Low-Cost, 900MHz, Low-Noise Amplifier and Downconverter Mixer

Transcription

1 19-193; Rev 1; 1/ EVALUATION KIT AVAILABLE Low-Cost, 9MHz, Low-Noise Amplifier General Description The s low-noise amplifier (LNA) and downconverter mixer comprise the major blocks of an RF front-end receiver. Optimized for 9MHz operation, the device s low noise figure, high gain, and high linearity make it ideal for cellular, cordless, and wireless data applications. A low supply current of.ma (high-gain mode) and 3.mA (low-gain mode) plus a low operating supply voltage range of +.V to +.V 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.1µa. The includes an LNA, LNA bypass switch, downconverter mixer, and local-oscillator () buffer. The LNA has a low noise figure of 1., a high gain of 1, and an input third-order intercept point (IP3) of -m. The mixer has a noise figure of 13, a gain of, and an input IP3 of +m. 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 operation of the IF ports offers improved even-order harmonic rejection and increased immunity to noise. An buffer allows the port to be driven with only -m of power. The is offered in a space-saving 1- pin QSOP package. Cellular/Cordless Phones Wireless Data Applications 9MHz ISM-Band Radios MHz European ISM Band Pin Configuration Features MHz to 1MHz RF Frequency Range +.V to +.V Single-Supply Operation Integrated LNA + Mixer + Buffer Logic-Controlled LNA Bypass Switch Reduces Supply Current LNA Performance (High/Low Gain) Gain: +1/-1 NF: 1./1 Input IP3: -m/+1m Mixer Performance (High/Low Gain) Gain: /. NF: 13/1 Input IP3: +m/-1.m Supply Current.mA (High Gain) 3.mA (Low Gain) <.1µA Supply Current in Shutdown Mode.µs Receiver Enable Time PART EEE Ordering Information TEMP. RANGE - C to + C PIN-PACKAGE 1 QSOP Functional Diagram TOP VIEW LNAOUT MIXIN LNAIN GAIN SHDN IFOUT+ IFOUT- LNAOUT MIXIN IFOUT+ IFOUT- LNAIN GAIN SHDN LNA POWER MANAGEMENT LNA BYPASS BUFFER MIXER QSOP Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1--9-, or visit Maxim s website at

2 Low-Cost, 9MHz, Low-Noise Amplifier ABSOLUTE MAXIMUM RATINGS to...-.3v to +V LNAIN Input Power (Ω source)...+1m Input Power (Ω source)...+1m MIXIN Input Power (Ω source)...+1m IFOUT+, IFOUT- to...-.3v to +V LNAOUT to...-.3v to +V GAIN, SHDN to...-.3v to ( +.3V) Continuous Power Dissipation (T A = + C) 1-Pin QSOP (derate.3mw/ C above + C)...mW Junction Temperature...+1 C Operating Temperature Range...- C to + C Storage Temperature Range...- C to +1 C Lead Temperature (soldering, 1s)...+3 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. DC ELECTRICAL CHARACTERISTICS ( = +.V to +.V, V SHDN = +V, V GAIN = +V, LNAIN = LNAOUT = MIXIN = = unconnected, IFOUT+ = IFOUT- =, T A = - C to + C. Typical values are at and = +3V, unless otherwise noted.) PARAMETER CONDITIONS MIN TYP MAX UNITS Supply Voltage Range.. V Operating Supply Current GAIN = (Note 1) GAIN = (Note 1) ma Shutdown Supply Current SHDN = (Note 1).1 1. µa Logic Input Voltage High GAIN, SHDN. V Logic Input Voltage Low GAIN, SHDN. V Logic Input Current V SHDN = V GAIN = to.v (Note 1) ±.1 ±1 µa AC ELECTRICAL CHARACTERISTICS ( EV kit, = V SHDN = +3V, f LNAIN = f MIXIN = MHz, f = 9MHz, P LNAIN = -3m, P = -m, P MIXIN = -m, differential IFOUT operation, Z o = Ω,, unless otherwise noted.) PARAMETER W-NOISE AMPLIFIER (LNA) RF Frequency Range (Note ) LNA Gain LNA Gain Variation over Temperature LNA Noise Figure LNA Input IP3 LNA Input 1 Compression LNAOUT Port Return Loss DOWNCONVERTER MIXER RF Frequency Range (Note ) Mixer Conversion Gain CONDITIONS MIN TYP MAX 1 GAIN = (Note 1) GAIN = (Note 1) GAIN =, T A = T MIN to T MAX (Note 3).9 1. GAIN = 1. GAIN = 1. GAIN = (Note ) -.1 GAIN = (Note ) +1. GAIN = -1. GAIN = -1. GAIN = GAIN = (Note 1)..1. GAIN = (Note 1)... UNITS MHz m m MHz

3 Low-Cost, 9MHz, Low-Noise Amplifier AC ELECTRICAL CHARACTERISTICS (continued) ( EV kit, = V SHDN = +3V, f LNAIN = f MIXIN = MHz, f = 9MHz, P LNAIN = -3m, P = -m, P MIXIN = -m, differential IFOUT operation, Z o = Ω,, unless otherwise noted.) PARAMETER Mixer Conversion Gain Variation over Temperature Mixer Noise Figure (SSB) Mixer Input IP3 (Note ) Port Return Loss -to-lnain Isolation -to-mixin Isolation LNAOUT-to-MIXIN Isolation OVERALL SYSTEM Receiver Enable Time GAIN =, T A = T MIN to T MAX (Note 3) GAIN = GAIN = 1.1 GAIN = GAIN = SHDN = or 3 (Note ) CONDITIONS MIN TYP MAX UNITS m µs Note 1: Note : Note 3: Note : Note : Note : Note : Performance at temperatures greater than or equal to + C are guaranteed by production test; performance at temperatures less than + C are guaranteed by design and characterization. This is the recommended operating frequency range. Maximum and minimum limits are guaranteed by design and device characterization and are not production tested. Two tones at MHz and.1mhz, -3m per tone. Two tones at MHz and.1mhz, -1m per tone. Two tones at MHz and.1mhz, -m per tone. Time from SHDN = high, until the cascaded receive gain is within 1 of its final value. Measured with pf blocking capacitors on LNAIN and LNAOUT. Matching network removed from IFOUT output. Typical Operating Characteristics ( EV kit, = V SHDN = +3V, f LNAIN = f MIXIN = MHz, f = 9MHz, P LNAIN = -3m, P = -m, P MIXIN = -m, differential IFOUT operation, Z o = Ω,, unless otherwise noted.) SUPPLY CURRENT (ma) SUPPLY CURRENT vs. SUPPLY VOLTAGE 1 9 T A = - C 3 T A = - C toc1 SHUTDOWN SUPPLY CURRENT (na) SHUTDOWN SUPPLY CURRENT vs. SUPPLY VOLTAGE SHDN = 1 T A = - C toc GAIN () LNA GAIN vs. SUPPLY VOLTAGE T A = - C TA = - C toc3 3

4 Low-Cost, 9MHz, Low-Noise Amplifier Typical Operating Characteristics (continued) ( EV kit, = V SHDN = +3V, f LNAIN = f MIXIN = MHz, f = 9MHz, P LNAIN = -3m, P = -m, P MIXIN = -m, differential IFOUT operation, Z o = Ω,, unless otherwise noted.) INPUT IP3 (m) LNA INPUT IP3 vs. SUPPLY VOLTAGE T A = - C T A = - C toc GAIN () LNA GAIN vs. FREQUENCY toc NOISE FIGURE () LNA NOISE FIGURE vs. FREQUENCY toc REVERSE ISOLATION () LNA REVERSE ISOLATION vs. FREQUENCY toc INPUT RETURN SS () LNA INPUT RETURN SS vs. FREQUENCY toc OUTPUT RETURN SS () LNA OUTPUT RETURN SS vs. FREQUENCY toc9 LNA S11 vs. FREQUENCY (MHz to 1MHz UNMATCHED) 1 1 HI toc1 GAIN () MIXER GAIN vs. SUPPLY VOLTAGE T A = - C T A = - C toc11 INPUT IP3 (m) MIXER INPUT IP3 vs. SUPPLY VOLTAGE 1 T A = + C T A = - C T A = - C toc1

5 Low-Cost, 9MHz, Low-Noise Amplifier Typical Operating Characteristics (continued) ( EV kit, = V SHDN = +3V, f LNAIN = f MIXIN = MHz, f = 9MHz, P LNAIN = -3m, P = -m, P MIXIN = -m, differential IFOUT operation, Z o = Ω,, unless otherwise noted.) GAIN () MIXER GAIN vs. IF FREQUENCY - BANDWIDTH DETERMINED BY -1 DIFFERENTIAL-TO-SINGLE-ENDED CONVERTER CIRCUIT IF toc13 GAIN () 3 1 MIXER GAIN vs. POWER POWER (m) toc1 NOISE FIGURE () MIXER NOISE FIGURE vs. POWER POWER (m) toc1 RETURN SS () PORT RETURN SS vs. FREQUENCY toc1

6 Low-Cost, 9MHz, Low-Noise Amplifier PIN 1, 3,, 11, 1, 1 NAME LNAIN GAIN FUNCTION Ground. Connect to ground plane with a low-inductance connection. Pin Description RF Input to LNA and LNA Bypass Switch. Requires an external matching network and a series DC-blocking capacitor. 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., 1 Supply Voltage. Bypass to at each pin with a pf capacitor as close to the pin as possible. SHDN Shutdown Control Logic-Level Input. Drive high or connect to for normal operation. Drive low to place the device in low-power shutdown mode. 9 IFOUT- 1 IFOUT+ Local-Oscillator Input to Downconverter Mixer. Requires a series DC-blocking capacitor and an impedance-setting resistor (typically Ω to ground). Inverting Side to Downconverter Mixer s Differential Open-Collector IF Output. Requires a pull-up inductor to for proper biasing, as well as a matching network to ensure optimum output power. Noninverting Side of Downconverter Mixer s Differential Open-Collector IF Output. Requires a pull-up inductor to for proper biasing, as well as a matching network to ensure optimum output power. 13 MIXIN RF Input to Downconverter Mixer. Requires an external matching network and series DC-blocking capacitor. 1 LNAOUT LNA Output. Internally matched to Ω. LNAOUT has an internal blocking capacitor. LNA INPUT MHz INPUT 9MHz 1 11 IFOUT+ 1 R* nh IFOUT- 9 GAIN- CONTROL INPUT SHUTDOWN INPUT.1µF Ω 1nH 33pF pf 3pF 1 LNAOUT 1 LNAIN 1 pf 3 1 GAIN SHDN 13 MIXIN 3.3pF 3pF pf 1pF nh pf LNA OUTPUT MIXER INPUT MHz IF OUTPUT MHz 1pF *OPTIONAL FOR BROADBAND MATCH. Figure 1. Typical Operating Circuit

7 Low-Cost, 9MHz, Low-Noise Amplifier Detailed Description The consists of five major components: a low-noise amplifier (LNA), an LNA bypass switch, a downconverter mixer, a local-oscillator () buffer, and a power-management block. Low-Noise Amplifier (LNA) The LNA is a wideband, single-ended cascode amplifier that operates over a wide range of frequencies. The input of the LNA (LNAIN) requires an appropriate matching network and a DC-blocking capacitor. The typical operating circuit shown in Figure 1 is optimized for frequencies around MHz, requiring only a.1µf capacitor in series with a 1nH inductor. See Table 1 for the LNA S parameters for matching to other frequencies. The output of the LNA (LNAOUT) is internally biased to. It is internally matched to Ω and incorporates an internal DC-blocking capacitor. LNA Bypass Switch and Gain Control When a large input signal is present, enable the LNA bypass function to increase linearity and reduce supply current. Set GAIN low to enable the LNA bypass function. Receive Mixer The downconverter mixer is a wideband, single-balanced design with a low noise figure and high linearity. The RF signal at the MIXIN port is mixed with the signal at the port, and is downconverted to an IF frequency at the differential IF port. RF Input The MIXIN input requires a simple external matching network and a series DC-blocking capacitor. See Figure 1 for a matching network example, optimized for MHz operation. Table lists mixer S parameters for matching to other frequencies. Table 1. LNA Typical S-Parameters (VCC = +3V, TA = + C) FREQUENCY (MHz) S11 MAG S11 PHASE S1 MAG S1 PHASE S1 MAG S1 PHASE S MAG S PHASE High-Gain Mode (GAIN = VCC) Low-Gain Mode (GAIN = )

8 Low-Cost, 9MHz, Low-Noise Amplifier Table. Mixer Typical S-Parameters ( = +3V, ) RF FREQUENCY (MHz) S11 MAG High-Gain Mode (GAIN = VCC) Low-Gain Mode (GAIN = ) S11 PHASE IF FREQUENCY (MHz) S MAG (IFOUT+ Port Only) S PHASE (IFOUT+ Port Only)

9 Low-Cost, 9MHz, Low-Noise Amplifier Local-Oscillator Input The port is the high-impedance input of the localoscillator buffer. It requires a series DC-blocking capacitor and a shunt resistor to ground to set the input impedance. See the Typical Operating Characteristics for a graph of Port Return Loss vs. Frequency. IF Output Port The mixer s downconverted output appears on the differential IFOUT+ and IFOUT- pins. The differential output can be converted to a single-ended output, as shown in the evaluation kit (EV kit). Refer to the Detailed Description in the EV kit data sheet. Shutdown Drive SHDN low to disable all device functions and place the in low-power shutdown mode. Drive SHDN high or connect it to to enable all device functions. Applications Information Layout Considerations A properly designed PC board is an essential part of any RF/microwave circuit. Note the IC s high-frequency inputs and outputs, and be sure to decouple the DC supply and control pins. For power-supply traces and connections, a star topology works well. Each node in the circuit has its own path to the central VCC node and a decoupling capacitor that provides a low impedance at the RF frequency of interest. The central also has a large decoupling capacitor. This provides good isolation between the different sections of the. TRANSISTOR COUNT: 9 Chip Information 9

10 Low-Cost, 9MHz, Low-Noise Amplifier Package Information QSOP.EPS 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. 1 Maxim Integrated Products, 1 San Gabriel Drive, Sunnyvale, CA 9-3- Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.