LTC5590 Dual 600MHz to 1.7GHz High Dynamic Range Downconverting Mixer. APPLICATIONS n 3G/4G Wireless Infrastructure Diversity Receivers

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1 FEATURES n Conversion Gain:.7 at 9MHz n : m at 9MHz n Noise Figure: 9.7 at 9MHz n. Under 5m Blocking n High Input P1 n 5 Channel Isolation at 9MHz n 1.W Power Consumption at.v n Low Power Mode for <.W Consumption n Enable Pins for Each Channel n 5Ω Single-Ended RF and LO Inputs n LO Input Matched In All Modes n m LO Drive Level n Small Package and Solution Size n to 5 C Operation APPLICATIONS n G/G Wireless Infrastructure Diversity Receivers (LTE, CDMA, GSM) n MIMO Infrastructure Receivers n High Dynamic Range Downmixer Applications L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. LTC559 Dual MHz to 1.7GHz High Dynamic Range Downconverting Mixer DESCRIPTION The LTC 559 is part of a family of dual-channel high dynamic range, high gain downconverting mixers covering the MHz to.5ghz RF frequency range. The LTC559 is optimized for MHz to 1.7GHz RF applications. The LO frequency must fall within the 7MHz to 1.5GHz range for optimum performance. A typical application is a LTE or GSM receiver with a 7MHz to 9MHz RF input and high side LO. The LTC559 s high conversion gain and high dynamic range enable the use of lossy IF filters in high selectivity receiver designs, while minimizing the total solution cost, board space and system-level variation. A low current mode is provided for additional power savings and each of the mixer channels has independent shutdown control. High Dynamic Range Dual Downconverting Mixer Family PART NUMBER RF RANGE LO RANGE LTC559 MHz to 1.7GHz 7MHz to 1.5GHz LTC GHz to.ghz 1.GHz to.1ghz LTC559 1.GHz to.7ghz 1.7GHz to.5ghz LTC559.GHz to.5ghz.1ghz to.ghz TYPICAL APPLICATION RF 7MHz TO 9MHz RF 7MHz TO 9MHz V CCIF.V or 5V V CCIF LNA LNA 1μF pf IMAGE BPF pf RFA IMAGE BPF pf pf RFB nh Wideband Receiver 1nF 1nF nh IFA + IFA IF IF IFB + IFB nh nh 1nF 19MHz SAW LO LO BIAS BIAS 1nF 19MHz SAW V CCA V CCB IF IF ENA LO ENB 19MHz BPF pf pf ADC 1μF ENA (V/.V) LO 9MHz pf SYNTH 19MHz BPF ENB (V/.V) ADC V CC.V V CC GC (), SSB () Wideband Conversion Gain and vs IF Frequency (Mixer Only, Measured on Evaluation Board) 7 LO = 9MHz 1 P LO = m RF = 9 ±MHz TEST CIRCUIT IN FIGURE IF FREQUENCY (MHz) 559 TA1b 7 5 (m) 559 TA1a 559f 1

2 LTC559 ABSOLUTE MAXIMUM RATINGS (Note 1) Supply Voltage (V CC )...V IF Supply Voltage (V CCIF )...5.5V Enable Voltage (ENA, ENB)....V to V CC +.V Bias Adjust Voltage (IFBA, IFBB)....V to V CC +.V Power Select Voltage (I SEL )....V to V CC +.V LO Input Power (MHz to GHz)...9m LO Input DC Voltage... ±.1V RFA, RFB Input Power (MHz to GHz)...m RFA, RFB Input DC Voltage... ±.1V Operating Temperature Range (T C )... to 5 C Storage Temperature Range... 5 C to C Junction Temperature (T J )... C PIN COIGURATION RFA CTA CTB RFB TOP VIEW IFA IFA + IFA IFBA VCCA 5 11 IFB IFB + IFB IFBB VCCB UH PACKAGE -LEAD (5mm 5mm) PLASTIC QFN T JMAX = C, θ JC = 7 C/W EXPOSED PAD (PIN 5) IS, MUST BE SOLDERED TO PCB I SEL ENA LO ENB ORDER IORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC559IUH#PBF LTC559IUH#TRPBF 559 -Lead (5mm 5mm) Plastic QFN to 5 C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: For more information on tape and reel specifications, go to: DC ELECTRICAL CHARACTERISTICS unless otherwise noted. Test circuit shown in Figure 1. (Note ) V CC =.V, V CCIF =.V, ENA = ENB = High, I SEL = Low, T C =, PARAMETER CONDITIONS MIN TYP MAX UNITS Power Supply Requirements (V CCA, V CCB, V CCIFA, V CCIFB ) V CCA, V CCB Supply Voltage (Pins, 19).1..5 V V CCIFA, V CCIFB Supply Voltage (Pins 9,, 1, ) V Mixer Supply Current (Pins, 19) Both Channels Enabled 1 ma IF Amplifier Supply Current (Pins 9,, 1, ) Both Channels Enabled 191 ma Total Supply Current (Pins 9,,, 19, 1, ) Both Channels Enabled 79 ma Total Supply Current Shutdown ENA = ENB = Low 5 μa Enable Logic Input (ENA, ENB) High = On, Low = Off ENA, ENB Input High Voltage (On).5 V ENA, ENB Input Low Voltage (Off). V ENA, ENB Input Current.V to V CC +.V μa Turn On Time.9 μs Turn Off Time 1 μs 559f

3 DC ELECTRICAL CHARACTERISTICS LTC559 V CC =.V, V CCIF =.V, ENA = ENB = High, I SEL = Low, T C =, unless otherwise noted. Test circuit shown in Figure 1. (Note ) PARAMETER CONDITIONS MIN TYP MAX UNITS Low Current Mode Logic Input (I SEL ) High = Low Power, Low = Normal Power Mode I SEL Input High Voltage.5 V I SEL Input Low Voltage. V I SEL Input Current.V to V CC +.V μa Low Current Mode Current Consumption (I SEL = High) Mixer Supply Current (Pins, 19) Both Channels Enabled 9 ma IF Amplifier Supply Current (Pins 9,, 1, ) Both Channels Enabled 1 ma Total Supply Current (Pins 9,,, 19, 1, ) Both Channels Enabled 9 5 ma AC ELECTRICAL CHARACTERISTICS V CC =.V, V CCIF =.V, ENA = ENB = High, I SEL = Low, T C =, P LO = m, P RF = m (Δf = MHz for two tone tests), unless otherwise noted. Test circuit shown in Figure 1. (Notes,, ) PARAMETER CONDITIONS MIN TYP MAX UNITS LO Input Frequency Range 7 to MHz RF Input Frequency Range Low Side LO High Side LO 1 to 17 to 1 MHz MHz IF Output Frequency Range Requires External Matching 5 to 5 MHz RF Input Return Loss Z O = 5Ω, 7MHz to MHz > LO Input Return Loss Z O = 5Ω, 7MHz to MHz > IF Output Impedance Differential at 19MHz Ω.pF R C LO Input Power f LO = 7MHz to MHz m LO to RF Leakage f LO = 7MHz to MHz < m LO to IF Leakage f LO = 7MHz to MHz < m RF to LO Isolation f RF = MHz to 17MHz >5 RF to IF Isolation f RF = MHz to 17MHz >17 Channel-to-Channel Isolation High Side LO Downmixer Application: I SEL = Low, RF = 7MHz to 1MHz, IF = 19MHz, f LO = f RF + f IF PARAMETER CONDITIONS MIN TYP MAX UNITS Conversion Gain RF = 7MHz RF = 9MHz RF = 1MHz Conversion Gain Flatness RF = 9 ±MHz, LO = 9MHz, IF = 19 ±MHz ±.5 Conversion Gain vs Temperature T C = ºC to 5ºC, RF = 195MHz. / C Input rd Order Intercept SSB Noise Figure RF = 7MHz RF = 9MHz RF = 1MHz RF = 7MHz RF = 9MHz RF = 1MHz f RF = MHz to 1MHz f RF = 1MHz to 17MHz.5 >5 > m m m 559f

4 LTC559 AC ELECTRICAL CHARACTERISTICS V CC =.V, V CCIF =.V, ENA = ENB = High, T C =, P LO = m, P RF = m (Δf = MHz for two tone tests), unless otherwise noted. Test circuit shown in Figure 1. (Notes, ) High Side LO Downmixer Application: I SEL = Low, RF = 7MHz to 1MHz, IF = 19MHz, f LO = f RF + f IF PARAMETER CONDITIONS MIN TYP MAX UNITS SSB Noise Figure Under Blocking f RF = 9MHz, f LO = 9MHz, f BLOCK = MHz P BLOCK = 5m P BLOCK = m. 1. LO-RF Output Spurious Product (f RF = f LO f IF /) LO-RF Output Spurious Product (f RF = f LO f IF /) f RF = 995MHz at m, f LO = 9MHz, f IF = 19MHz f RF =.7MHz at m, f LO = 9MHz, f IF = 19MHz Input 1 Compression f RF = 9MHz, V CCIF =.V f RF = 9MHz, V CCIF = 5V 77 c 77 c.7.1 m m Low Power Mode, High Side LO Downmixer Application: I SEL = High, RF = 7MHz to 1MHz, IF = 19MHz, f LO = f RF + f IF PARAMETER CONDITIONS MIN TYP MAX UNITS Conversion Gain RF = 9MHz 7.7 Input rd Order Intercept RF = 9MHz 1.5 m SSB Noise Figure RF = 9MHz 9.9 Input 1 Compression RF = 9MHz, V CCIF =.V RF = 9MHz, V CCIF = 5V..9 m m Low Side LO Downmixer Application: I SEL = Low, RF = 1MHz to MHz, IF = 19MHz, f LO = f RF f IF PARAMETER CONDITIONS MIN TYP MAX UNITS Conversion Gain RF = 1MHz RF = MHz RF = MHz Conversion Gain Flatness RF = ±MHz, LO = MHz, IF = 19 ±MHz ±. Conversion Gain vs Temperature T C = ºC to 5ºC, RF = MHz. / C Input rd Order Intercept SSB Noise Figure SSB Noise Figure Under Blocking RF-LO Output Spurious Product (f RF = f LO + f IF /) RF-LO Output Spurious Product (f RF = f LO + f IF /) Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note : The LTC559 is guaranteed functional over the case operating temperature range of to 5 C. (θ JC = 7 C/W) RF = 1MHz RF = MHz RF = MHz RF = 1MHz RF = MHz RF = MHz f RF = MHz, f LO = MHz, f BLOCK = MHz P BLOCK = 5m P BLOCK = m f RF = MHz at m, f LO = MHz, f IF = 19MHz f RF = 7.MHz at m, f LO = MHz, f IF = 19MHz Input 1 Compression RF = MHz, V CCIF =.V RF = MHz, V CCIF = 5V m m m 7 c 7 c 11.. m m Note : SSB Noise Figure measured with a small-signal noise source, bandpass filter and matching pad on RF input, bandpass filter and matching pad on the LO input, and no other RF signals applied. Note : Channel A to channel B isolation is measured as the relative IF output power of channel B to channel A, with the RF input signal applied to channel A. The RF input of channel B is 5Ω terminated and both mixers are enabled. 559f

5 TYPICAL AC PERFORMANCE CHARACTERISTICS LTC559 High Side LO V CC =.V, V CCIF =.V, ENA = ENB = High, I SEL = Low, T C =, P LO = m, P RF = m ( m/tone for two-tone tests, Δf = MHz), IF = 19MHz, unless otherwise noted. Test circuit shown in Figure 1. (m) Conversion Gain and vs RF Frequency SSB vs RF Frequency Channel Isolation vs RF Frequency C 5 C RF FREQUENCY (MHz) () SSB () C 5 C RF FREQUENCY (MHz) ISOLATION () RF FREQUENCY (MHz) 559 G1 559 G 559 G (), (m) 7MHz Conversion Gain, and vs LO Power 1 5 C 1 LO INPUT POWER (m) SSB () (), (m) 9MHz Conversion Gain, and vs LO Power 1 5 C 1 LO INPUT POWER (m) SSB () GC (), (m) 1 1MHz Conversion Gain, and vs LO Power 5 C LO INPUT POWER (m) 1 SSB () 559 G 559 G5 559 G GC (), (m) 1 Conversion Gain, and vs Supply Voltage (Single Supply) RF = 9MHz V CC = V CCIF 5 C V CC, V CCIF SUPPLY VOLTAGE (V) 1 SSB () GC (), (m) Conversion Gain, and vs Supply Voltage (Dual Supply) 1 RF = 9MHz V CC =.V 5 C V CCIF SUPPLY VOLTAGE (V) SSB () (), (m), P1 (m) 1 Conversion Gain, and RF Input P1 vs Temperature RF = 9MHz P1 V CCIF =.V V CCIF = 5V 5 1 CASE TEMPERATURE ( C) 559 G7 559 G 559 G9 559f 5

6 LTC559 TYPICAL AC PERFORMANCE CHARACTERISTICS High Side LO V CC =.V, V CCIF =.V, ENA = ENB = High, I SEL = Low, T C =, P LO = m, P RF = m ( m/tone for two-tone tests, Δf = MHz), IF = 19MHz, unless otherwise noted. Test circuit shown in Figure 1. OUTPUT POWER (m/tone) 5 7 -Tone IF Output Power, IM and IM5 vs RF Input Power IF OUT RF1 = 99MHz RF = 91MHz LO = 9MHz IM IM5 9 RF INPUT POWER (m/tone) 559 G OUTPUT POWER (m) 5 7 Single-Tone IF Output Power, and Spurs vs RF Input Power IF OUT (RF = 9MHz) LO = 9MHz LO-RF (RF =.7MHz) LO-RF (RF = 995MHz) 9 RF INPUT POWER (m) 559 G11 RELATIVE SPUR LEVEL (c) and Spur Suppression vs LO Input Power LO-RF (RF = 995MHz) LO-RF (RF =.7MHz) IF = 19MHz P RF = m LO = 9MHz LO INPUT POWER (m) 559 G SSB () 1 SSB Noise Figure vs RF Blocker Power LO Leakage vs LO Frequency RF Isolation vs RF Frequency P LO = m P LO = m P LO = m P LO = m RF = 9MHz BLOCKER = MHz LO LEAKAGE (m) 5 LO-IF LO-RF ISOLATION () 7 5 RF-LO RF-IF 5 5 RF BLOCKER POWER (m) LO FREQUENCY (MHz) RF FREQUENCY (MHz) G1 559 G 559 G DISTRIBUTION (%) 5 Conversion Gain Distribution Distribution SSB Noise Figure Distribution RF = 9MHz 5 C 5 DISTRIBUTION (%) RF = 9MHz 5 C DISTRIBUTION (%) C RF = 9MHz.5 9 GAIN () () NOISE FIGURE () G 559 G G1 559f

7 TYPICAL AC PERFORMANCE CHARACTERISTICS LTC559 Low Power Mode, High Side LO V CC =.V, V CCIF =.V, ENA = ENB = High, I SEL = High, T C =, P LO = m, P RF = m ( m/tone for two-tone tests, Δf = MHz), IF = 19MHz, unless otherwise noted. Test circuit shown in Figure 1. (m) Conversion Gain and vs RF Frequency C 5 C RF FREQUENCY (MHz) () SSB () SSB vs RF Frequency 5 C 5 C RF FREQUENCY (MHz) OUTPUT POWER (m/tone) 5 7 -Tone IF Output Power, IM and IM5 vs RF Input Power RF1 = 99MHz RF = 91MHz LO = 9MHz IF OUT IM IM5 9 RF INPUT POWER (m/tone) 559 G G 559 G1 (), (m) 1 7MHz Conversion Gain, and vs LO Power 5 C LO INPUT POWER (m) 1 SSB () GC (), (m) 1 9MHz Conversion Gain, and vs LO Power 5 C LO INPUT POWER (m) 1 SSB () (), (m) 1 1MHz Conversion Gain, and vs LO Power 5 C LO INPUT POWER (m) 1 SSB () 559 G 559 G 559 G GC (), (m) 1 Conversion Gain, and vs Supply Voltage (Single Supply) RF = 9MHz V CC = V CCIF 5 C V CC, V CCIF SUPPLY VOLTAGE (V) 1 SSB () GC (), (m) 1 Conversion Gain, and vs Supply Voltage (Dual Supply) RF = 9MHz V CC =.V 5 C V CCIF SUPPLY VOLTAGE (V) 1 SSB () (), (m), P1 (m) 1 Conversion Gain, and RF Input P1 vs Temperature RF = 9MHz P1 V CCIF =.V V CCIF = 5V 5 1 CASE TEMPERATURE ( C) 559 G5 559 G 559 G7 559f 7

8 LTC559 TYPICAL AC PERFORMANCE CHARACTERISTICS Low Side LO V CC =.V, V CCIF =.V, ENA = ENB = High, I SEL = Low, T C =, P LO = m, P RF = m ( m/tone for two-tone tests, Δf = MHz), IF = 19MHz, unless otherwise noted. Test circuit shown in Figure 1. (m) Conversion Gain and vs RF Frequency C 5 C 1 11 G C RF FREQUENCY (MHz) GC () SSB () SSB vs RF Frequency 5 C 5 C RF FREQUENCY (MHz) SSB () 1 SSB Noise Figure vs RF Blocker Level P LO = m P LO = m P LO = m P LO = m RF = MHz BLOCKER = MHz 5 5 RF BLOCKER LEVEL (m) 559 G 559 G9 559 G 1MHz Conversion Gain, and vs LO Power MHz Conversion Gain, and vs LO Power MHz Conversion Gain, and vs LO Power (), (m) 1 5 C SSB () (), (m) 1 5 C SSB () GC (), (m) 1 5 C SSB () LO INPUT POWER (m) LO INPUT POWER (m) LO INPUT POWER (m) 559 G1 559 G 559 G Conversion Gain, and vs Supply Voltage (Single Supply) Conversion Gain, and vs Supply Voltage (Dual Supply) Conversion Gain, and RF Input P1 vs Temperature GC (), (m) 1 RF = MHz V CC = V CCIF 5 C SSB () GC (), (m) 1 RF = MHz V CC =.V 5 C SSB () (), (m), P1 (m) 1 RF = MHz P1 V CCIF =.V V CCIF = 5V V CC, V CCIF SUPPLY VOLTAGE (V) V CCIF SUPPLY VOLTAGE (V) 5 1 CASE TEMPERATURE ( C) 559 G 559 G5 559 G 559f

9 TYPICAL DC PERFORMANCE CHARACTERISTICS I SEL = Low, ENA = ENB = High, test circuit shown in Figure 1. SUPPLY CURRENT (ma) V CC Supply Current vs Supply Voltage (Mixer and LO Amplifier) V CCIF = V CC 5 C 5 C V CC SUPPLY VOLTAGE (V) SUPPLY CURRENT (ma) 1 1 V CCIF Supply Current vs Supply Voltage (IF Amplifier) V CC =.V. 5 C 5 C V CCIF SUPPLY VOLTAGE (V) SUPPLY CURRENT (ma) LTC559 Total Supply Current vs Temperature (V CC + V CCIF ) V CC =.V, V CCIF = 5V (DUAL SUPPLY) V CC = V CCIF =.V (SINGLE SUPPLY) 5 1 CASE TEMPERATURE ( C) 559 G7 559 G 559 G9 I SEL = High, ENA = ENB = High, test circuit shown in Figure 1. SUPPLY CURRENT (ma) V CC Supply Current vs Supply Voltage (Mixer and LO Amplifier) V CCIF = V CC 5 C 5 C SUPPLY CURRENT (ma) V CCIF Supply Current vs Supply Voltage (IF Amplifier) V CC =.V 5 C 5 C SUPPLY CURRENT (ma) Total Supply Current vs Temperature (V CC + V CCIF ) V CC =.V, V CCIF = 5V (DUAL SUPPLY) V CC = V CCIF =.V (SINGLE SUPPLY) V CC SUPPLY VOLTAGE (V) V CCIF SUPPLY VOLTAGE (V) CASE TEMPERATURE ( C) 559 G 559 G1 559 G 559f 9

10 LTC559 PIN FUNCTIONS RFA, RFB (Pins 1, ): Single-Ended RF Inputs for Channels A and B. These pins are internally connected to the primary sides of the RF input transformers, which have low DC resistance to ground. Series DC-blocking capacitors should be used to avoid damage to the integrated transformer when DC voltage is present at the RF inputs. The RF inputs are impedance matched when the LO input is driven with a ±m source between 7MHz and 1.5GHz and the channels are enabled. CTA, CTB (Pins, 5): RF Transformer Secondary Center- Tap on Channels A and B. These pins may require bypass capacitors to ground to optimize performance. Each pin has an internally generated bias voltage of 1.V and must be DC-isolated from ground and V CC. (Pins,, 7, 1,,, Exposed Pad Pin 5): Ground. These pins must be soldered to the RF ground plane on the circuit board. The exposed pad metal of the package provides both electrical contact to ground and good thermal contact to the printed circuit board. IFB, IFA (Pins, ): DC Ground Returns for the IF Amplifiers. These pins must be connected to ground to complete the DC current paths for the IF amplifiers. Chip inductors may be used to tune LO-IF and RF-IF leakage. Typical DC current is 9mA for each pin. IFB +, IFB, IFA, IFA + (Pins 9,, 1, ): Open-Collector Differential Outputs for the IF Amplifiers of Channels B and A. These pins must be connected to a DC supply through impedance matching inductors, or transformer center-taps. Typical DC current consumption is ma into each pin. IFBB, IFBA (Pins 11, ): Bias Adjust Pins for the IF Amplifiers. These pins allow independent adjustment of the internal IF buffer currents for channels B and A, respectively. The typical DC voltage on these pins is.v. If not used, these pins must be DC isolated from ground and V CC. V CCB and V CCA (Pins, 19): Power Supply Pins for the LO Buffers and Bias Circuits. These pins must be connected to a regulated.v supply with bypass capacitors located close to the pins. Typical current consumption is 9mA per pin. ENB, ENA (Pins, 17): Enable Pins. These pins allow Channels B and A, respectively, to be independently enabled. An applied voltage of greater than.5v activates the associated channel while a voltage of less than.v disables the channel. Typical input current is less than μa. These pins must not be allowed to float. LO (Pin ): Single-Ended Local Oscillator Input. This pin is internally connected to the primary side of the LO input transformer and has a low DC resistance to ground. Series DC-blocking capacitors should be used to avoid damage to the integrated transformer when DC voltage present at LO input. The LO input is internally matched to 5Ω for all states of ENA and ENB. I SEL (Pin 1): Low Current Select Pin. When this pin is pulled low (<.V), both mixer channels are biased at the normal current level for best RF performance. When greater than.5v is applied, both channels operate at reduced current, which provides reasonable performance at lower power consumption. This pin must not be allowed to float. 559f

11 BLOCK DIAGRAM LTC559 1 RFA CTA 1 19 IFA IFA + IFA IFBA V CCA IF LO BIAS I SEL 1 ENA 17 LO 5 CTB RFB 7 IFB IFB + IF IFB LO BIAS IFBB 9 11 V CCB ENB BD 559f 11

12 LTC559 TEST CIRCUIT T1A :1 IFA 5Ω V CCIF.V TO 5V C L1A C7A LA C5A V CC.V... RF BIAS DC17A EVALUATION BOARD STACK-UP (NELCO N-1) RFA 5Ω C1A 1 1 IFA IFA + IFA IFBA RFA 19 V CCA I SEL 1 CA ISEL (V/.V) C CTA ENA 17 ENA (V/.V) LTC559 LO C LO 5Ω RFB 5Ω C1B 5 CTB IFB IFB + IFB IFBB V CCB ENB RFB 1 ENB (V/.V) C5B CB 559 TC1 LB L1B C7B :1 T1B IFB 5Ω L1, L vs IF FREQUENCIES IF (MHz) L1, L (nh) REF DES VALUE SIZE VENDOR C1A, C1B pf AVX C pf AVX CA, CB pf AVX C5A, C5B C, C 1μF AVX C7A, C7B pf AVX L1A, L1B, nh Coilcraft LA, LB T1A, T1B TC-1W-7ALN+ Mini-Circuits Figure 1. Standard Downmixer Test Circuit Schematic (19MHz) 559f

13 APPLICATIONS IORMATION Introduction The LTC559 consists of two identical mixer channels driven by a common LO input signal. Each high linearity mixer consists of a passive double-balanced mixer core, IF buffer amplifier, LO buffer amplifier and bias/enable circuits. See the Pin Functions and Block Diagram sections for a description of each pin. Each of the mixers can be shutdown independently to reduce power consumption and low current mode can be selected that allows a trade-off between performance and power consumption. The RF and LO inputs are single-ended and are internally matched to 5Ω. Low side or high side LO injection can be used. The IF outputs are differential. The evaluation circuit, shown in Figure 1, utilizes bandpass IF output matching and an IF transformer to realize a 5Ω single-ended IF output. The evaluation board layout is shown in Figure. LTC559 The secondary winding of the RF transformer is internally connected to the channel A passive mixer core. The centertap of the transformer secondary is connected to Pin (CTA) to allow the connection of bypass capacitor, CA. The value of CA is LO frequency-dependent and is not required for most applications, though it can improve in some cases. When used, it should be located within mm of Pin for proper high frequency decoupling. The nominal DC voltage on the CTA pin is 1.V. For the RF inputs to be properly matched, the appropriate LO signal must be present at the LO input. The RF input impedance is also dependent on the LO frequency, as shown in Figure, which shows the RF input return loss for various LO frequencies with a C1A value of pf. A broadband impedance match is achieved over the 7MHz to 1.GHz range. Outside this frequency range, the desired impedance match can be obtained through adjustment of external component values. LTC559 RFA C1A 1 RFA TO CHANNEL A MIXER CTA CA Figure. Evaluation Board Layout RF Inputs The RF inputs of channels A and B are identical. The RF input of channel A, shown in Figure, is connected to the primary winding of an integrated transformer. A 5Ω match is realized when a series external capacitor, C1A, is connected to the RF input. C1A is also needed for DC blocking if the source has DC voltage present, since the primary side of the RF transformer is internally DC-grounded. The DC resistance of the primary is approximately.5ω. 559 F RETURN LOSS () 559 F Figure. Channel A RF Input Schematic 5 5 LO = 7MHz LO = 9MHz LO = MHz FREQUENCY (MHz) Figure. RF Port Return Loss 559 F 559f 1

14 LTC559 APPLICATIONS IORMATION The RF input impedance and input reflection coefficient, versus RF frequency, are listed in Table 1. The reference plane for this data is Pin 1 of the IC, with no external matching, and the LO is driven at 1.9GHz. Table 1. RF Input Impedance and S11 (at Pin 1, No External Matching, f LO = 1.9GHz) FREQUENCY RF INPUT S11 (GHz) IMPEDANCE MAG ANGLE.. + j j j j j j j j j j j j TO MIXER A TO MIXER B LTC559 BIAS BIAS Figure 5. LO Input Schematic I SEL 1 ENA 17 LO ENB 559 F5 LO Input The LO input, shown in Figure 5, is connected to the primary winding of an integrated transformer. A 5Ω impedance match is realized at the LO port by adding an external series capacitor, C. This capacitor is also needed for DC blocking if the LO source has DC voltage present, since the primary side of the LO transformer is DC-grounded internally. The DC resistance of the primary is approximately.5ω. C LO The secondary of the transformer drives a pair of high speed limiting differential amplifiers for channels A and B. The LTC559 s LO amplifiers are optimized for the 7MHz to 1.5GHz LO frequency range; however, LO frequencies outside this frequency range may be used with degraded performance. The LO port is always 5Ω matched when V CC is applied, even when one or both of the channels is disabled. This helps to reduce frequency pulling of the LO source when the mixer is switched between different operating states. Figure illustrates the LO port return loss for the different operating modes. RETURN LOSS () BOTH CHANNELS ON ONE CHANNEL ON BOTH CHANNELS OFF FREQUENCY (MHz) Figure. LO Input Return Loss 559 F The nominal LO input level is m, though the limiting amplifiers will deliver excellent performance over a ±m input power range. Table lists the LO input impedance and input reflection coefficient versus frequency. Table. LO Input Impedance vs Frequency (at Pin, No External Matching, ENA = ENB = High) FREQUENCY INPUT S11 (GHz) IMPEDANCE MAG ANGLE j j j j j j j j j.. 559f

15 APPLICATIONS IORMATION IF Outputs The IF amplifiers in channels A and B are identical. The IF amplifier for channel A, shown in Figure 7, has differential open collector outputs (IFA + and IFA ), a DC ground return pin (IFA), and a pin for adjusting the internal bias (IFBA). The IF outputs must be biased at the supply voltage (V CCIFA ), which is applied through matching inductors L1A and LA. Alternatively, the IF outputs can be biased through the center tap of a transformer (T1A). The common node of L1A and LA can be connected to the center tap of the transformer. Each IF output pin draws approximately ma of DC supply current (9mA total). An external load resistor, RA, can be used to improve impedance matching if desired. IFA (Pin ) must be grounded or the amplifier will not draw DC current. Inductor LA may improve LO-IF and RF-IF leakage performance in some applications, but is otherwise not necessary. Inductors should have small resistance for DC. High DC resistance in LA will reduce the IF amplifier supply current, which will degrade RF performance. LTC559 For optimum single-ended performance, the differential IF output must be combined through an external IF transformer or a discrete IF balun circuit. The evaluation board (see Figures 1 and ) uses a :1 IF transformer for impedance transformation and differential to single-ended conversion. It is also possible to eliminate the IF transformer and drive differential filters or amplifiers directly. At IF frequencies, the IF output impedance can be modeled as 79Ω in parallel with.pf. The equivalent small-signal model, including bondwire inductance, is shown in Figure. Frequency-dependent differential IF output impedance is listed in Table. This data is referenced to the package pins (with no external components) and includes the effects of IC and package parasitics. LTC559 1 IFA + IFA.9nH RIF CIF.9nH LA (OR SHORT) 9mA IA LTC559 L1A V CCIFA IFA + T1A RA IF Figure 7. IF Amplifier Schematic with Bandpass Match :1 C7A LA C5A IFA 1 IFBA IFA ma R1A (OPTION TO REDUCE DC POWER) BIAS V CCA 559 F7 Figure. IF Output Small-Signal Model Bandpass IF Matching The bandpass IF matching configuration, shown in Figures 1 and 7, is best suited for IF frequencies in the 9MHz to 5MHz range. Resistor RA may be used to reduce the IF output resistance for greater bandwidth and inductors L1A and LA resonate with the internal IF output capacitance at the desired IF frequency. The value of L1A, LA can be estimated as follows: L1A = LA = f IF 1 ( ) C IF where C IF is the internal IF capacitance (listed in Table ). 559 F 559f

16 LTC559 APPLICATIONS IORMATION Values of L1A and LA are tabulated in Figure 1 for various IF frequencies. The measured IF output return loss for bandpass IF matching is plotted in Figure 9. Table. IF Output Impedance vs Frequency DIFFERENTIAL OUTPUT FREQUENCY (MHz) IMPEDANCE (R IF X IF (C IF )) 9 j (.9pF) j7 (.pf) j1 (.pf) j (.1pF) 77 j5 (.1pF) 7 j (.pf) 5 j177 (.pf) Figure 9. IF Output Return Loss with Bandpass Matching RETURN LOSS () nH nh nh 5nH nh nh FREQUENCY (MHz) 559 F9 Lowpass IF Matching For IF frequencies below 9MHz, the inductance values become unreasonably high and the lowpass topology shown in Figure 9 is preferred. This topology also can provide improved RF to IF and LO to IF isolation. V CCIFA is supplied through the center tap of the :1 transformer. A lowpass impedance transformation is realized by shunt elements RA and C9A (in parallel with the internal RIF and CIF), and series inductors L1A and LA. Resistor RA is used to reduce the IF output resistance for greater bandwidth, or it can be omitted for the highest conversion gain. The final impedance transformation to 5Ω is realized by transformer T1A. The measured return loss is shown in Figure 11 for different values of inductance (C9A = OpF). The case with nh inductors and RA = 1k is also shown. The LTC559 demo board (see Figure ) V CCIFA.1 TO 5.V C7A L1A IFA + T1A RA C9A LTC559 Figure. IF Output with Lowpass Matching RETURN LOSS () 5 5 nh Figure 11. IF Output Return Loss with Lowpass Matching has been laid out to accommodate this matching topology with only minor modifications. IF Amplifier Bias The IF amplifier delivers excellent performance with V CCIF =.V, which allows a single supply to be used for V CC and V CCIF. At V CCIF =.V, the RF input P1 of the mixer is limited by the output voltage swing. For higher P1, in this case, resistor RA (Figure 7) can be used to reduce the output impedance and thus the voltage swing, thus improving P1. The trade-off for improved P1 will be lower conversion gain. With V CCIF increased to 5V the P1 increases by over, at the expense of higher power consumption. Mixer P1 performance at 9MHz is tabulated in Table for V CCIF values of.v and 5V. For the highest conversion gain, high-q wire-wound chip inductors are recommended for L1A and LA. Low cost multilayer chip inductors may be substituted, with a slight reduction in conversion gain. :1 C5A 1nH nh + 1kΩ nh LA 1 IFA IFA 5Ω 5 5 FREQUENCY (MHz) 559 F F 559f

17 APPLICATIONS IORMATION Table. Performance Comparison with V CCIF =.V and 5V (RF = 9MHz, High Side LO, IF = 19MHz) V CCIF (V) RA (Ω) I CCIF (ma) () P1 (m) (m) (). Open k Open The IFBA pin (Pin ) is available for reducing the DC current consumption of the IF amplifier, at the expense of. The nominal DC voltage at Pin is.1v, and this pin should be left open-circuited for optimum performance. The internal bias circuit produces a ma reference for the IF amplifier, which causes the amplifier to draw approximately 9mA. If resistor R1A is connected to Pin as shown in Figure 7, a portion of the reference current can be shunted to ground, resulting in reduced IF amplifier current. For example, R1A = 1k will shunt away 1mA from Pin and the IF amplifier current will be reduced by % to approximately 9mA. Table 5 summarizes RF performance versus IF amplifier current. Table 5. Mixer Performance with Reduced IF Amplifier Current RF = 9MHz, High Side LO, IF = 19MHz, V CC = V CCIF =.V R1 I CCIF (ma) () (m) P1 () () Open kΩ kΩ kΩ RF = MHz, Low Side LO, IF = 19MHz, V CC = V CCIF =.V R1 I CCIF (ma) () (m) P1 (m) () Open kΩ kΩ kΩ Low Power Mode Both mixer channels can be set to low power mode using the I SEL pin. This allows flexibility to select a reduced current mode of operation when lower RF performance is acceptable, reducing power consumption by 7%. Figure shows a simplified schematic of the I SEL pin interface. LTC559 When I SEL is set low (<.V), both channels operate at nominal DC current. When I SEL is set high (>.5V), the DC current in both channels is reduced, thus reducing power consumption. The performance in low power mode and normal power mode are compared in Table. 19 V CCA I SEL 1 5Ω LTC559 V CCB 559 F1 Figure. I SEL Interface Schematic Table. Performance Comparison Between Different Power Modes RF = 9MHz, High Side LO, IF = 19MHz, V CC = V CCIF =.V I SEL I TOTAL (ma) () (m) P1 (m) () Low High Enable Interface Figure 1 shows a simplified schematic of the ENA pin interface (ENB is identical). To enable channel A, the ENA voltage must be greater than.5v. If the enable function is not required, the enable pin can be connected directly to V CC. The voltage at the enable pin should never exceed the power supply voltage (V CC ) by more than.v. If this V CCA ENA 5Ω LTC559 BIAS A BIAS B ESD CL Figure 1. ENA Interface Schematic 559 F1 559f 17

18 LTC559 APPLICATIONS IORMATION should occur, the supply current could be sourced through the ESD diode, potentially damaging the IC. The Enable pins must be pulled high or low. If left floating, the on/off state of the IC will be indeterminate. If a three-state condition can exist at the enable pins, then a pull-up or pull-down resistor must be used. Supply Voltage Ramping Fast ramping of the supply voltage can cause a current glitch in the internal ESD protection circuits. Depending on the supply inductance, this could result in a supply volt- age transient that exceeds the maximum rating. A supply voltage ramp time of greater than 1ms is recommended. Spurious Output Levels Mixer spurious output levels versus harmonics of the RF and LO are tabulated in Tables 7 and for frequencies up to GHz. The spur levels were measured on a standard evalution board using the test circuit shown in Figure 1. The spur frequencies can be calculated using the following equation: f SPUR = (M f RF ) (N f LO ) Table 7. IF Output Spur Levels (c), High Side LO (RF = 9MHz, P RF = m, P LO = m, V CC = V CCIF =.V, T C = ) N * * * * * * * * 1.5 * * * * * * * M * * * 7. * * * * * * * 5 * * * * * * * * * * * * * * * * * * * * * * 7 * * * * * * * * * * * * * * * * * * * * * * 9 * * * * * * * * * * * * * * * * * * * * * * *Less than c Table. IF Output Spur Levels (c), Low Side LO (RF = MHz, P RF = m, P LO = m, V CC = V CCIF =.V, T C = ) N * * *.. * 9. * * *.7 * * * * * * * M * * * * * * * * * * * 5 * * * * * * * * * * * * * * * * * * * * * * 7 * * * * * * * * * * * * * 9.7 * * * * * * * 9 * * 95. * * * * * * 9.5 * * * * * *Less than c 1 559f

19 PACKAGE DESCRIPTION Please refer to for the most recent package drawings. LTC559 UH Package -Lead Plastic QFN (5mm 5mm) (Reference LTC DWG # Rev A) REF PACKAGE OUTLINE PIN 1 TOP MARK (NOTE ) BSC RECOMMENDED SOLDER PAD LAYOUT APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED R =.5 BOTTOM VIEW EXPOSED PAD TYP.75.5 R =. TYP..5 PIN 1 NOTCH R =. TYP OR.5 5 CHAMFER REF..... REF NOTE: 1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE. DRAWING NOT TO SCALE. ALL DIMENSIONS ARE IN MILLIMETERS. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED.mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE..5.5 BSC (UH) QFN 7 REV A Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 559f 19

20 LTC559 TYPICAL APPLICATION V CCIF.V RFA 5Ω TO CHANNEL B pf Downconverting Mixer with MHz Lowpass IF Matching 1μF 1 pf TC-1W-7ALN+ :1 nh 1k LTC559 CHANNEL A 1 nh IFA IFA + IFA IFBA RFA CTA IFA 5Ω 19 V CCA I SEL 1 ENA 17 LO pf pf I SEL ENA 1μF V CC.V TO CHANNEL B LO 5Ω (), SSB () Conversion Gain, and vs RF Frequency T C = IF = MHz RF FREQUENCY (MHz) 559 TAb (m) CHANNEL B NOT SHOWN 559 TA RELATED PARTS PART NUMBER DESCRIPTION COMMENTS Infrastructure LTC559 MHz to GHz, Dual Active Downconverting Gain,.7m and 11.7 at 195MHz,.V/1mA Supply Mixer LT557 MHz to.7ghz, 5V Downconverting Mixer. Gain,.5m and.5 at 19MHz, 5V/7mA Supply LT5557 MHz to.ghz,.v Downconverting Mixer.9 Gain,.7m and 11.7 at 195MHz,.V/mA Supply LTC GHz -Bit ADC Buffer.5m OIP to MHz, Programmable Fast Recovery Output Clamping LTC 1 Linear Analog VGA 5m OIP at MHz, Continuous Gain Range to 17 LTC55X MHz to GHz Downconverting Mixer Family Gain, >5m,,.V/mA Supply LT555 Ultralow Distort IF Digital VGA m OIP at MHz, to 1 Gain Range,.5 Gain Steps LT557 MHz to.7ghz Upconverting Mixer 7m OIP at 9MHz,.m at 1.95GHz, Integrated RF Transformer LT GHz to.ghz Upconverting Mixer 7.m OIP at.ghz, = 9.9,.V Supply, Single-Ended LO and RF Ports RF Power Detectors LTC551 GHz Low Power RMS Detector Dynamic Range, ±1 Accuracy Overtemperature, 1.5mA Supply Current LTC55 GHz RMS Power Detector MHz to GHz, Up to 57 Dynamic Range, ±.5 Accuracy Overtemperature LTC55 Dual GHz RMS Power Detector Measures VSWR MHz to GHz, Up to Dynamic Range, > Channel-to-Channel Isolation, Difference Output for vs WR Measurement ADCs LTC5 -Bit, 5Msps Dual ADC 7. SNR, > SFDR, 79mW Power Consumption LTC -Bit, 5Msps Dual ADC Ultralow Power 7. SNR, mw/channel Power Consumption LTC- -Bit, 5Msps ADC 5. SNR, 7 SFDR, 7mW Power Consumption LT 11 PRINTED IN USA Linear Technology Corporation McCarthy Blvd., Milpitas, CA () -19 FAX: () LINEAR TECHNOLOGY CORPORATION f