UTCLD1117/A LINEAR INTEGRATED CIRCUIT

11

QW-R102-006,H

LD1117/A ADJUSTABLE APPLICATION NOTE

The LD1117/A ADJUSTABLE has a thermal stabilized 1.25

±0.012V reference voltage between the OUT and ADJ

R1 is normally fixed to 120

Ω. From figure 7 we obtain:

In order to have the better load regulation it is important to realize a good Kelvin connection of R1 and R2 resistors.

In particular R1 connection must be realized very close to OUT and ADJ pin, while R2 ground connection must be

placed as near as possible to the negative Load pin. Ripple rejection can be improved by introducing a 10

µF

electrolytic capacitor placed in parallel to the R2 resistor (See Fig. 8)

FIG.7 Adjustable Output Voltage Application Circuit

FIG.8 Adjustable Output Voltage Application with improved Ripple Rejection.