EVALUATION KIT AVAILABLE MAX12000 1575MHz GPS Front-End Amplifier General Description The MAX12000 GPS front-end amplifier IC is designed for marine GPS satellite navigation antenna modules or for any application that needs to compensate for cable losses from the GPS antenna to receiver. Two unconditionally stable low-noise amplifier stages provide the high gain and integrated I/O matching to minimize the need for external matching components and eliminate the need for additional gain stages. The MAX12000 features the option to place a bandpass ceramic or SAW filter between the two amplifier stages to provide a narrow-band output to further improve the noise performance of the GPS receiver. Additionally, a 3.4dB gain step is provided to compensate for cable loss variation between different applications. The MAX12000 is designed to operate at the GPS frequency of 1575MHz with a 34.8dB typical cascaded gain and a 25mA supply current. The two LNA stages allow the use of a wide range of GPS filter types for maximum flexibility in system design. The final RF output pin, which drives the cable to the GPS receiver, is also the power-supply connection that accepts a DC supply in the +3.0V to +5.5V range. Alternatively, the DC supply can be applied to pin 4. Features ●● First Amp Noise Figure*: 1.0dB ●● High Gain**: 34.8dB ●● 3.4dB Gain Step ●● Integrated 50Ω Output Matching ●● 3.0V to 5.5V Supply Voltage Range ●● Small, Low-Cost Package (3mm x 3mm) ●● ESD Protected to ±1kV Human Body Model *Without external input impedance match. **First amplifier input is impedance matched (S11 = -10dB). Second amplifier set to high gain. Amplifiers cascaded without interstage filter. Ordering Information PART TEMP RANGE PINPACKAGE MAX12000ETB+ -40°C to +85°C 10 TDFN +Denotes a lead(Pb)-free/RoHS-compliant package. The GPS front-end amplifier is designed on a low-noise, advanced SiGe process and is available in a lead-free, 10-pin TDFN surface-mount package (3mm x 3mm). Typical Operating Circuit appears at end of data sheet. Applications ●● Marine GPS Receivers Pin Configuration/Functional Diagram TOP VIEW + RFIN2 1 GND 2 GND 3 EXTCAP/ALT_VCC 4 RFOUT2/VCC 5 AMP 2 AMP 1 DC GENERATION TDFN 19-4021; Rev 1; 9/14 10 RFOUT1 MAX12000 9 GND 8 GND 7 GAIN_SELECT 6 RFIN1 MAX12000 1575MHz GPS Front-End Amplifier Absolute Maximum Ratings RFOUT1, RFOUT2, EXTCAP to GND...... -0.3V to (VCC + 0.5V) RFIN1 Input Power (50Ω source)....................................+15dBm RFIN1 to GND.......................................................-0.3V to +0.3V RFIN2 to GND.......................................................-0.3V to +1.0V GAIN_SELECT to GND............................. -0.3V to (VCC + 0.3V) Continuous Power Dissipation (TA = +70°C) 10-Pin TDFN (derate 18.5mW/°C above +70°C).......1481mW Operating Ambient Temperature Range............ -40°C to +105°C Maximum Junction Temperature......................................+150°C Storage Temperature Range............................. -65°C to +150°C Lead Temperature (soldering, 10s).................................. +300°C 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. CAUTION! ESD SENSITIVE DEVICE DC Electrical Characteristics (VCC = +3.0V to +5.5V, TA = -40°C to +85°C. Typical values are at +5.0V and at TA = +25°C. Pin 7 open, unless otherwise noted.) (Note 1) PARAMETER Supply Voltage SYMBOL VCC Supply Current ICC Gain-Select Input Current IIL CONDITIONS MIN TYP 3.0 TA = +25°C 15.0 TA = -40°C to 105°C (Note 2) 25 MAX UNITS 5.5 V 30.2 33 VIL = 0V 20 100 mA µA AC Electrical Characteristics (VCC = +3.0V to +5.5V, PIN = -40dBm, fIN = 1575MHz, TA = -40°C to +85°C. Typical values are at +5.0V and at TA = +25°C. Input matched to 50Ω, load = 50Ω, pin 7 open, unless otherwise noted.) (Note 1) PARAMETER Operation Frequency AMP 1 Gain SYMBOL fRF |S21| CONDITIONS MIN 50W source with no input match (Note 3) 15.0 50W source with input match AMP 1 Output Return Loss AMP 1 Reverse Isolation AMP 2 Gain AMP 2 Gain Step www.maximintegrated.com 16.7 NF IIP3 No input match (Notes 3, 4) Two tones at 1574.5MHz and 1575.5MHz, -35dBm per tone 1 50W source with no input match (Note 3) |S11| No input match (Note 3) |S22| |S12| |S21| Gain change when pin 7 is shorted to GND OIP3 dB dB 1.3 dB -12 dBm -19 dBm -4.4 dB -14.5 dB -33 dB 15.0 17 19.6 dB -2.8 -3.4 -4.0 dB 1 NF UNITS MHz 18.5 0.3 AMP 2 Gain Variation Over Temperature AMP 2 Noise Figure AMP 2 Output Third-Order Intercept Point AMP 2 Output 1dB Compression Point MAX 17.8 AMP 1 Gain Variation Over Temperature AMP 1 Noise Figure AMP 1 Input Third-Order Intercept Point AMP 1 Input 1dB Compression Point AMP 1 Input Return Loss TYP 1575 (Note 4) Two tones at 1574.5MHz and 1575.5MHz, -30dBm per tone 2.0 1.5 dB 2.4 dB 16.0 dBm 5.3 dBm Maxim Integrated │ 2 MAX12000 1575MHz GPS Front-End Amplifier AC Electrical Characteristics (continued) (VCC = +3.0V to +5.5V, PIN = -40dBm, fIN = 1575MHz, TA = -40°C to +85°C. Typical values are at +5.0V and at TA = +25°C. Input matched to 50Ω, load = 50Ω, pin 7 open, unless otherwise noted.) (Note 1) PARAMETER SYMBOL AMP 2 Input Return Loss AMP 2 Output Return Loss MIN TYP |S22| AMP 2 Reverse Isolation Note Note Note Note CONDITIONS |S11| |S12| MAX UNITS -21 dB -8.8 dB -25 dB 1: At TA = -40°C, the minimum and maximum values are guaranteed by design and characterization, unless otherwise noted. 2: At TA = -40°C and +105°C, the maximum value is guaranteed by design and characterization. 3: Measured using MAX12000 evaluation board with a DC-blocking capacitor at the input of LNA 1. 4: At TA = +25°C, the maximum value is guaranteed by design and characterization. Specification is corrected for board losses on the MAX12000 EV kit. Typical Operating Characteristics (PIN = -40dBm, fIN = 1575MHz, inputs and outputs are terminated to 50Ω, VCC = +5.0V, TA = +25°C, unless otherwise noted.) 1.0 0.9 0.8 3.5 3.0 2.5 2.0 0.7 1.5 0.6 1.0 -40 -20 0 20 40 60 80 100 HIGH-GAIN MODE -40 -20 0 AMP 1 GAIN vs. SUPPLY VOLTAGE (WITH EXTERNAL INPUT IMPEDANCE MATCH) TA = -40°C TA = +25°C 17.8 17.7 TA = +85°C 17.6 17.5 17.3 3.0 3.5 4.0 4.5 SUPPLY VOLTAGE (V) www.maximintegrated.com 5.0 5.5 80 21.5 100 TA = -40°C 3.0 3.5 4.0 4.5 5.0 AMP 2 GAIN vs. SUPPLY VOLTAGE (PIN 7 SHORT TO GND) 15.0 14.5 TA = -40°C 14.0 TA = +25°C 16.5 3.0 23.5 AMP 2 GAIN vs. SUPPLY VOLTAGE (PIN 7 OPEN) 17.0 15.5 TA = +25°C SUPPLY VOLTAGE (V) 16.0 TA = +105°C 17.4 60 17.5 GAIN (dB) GAIN (dB) 17.9 40 24.5 22.5 MAX12000 toc05 18.0 18.0 MAX12000 toc04 18.1 20 TA = +85°C 25.5 TEMPERATURE (°C) TEMPERATURE (°C) 3.5 4.0 13.0 TA = +105°C 12.5 SUPPLY VOLTAGE (V) 5.0 5.5 12.0 5.5 TA = -40°C 13.5 TA = +85°C 4.5 MAX12000 toc03 LOW-GAIN MODE 4.0 TA = +105°C 26.5 MAX12000 toc06 1.1 27.5 SUPPLY CURRENT (mA) 4.5 NOISE FIGURE (dB) 1.2 5.0 GAIN (dB) 1.3 NOISE FIGURE (dB) 5.5 MAX12000 toc01 1.4 SUPPLY VOLTAGE vs. CURRENT (PIN 7 OPEN) AMP 2 NOISE FIGURE vs. TEMPERATURE MAX12000 toc02 AMP 1 NOISE FIGURE vs. TEMPERATURE (WITHOUT EXTERNAL INPUT IMPEDANCE MATCH) TA = +25°C TA = +85°C TA = +105°C 3.0 3.5 4.0 4.5 5.0 5.5 SUPPLY VOLTAGE (V) Maxim Integrated │ 3 MAX12000 1575MHz GPS Front-End Amplifier Typical Operating Characteristics (continued) (PIN = -40dBm, fIN = 1575MHz, inputs and outputs are terminated to 50Ω, VCC = +5.0V, TA = +25°C, unless otherwise noted.) 15 10 8 LOW-GAIN MODE 6 14 4 13 2 800 1000 1200 1400 1600 1800 0 2000 800 1000 1200 1400 1600 1800 -19 -20 -22 2000 FREQUENCY (MHz) AMP 2 OUTPUT P1dB vs. TEMPERATURE (PIN 7 OPEN) AMP 1 S11 (WITHOUT EXTERNAL INPUT IMPEDANCE MATCH) -20 0 20 40 60 80 60 80 100 -10 -4.0 -12 -4.5 -14 800 TEMPERATURE (°C) 1000 1200 1400 1600 1800 -16 2000 800 1000 FREQUENCY (MHz) 1200 1400 1600 1800 2000 FREQUENCY (MHz) AMP 2 S11 AMP 2 S22 -5 MAX12000 toc14 -4 MAX12000 toc13 0 -6 -8 -10 -10 S22 (dB) S11 (dB) 40 -8 -3.5 -5.0 100 20 -6 S22 (dB) S11 (dB) -40 0 AMP 1 S22 -3.0 5.0 -20 -4 MAX12000 toc11 -2.5 5.2 -40 TEMPERATURE (°C) -2.0 5.4 MAX12000 toc09 -18 -21 FREQUENCY (MHz) 5.6 4.8 -17 INPUT P1dB (dBm) GAIN (dB) 16 5.8 -16 12 17 12 HIGH-GAIN MODE 14 MAX12000 toc10 GAIN (dB) 18 16 MAX12000 toc12 19 OUTPUT P1dB (dB) 18 MAX12000 toc07 20 AMP 1 INPUT P1dB vs. TEMPERATURE (WITHOUT EXTERNAL INPUT IMPEDANCE MATCH) AMP 2 GAIN vs. FREQUENCY MAX12000 toc08 AMP 1 GAIN vs. FREQUENCY (WITH EXTERNAL INPUT IMPEDANCE MATCH) -15 -12 -14 -16 -18 -20 -20 -25 800 1000 1200 1400 1600 FREQUENCY (MHz) www.maximintegrated.com 1800 2000 -22 800 1000 1200 1400 1600 1800 2000 FREQUENCY (MHz) Maxim Integrated │ 4 MAX12000 1575MHz GPS Front-End Amplifier Typical Operating Characteristics (continued) (PIN = -40dBm, fIN = 1575MHz, inputs and outputs are terminated to 50Ω, VCC = +5.0V, TA = +25°C, unless otherwise noted.) AMP 1 S12 AMP 2 S12 -36 -38 MAX12000 toc16 -24 S12 (dB) S12 (dB) -34 -40 800 -20 MAX12000 toc15 -32 -28 -32 -36 1000 1200 1400 1600 1800 2000 -40 800 FREQUENCY (MHz) 1000 1200 1400 1600 1800 2000 FREQUENCY (MHz) Pin Description PIN NAME FUNCTION 1 RFIN2 Amplifier 2 Input. Incorporates an internal DC-blocking capacitor and is internally matched to 50W. This input is designed to be connected to a bandpass filter. 2, 3, 8, 9 GND 4 EXTCAP/ ALT_VCC External Smoothing Capacitor for Internal Supply Voltage or Can Be Used as the External DC Supply Pin to Eliminate the Need for a Bias-T on Pin 5 5 RFOUT2/VCC Amplifier 2 Output. Incorporates an internal DC-blocking capacitor and is internally matched to 50W. DC bias on this pin serves as the power supply through a bias-T. 6 7 RFIN1 Electrical Ground Amplifier 1 Input. Requires external DC-blocking capacitor and matching components. GAIN_SELECT AMP 2 Gain Select. Open is high-gain mode. Short to ground is low-gain mode. 10 RFOUT1 Amplifier 1 Output. Incorporates an internal DC-blocking capacitor and is internally matched to 50W. This output is designed to drive a bandpass filter. EP Exposed Pad Ground. The exposed pad must be soldered to the circuit board for proper thermal and electrical performance. www.maximintegrated.com Maxim Integrated │ 5 MAX12000 1575MHz GPS Front-End Amplifier Detailed Description Supply The IC power can be supplied from the navigation system through the RF cable (pin 5). An integrated filter circuit is connected to the output of LNA 2 to separate the supply voltage from the GPS signal. Alternatively, the supply voltage can be applied to the external capacitor pin (pin 4). The MAX12000 IC contains two LNA stages tuned for use at 1575MHz. AMP 1 AMP 1 has an internal load that limits the bandwidth and provides a 50Ω output impedance through a DC-blocking capacitor. The internal biasing for AMP 1 suppresses gain variation with changes in temperature and supply voltage. At the input, an integrated DC-blocking capacitor and matching network are intentionally omitted to allow selection of external components to optimize for noise or gain. Layout Considerations For best performance, carefully lay out the printed circuit board using high-frequency techniques. Use controlled-impedance transmission lines to interface with the MAX12000 high-speed inputs and outputs and isolate the input signals from the output signals as much as possible. For improved noise figure, keep the connection to the input of LNA 1 as short as possible. A power-supply decoupling capacitor should be placed very close to pin 4 and connected directly to a ground plane. If low-gain selection for LNA 2 is required, connect pin 7 directly to the ground plane with a very short printed circuit board trace. Good grounding is critical for this device. The backside ground plane should be as close as possible. See Figure 1 for printed circuit board layout. AMP 2 with Gain Step The output of AMP 2 has the dual role of providing both the RF output drive and receiving the DC power supply through a single cable. Both the input and output ports of AMP 2 are internally matched to 50Ω impedance at 1575MHz. A 3.4dB gain switch can be used to adjust the gain for different applications. The gain-select pin is connected to an inverter with an internal pullup resistor. Hence, the gain-select pin is set by default to high-gain mode. Shorting the gain-select pin to ground sets the gain stage to a 3.4dB lower gain. As with AMP 1, AMP 2 has an internal load that limits the bandwidth, and the amplifier’s internal biasing suppresses gain variation with changes in temperature and supply voltage. Typical Operating Circuit SAW PINNING: 1 = LNA 2 INPUT 2 = GND 3 = GND 4 = EXTCAP/ALT_VCC 5 = LNA 2 OUTPUT/VCC 6 = LNA 1 INPUT 7 = GAIN SETTING 8 = GND 9 = GND 10 = LNA 1 OUTPUT MATCHING NETWORK/ DC BLOCK 6 4 VCC REG VCC REG LNA 1 LNA 2 5 7 MAX12000 8/9 EXPOSED PADDLE www.maximintegrated.com 1 10 2/3 OUTPUT GAIN SETTING OPEN = 31.4dB GAIN SHORT TO GROUND = 28dB GAIN Maxim Integrated │ 6 MAX12000 1575MHz GPS Front-End Amplifier Figure 1. Layout of the Evaluation Board Realized on 0.8mm FR4 (Not to Scale) www.maximintegrated.com Maxim Integrated │ 7 MAX12000 1575MHz GPS Front-End Amplifier Package Information 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 DOCUMENT NO. LAND PATTERN NO. 10 TDFN T1033-2 21-0137 90-0061 www.maximintegrated.com Maxim Integrated │ 8 MAX12000 1575MHz GPS Front-End Amplifier Revision History REVISION NUMBER REVISION DATE 0 3/06 Initial release — 1 9/14 Removed automotive reference from data sheet 1 DESCRIPTION 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. 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