MAX2685 19-1493 Rev 1 12/00 Low-Cost, 900MHz, Low-Noise Amplifier and Downconverter Mixer General Description Features The MAX2685s low-noise amplifier (LNA) and down- 800MHz to 1000MHz RF Frequency Range converter mixer comprise the major blocks of an RF +2.7V to +5.5V Single-Supply Operation front-end receiver. Optimized for 900MHz operation, the devices low noise figure, high gain, and high linear- Integrated LNA + Mixer + LO Buffer ity make it ideal for cellular, cordless, and wireless data Logic-Controlled LNA Bypass Switch Reduces applications. A low supply current of 8.5mA (high-gain mode) and 3.8mA (low-gain mode) plus a low operating Supply Current supply voltage range of +2.7V to +5.5V make it suitable LNA Performance (High/Low Gain) for use in 3-cell NiCd or 1-cell lithium-ion (Li+) battery Gain: +15dB/-12dB applications. A low-power shutdown mode further NF: 1.4dB/12dB extends battery life by reducing supply current below Input IP3: -4dBm/+16dBm 0.1A. Mixer Performance (High/Low Gain) The MAX2685 includes an LNA, LNA bypass switch, Gain: 6dB/4.6dB downconverter mixer, and local-oscillator (LO) buffer. The LNA has a low noise figure of 1.4dB, a high gain of NF: 13dB/12dB 15dB, and an input third-order intercept point (IP3) of Input IP3: +7dBm/-1.5dBm -4dBm. The mixer has a noise figure of 13dB, a gain of Supply Current 6dB, and an input IP3 of +7dBm. In addition, an LNA 8.5mA (High Gain) bypass switch allows two levels of gain, reducing 3.8mA (Low Gain) power consumption when high gain is not needed. <0.1A Supply Current in Shutdown Mode The downconverter mixer has a single-ended RF input port and differential IF output ports. Differential opera- 0.8s Receiver Enable Time tion of the IF ports offers improved even-order harmonic rejection and increased immunity to noise. An LO buffer allows the LO port to be driven with only -8dBm of LO Ordering Information power. The MAX2685 is offered in a space-saving 16- pin QSOP package. PART TEMP. RANGE PIN-PACKAGE Applications MAX2685EEE -40C to +85C 16 QSOP Cellular/Cordless Phones 900MHz ISM-Band Radios Wireless Data 868MHz European ISM Band Functional Diagram Pin Configuration LNAOUT MIXIN TOP VIEW LNA 1 16 MIXER GND LNAOUT IFOUT+ 2 15 LNAIN LNAIN V CC IFOUT- 3 14 GND GND LNA BYPASS 4 13 GAIN GAIN MIXIN 5 12 V GND CC MAX2685 6 11 MAX2685 SHDN GND LO V CC BUFFER 7 10 POWER LO IFOUT+ SHDN MANAGEMENT 8 9 GND GND IFOUT- QSOP LO Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLELow-Cost, 900MHz, Low-Noise Amplifier and Downconverter Mixer ABSOLUTE MAXIMUM RATINGS V to GND..............................................................-0.3V to +6V Continuous Power Dissipation (T = +70C) CC A LNAIN Input Power (50 source)...................................+10dBm 16-Pin QSOP (derate 8.3mW/C above +70C)............667mW LO Input Power (50 source) ........................................+10dBm Junction Temperature......................................................+150C MIXIN Input Power (50 source) ...................................+10dBm Operating Temperature Range ...........................-40C to +85C IFOUT+, IFOUT- to GND ..........................................-0.3V to +6V Storage Temperature Range .............................-65C to +150C LNAOUT to GND ......................................................-0.3V to +6V Lead Temperature (soldering, 10s) .................................+300C GAIN, SHDN to GND..................................-0.3V to (V + 0.3V) CC 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 (V = +2.7V to +5.5V, V = +2V, V = +2V, LNAIN = LNAOUT = MIXIN = LO = unconnected, IFOUT+ = IFOUT- = V , T CC SHDN GAIN CC A = -40C to +85C. Typical values are at T = +25C and V = +3V, unless otherwise noted.) A CC PARAMETER CONDITIONS MIN TYP MAX UNITS Supply Voltage Range 2.7 5.5 V GAIN = V (Note 1) 8.5 14.1 CC Operating Supply Current mA GAIN = GND (Note 1) 3.8 6.4 Shutdown Supply Current 0.1 1.0 A SHDN = GND (Note 1) Logic Input Voltage High GAIN, SHDN 2.0 V Logic Input Voltage Low GAIN, SHDN 0.5 V Logic Input Current V = V = 0 to 5.5V (Note 1) 0.01 1 A SHDN GAIN AC ELECTRICAL CHARACTERISTICS (MAX2685 EV kit, V = V = +3V, f = f = 880MHz, f = 960MHz, P = -30dBm, P = -8dBm, P = -25dBm, CC SHDN LNAIN MIXIN LO LNAIN LO MIXIN differential IFOUT operation, Z = 50 , T = +25C, unless otherwise noted.) o A PARAMETER CONDITIONS MIN TYP MAX UNITS LOW-NOISE AMPLIFIER (LNA) RF Frequency Range (Note 2) 800 1000 MHz GAIN = V (Note 1) 13 15 16.2 CC LNA Gain dB GAIN = GND (Note 1) -14 -12 -10.3 LNA Gain Variation over Temperature GAIN = V , T = T to T (Note 3) 0.9 1.6 dB CC A MIN MAX GAIN = V 1.4 CC LNA Noise Figure dB GAIN = GND 12.2 GAIN = V (Note 4) -4.1 CC LNA Input IP3 dBm GAIN = GND (Note 5) +16.2 LNA Input 1dB Compression GAIN = V -18.4 dBm CC GAIN = V -18.6 CC LNAOUT Port Return Loss dB GAIN = GND -11.3 DOWNCONVERTER MIXER RF Frequency Range (Note 2) 800 1000 MHz GAIN = V (Note 1) 4.7 6.1 7.0 CC Mixer Conversion Gain dB GAIN = GND (Note 1) 2.5 4.6 6.0 2 MAX2685