EVALUATION KIT AVAILABLE MAX2181 FM Automotive Low-Noise Amplifier General Description Features The MAX2181 is a highly integrated FM variable-gain low-noise amplifier ideal for use in automotive FM and FM-diversity active antenna applications. The device features an FM signal path, providing 30dB of gain range, controlled by an on-chip power detector. The FM signal path covers 76MHz to 162.5MHz. ● +6V to +24V Supply Voltage Range ● Integrated AGC Function Eliminates External Pin Diodes ● High Dynamic Range ● Low-Noise, Sub 3dB Noise Figure The device integrates a voltage regulator and pass transistor, allowing operation using battery voltages in the +6V to +24V range. On-chip thermal protection automatically limits junction temperatures during extreme thermal conditions. ● Low External BOM The device is available in a small, 3mm x 3mm TQFN package and operates over the extended industrial temperature range (-40ºC to +85ºC). ● Integrated Power Detector ● Integrated Thermal Protection ● Small Package (3mm x 3mm TQFN) ● Integrated Pass Device and Linear Regulator ● Integrated Antenna Sense Ordering Information appears at end of data sheet. Applications For related parts and recommended products to use with this part, refer to www.maximintegrated.com/MAX2181.related. ● Automotive Active Antenna Simplified Block Diagram FM VCC MAX2181 DET VCC 19-6558; Rev 0; 12/12 VREG VANT FM OUTPUT MAX2181 FM Automotive Low-Noise Amplifier Absolute Maximum Ratings VBATT.....................................................................-0.5V to +26V LDO..........................................................................-0.5V to +6V FMOUT.................................................................. -0.5V to VLDO Short-Circuit Protection FMOUT................................... Indefinite FMIN......................................................................... 130dBµVRF Continuous Power Dissipation (TA = +70ºC) (derate 20.8mW/ºC above +70ºC)...........................1666.7mW θJC (Junction to Case) (Note 1).........................................7ºC/W θJA (Junction to Ambient) (Note 1)..................................48ºC/W Operating Temperature Range.............................-40ºC to +85ºC Junction Temperature....................................................... +150ºC Storage Temperature Range..............................-65ºC to +165ºC Lead Temperature (TQFN only, soldering, 10s)............... +300ºC Soldering Temperature (reflow)........................................ +260ºC Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. 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 (MAX2181 Evaluation Kit as shown, VBATT = 8V to 15V, TA = -40ºC to +85ºC, unless otherwise noted. Typical values are at VBATT = 10V, TA = +25ºC.) (Note 2) PARAMETER CONDITIONS MIN TYP MAX Operational range 8 10 15 Functional range (Note 3) 15 UNITS SUPPLY VOLTAGE (VBATT) VBATT 24 Voltage Regulation VLDO (Pin 12) 5.1 Supply Current Normal operation (VANTSENSE = 0V or 6V < VANTSENSE = 12V) 56 Antenna fault, ANTSENSE open 15 V V 68 mA 25 GAIN CONTROL AND AGC CONTROL (FMDET, FMGAIN, ANTSENSE) Ground ANTSENSE -50 Open µA 2.5 LDO FMDET Ground FMGAIN Open LDO www.maximintegrated.com -65 LDO Ground V 50 50 -50 µA µA µA 2.5 V 50 µA Maxim Integrated │ 2 MAX2181 FM Automotive Low-Noise Amplifier AC Electrical Characteristics (MAX2181 Evaluation Kit, VBATT = 8V to 15V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VBATT = 10V, load impedance = 50Ω, FMGAIN connected to ground, tuned for 87MHz to 108MHz, TA = +25°C.) (Note 2) PARAMETER CONDITIONS Frequency Range Power Gain Maximum Gain Flatness MIN TYP 76 MAX UNITS 162.5 MHz fIN = 97MHz, FMGAIN connected to VLDO fIN = 97MHz, FMGAIN open 6.0 8.3 10 5.0 7.2 9.0 fIN = 97MHz, FMGAIN connected to ground 4.0 6.0 8.0 76MHz to 90MHz (Notes 4, 5) 0.5 87MHz to 108MHz (Note 4) 0.5 162.5MHz relative to 97MHz Noise Figure fIN = 97MHz, TA = +25ºC Input Return Loss dB dB 3.2 2.75 dB 50Ω source 10 dB Output Return Loss 50Ω load 15 dB Gain Control Range fIN = 97MHz 32 dB IMD3 VIN = +120dBµV/tone, +100dBµV AGC threshold, 99.5MHz and 100.5MHz tones 66 dBc Minimum output threshold 92 Maximum output threshold 106 AGC Threshold AGC Threshold Variation Relative to 97MHz tone (76MHz to 108MHz) 28 1 dBµV dB Note 2: M in and max values are production tested at TA = +25ºC and +85ºC. Min and Max limits at TA = -40ºC are guaranteed by design and characterization. Note 3: Device automatically reduces current to limit die temperature within a safe range, but otherwise remains functional. Note 4: Guaranteed by design and characterization. Note 5: Tuned for 76MHz to 90MHz. www.maximintegrated.com Maxim Integrated │ 3 MAX2181 FM Automotive Low-Noise Amplifier Typical Operating Characteristics (MAX2181 Evaluation Kit, VBATT = 10V, tuned for 87MHz to 108MHz, FMGAIN connected to ground, TA = +25°C, unless otherwise noted.) 30 TA = +85°C 5.15 TA = +105°C 15 20 5.00 25 5 10 15 VBATT (V) 6.5 TA = -40°C 11 GAIN (dB) 5.5 5.0 8 7 6 3 3.0 2 100 150 200 50 FREQUENCY (MHz) 80 CLOSED-LOOP OUTPUT POWER 60 IM3 INPUT TONES AT 99MHz AND 100MHz 40 20 75 85 95 105 115 INPUT POWER PER TONE (dBµV) www.maximintegrated.com 125 MAX2181 toc03 10 12 3.0 VFMGAIN = VLDO 2.5 150 2.0 200 100 50 150 FREQUENCY (MHz) CLOSED-LOOP OUTPUT POWER AND IM3 vs. INPUT POWER 100 0 100 8 VFMGAIN = 0V 3.5 FREQUENCY (MHz) MAX2181 toc07 OUTPUT POWER AND IM3 (dBµV) 120 6 NOISE FIGURE vs. FREQUENCY 4.0 VFMGAIN = 0V 4 3.5 50 VFMGAIN = VLDO 5 TA = +25°C T = +105°C A 4.0 4 VBATT (V) FMGAIN = HIGH-Z 10 9 6.0 4.5 2 120 CLOSED-LOOP OUTPUT POWER AND IM2 vs. INPUT POWER MAX2181 toc08 TA = +85°C 7.0 2.0 25 GAIN vs. FREQUENCY 12 MAX2181 toc04 7.5 TA = -40°C VBATT (V) GAIN vs. FREQUENCY 8.0 20 NOISE FIGURE (dB) 10 TA = +25°C 2.5 OUTPUT POWER AND IM2 (dBµV) 5 TA = +85°C 4.0 3.0 TA = +25°C 5.05 MAX2181 toc05 10 TA = +105°C 4.5 3.5 5.10 20 GAIN (dB) 5.0 VLDO (V) TA = -40°C 40 5.5 TA = +85°C TA = -40°C 5.20 VLDO (V) IBATT (mA) 50 0 TA = +105°C 5.25 VLDO vs. VBATT 6.0 MAX2181 toc06 MAX2181 toc01 TA = +25°C 60 VLDO vs. VBATT 5.30 MAX2181 toc02 IBATT vs. VBATT 70 100 80 CLOSED-LOOP OUTPUT POWER 60 40 IM2 (A-B) 20 0 75 85 95 INPUT TONES AT 99MHz AND 100MHz 105 115 125 INPUT POWER PER TONE (dBµV) Maxim Integrated │ 4 MAX2181 FM Automotive Low-Noise Amplifier FMDET FMOUT N.C. TOP VIEW LDO Pin Configuration 12 11 10 9 VBATT 13 N.C. 14 MAX2181 N.C. 15 1 2 3 4 FMIN ANTSENSE FMGAIN + RBIAS N.C. 16 8 FMAGC 7 N.C. 6 N.C. 5 N.C. TQFN Pin Description PIN NAME 1 RBIAS Connect a 1% tolerance 20kΩ resistor to ground. 2 FMIN FM Input. AC couple to FM input bandpass filter. 3 ANTSENSE 4 FMGAIN 5–7, 9, 14–16 N.C. 8 FMAGC FM AGC Control Line. Connect a 1µF capacitor to ground. 10 FMOUT FM VGA Output 11 FMDET FM Attack Point Trim. Connect the desired resistor to ground. 12 LDO DC Regulator Output. Connect a bypass capacitor to ground. 13 VBATT — EP www.maximintegrated.com FUNCTION Connect to antenna input connector center conductor through a 100kΩ resistor. FM Gain Trim. Connect to ground, leave open, or connect to VLDO for the desired FM gain. No Connection to Die. Suggested thermal path on Layer 1 of PCB for packages exposed pad to thermal sink. Battery Supply Pin Exposed Pad. Ground. Maxim Integrated │ 5 MAX2181 FM Automotive Low-Noise Amplifier Detailed Description Antenna Sensing Setting Signal Path Gain and AGC Attack Point The MAX2181 allows independent variation of the gain and AGC attack points on the FM signal path. Gain and attack point are adjusted by changing the conditions on the FMGAIN and FMDET pins. FM Signal Path Typical FM gain can be set using the FMGAIN pin as shown in Table 1. The output attack point of the FM signal path is adjusted by changing the resistor RFMDET, connected to the FMDET pin. Table 2 shows the attack point associated with several resistor values. Table 1. FM Signal Path Gain PIN FMGAIN FM GAIN (dB, TYP) Ground 6.0 Open 7.2 VLDO 8.3 Table 2. FM Signal Path Attack Point RFMDET (kΩ) FM OUTPUT ATTACK POINT (dBµV, TYP) 0 92 13 93.5 22 95 33 97 43 99 51 101.5 62 104 71 106 www.maximintegrated.com 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 100kΩ resistor enables this function. If a DC bias of 6V to 12V 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 15mA to 25mA. 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 that is designed for a low thermal resistance. A thermal ground must be placed near the device. This can consist of a mounting screw to a large thermal mass, ideally placed no more than 5mm from the package. The backside ground of the MAX2181 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 5-7 and 14-16, and proceeding to the mounting hole further improves thermal performance. The MAX2181 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 +85ºC and VBATT up to +15V, the thermal protection does not engage. Refer to www.maximintegrated.com for the MAX2181 Evaluation Kit schematic, Gerber data, PADS layout file, and BOM information. Maxim Integrated │ 6 MAX2181 FM Automotive Low-Noise Amplifier Typical Application Circuit FM OUTPUT 47µH BAS316 C2 100pF VLDO 105Ω VLDO 0.47µF 0.1µF 9 13 8 14 7 MAX2181 15 5 + RBIAS 20kΩ 2 3 27nH 33pF FMAGC 1µF N.C. N.C. N.C. 4 FMGAIN 16 6 1 www.maximintegrated.com N.C. 10 ANTSENSE N.C. 11 FMIN N.C. FMOUT FMDET VLDO N.C. L1 470nH 43kΩ 12 VBATT 62Ω 10µF 10µF 10µF L2: FOR 76MHz TO 100MHz, L2 = 100nH FOR 87MHz TO 108MHz, L2 = 82nH Maxim Integrated │ 7 MAX2181 FM Automotive Low-Noise Amplifier Ordering Information PART Package Information TEMP RANGE PIN-PACKAGE MAX2181ETE+ -40°C to +85°C 16 TQFN-EP* MAX2181ETE/V+ -40°C to +85°C 16 TQFN-EP* +Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed pad. /V denotes an automotive qualified part. www.maximintegrated.com For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. 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. 16 TQFN T1633+2 21-0136 90-0030 Maxim Integrated │ 8 MAX2181 FM Automotive Low-Noise Amplifier Revision History REVISION NUMBER REVISION DATE 0 12/12 DESCRIPTION Initial release PAGES CHANGED — For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com. Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. © 2012 Maxim Integrated Products, Inc. │ 9 MAX2181 www.maximintegrated.com FM Automotive Low-Noise Amplifier Maxim Integrated │ 10