SG137A/SG137 SERIES

2/92 Rev 1.1 2/94

Copyright

© 1994

11861 Western Avenue

∞

∞

∞

∞

∞ Garden Grove, CA 92841

4

(714) 898-8121

∞

∞

∞

∞

∞ FAX: (714) 893-2570

FIGURE 6.

ADJUSTMENT CURRENT VS. TEMPERATURE

FIGURE 5.

INPUT/OUTPUT DIFFERENTIAL

VS. OUTPUT CURRENT

FIGURE 3.

CURRENT VS. INPUT/OUTPUT DIFFERENTIAL

FIGURE 2.

REFERENCE VOLTAGE VS. TEMPERATURE

FIGURE 1.

INPUT/OUTPUT DIFFERENTIAL

VS. OUTPUT CURRENT

FIGURE 4. *

OUTPUT VOLTAGE DEVIATION

VS. OUTPUT CURRENT

CHARACTERISTIC CURVES

* The SG137A has load regulation compensation which

makes the typical unit read close to zero. This band

represents the typical production spread.

APPLICATION INFORMATION

OUTPUT VOLTAGE

The output voltage is determined by two external resistors, R

R

The exact formula for the output voltage is:

V

+ I

(

)

Where: V

In most applications, the second term is small enough to be

ignored, typically about 0.5% of V

In more critical applica-

tions, the exact formula should be used, with I

Solving for R

Smaller values of R

output voltage, but the no-load current drain on the regulator will

be increased. Typical values for R

giving 12.5 mA and 4.2mA no-load current respectively. There

is an additional consideration in selecting R

current specification of the regulator. The operating current of

R

V

V

REF

R

1

+ I

ADJ

FIGURE 6

R

R

1