CLM2931

CORPORATION

CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025

PARAMETER

CLM2931C

UNITS

CONDITIONS

MIN

TYP

MAX

Output Voltage Range

3.0

24

V

Line Regulation

0.2

1.5

mV

Load Regulation

0.3

1.0

mV

Output Impedance

40

m

Ω/V

100mADC and 10mArms, 100Hz-10kHz

Quiescent Current

0.4

15

0.8

1.0

1.0

mA

mA

mA

Ω

Output Noise Voltage

100

µVrms

10Hz-100kHz

Long Term Stability

0.4

%/1000h

Ripple Rejection

0.02

%/V

Dropout Voltage

0.05

0.3

0.2

0.6

V

V

Maximum Operational Input Voltage

26

33

V

Maximum Line Transient

60

70

V

Reverse Polarity Input Voltage, DC

-15

-30

V

Ω

Reverse Polarity Input Voltage, Transient

-50

-80

V

Ω

On/Off Threshold Current

20

50

µA

Threshold Votage

On

Off

3.25

2.0

2.2

1.2

V

Note 1: See TYPICAL APPLICATIONS notes to ensure constant junction temperature, low duty cycle pulse testing used.

Note 2: All limits are at 25

Note 3: The maximum power dissipation is a function of maximum junction temperature, total thermal resistance, and ambient temperature.

Note 4: Human body model, 100

µF discharged through 1.5KΩ.

APPLICATION HINTS

The CLM2931 requires an output capacitor for device stability.

The value required varies greatly depending upon the

application circuit and other factors.

The high frequency

characteristics of electolytic capacitors depend greatly on the

type and also on the manufacturer. Sometimes only bench

testing is the only means to determine the proper capacitor

type and value. The high quality 100

µF aluminum electrolytic

covers all general application circuits, this stability can be

obtained with a tantalum electrolytic value of 47

µF.

Another critical point of electrolytic characteristics is its

performance over temperature. The CLM2931 is designed to

operate starting at -40

electrolytic. Higher temperatures are generally no problem.

The electrolytic type in aluminum will freeze at around -30

This could cause an oscillation at output of regulator. At a

lower temperature requirement by many applications the

capacitor should maintain its performance. So as a result, for an

application which regulator junction temperature does not exceed

25

over the value needed for the entire temperature range.

Other points with linear regulators is that the twitch higher

output current stability decreases. In most applications the

CLM2931 is operating at a few milliamps.

In these

applications the output capacitance can be further reduced.

For example, when the regulator is running at 10mA output

current the output capacitance value is half compared to the

same regulator that is running at 100mA.

With the CLM2931CT adjustable regulator, the minimum value

of output capacitance is a function of the output voltage. The

value decreases with higher output voltages, since the

internal loop gain is reduced.

The worst case occurs at the lower temperature and

maximum operating currents, the entire circuit and the

electrolytic,

should

be

cooled

down to the

minimum

temperature. The minimum of 0.6 volts required at the input

of regulator above the output to keep the power dissipation

and die heating to its minimum.

After the value for the

capacitor has been determined for actual use, the value

should be doubled.