AM/FM Car Antenna Low-Noise Amplifier

Transcription

1 19-; Rev ; /1 EVALUATION KIT AVAILABLE AM/FM Car Antenna Low-Noise Amplifier General Description The is a highly integrated AM/FM variable-gain low-noise amplifier ideal for use in automotive active antenna applications. The device features separate AM and FM signal paths, each providing db of gain range, controlled by individual on-chip power detectors. The AM signal path covers a 1kHz to MHz input frequency range, while the FM signal path covers MHz to 1.MHz. The device integrates a voltage regulator and pass transistor, allowing operation using battery voltages in the +V to +V range. On-chip thermal protection automatically limits junction temperatures during extreme thermal conditions. The device is available in a small, mm x mm, TQFN package and operates over the extended industrial temperature range (-NC to +NC). Automotive Active Antenna Applications S +V to +V Supply Voltage Range Features S Integrated AGC Function Eliminates External Pin Diodes S High Dynamic Range S Low-Noise Design S Low External BOM S Integrated Thermal Protection S Small Package (mm x mm TQFN) Ordering Information PART TEMP RANGE PIN-PACKAGE ETG+ -NC to +NC TQFN-EP* +Denotes a lead(pb)-free/rohs-compliant package. *EP = Exposed pad. Simplified Block Diagram FM DET V REG VANT OUTPUT AM/FM AM DET Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1--9-, or visit Maxim s website at

2 ABSOLUTE MAXIMUM RATINGS V BATT...-.V to +V LDO...-.V to +V FMOUT, AMOUT...-.V to Short-Circuit Protection FMOUT, AMOUT... Indefinite FMIN, AMIN...1V PP Continuous Power Dissipation (T A = +NC) (derate.mw/nc above +NC)...mW B JC (Junction to Case) (Note 1)...NC/W B JA (Junction to Ambient) (Note 1)...NC/W Operating Temperature Range... -NC to +NC Junction Temperature...+1NC Storage Temperature Range... -NC to +1NC Lead Temperature (TQFN only, soldering, 1s)...+NC Soldering Temperature (reflow)...+nc Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD1-, using a fourlayer board. For detailed information on package thermal considerations, refer to CAUTION! ESD SENSITIVE DEVICE Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. DC ELECTRICAL CHARACTERISTICS ( Evaluation Kit as shown, V BATT = V to 1V, T A = -NC to +NC, unless otherwise noted. Typical values are at V BATT = 1V, T A = +NC.) (Note ) PARAMETER CONDITIONS MIN TYP MAX UNITS SUPPLY VOLTAGE (V BATT ) Operational range 1 1 V BATT Functional range (Note ) 1 Voltage Regulation (pin 1). V Supply Current Normal operation (V ANTSENSE = V or V < V ANTSENSE < 1V) 9 Antenna fault, ANTSENSE open 1 GAIN CONTROL AND AGC CONTROL (AM_GAIN, AM_DET, FM_DET, FM_GAIN, ANT_SENSE) ANTSENSE FMDET Digital Control AC ELECTRICAL CHARACTERISTICS ( Evaluation Kit, T A = -NC to +NC, V BATT = V to 1V, unless otherwise noted. Typical values are at V BATT = 1V, T A = +NC, load impedance = I, AM channel bandwidth = 9kHz, RAM = 1I (AM gain = db), FM low-gain configuration, FM gain = db.) (Note ) AM AMPLIFIER Ground - FA Open. V LDO FA Ground - LDO Ground - FA Open. V LDO FA PARAMETER CONDITIONS MIN TYP MAX UNITS Frequency Range.1 MHz Voltage Gain Maximum RAM = short, f IN = 1MHz. db Voltage Gain Minimum RAM = I, f IN = 1MHz db Input Capacitance f IN = 1MHz 1. pf Output Impedance f IN = 1MHz 1 I V ma FA

3 AC ELECTRICAL CHARACTERISTICS (continued) ( Evaluation Kit, T A = -NC to +NC, V BATT = V to 1V, unless otherwise noted. Typical values are at V BATT = 1V, T A = +NC, load impedance = I, AM channel bandwidth = 9kHz, RAM = 1I (AM gain = db), FM low-gain configuration, FM gain = db.) (Note ) PARAMETER CONDITIONS MIN TYP MAX UNITS.1MHz to.mhz (Note ) Gain Response.MHz to 1.1MHz (Note ) (Relative to 1MHz).9MHz to MHz (Note ) db MHz to MHz - +1 Gain Control Range At 1MHz db.1mhz to.mhz - Output Noise.MHz to 1.1MHz - dbfv.9mhz to MHz - IMD V IN = +1dBFV/tone, +dbfv AGC threshold,.mhz and.mhz tones - db IMD V IN = +1dBFV/tone, +dbfv AGC threshold,.mhz and.mhz tones - db AGC Threshold Output level, f IN = 1MHz, AMDET connected to ground 9 Output level, f IN = 1MHz, AMDET open Output level, f IN = 1MHz, AMDET connected to LDO AGC Threshold Variation Relative to 1MHz tone (1kHz < f IN < 11kHz). db FM AMPLIFIER Frequency Range 1. MHz f IN = 9MHz, FMGAIN connected to LDO.. 1 Power Gain Maximum f IN = 9MHz, FMGAIN connected to LDO, FM high-gain db 1. configuration (Note ) Power Gain Minimum f IN = 9MHz, FMGAIN = short... db MHz to 9MHz (Note ). Gain Flatness MHz to 1MHz (Note ). db 1.MHz relative to 9MHz. Noise Figure f IN = 9MHz, T A = +NC (Note ). db Input Return Loss I source 1 db Output Return Loss I load 1 db Gain Control Range f IN = 9MHz 9 db IMD (FM to AM) Output tones of 1MHz and 1MHz, +1dBFV AGC threshold (A - B) dbfv V IN = +1dBFV/tone, +1dBFV AGC threshold, 1MHz and 1MHz tones IMD V IN = +1dBFV/tone, +1dBFV AGC threshold, 1MHz and 1MHz tones, FM high-gain configuration (Note ) Minimum output threshold 9 AGC Threshold dbfv Maximum output threshold 1 AGC Threshold Variation Relative to 9MHz tone (MHz to 1MHz) 1 db Note : Min and max values are production tested at T A = +NC and +NC. Min and Max limits at T A = -NC are guaranteed by design and characterization. Note : Device automatically reduces current to limit die temperature within a safe range, but otherwise remains functional. Note : Guaranteed by design and characterization. Note : FM high-gain configuration. See the Evalutation Kit schematic. dbfv db

4 Typical Operating Characteristics ( Evaluation Kit, low-gain configuration, V BATT = 1V, T A = + C, unless otherwise noted.) IBATT (ma) 9 1 T A = + C I BATT vs. V BATT T A = - C T A = +1 C T A = + C toc1 VLDO (V) T A = - C T A = + C vs. V BATT T A = +1 C T A = + C toc V BATT (V) V BATT (V) vs. VBATT toc AM GAIN vs. FREQUENCY T A = - C toc VLDO (V) T A = +1 C T A = + C T A = + C AM GAIN (db) T A = C T A = + C T A = + C T A = +1 C 1 T A = - C V BATT (V) FREQUENCY (MHz) AM GAIN (db) AM GAIN vs. RAM toc FM GAIN (db) FM GAIN vs. FREQUENCY T A = - C T A = + C T A = + C T A = C T A = +1 C MAX19 toc RAM (I) FREQUENCY (MHz)

5 Typical Operating Characteristics (continued) ( Evaluation Kit, low-gain configuration, V BATT = 1V, T A = + C, unless otherwise noted.) FM GAIN (db) 1 9 FM GAIN vs. FREQUENCY V FMGAIN = V V FMGAIN = HIGH-Z V FMGAIN = V 1 1 FREQUENCY (MHz) MAX19 toc OUTPUT POWER AND IM (dbµv) 9 1 AM OUTPUT POWER AND IM vs. INPUT POWER OUTPUT POWER INPUT TONES AT khz AND khz IM INPUT POWER PER TONE (dbµv) toc OUTPUT POWER AND IM (dbµv) 9 AM OUTPUT POWER AND IM vs. INPUT POWER OUTPUT POWER INPUT TONES AT khz AND khz IM (A + B) 1 IM (A - B) INPUT POWER PER TONE (dbµv) toc9 NOISE FIGURE (db) FM NOISE FIGURE vs. FREQUENCY LOW-GAIN CONFIGURATION HIGH-GAIN CONFIGURATION FREQUENCY (MHz) toc1 OUTPUT POWER AND IM (dbµv) 1 1 FM OUTPUT POWER AND IM vs. INPUT POWER INPUT TONES AT 1MHz AND 1MHz OUTPUT POWER IM INPUT POWER PER TONE (dbµv) toc11 OUTPUT POWER AND IM (dbµv) 1 1 FM OUTPUT POWER AND IM vs. INPUT POWER INPUT TONES AT 1MHz AND 1MHz OUTPUT POWER IM (A - B) INPUT POWER PER TONE (dbµv) toc1

6 TOP VIEW V BATT NC NC NC NC AMCMP 1 RBIAS AMGAIN AMDET 1 AMAGC LDO AMBYP FMOUT FMIN FMFB FMDET + AMIN AMOUT 11 FMAGC EP TQFN (mm mm) ANTSENSE 1 9 FMGAIN FMBYP N.C. FMBYP1 Pin Configuration Pin Description PIN NAME DESCRIPTION 1 AMGAIN AM Gain Adjust. Per Table 1, place resistor to ground for desired voltage gain. See the Detailed Description section. AMAGC AM AGC AC Ground. Connect a.1ff capacitor to ground. AMIN AM Input. AC-couple to AM input lowpass filter. AMBYP AM AC Ground. Connect a.1ff capacitor to ground. FMIN FM Input. AC-couple to FM input bandpass filter. ANTSENSE Connect to Antenna Input Connector Center Conductor Through a 1kI Resistor. See the Detailed Description section. FMBYP1 FM AC Ground. Connect a 1pF capacitor to ground. N.C. No Connection to Die 9 FMBYP FM AC Ground. Connect a 1pF capacitor to ground. 1 FMGAIN FM Gain Adjust. Connect to ground, leave open, or connect to LDO for the desired FM gain. See the Detailed Description section. 11 FMAGC FM AGC AC Ground. Connect a.1ff capacitor to ground. 1 FMDET FM Attack Point Adjust. Connect the desired resistor to ground. See the Detailed Description section. 1 FMFB FM Feedback. Connect through resistor RFM and a pf capacitor to FMOUT. See the Evalutation Kit schematic. 1 FMOUT FM Output 1 LDO DC Regulator Output. Connect a 1FF and 1pF capacitor to ground. 1 AMOUT AM Output 1 AMDET AM Attack Point Adjust. Connect to ground, leave open, or connect to LDO for the desired AM attack point. See the Detailed Description section.

7 PIN NAME DESCRIPTION 1 RBIAS Connect a 1% Tolerance ki Resistor to Ground 19 V BATT Battery Supply, 1,, NC, NC, NC, NC AMCMP Pin Description (continued) No Connection to Die. Use as a thermal path on layer 1 of PCB from exposed pad to thermal sink. AM Compensation. Leave open for RAM < I and short for RAM R I. See the Detailed Description section. EP Exposed Pad. Ground. Detailed Description Setting Signal Path Gain and AGC Attack Point The allows independent variation of the gain and AGC attack points on the AM and FM signal paths. Gain and attack point are adjusted by changing the conditions on the AMGAIN, AMDET, FMGAIN, and FMDET pins. AM Signal Path The gain of the AM signal path is adjusted by changing the resistor RAM, which is connected to AMGAIN through a.1ff capacitor. Table 1 shows the gain associated with several resistor values. The output attack point of the AM signal path can be set to one of three values depending on the state of the AMDET pin, as shown in Table. Table 1. AM Signal Path Gain RAM (I) AM GAIN (db, TYP) Table. AM Signal Path Attack Point PIN AMDET AM OUTPUT ATTACK POINT (dbµv, TYP) Ground 9 Open Note: For values of RAM R I, pin AMCMP must be shorted to ground. For values of RAM < I, leave AMCMP open. FM Signal Path The FM signal path can be configured for either highgain or low-gain operation. In the high-gain configuration, typical FM gain is 1.dB. In the low-gain configuration, typical FM gain can be set using the FMGAIN pin as shown in Table. Component values for high-gain and low-gain configurations are shown in Table. The output attack point of the FM signal path is adjusted by changing the resistor RFMDET, connected to the FMDET pin. Table shows the attack point associated with several resistor values. Table. FM Signal Path Gain PIN FMGAIN FM GAIN (db, TYP) Ground. Open.1. Table. FM Signal Path Attack Point RFMDET (ki) FM OUTPUT ATTACK POINT (dbµv, TYP)

8 Antenna Sensing In some applications, a bias voltage might be present on the car antenna or the car antenna might be DC shorted to ground in normal operation. In these situations, the device can sense an antenna fault condition and report this by setting the VBATT current. Connecting the ANTSENSE pin to the car antenna through a 1kI resistor enables this function. If a DC bias of V to 1V is present on the antenna, the device operates normally. If the antenna is DC shorted to ground, the device also operates normally. However, if the antenna is a DC open circuit, the device VBATT current drops to a value between 1mA to ma. This provides a method for the car audio system to detect an antenna fault. If this function is not required, the ANTSENSE pin should be connected to ground. Layout Recommendations For best performance, the device must be mounted on a PCB which is designed for a low thermal resistance. A thermal ground must be placed near the device. This Table. FM Signal Path Component Values COMPONENT HIGH-GAIN CONFIGURATION LOW-GAIN CONFIGURATION C1 pf 1pF C 1pF Open C pf 1pF R1 I Open RFM 9I Short L1 1nH Open L 1nH nh can consist of a mounting screw to a large thermal mass, ideally placed no more than mm from the package. The backside ground of the must be connected to a thermal ground plane on the PCB using at least nine plated through holes. Finally, a wide trace on the PCB top metal from the paddle area, connecting pins, and proceeding to the mounting hole further improves thermal performance. The is equipped with thermal-protection circuitry that maintains junction temperature at safe levels when the device is operated outside its specified operating range. For ambient temperatures up to +NC and VBATT up to +1V, the thermal protection does not engage. Refer to for the Evaluation Kit schematic, Gerber data, PADS layout file, and BOM information. Package Information For the latest package outline information and land patterns, go to Note that a +, #, or - in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. TQFN T

9 1pF AM OUTPUT J 1µF.1µF Evaluation Kit FM OUTPUT J R1 C L RFM V BATT JP JP1 V BATT NC NC NC NC AMCMP RBIAS RBIAS AMDET AMGAIN AMAGC LDO FMOUT FMFB µF.1µF AMIN AMOUT.1µF 1 9 EP EP AMBYP FMIN ANTSENSE pf JP RFMDET FMDET.1µF FMAGC FMGAIN 1pF FMBYP N.C. 1pF FMBYP1 JP RAM 1Ω pf C1 L1 J J1 C 9

10 REVISION NUMBER REVISION DATE DESCRIPTION Revision History PAGES CHANGED /1 Initial release Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 1 Maxim Integrated Products, 1 San Gabriel Drive, Sunnyvale, CA Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.