + R2)/R2. For example, at a programmed output voltage of 5V, the Error output is guaranteed to go low when the output drops by

95mV x 5V/1.235V = 384mV. Thresholds remain constant as a percent of V

typically 5% below nominal, 7.5% guaranteed.

Note 7:

V

Note 8:

The junction-to-ambient thermal resistance of the TO-92 package is 180

°C/W with 0.4” leads and 160°C/W with 0.25” leads to a PC board.

The thermal resistance of the 8-pin DIP package is 105

°C/W junction-to-ambient when soldered directly to a PC board. Junction-to-ambient

thermal resistance for the SOIC (M) package is 160

°C/W.

Note 9:

May exceed input supply voltage.

Note 10: When used in dual-supply systems where the output terminal sees loads returned to a negative supply, the output voltage should be diode-

clamped to ground.

Note 11:V

Note 12: Output or reference voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range.

Note 13: Thermal regulation is defined as the change in output voltage at a time T after a change in power dissipation is applied, excluding load or line

regulation effects. Specifications are for a 50mA load pulse at V

Note 14: Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to heating

effects are covered in the specification for thermal regulation.

Note 15: Line regulation for the LP2951 is tested at 150

°C for I

0.2%. See Typical Performance Characteristics for line regulation versus temperature and load current.