U4254BM-M

Features High Dynamic Range for AM and FM Integrated AGC for FM High Intercept Point 3rd-order for FM FM Amplifier Adjustable to Various Cable Impedances High Intercept Point 2nd-order for AM Low-noise Output Voltage Low-power Consumption Electrostatic sensitive device. Observe precautions for handling. Low-noise AM/FM Antenna Impedance Matching IC U4254BM-M Description The U4254BM-M is an integrated low-noise AM/FM antenna impedance matching circuit in BiCMOS technology. The device is designed specifically for car applications and is suitable for windshield and roof antennas. Figure 1. Block Diagram FMIN GND1 FMGAIN AGC VS 1 2 3 4 14 IAGC FM 15 FMOUT AGC 13 AGCADJ VREF2 5 VREF 12 VREF1 11 AMIN 8 AMOUT1 AMOUT AM 7 GND2 10 Rev. 4772B–AUDR–11/03 Pin Configuration Figure 2. Pinning SO16 FMIN 1 2 16 NC 15 FMOUT 14 VS GND1 FMGAIN 3 AGC VREF2 NC 4 5 6 7 8 13 AGCADJ 12 VREF1 11 AMOUT1 10 AMOUT 9 NC GND2 AMIN Pin Description Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Symbol FMIN GND1 FMGAIN AGC VREF2 NC GND2 AMIN NC AMOUT AMOUT1 VREF1 AGCADJ VS FMOUT NC Function FM input Ground for FM part FM gain adjustment AGC output Reference voltage 2 output Not connected Ground for AM part AM input Not connected AM output AM output Reference voltage 1 output Adjustment FM wide-band AGC threshold Supply voltage FM output Not connected 2 U4254BM-M 4772B–AUDR–11/03 U4254BM-M Pin Description FMIN FMIN, a bipolar transitor’s base is the input of the FM amp...