ATR4251C Low-noise, High-dynamic-range AM/FM Antenna Amplifier IC DATASHEET Features High dynamic range for AM and FM Integrated AGC for AM and FM High intercept point 3rd order for FM FM amplifier adjustable to various cable impedances High intercept point 2nd and 3rd order for AM Low noise output voltage Low power consumption Low output impedance AM 9258E-AUDR-11/141. Description The Atmel ATR4251C is an integrated low-noise AM/FM antenna amplifier with integrated AGC in BiCMOS2S technology. The device is designed in particular for car applications, and is suitable for windshield and roof antennas. Figure 1-1. Block Diagram QFN24 Package FM FM FM AGC VREF1 IN GAIN GND2 OUT IN Paddle = GND 24 23 22 21 20 19 FM NC* NC* 1 amplifier 18 GND VS BAND 2 17 GAP AGC1 AGC AGCCONST 3 16 AGC2 VREF4 4 15 VREF2 AMOUT1 5 14 AM AGC AMIN GND1 (AM) 6 13 7819 0 1112 CREG AGC AGC T NC* NC* AMIN AM CONST * Pin must not be connected to any other pin or supply chain except GND. Figure 1-2. Block Diagram SSO20 Package FMGAIN 1 20 GND2 FM amplifier FMIN 2 19 FMOUT VREF1 3 18 AGCIN AGC GND 4 17 VS AGC1 5 16 AGCCONST Band gap AGC2 6 15 VREF4 VREF2 7 14 AMOUT1 AMIN1 8 AM 13 GND1 CREG 9 12 TCONST AGC (AM) AGCAMIN 10 11 AGCAM SSO20 2 ATR4251C DATASHEET 9258EAUDR11/14