MAX2685EEE-T Fast Delivery |IC PHOENIX CO.,LIMITED

MAX2685EEE-T ,Low-Cost, 900MHz, Low-Noise Amplifier and Downconverter MixerApplicationsMAX2685EEE -40°C to +85°C 16 QSOPCellular/Cordless Phones 900MHz ISM-Band RadiosWireles ..
MAX268ACWG+ ,Pin-Programmable Universal and Bandpass FiltersELECTRICAL CHARACTERISTICS (Continued) (v* Td." +5v, v- = -5v, CLK, = CLKB = , 5V, 1.5MHz, tas/to ..
MAX268BCNG ,Pin Programmable Universal and Bandpass FiltersELECTRICAL CHARACTERISTICS (Continued) (v* Td." +5v, v- = -5v, CLK, = CLKB = , 5V, 1.5MHz, tas/to ..
MAX268BCNG ,Pin Programmable Universal and Bandpass FiltersELECTRICAL CHARACTERISTICS (V+ = +5V, If" = AN, CLKA = CLK,3 = , 5V, 1.5MHz, fCLK/f0 = 197.92 for ..
MAX268BCNG+ ,Pin-Programmable Universal and Bandpass FiltersELECTRICAL CHARACTERISTICS (Continued) (v* Td." +5v, v- = -5v, CLK, = CLKB = , 5V, 1.5MHz, tas/to ..
MAX268BENG ,Pin Programmable Universal and Bandpass FiltersFeatures . Filter Design Software Available . 32-Step Center Frequency Control . 128-Step 0 Cont ..
MAX603CPA ,5V/3.3V or Adjustable, Low-Dropout, Low IQ, 500mA Linear RegulatorsFeatures' 500mA Output Current, with Foldback CurrentThe MAX603/MAX604 low-dropout, low quiescent c ..
MAX603CPA ,5V/3.3V or Adjustable, Low-Dropout, Low IQ, 500mA Linear RegulatorsApplicationsMAX604EPA -40°C to +85°C 8 Plastic DIP5V and 3.3V RegulatorsMAX604ESA -40°C to +85°C 8 ..
MAX603CPA+ ,5V/3.3V or Adjustable, Low-Dropout, Low-IQ, 500mA Linear RegulatorsApplicationsMAX604EPA -40°C to +85°C 8 Plastic DIP5V and 3.3V RegulatorsMAX604ESA -40°C to +85°C 8 ..
MAX603CSA ,5V/3.3V or Adjustable, Low-Dropout, Low IQ, 500mA Linear RegulatorsELECTRICAL CHARACTERISTICS(V = 6V (MAX603) or 4.3V (MAX604), C = C = 10µF, OFF = V , SET = GND, T = ..
MAX603CSA ,5V/3.3V or Adjustable, Low-Dropout, Low IQ, 500mA Linear RegulatorsELECTRICAL CHARACTERISTICS (continued)(V = 6V (MAX603) or 4.3V (MAX604), C = C = 10µF, OFF = V , SE ..
MAX603CSA ,5V/3.3V or Adjustable, Low-Dropout, Low IQ, 500mA Linear RegulatorsGeneral Description ________

MAX2685EEE-T
Low-Cost, 900MHz, Low-Noise Amplifier and Downconverter Mixer
General Description
The MAX2685’s low-noise amplifier (LNA) and down-
converter mixer comprise the major blocks of an RF
front-end receiver. Optimized for 900MHz operation,
the device’s low noise figure, high gain, and high linear-
ity make it ideal for cellular, cordless, and wireless data
applications. A low supply current of 8.5mA (high-gain
mode) and 3.8mA (low-gain mode) plus a low operating
supply voltage range of +2.7V to +5.5V make it suitable
for use in 3-cell NiCd or 1-cell lithium-ion (Li+) battery
applications. A low-power shutdown mode further
extends battery life by reducing supply current below
0.1µA.
The MAX2685 includes an LNA, LNA bypass switch,
downconverter mixer, and local-oscillator (LO) buffer.
The LNA has a low noise figure of 1.4dB, a high gain of
15dB, and an input third-order intercept point (IP3) of
-4dBm. The mixer has a noise figure of 13dB, a gain of
6dB, and an input IP3 of +7dBm. In addition, an LNA
bypass switch allows two levels of gain, reducing
power consumption when high gain is not needed.
The downconverter mixer has a single-ended RF input
port and differential IF output ports. Differential opera-
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
power. The MAX2685 is offered in a space-saving 16-
pin QSOP package.
Applications
Cellular/Cordless Phones900MHz ISM-Band Radios
Wireless Data868MHz European ISM Band
Features800MHz to 1000MHz RF Frequency Range+2.7V to +5.5V Single-Supply OperationIntegrated LNA + Mixer + LO Buffer Logic-Controlled LNA Bypass Switch Reduces
Supply CurrentLNA Performance (High/Low Gain)
Gain: +15dB/-12dB
NF: 1.4dB/12dB
Input IP3: -4dBm/+16dBmMixer Performance (High/Low Gain)
Gain: 6dB/4.6dB
NF: 13dB/12dB
Input IP3: +7dBm/-1.5dBmSupply Current
8.5mA (High Gain)
3.8mA (Low Gain)<0.1µA Supply Current in Shutdown Mode0.8µs Receiver Enable Time
MAX2685
Low-Cost, 900MHz, Low-Noise Amplifier
and Downconverter Mixer
VCC
IFOUT+
IFOUT-
MAX2685
LNAIN
GAIN
LNA
LNAOUTMIXIN
LNA BYPASS
BUFFER
MIXER
SHDNPOWER
MANAGEMENT
GND
LNAOUT
GND
VCC
VCC
MIXIN
GND
GND
IFOUT+
IFOUT-
TOP VIEW
MAX2685
QSOP
LNAIN
SHDN
GAIN
GND
GND
GND
Functional Diagram
19-1493; Rev 1; 12/00
PART
MAX2685EEE-40°C to +85°C
TEMP. RANGEPIN-PACKAGE
16 QSOP
EVALUATION KIT
AVAILABLE
Pin Configuration
Ordering Information
MAX2685
Low-Cost, 900MHz, Low-Noise Amplifier
and Downconverter Mixer
ABSOLUTE MAXIMUM RATINGS
DC ELECTRICAL CHARACTERISTICS
(VCC= +2.7V to +5.5V,VSHDN= +2V, VGAIN= +2V, LNAIN = LNAOUT = MIXIN = LO = unconnected, IFOUT+ = IFOUT- = VCC, TA
= -40°C to +85°C. Typical values are at TA= +25°C and VCC= +3V, unless otherwise noted.)
AC ELECTRICAL CHARACTERISTICS
(MAX2685 EV kit, VCC= VSHDN= +3V, fLNAIN= fMIXIN= 880MHz, fLO= 960MHz, PLNAIN = -30dBm, PLO= -8dBm, PMIXIN= -25dBm,
differential IFOUT operation, Zo= 50Ω, TA= +25°C, unless otherwise noted.)
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.
VCCto GND..............................................................-0.3V to +6V
LNAIN Input Power (50Ωsource)...................................+10dBm
LO Input Power (50Ωsource)........................................+10dBm
MIXIN Input Power (50Ωsource)...................................+10dBm
IFOUT+, IFOUT- to GND..........................................-0.3V to +6V
LNAOUT to GND......................................................-0.3V to +6V
GAIN, SHDNto GND..................................-0.3V to (VCC+ 0.3V)
Continuous Power Dissipation (TA= +70°C)
16-Pin QSOP (derate 8.3mW/°C above +70°C)............667mW
Junction Temperature......................................................+150°C
Operating Temperature Range...........................-40°C to +85°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
SHDN= GND(Note 1)
GAIN = VCC (Note 1)
GAIN, SHDN
GAIN, SHDN
VSHDN= VGAIN= 0 to 5.5V(Note 1)
CONDITIONS0.11.0Shutdown Supply Current
8.514.12.75.5Supply Voltage Range2.0Logic Input Voltage High0.5Logic Input Voltage Low±0.01±1Logic Input Current
UNITSMINTYPMAXPARAMETER
GAIN = GND(Note 1)mA3.86.4Operating Supply Current
GAIN = GND(Note 1)dB-14-12-10.3
GAIN = VCC, TA= TMINto TMAX(Note 3)
LNA GainGAIN = VCC (Note 1)
GAIN = VCC
GAIN = GND
GAIN = VCC
CONDITIONS0.91.6LNA Gain Variation over Temperature1516.2
1.4dB12.2LNA Noise Figure
-18.4LNA Input 1dB Compression
UNITSMINTYPMAXPARAMETER
MHz8001000RF Frequency Range (Note 2)
GAIN = VCC
GAIN = GND
dBm
-18.6dB-11.3LNAOUT Port Return Loss
MHz8001000RF Frequency Range (Note 2)
GAIN = GND(Note 1)dB2.54.66.0Mixer Conversion GainGAIN = VCC (Note 1)4.76.17.0
GAIN = VCC (Note 4)
GAIN = GND (Note 5)
-4.1dBm+16.2LNA Input IP3
LOW-NOISE AMPLIFIER (LNA)
DOWNCONVERTER MIXER
MAX2685
Low-Cost, 900MHz, Low-Noise Amplifier
and Downconverter Mixer
AC ELECTRICAL CHARACTERISTICS (continued)
(MAX2685 EV kit, VCC= VSHDN= +3V, fLNAIN= fMIXIN= 880MHz, fLO= 960MHz, PLNAIN = -30dBm, PLO= -8dBm, PMIXIN= -25dBm,
differential IFOUT operation, Zo= 50Ω, TA= +25°C, unless otherwise noted.)
Note 1:Performance at temperatures greater than or equal to +25°C are guaranteed by production test; performance at tempera-
tures less than +25°C are guaranteed by design and characterization.
Note 2:This is the recommended operating frequency range.
Note 3:Maximum and minimum limits are guaranteed by design and device characterization and are not production tested.
Note 4:Two tones at 880MHz and 880.1MHz, -30dBm per tone.
Note 5:Two tones at 880MHz and 880.1MHz, -10dBm per tone.
Note 6:Two tones at 880MHz and 880.1MHz, -25dBm per tone.
Note 7:Time from SHDN= high, until the cascaded receive gain is within 1dB of its final value. Measured with 47pF blocking
capacitors on LNAIN and LNAOUT. Matching network removed from IFOUT output.
Typical Operating Characteristics
(MAX2685 EV kit, VCC= VSHDN= +3V, fLNAIN= fMIXIN= 880MHz, fLO= 960MHz, PLNAIN = -30dBm, PLO= -8dBm, PMIXIN= -25dBm,
differential IFOUT operation, Zo= 50Ω, TA= +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX2685 toc01
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
GAIN = HIGH
GAIN = LOW
TA = +85°C
TA = +25°CTA = -40°C
TA = +85°C
TA = +25°C
TA = -40°C
SHUTDOWN SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX2685 toc02
SUPPLY VOLTAGE (V)
SHUTDOWN SUPPLY CURRENT (nA)
SHDN = GND
TA = -40°C
TA = +25°C
TA = +85°C
LNA GAIN vs. SUPPLY VOLTAGE
MAX2685 toc03
SUPPLY VOLTAGE (V)
GAIN (dB)
GAIN = HIGH
GAIN = LOWTA = +85°C
TA = +25°CTA = -40°C
TA = +85°CTA = +25°C
TA = -40°C
GAIN = GNDdB12.1Mixer Noise Figure (SSB)
GAIN = VCC, TA= TMINto TMAX(Note 3)
GAIN = VCC12Mixer Conversion Gain Variation over
Temperature
(Note 7)
GAIN = VCC
GAIN = GND
CONDITIONS0.8Receiver Enable TimedBm-1.5Mixer Input IP3 (Note 6)LO Port Return Loss
UNITSMINTYPMAXPARAMETERSHDN= VCCor GND53LO-to-LNAIN IsolationLNAOUT-to-MIXIN IsolationLO-to-MIXIN Isolation
OVERALL SYSTEM
MAX2685
Low-Cost, 900MHz, Low-Noise Amplifier
and Downconverter Mixer
Typical Operating Characteristics (continued)
(MAX2685 EV kit, VCC= VSHDN= +3V, fLNAIN= fMIXIN= 880MHz, fLO= 960MHz, PLNAIN = -30dBm, PLO= -8dBm, PMIXIN= -25dBm,
differential IFOUT operation, Zo= 50Ω, TA= +25°C, unless otherwise noted.)
LNA INPUT IP3 vs. SUPPLY VOLTAGE
MAX2685 toc04
SUPPLY VOLTAGE (V)
INPUT IP3 (dBm)
GAIN = HIGH
GAIN = LOW
TA = +85°C
TA = +25°C
TA = -40°C
TA = +85°C
TA = +25°C
TA = -40°C
LNA GAIN vs. FREQUENCY
MAX2685 toc05
FREQUENCY (MHz)
GAIN (dB)
GAIN = HIGH
GAIN = LOW
LNA NOISE FIGURE vs. FREQUENCY
MAX2685 toc06
FREQUENCY (MHz)
NOISE FIGURE (dB)
LNA REVERSE ISOLATION vs. FREQUENCY
MAX2685 toc07
FREQUENCY (MHz)
REVERSE ISOLATION (dB)
GAIN = HIGH
GAIN = LOW
LNA S11 vs. FREQUENCY
(800MHz to 1000MHz UNMATCHED)
MAX2685 toc10
GAIN = HIGH
GAIN = LOW
LNA INPUT RETURN LOSS vs. FREQUENCY
MAX2685 toc08
FREQUENCY (MHz)
INPUT RETURN LOSS (dB)
GAIN = HIGH
GAIN = LOW
LNA OUTPUT RETURN LOSS vs. FREQUENCY
MAX2685 toc09
FREQUENCY (MHz)
OUTPUT RETURN LOSS (dB)
GAIN = HIGH
GAIN = LOW
MIXER GAIN vs. SUPPLY VOLTAGE
MAX2685 toc11
SUPPLY VOLTAGE (V)
GAIN (dB)
TA = -40°C
TA = +85°C
TA = +85°C
TA = +25°C
TA = +25°C
TA = -40°C
GAIN = HIGH
GAIN = LOW
MIXER INPUT IP3 vs. SUPPLY VOLTAGE
MAX2685 toc12
SUPPLY VOLTAGE (V)
INPUT IP3 (dBm)
GAIN = HIGH
GAIN = LOW
TA = +85°C
TA = +25°C
TA = -40°C
TA = +85°C
TA = +25°C
TA = -40°C
MAX2685
Low-Cost, 900MHz, Low-Noise Amplifier
and Downconverter Mixer
Typical Operating Characteristics (continued)
(MAX2685 EV kit, VCC= VSHDN= +3V, fLNAIN= fMIXIN= 880MHz, fLO= 960MHz, PLNAIN = -30dBm, PLO= -8dBm, PMIXIN= -25dBm,
differential IFOUT operation, Zo= 50Ω, TA= +25°C, unless otherwise noted.)
MIXER GAIN vs. IF FREQUENCY
MAX2685 toc13
IF FREQUENCY (MHz)
GAIN (dB)
BANDWIDTH DETERMINED BY
DIFFERENTIAL-TO-SINGLE-ENDED
CONVERTER CIRCUIT
GAIN = HIGH
GAIN = LOW
MIXER GAIN vs. LO POWER
MAX2685 toc14
LO POWER (dBm)
GAIN (dB)
GAIN = HIGH
GAIN = LOW
MIXER NOISE FIGURE vs. LO POWER
MAX2685 toc15
LO POWER (dBm)
NOISE FIGURE (dB)GAIN = HIGH
GAIN = LOW
LO PORT RETURN LOSS vs. FREQUENCY
MAX2685 toc16
FREQUENCY (MHz)
RETURN LOSS (dB)
MAX2685
Low-Cost, 900MHz, Low-Noise Amplifier
and Downconverter Mixer
Pin Description
NAMEFUNCTION
1, 3, 8,
11, 12, 14GNDGround. Connect to ground plane with a low-inductance connection.LNAINRF Input to LNA and LNA Bypass Switch. Requires an external matching network and a series
DC-blocking capacitor.
PINGAIN
Gain Control Logic-Level Input. Drive high to enable the LNA, open the LNA bypass switch, and
increase the receiver’s gain. Drive low to disable the LNA, close the LNA bypass switch, and reduce
the receiver’s gain.
5, 15VCCSupply Voltage. Bypass VCCto GND at each pin with a 47pF capacitor as close to the pin as possible.SHDNShutdown Control Logic-Level Input. Drive high or connect to VCCfor normal operation. Drive low to
place the device in low-power shutdown mode.LOLocal-Oscillator Input to Downconverter Mixer. Requires a series DC-blocking capacitor and an imped-
ance-setting resistor (typically 75Ωto ground).IFOUT-Inverting Side to Downconverter Mixer’s Differential Open-Collector IF Output. Requires a pull-up induc-
tor to VCCfor proper biasing, as well as a matching network to ensure optimum output power.IFOUT+Noninverting Side of Downconverter Mixer’s Differential Open-Collector IF Output. Requires a pull-up
inductor to VCCfor proper biasing, as well as a matching network to ensure optimum output power. MIXINRF Input to Downconverter Mixer. Requires an external matching network and series DC-blocking
capacitor. LNAOUTLNA Output. Internally matched to 50Ω. LNAOUT has an internal blocking capacitor.
LNA
INPUT
880MHz
MAX2685
6pF
6pF
3.3pF
300pF
300pF
LNA
OUTPUT
MIXER
INPUT
880MHz
47pF
12pF
IF
OUTPUT
80MHz
0.1μF12nH330pF
75Ω8
GNDLNAOUT
MIXIN
GND
*OPTIONAL FOR BROADBAND MATCH.
IFOUT-
IFOUT+
680nH820nH
LNAINVCCVCC
VCC
VCC
47pF
GAIN
VCC
SHDN
GND
GND
GND
GND
GAIN-
CONTROL
INPUT
SHUTDOWN
INPUT
1000pF
INPUT
960MHz
Figure 1. Typical Operating Circuit

Partno	Mfg	Dc	Qty	Available	Descript
MAX2685EEE-T \|MAX2685EEET	MAXIM	N/a	2500	avai	Low-Cost, 900MHz, Low-Noise Amplifier and Downconverter Mixer