19-5655; Rev 0; 6/11 EVALUATION KIT AVAILABLE MAX2670 GPS/GNSS Front-End Amplifier General Description Features The MAX2670 GPS/GNSS front-end amplifier IC is designed for automotive and marine GPS/GNSS satellite navigation antenna modules or for any application that needs to compensate for cable losses from the 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 device 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/GNSS receiver. Additionally, a 3.4dB gain step is provided to compensate for cable loss variation between different applications. S First Amplifier Noise Figure*: 1.0dB The device is designed to operate across all GNSS frequency standards with a 34.8dB typical cascaded gain and a 25mA supply current. The two LNA stages allow the use of a wide range of GNSS filter types for maximum flexibility in system design. The final RF output pin, which drives the cable to the GNSS 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. Integrated Automotive and Marine GPS Receivers Active Antennas This GPS/GNSS front-end amplifier is designed on a lownoise, advanced SiGe process and is available in a leadfree, 10-pin TDFN surface-mount package (3mm x 3mm). S High Gain**: 34.8dB S 3.4dB Gain Step S Shared VCC and RFOUT2 Pin S Integrated 50I Output Matching S 3.0V to 5.5V Supply Voltage Range S Small, Low-Cost Package (3mm x 3mm) S AEC-Q100 Qualified S ESD Protected to ±2kV Human Body Model Applications *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 appears at end of data sheet. Typical Operating Circuit appears at end of data sheet. Functional Diagram TOP VIEW + RFIN2 1 GND 2 GND 3 EXTCAP/ALT_VCC 4 RFOUT2/VCC 5 10 RFOUT1 MAX2670 AMP 2 AMP 1 DC GENERATION 9 GND 8 GND 7 GAIN_SELECT 6 RFIN1 TDFN For related parts and recommended products to use with this part, refer to www.maxim-ic.com/MAX2670.related. ����������������������������������������������������������������� Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. MAX2670 GPS/GNSS Front-End Amplifier ABSOLUTE MAXIMUM RATINGS RFOUT1, RFOUT2, EXTCAP to GND........ -0.3V to (VCC + 0.5V) RFIN1 Input Power (50I source)................................... +15dBm GAIN_SELECT to GND.............................. -0.3V to (VCC + 0.3V) Continuous Power Dissipation (TA = +70NC) TDFN (derate 18.5mW/NC above +70NC)...................1481mW Operating Ambient Temperature Range.......... -40NC to +105NC Maximum Junction Temperature......................................+150NC Storage Temperature Range............................. -65NC to +150NC Lead Temperature (soldering, 10s).................................+300NC Soldering Temperature (reflow).......................................+260NC 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 (VIN = 3.0V to 5.5V, TA = -40NC to +105NC. Typical values are at +5.0V and at TA = +25NC. Pin 7 open, unless otherwise noted.) (Note 1) PARAMETER Supply Voltage SYMBOL CONDITIONS VCC Supply Current ICC Gain-Select Input Current IIL MIN TYP 3.0 15.0 TA = +25NC 25 MAX UNITS 5.5 V 30 30 TA = -40NC to 105NC VIL = 0V 20 100 mA FA AC ELECTRICAL CHARACTERISTICS (VCC = 3.0V to 5.5V, PIN = -40dBm, fIN = 1575MHz, TA = -40NC to +105NC. Typical values are at 5.0V and at TA = +25NC. Input matched to 50I, load = 50I, pin 7 open, unless otherwise noted.) (Note 1) PARAMETER Operation Frequency SYMBOL |S21| AMP 1 Gain CONDITIONS MIN fRF TYP MAX 1575 50I source with no input match (Note 2) 14.5 16.7 MHz 19 17.8 50I source with input match AMP 1 Gain Variation Over Temperature UNITS dB 0.3 dB 1 dB AMP 1 Noise Figure NF No input match (Notes 2, 3) AMP 1 Input Third-Order Intercept Point IIP3 Two tones at 1574.5MHz and 1575.5MHz, -35dBm per tone -12 dBm 50I source with no input match (Note 2) -19 dBm -4.4 dB -14.5 dB AMP 1 Input 1dB Compression Point AMP 1 Input Return Loss |S11| AMP 1 Output Return Loss |S22| AMP 1 Reverse Isolation |S12| AMP 2 Gain |S21| AMP 2 Gain Step No input match (Note 2) -33 Gain change when pin 7 is shorted to GND AMP 2 Gain Variation Over Temperature AMP 2 Noise Figure NF (Note 3) dB 14.5 17 21 dB -2.5 -3.4 -4.0 dB 1 dB 2.0 dB ����������������������������������������������������������������� Maxim Integrated Products 2 MAX2670 GPS/GNSS Front-End Amplifier AC ELECTRICAL CHARACTERISTICS (continued) (VCC = 3.0V to 5.5V, PIN = -40dBm, fIN = 1575MHz, TA = -40NC to +105NC. Typical values are at 5.0V and at TA = +25NC. Input matched to 50I, load = 50I, pin 7 open, unless otherwise noted.) (Note 1) PARAMETER SYMBOL AMP 2 Output Third-Order Intercept Point CONDITIONS MIN TYP Two tones at 1574.5MHz and 1575.5MHz, -30dBm per tone OIP3 AMP 2 Output 1dB Compression Point MAX UNITS 16.0 dBm 5.3 dBm AMP 2 Input Return Loss |S11| -21 dB AMP 2 Output Return Loss |S22| -8.8 dB AMP 2 Reverse Isolation |S12| -25 dB Note 1: TA = +25NC and TA = +105NC are guaranteed by production test. At TA = -40NC, the minimum and maximum values are guaranteed by design and characterization, unless otherwise noted. Note 2: Measured using the MAX2670 evaluation board with a DC-blocking capacitor at the input of LNA 1. Note 3: At TA = +25NC, the maximum value is guaranteed by design and characterization. Specification is corrected for board losses on the MAX2670 EV kit. Typical Operating Characteristics (PIN = -40dBm, fIN = 1575MHz, inputs and outputs are terminated to 50I, VCC = 5.0V, TA = +25NC, unless otherwise noted.) 5.0 4.5 NOISE FIGURE (dB) NOISE FIGURE (dB) 1.2 1.1 1.0 0.9 0.8 LOW-GAIN MODE 4.0 3.5 3.0 2.5 2.0 0.7 1.5 0.6 1.0 -40 -20 0 20 40 60 TEMPERATURE (°C) 80 100 HIGH-GAIN MODE 27.5 SUPPLY CURRENT (mA) 1.3 MAX2670 toc02 5.5 MAX2670 toc01 1.4 SUPPLY VOLTAGE vs. CURRENT (PIN 7 OPEN) AMP 2 NOISE FIGURE vs. TEMPERATURE TA = +105°C 26.5 MAX2670 toc03 AMP 1 NOISE FIGURE vs. TEMPERATURE (WITHOUT EXTERNAL INPUT IMPEDANCE MATCH) TA = +85°C 25.5 24.5 TA = +25°C 23.5 22.5 TA = -40°C 21.5 -40 -20 0 20 40 60 TEMPERATURE (°C) 80 100 3.0 3.5 4.0 4.5 5.0 5.5 SUPPLY VOLTAGE (V) ����������������������������������������������������������������� Maxim Integrated Products 3 MAX2670 GPS/GNSS Front-End Amplifier Typical Operating Characteristics (continued) (PIN = -40dBm, fIN = 1575MHz, inputs and outputs are terminated to 50I, VCC = 5.0V, TA = +25NC, unless otherwise noted.) TA = -40°C TA = +85°C 17.5 3.0 3.5 4.0 4.5 5.0 5.5 TA = -40°C 13.5 TA = +85°C 13.0 TA = +105°C 12.5 TA = +25°C TA = +85°C TA = +105°C 12.0 3.0 3.5 4.0 4.5 5.0 3.0 5.5 3.5 4.0 4.5 5.0 5.5 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) AMP 1 GAIN vs. FREQUENCY (WITH EXTERNAL INPUT IMPEDANCE MATCH) AMP 2 GAIN vs. FREQUENCY AMP 1 INPUT P1dB vs. TEMPERATURE (WITHOUT EXTERNAL INPUT IMPEDANCE MATCH) 16 HIGH-GAIN MODE 14 18 GAIN (dB) 16 15 10 8 LOW-GAIN MODE 6 14 4 13 2 -17 INPUT P1dB (dBm) 12 17 1000 1200 1400 1600 1800 800 2000 1000 1200 1400 1600 1800 -22 2000 -2.5 5.0 4.8 60 TEMPERATURE (°C) 80 100 60 80 100 -8 -3.5 -10 -4.0 -12 -4.5 -14 -16 -5.0 40 40 -6 S22 (dB) S11 (dB) 5.2 20 AMP 1 S22 -3.0 5.4 0 -4 MAX2670 toc11 5.6 20 -20 TEMPERATURE (°C) -2.0 MAX2670 toc10 5.8 0 -40 AMP 1 S11 (WITHOUT EXTERNAL INPUT IMPEDANCE MATCH) AMP 2 OUTPUT P1dB vs. TEMPERATURE (PIN 7 OPEN) -20 -20 FREQUENCY (MHz) FREQUENCY (MHz) -40 -19 MAX2670 toc12 800 -18 -21 0 12 MAX2670 toc09 19 -16 MAX2670 toc08 18 MAX2670 toc07 20 GAIN (dB) TA = +25°C 16.5 15.5 17.3 OUTPUT P1dB (dB) 14.0 17.0 16.0 TA = +105°C 17.4 14.5 GAIN (dB) 17.7 17.6 15.0 TA = -40°C TA = +25°C 17.8 17.5 GAIN (dB) GAIN (dB) 17.9 AMP 2 GAIN vs. SUPPLY VOLTAGE (PIN 7 SHORT TO GND) MAX2670 toc05 18.0 18.0 MAX2670 toc04 18.1 AMP 2 GAIN vs. SUPPLY VOLTAGE (PIN 7 OPEN) MAX2670 toc06 AMP 1 GAIN vs. SUPPLY VOLTAGE (WITH EXTERNAL INPUT IMPEDANCE MATCH) 800 1000 1200 1400 1600 FREQUENCY (MHz) 1800 2000 800 1000 1200 1400 1600 1800 2000 FREQUENCY (MHz) ����������������������������������������������������������������� Maxim Integrated Products 4 MAX2670 GPS/GNSS Front-End Amplifier Typical Operating Characteristics (continued) (PIN = -40dBm, fIN = 1575MHz, inputs and outputs are terminated to 50I, VCC = 5.0V, TA = +25NC, unless otherwise noted.) AMP 2 S11 AMP 2 S22 -5 MAX2670 toc14 -4 MAX2670 toc13 0 -6 -8 -10 S22 (dB) S11 (dB) -10 -15 -12 -14 -16 -18 -20 -20 -25 800 1000 1200 1400 1600 1800 -22 800 2000 1000 FREQUENCY (MHz) AMP 1 S12 1600 1800 2000 1800 2000 AMP 2 S12 -24 S12 (dB) -36 -38 MAX2670 toc16 MAX2670 toc15 -20 -34 S12 (dB) 1400 FREQUENCY (MHz) -32 -40 800 1200 -28 -32 -36 1000 1200 1400 1600 FREQUENCY (MHz) 1800 2000 -40 800 1000 1200 1400 1600 FREQUENCY (MHz) ����������������������������������������������������������������� Maxim Integrated Products 5 MAX2670 GPS/GNSS Front-End Amplifier Pin Configuration TOP VIEW + RFIN2 1 10 RFOUT1 GND 2 9 GND GND 3 8 GND EXTCAP/ALT_VCC 4 7 GAIN_SELECT RFOUT2/VCC 5 6 RFIN1 MAX2670 EP TDFN Pin Description PIN NAME 1 RFIN2 Amplifier 2 Input. Incorporates an internal DC-blocking capacitor and is internally matched to 50I. This input is designed to be connected to a bandpass filter. 2, 3, 8, 9 GND Electrical Ground 4 EXTCAP/ALT_VCC 5 RFOUT2/VCC 6 RFIN1 7 GAIN_SELECT 10 RFOUT1 EP — FUNCTION 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 RFOUT2/VCC. Amplifier 2 Output. Incorporates an internal DC-blocking capacitor and is internally matched to 50I. DC bias on this pin serves as the power supply through a bias-T. Amplifier 1 Input. Requires external DC-blocking capacitor and matching components. AMP 2 Gain Select. Open is high-gain mode. Short to ground is low-gain mode. Amplifier 1 Output. Incorporates an internal DC-blocking capacitor and is internally matched to 50I. This output is designed to drive a bandpass filter. Exposed Pad Ground. The exposed pad must be soldered to the circuit board for proper thermal and electrical performance. ����������������������������������������������������������������� Maxim Integrated Products 6 MAX2670 GPS/GNSS Front-End Amplifier Alternate Supply (ALT_VCC) Detailed Description The IC power can be supplied from the navigation system through RFOUT2 (pin 5). An integrated filter 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 MAX2670 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 50I 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 PCB using high-frequency techniques. Use controlled-impedance transmission lines to interface with the MAX2670 highspeed 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 PCB trace. Good grounding is critical for this device. The backside ground plane should be as close as possible. 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 50I 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. Refer to www.maxim-ic.com for the MAX2670 Evaluation Kit schematic, gerber data, pads layout file and BOM information. Typical Operating Circuit SAW LNA1 INPUT LNA2 INPUT 1 10 VCC REG 6 ALT_VCC 4 VCC REG LNA 1 LNA 2 5 7 8/9 EXPOSED PAD MAX2670 2/3 RFOUT2/VCC GAIN_SELECT OPEN = 31.4dB GAIN SHORT TO GROUND = 28dB GAIN ����������������������������������������������������������������� Maxim Integrated Products 7 MAX2670 GPS/GNSS Front-End Amplifier Package Information Ordering Information PART TEMP RANGE PIN-PACKAGE MAX2670GTB+T -40NC to +105NC 10 TDFN-EP* MAX2670GTB/V+T -40NC to +105NC 10 TDFN-EP* +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. *EP = Exposed pad. /V denotes automotive qualified part. For the latest package outline information and land patterns (footprints), go to www.maxim-ic.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. 10 TDFN-EP T1033+2 21-0137 90-0061 ����������������������������������������������������������������� Maxim Integrated Products 8 MAX2670 GPS/GNSS Front-End Amplifier Revision History REVISION NUMBER REVISION DATE 0 6/11 DESCRIPTION Initial release PAGES CHANGED — 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. 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 Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2011 Maxim Integrated Products 9 Maxim is a registered trademark of Maxim Integrated Products, Inc.