Advanced Monolithic Systems, Inc.

6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140

AMS2942

BLOCK DIAGRAM AND TYPICAL APPLICATIONS

AMS2942

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.

µA and C

µF. Limits appearing in boldface type apply over the

°C, V

SHUTDOWN

≤ 0.8V.

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 100 mV 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

at a programmed output voltage of 5V, the error output is guaranteed to go low when the output drops by 95 mV x 5V/1.235 = 384 mV. Thresholds remain constant

≤V

out

≤ (V

≤V

in

≤42V, 100µA≤I

L

≤ 100 mA, T

J

≤ T

Note 8: The junction-to-ambient thermal resistance is 120

°C/W for the molded plastic SO-8 (S), when the package is soldered directly to the PCB.

≥ 2.5V, V

IN

≤ 42V, V

Note 10: Output or reference voltage temperature coefficients defined as the worst case voltage change divided by the total temperature range.

Note 11: 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

Note 12: 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 under the specification for thermal regulation.

Note 13: Line regulation is tested at 150

°C for I

µA and T

°C, line regulation is guaranteed by design to 0.2%. See typical

performance characteristics for line regulation versus temperature and load current.

INPUT

OUTPUT

GROUND

ERROR

AMPLIFIER

1.23V

REFERENCE

39V to 45V UNREGULATED DC

+

+

+

+

-

SHUT-

DOWN

FEED-

BACK

ERROR

TO CMOS

OR TTL

+

-

+

330k

Ω

FROM

CMOS

OR TTL

50mV

ERROR DETECTION COMPARATOR

298k

Ω

10k

Ω

10

µF

V