U4254BM-M Datasheet, PDF (6/14 Pages) ATMEL Corporation – Low-noise AM/FM Antenna Impedance Matching IC

VREF2
GND2
Figure 10. Internal Circuit at Pin VREF1
VS
GND1
ESD
12
VREF1
For the DC biasing of the FM amplifier, a second voltage reference circuit is integrated.
Since the collector current is temperature independent, the output voltage has a nega-
tive temperature coefficient of about -1 mV/K. To stabilize this voltage, an external
capacitor to ground of a few nF is recommended.
Figure 11. Internal Circuit at Pin VREF2
5
VREF2
GND1
ESD
GND2 is the ground for the AM amplifier.
6 U4254BM-M
4772B–AUDR–11/03