LT5579 1.5GHz to 3.8GHz High Linearity Upconverting Mixer FEATURES DESCRIPTION n The LT®5579 mixer is a high performance upconverting mixer optimized for frequencies in the 1.5GHz to 3.8GHz range. The single-ended LO input and RF output ports simplify board layout and reduce system cost. The mixer needs only –1dBm of LO power and the balanced design results in low LO signal leakage to the RF output. At 2.6GHz operation, the LT5579 provides high conversion gain of 1.3dB, high OIP3 of +26dBm and a low noise floor of –157.5dBm/Hz at a –5dBm RF output signal level. n n n n n n n n High Output IP3: +27.3dBm at 2.14GHz Low Noise Floor: –158dBm/Hz (POUT = –5dBm) High Conversion Gain: 2.6dB at 2.14GHz Wide Frequency Range: 1.5GHz to 3.8GHz* Low LO Leakage Single-Ended RF and LO Low LO Drive Level: –1dBm Single 3.3V Supply 5mm × 5mm QFN24 Package The LT5579 offers a high performance alternative to passive mixers. Unlike passive mixers, which have conversion loss and require high LO drive levels, the LT5579 delivers conversion gain at significantly lower LO input levels and is less sensitive to LO power level variations. The lower LO drive level requirements, combined with the excellent LO leakage performance, translate into lower LO signal contamination of the output signal. APPLICATIONS n n n n GSM/EDGE, W-CDMA, UMTS, LTE and TD-SCDMA Basestations 2.6GHz and 3.5GHz WiMAX Basestations 2.4GHz ISM Band Transmitters High Performance Transmitters L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. *Operation over wider frequency range is possible with reduced performance. Consult Linear Technology for information and assistance. TYPICAL APPLICATION Frequency Upconversion in 2.14GHz W-CDMA Transmitter LO INPUT –1dBm (TYP) Gain, NF and OIP3 vs RF Output Frequency LO 30 GND BIAS 11Ω IF INPUT 40nH MABAES0061 82pF 4:1 1 5 2 3 IF+ 0.45pF 33pF RF OUTPUT OIP3 25 20 TA = 25°C VCC = 3.3V fIF = 240MHz fLO = fRF + fIF 15 SSB NF 10 5 GAIN IF– 4 82pF 1.8nH RF GAIN (dB), NF (dB), OIP3 (dBm) LT5579 0 1900 40nH 11Ω VCC 1μF 100pF 2000 2100 2200 2300 RF FREQUENCY (MHz) 2400 5579 TA01a 1nF VCC 3.3V 5579 TA01b 5579f 1 LT5579 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) Supply Voltage .........................................................3.6V LO Input Power ..................................................+10dBm LO Input DC Voltage ........................–0.3V to VCC + 0.3V RF Output DC Current ............................................60mA IF Input Power (Differential)...............................+13dBm IF+, IF– DC Currents ...............................................60mA TJMAX .................................................................... 150°C Operating Temperature Range.................. –40°C to 85°C Storage Temperature Range................... –65°C to 150°C GND GND GND LO GND GND TOP VIEW 24 23 22 21 20 19 GND 1 18 GND GND 2 17 GND IF+ 3 16 GND 25 IF– 4 15 RF GND 9 10 11 12 VCC 8 VCC 7 VCC 13 GND VCC 14 GND GND 6 GND GND 5 UH PACKAGE 24-LEAD (5mm s 5mm) PLASTIC QFN TJMAX = 150°C, θJA = 34°C/W EXPOSED PAD (PIN 25) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT5579IUH#PBF LT5579IUH#TRPBF 5579 24-Lead (5mm × 5mm) Plastic QFN –40°C to 85°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: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/ DC ELECTRICAL CHARACTERISTICS PARAMETER VCC = 3.3V, TA = 25°C (Note 3), unless otherwise noted. CONDITIONS MIN TYP MAX UNITS Power Supply Requirements (VCC) Supply Voltage 3.3 3.6 VDC Supply Current VCC = 3.3V, PLO = –1dBm VCC = 3.6V, PLO = –1dBm 3.15 226 241 250 mA mA Input Common Mode Voltage (VCM) Internally Regulated 570 AC ELECTRICAL CHARACTERISTICS mV (Notes 2, 3) PARAMETER CONDITIONS IF Input Frequency Range (Note 4) Requires Matching MIN LF to 1000 TYP MAX UNITS MHz LO Input Frequency Range (Note 4) Requires Matching Below 1GHz 750 to 4300 MHz RF Output Frequency Range (Note 4) Requires Matching 900 to 3900 MHz 5579f 2 LT5579 AC ELECTRICAL CHARACTERISTICS VCC = 3.3V, TA = 25°C, PRF = –5dBm (–5dBm/tone for 2-tone tests, Δf = 1MHz), PLO = –1dBm, unless otherwise noted. Test circuits are shown in Figure 1. (Notes 2, 3) PARAMETER IF Input Return Loss LO Input Return Loss RF Output Return Loss LO Input Power CONDITIONS ZO = 50Ω, External Match ZO = 50Ω, 1100MHz to 4000MHz ZO = 50Ω, External Match MIN TYP 15 >9 >10 –5 to 2 MAX UNITS dB dB dB dBm MAX UNITS dB dB dB dB dB/°C dB/°C dB/°C dB/°C dBm dBm dBm dBm dBm dBm dBm dBm dB dB dB dB dBm/Hz dBm/Hz dBm/Hz dBm/Hz dBm dBm dBm dBm dB dB dB dB dBm dBm dBm dBm dBm dBm dBm dBm VCC = 3.3V, TA = 25°C, PRF = –5dBm (–5dBm/tone for 2-tone tests, Δf = 1MHz), PLO = –1dBm, unless otherwise noted. Low side LO for 1750MHz and 3600MHz. High side LO for 2140MHz and 2600MHz. (Notes 2, 3, 4) PARAMETER Conversion Gain Conversion Gain vs Temperature (TA = –40°C to 85°C) Output 3rd Order Intercept Output 2nd Order Intercept Single Sideband Noise Figure Output Noise Floor (POUT = –5dBm) Output 1dB Compression IF to LO Isolation LO to IF Leakage LO to RF Leakage CONDITIONS fIF = 240MHz, fRF = 1750MHz fIF = 240MHz, fRF = 2140MHz fIF = 456MHz, fRF = 2600MHz fIF = 456MHz, fRF = 3600MHz fIF = 240MHz, fRF = 1750MHz fIF = 240MHz, fRF = 2140MHz fIF = 456MHz, fRF = 2600MHz fIF = 456MHz, fRF = 3600MHz fIF = 240MHz, fRF = 1750MHz fIF = 240MHz, fRF = 2140MHz fIF = 456MHz, fRF = 2600MHz fIF = 456MHz, fRF = 3600MHz fIF = 240MHz, fRF = 1750MHz fIF = 240MHz, fRF = 2140MHz fIF = 456MHz, fRF = 2600MHz fIF = 456MHz, fRF = 3600MHz fIF = 240MHz, fRF = 1750MHz fIF = 240MHz, fRF = 2140MHz fIF = 456MHz, fRF = 2600MHz fIF = 456MHz, fRF = 3600MHz fIF = 240MHz, fRF = 1750MHz fIF = 240MHz, fRF = 2140MHz fIF = 456MHz, fRF = 2600MHz fIF = 456MHz, fRF = 3600MHz fIF = 240MHz, fRF = 1750MHz fIF = 240MHz, fRF = 2140MHz fIF = 456MHz, fRF = 2600MHz fIF = 456MHz, fRF = 3600MHz fIF = 240MHz, fRF = 1750MHz fIF = 240MHz, fRF = 2140MHz fIF = 456MHz, fRF = 2600MHz fIF = 456MHz, fRF = 3600MHz fIF = 240MHz, fRF = 1750MHz fIF = 240MHz, fRF = 2140MHz fIF = 456MHz, fRF = 2600MHz fIF = 456MHz, fRF = 3600MHz fIF = 240MHz, fRF = 1750MHz fIF = 240MHz, fRF = 2140MHz fIF = 456MHz, fRF = 2600MHz fIF = 456MHz, fRF = 3600MHz 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 2: Each set of frequency conditions requires appropriate matching (see Figure 1). MIN TYP 1.8 2.6 1.3 –0.5 –0.020 –0.020 –0.027 –0.027 29 27.3 26.2 23.2 41 42 45 54 9.2 9.9 12 12 –159.5 –158.1 –157.5 –155.5 13.3 13.9 13.7 10.7 83 81 74 73 –23 –28 –26 –22 –39 –35 –36 –35 Note 3: The LT5579 is guaranteed to meet specified performance from –40°C to 85°C Note 4: SSB noise figure measurements performed with a small-signal noise source and bandpass filter on LO signal generator. No other IF signal applied. 5579f 3 LT5579 TYPICAL DC PERFORMANCE CHARACTERISTICS (Test Circuit Shown in Figure 1) Supply Current vs Supply Voltage 255 SUPPLY CURRENT (mA) 245 235 225 215 85°C 25°C –40°C 205 195 3.0 3.1 3.2 3.3 3.4 SUPPLY VOLTAGE (V) 3.5 3.6 5579 G01 TYPICAL AC PERFORMANCE CHARACTERISTICS 3300MHz to 3800MHz Application: VCC = 3.3V, TA = 25°C, fIF = 456MHz, PIF = –5dBm (–5dBm/tone for 2-tone tests, Δf = 1MHz), low side LO, PLO = –1dBm, output measured at 3600MHz, unless otherwise noted. (Test circuit shown in Figure 1) Gain Distribution at 3600MHz TA = 90°C TA = 25°C TA = –45°C 14 TA = 90°C TA = 25°C TA = –45°C 25 12 15 10 DISTRIBUTION (%) DISTRIBUTION (%) 20 30 16 TA = 90°C TA = 25°C TA = –45°C DISTRIBUTION (%) 25 SSB Noise Figure Distribution at 3600MHz OIP3 Distribution at 3600MHz 10 8 6 20 15 10 4 5 5 2 0 –2.5 –2.0 –1.5 –1.0 –0.5 0 GAIN (dB) 0 0 0.5 1.0 1.5 5579 G02 19 20 21 23 22 OIP3 (dBm) 24 25 26 5579 G03 10 11 12 13 NOISE FIGURE (dB) 14 5579 G04 5579f 4 LT5579 TYPICAL AC PERFORMANCE CHARACTERISTICS 3300MHz to 3800MHz Application: VCC = 3.3V, TA = 25°C, fIF = 456MHz, PIF = –5dBm (–5dBm/tone for 2-tone tests, Δf = 1MHz), low side LO, PLO = –1dBm, output measured at 3600MHz, unless otherwise noted. (Test circuit shown in Figure 1) Conversion Gain and OIP3 vs RF Output Frequency SSB Noise Figure vs RF Output Frequency 16 28 0 20 18 OIP3 12 LO-RF Leakage vs RF Output Frequency 24 –10 4 16 GAIN 0 LO LEAKAGE (dBm) 20 85°C 25°C –40°C NOISE FIGURE (dB) 8 OIP3 (dBm) GAIN (dB) 16 14 12 10 –20 –30 8 12 –4 8 3200 3300 3400 3500 3600 3700 3800 3900 RF FREQUENCY (MHz) –40 85°C 25°C –40°C 6 4 3200 3300 3400 3500 3600 3700 3800 3900 RF FREQUENCY (MHz) 5579 G05 85°C 25°C –40°C –50 3200 3300 3400 3500 3600 3700 3800 3900 RF FREQUENCY (MHz) 5579 G06 Conversion Gain and OIP3 vs LO Input Power 5579 G07 SSB Noise Figure vs LO Input Power 16 26 12 22 Conversion Gain and OIP3 vs Supply Voltage 16 20 26 18 14 GAIN 14 12 10 –13 –5 –1 –9 LO INPUT POWER (dBm) 3 6 4 –14 –6 –10 –2 LO INPUT POWER (dBm) 5579 G08 4 –4 2 3.0 3.1 3.2 3.3 3.4 SUPPLY VOLTAGE (V) 0 –20 –20 6 3.6 3.5 5579 G10 IM2 Level vs RF Output Power (2-Tone) 0 14 10 5579 G09 IM3 Level vs RF Output Power (2-Tone) 18 85°C 25°C –40°C 0 85°C 25°C –40°C 6 –4 –17 8 GAIN 8 10 0 OIP3 GAIN (dB) GAIN (dB) 4 22 16 OIP3 (dBm) 18 85°C 25°C –40°C OIP3 (dBm) 8 NOISE FIGURE (dB) 12 OIP3 SSB Noise Figure vs Supply Voltage 20 18 –40 –60 –80 –100 2 4 –12 –10 –8 –6 –4 –2 0 RF OUTPUT POWER (dBm/TONE) –40 –60 –80 85°C 25°C –40°C 6 5579 G11 NOISE FIGURE (dB) IM2 LEVEL (dBc) IM3 LEVEL (dBc) 16 14 12 10 8 85°C 25°C –40°C –100 2 4 –12 –10 –8 –6 –4 –2 0 RF OUTPUT POWER (dBm/TONE) 85°C 25°C –40°C 6 6 5579 G12 4 3.0 3.1 3.2 3.4 3.3 SUPPLY VOLTAGE (V) 3.5 3.6 5579 G13 5579f 5 LT5579 TYPICAL AC PERFORMANCE CHARACTERISTICS 2300MHz to 2700MHz Application: VCC = 3.3V, TA = 25°C, fIF = 456MHz, PIF = –5dBm (–5dBm/tone for 2-tone tests, Δf = 1MHz), high side LO, PLO = –1dBm, output measured at 2600MHz, unless otherwise noted. (Test circuit shown in Figure 1) Conversion Gain and OIP3 vs RF Output Frequency SSB Noise Figure vs RF Output Frequency 30 16 LO-RF Leakage vs RF Output Frequency 0 18 85°C 25°C –40°C 16 –10 26 GAIN (dB) GAIN 4 22 85°C 25°C –40°C 18 OIP3 (dBm) 8 LO LEAKAGE (dBm) 14 OIP3 NOISE FIGURE (dB) 12 12 10 8 6 14 0 –4 2200 2300 2 2200 10 2800 2400 2500 2600 2700 RF FREQUENCY (MHz) 2300 2400 2500 2600 2700 RF FREQUENCY (MHz) –30 –40 85°C 25°C –40°C 4 –20 –50 2200 2800 2300 2400 2500 2600 2700 RF FREQUENCY (MHz) 5579 G16 5579 G15 5579 G14 Conversion Gain and OIP3 vs LO Input Power SSB Noise Figure vs LO Input Power 16 28 12 24 Conversion Gain and OIP3 vs Supply Voltage 16 18 28 16 16 0 12 GAIN (dB) GAIN (dB) GAIN 4 10 8 6 12 –13 –5 –1 –9 LO INPUT POWER (dBm) 3 8 2 –14 5579 G17 16 2 12 3.0 3.1 3.4 3.2 3.3 SUPPLY VOLTAGE (V) 3.5 IM2 Level vs RF Output Power (2-Tone) 0 0 –20 –20 8 3.6 5579 G19 5579 G18 IM3 Level vs RF Output Power (2-Tone) 20 GAIN 4 –4 –6 –10 –2 LO INPUT POWER (dBm) 85°C 25°C –40°C 8 0 85°C 25°C –40°C 4 –4 –17 24 OIP3 (dBm) 20 OIP3 (dBm) 85°C 25°C –40°C 8 OIP3 12 14 NOISE FIGURE (dB) OIP3 2800 SSB Noise Figure vs Supply Voltage 18 –40 –60 14 NOISE FIGURE (dB) IM2 LEVEL (dBc) IM3 LEVEL (dBc) 16 –40 –60 12 10 8 6 –80 –80 85°C 25°C –40°C –100 2 4 –12 –10 –8 –6 –4 –2 0 RF OUTPUT POWER (dBm/TONE) 6 5579 G20 85°C 25°C –40°C –100 2 4 –12 –10 –8 –6 –4 –2 0 RF OUTPUT POWER (dBm/TONE) 85°C 25°C –40°C 4 6 5579 G21 2 3.0 3.1 3.2 3.4 3.3 SUPPLY VOLTAGE (V) 3.5 3.6 5579 G22 5579f 6 LT5579 TYPICAL PERFORMANCE CHARACTERISTICS 2140MHz Application: VCC = 3.3V, TA = 25°C, fIF = 240MHz, PIF = –5dBm (–5dBm/tone for 2-tone tests, Δf = 1MHz), high side LO, PLO = –1dBm, output measured at 2140MHz, unless otherwise noted. (Test circuit shown in Figure 1) Conversion Gain and OIP3 vs RF Output Frequency SSB Noise Figure vs RF Output Frequency 16 30 12 26 LO-RF Leakage vs RF Output Frequency 18 0 16 18 LO LEAKAGE (dBm) GAIN (dB) GAIN 4 OIP3 (dBm) 22 8 –10 14 NOISE FIGURE (dB) OIP3 12 10 8 –20 –30 6 0 14 85°C 25°C –40°C –4 1950 2 1950 10 2350 2150 2250 2050 RF FREQUENCY (MHz) –40 85°C 25°C –40°C 4 2150 2050 2250 RF FREQUENCY (MHz) 85°C 25°C –40°C –50 1950 2350 2150 2050 2250 RF FREQUENCY (MHz) 2350 5579 G24 5579 G23 Conversion Gain and OIP3 vs LO Input Power 5579 G25 SSB Noise Figure vs LO Input Power 16 30 12 26 Conversion Gain and OIP3 vs Supply Voltage 16 18 30 GAIN (dB) GAIN 4 0 18 –4 –17 –13 –5 –1 –9 LO INPUT POWER (dBm) 12 10 8 22 GAIN 4 10 0 85°C 25°C –40°C 4 3 8 18 6 14 85°C 25°C –40°C 26 OIP3 OIP3 (dBm) 22 OIP3 (dBm) 8 12 14 GAIN (dB) OIP3 NOISE FIGURE (dB) 16 2 –14 –6 –10 –2 LO INPUT POWER (dBm) 2 5579 G26 –4 3.0 3.1 3.2 3.3 3.4 SUPPLY VOLTAGE (V) 3.5 5579 G27 IM3 Level vs RF Output Power (2-Tone) 0 –20 –20 10 3.6 5579 G19 IM2 Level vs RF Output Power (2-Tone) 0 14 85°C 25°C –40°C SSB Noise Figure vs Supply Voltage 18 –40 –60 14 NOISE FIGURE (dB) IM2 LEVEL (dBc) IM3 LEVEL (dBc) 16 –40 –60 12 10 8 6 –80 –100 –10 –80 85°C 25°C –40°C 0 –8 –6 –4 –2 2 4 RF OUTPUT POWER (dBm/TONE) 6 5579 G29 –100 –10 85°C 25°C –40°C 0 –8 –6 –4 –2 2 4 RF OUTPUT POWER (dBm/TONE) 85°C 25°C –40°C 4 6 5579 G30 2 3.0 3.1 3.2 3.4 3.3 SUPPLY VOLTAGE (V) 3.5 3.6 5579 G31 5579f 7 LT5579 TYPICAL PERFORMANCE CHARACTERISTICS 1750MHz Application: VCC = 3.3V, TA = 25°C, fIF = 240MHz, PIF = –5dBm (–5dBm/tone for 2-tone tests, Δf = 1MHz), low side LO, PLO = –1dBm, output measured at 1750MHz, unless otherwise noted. (Test circuit shown in Figure 1) Conversion Gain and OIP3 vs RF Output Frequency SSB Noise Figure vs RF Output Frequency 30 16 18 OIP3 26 18 12 10 8 2 1650 10 1900 1800 1850 1750 RF FREQUENCY (MHz) 1700 1750 1850 1800 RF FREQUENCY (MHz) Conversion Gain and OIP3 vs LO Input Power 1800 1850 1750 RF FREQUENCY (MHz) 1900 Conversion Gain and OIP3 vs Supply Voltage 16 18 30 32 16 26 GAIN 18 NOISE FIGURE (dB) 22 12 10 8 28 OIP3 8 GAIN 4 24 85°C 25°C –40°C 20 OIP3 (dBm) 8 12 14 GAIN (dB) OIP3 OIP3 (dBm) GAIN (dB) 1700 5579 G34 SSB Noise Figure vs LO Input Power 16 4 –50 1650 1900 5579 G33 5579 G32 12 –30 –40 85°C 25°C –40°C 4 1700 –20 6 14 0 LO LEAKAGE (dBm) 22 NOISE FIGURE (dB) GAIN (dB) GAIN –4 1650 85°C 25°C –40°C –10 14 OIP3 (dBm) 85°C 25°C –40°C 4 0 16 12 8 LO-RF Leakage vs RF Output Frequency 6 0 –4 –17 14 85°C 25°C –40°C –13 –5 –1 –9 LO INPUT POWER (dBm) 3 2 –17 10 0 85°C 25°C –40°C 4 –13 –9 –1 –5 LO INPUT POWER (dBm) 3 –4 16 3.0 3.1 3.2 3.3 3.4 SUPPLY VOLTAGE (V) 5579 G36 5579 G35 IM3 Level vs RF Output Power (2-Tone) 5579 G37 IM2 Level vs RF Output Power (2-Tone) 0 0 –20 –20 12 3.6 3.5 SSB Noise Figure vs Supply Voltage 18 –40 –60 14 NOISE FIGURE (dB) IM2 LEVEL (dBc) IM3 LEVEL (dBc) 16 –40 –60 12 10 8 6 –80 –100 –10 –80 85°C 25°C –40°C 0 –8 –6 –4 –2 2 4 RF OUTPUT POWER (dBm/TONE) 6 5579 G38 –100 –10 85°C 25°C –40°C 0 –8 –6 –4 –2 2 4 RF OUTPUT POWER (dBm/TONE) 85°C 25°C –40°C 4 6 5579 G39 2 3.0 3.1 3.2 3.4 3.3 SUPPLY VOLTAGE (V) 3.5 3.6 5579 G40 5579f 8 LT5579 PIN FUNCTIONS GND (Pins 1, 2, 5-7, 12-14, 16-18, 19-21, 23, 24): Ground Connections. These pins are internally connected to the exposed pad and should be soldered to a low impedance RF ground on the printed circuit board. IF+, IF– (Pins 3, 4): Differential IF Input. The common mode voltage on these pins is set internally to 570mV. The DC current from each pin is determined by the value of an external resistor to ground. The maximum DC current through each pin is 60mA. VCC (Pins 8-11): Power Supply Pins for the IC. These pins are connected together internally. Typical current consumption is 226mA. These pins should be connected together on the circuit board with external bypass capacitors of 1000pF, 100pF and 10pF located as close to the pins as possible. RF (Pin 15): Single-Ended RF Output. This pin is connected to an internal transformer winding. The opposite end of the winding is grounded internally. An impedance transformation may be required to match the output and a DC decoupling capacitor is required if the following stage has a DC bias voltage present. LO (Pin 22): Single-Ended Local Oscillator Input. An internal series capacitor acts as a DC block to this pin. Exposed Pad (Pin 25): PGND. Electrical and thermal ground connection for the entire IC. This pad must be soldered to a low impedance RF ground on the printed circuit board. This ground must also provide a path for thermal dissipation. 5579f 9 LT5579 BLOCK DIAGRAM 25 15 EXPOSED PAD RF VCC 22 LO DOUBLE BALANCED MIXER LO BUFFER VCC VCC2 BIAS VCC2 VCC 10 9 8 VCM CTRL IF+ 3 GND PINS ARE NOT SHOWN VCC 11 IF– 4 5579 BD 5579f 10 LT5579 TEST CIRCUIT LO INPUT R1 2 GND GND LO GND 4 IF– 6 L2 GND GND 5 C2 GND IF+ GND RF GND GND GND R2 GND 7 8 9 18 17 16 L3 15 14 TL3 RF OUTPUT C8 13 GND C3 GND VCC TL2 GND 3 VCC C9 GND VCC TL1 GND VCC IF INPUT 1 L1 C1 GND T1 4:1 24 23 22 21 20 19 10 11 12 VCC C4 C5 C6 C7 5579 F01 REF DES C1, C2 fRF = 1750MHz fIF = 240MHz fRF = 2140MHz fIF = 240MHz fRF = 2600MHz fIF = 456MHz fRF = 3600MHz fIF = 456MHz SIZE COMMENTS 82pF 82pF 33pF 33pF 0402 AVX C3 — — 2.7pF 1.8pF 0402 AVX C4 100pF 100pF 100pF 100pF 0402 AVX C5 10pF 10pF 10pF 10pF 0603 AVX C6 1nF 1nF 1nF 1nF 0402 AVX C7 1μF 1μF 1μF 1μF 0603 Taiyo Yuden LMK107BJ105MA C8 1.2pF 0.45pF — 0.7pF 0402 AVX ACCU-P C9 33pF 33pF 33pF 33pF 0402 AVX L1, L2 40nH 40nH 40nH 40nH 0402 Coilcraft 0402CS L3 R1, R2 T1 TL1, TL2* TL3 6.8nH 1.8nH 1nH 0Ω 0402 Toko LL1005-FHL/0Ω Jumper 11Ω, 0.1% 11Ω, 0.1% 11Ω, 0.1% 11Ω, 0.1% 0603 IRC PFC-W0603R-03-11R1-B 4:1 4:1 4:1 4:1 SM-22 — — 1.3mm 1.9mm — ZO = 70Ω Microstrip 2.3mm 2.3mm 2.3mm 2.3mm — ZO = 70Ω Microstrip M/A-COM MABAES0061 *Center-to-center spacing between C9 and C3. Center of C9 is 3.0mm from the edge of the IC package for all cases. Figure 1. Test Circuit Schematic 5579f 11 LT5579 APPLICATIONS INFORMATION The LT5579 uses a high performance LO buffer amplifier driving a double-balanced mixer core to achieve frequency conversion with high linearity. Internal baluns are used to provide single-ended LO input and RF output ports. The IF input is differential. The LT5579 is intended for operation in the 1.5GHz to 3.8GHz frequency range, though operation outside this range is possible with reduced performance. The purpose of the inductors (L1 and L2) is to reduce the loading effects of R1 and R2. The impedances of L1 and L2 should be at least several times greater than the IF input impedance at the desired IF frequency. The self-resonant frequency of the inductors should also be at least several times the IF frequency. Note that the DC resistances of L1 and L2 will affect the DC current and may need to be accounted for in the selection of R1 and R2. IF Input Interface L1 and L2 should connect to the signal lines as close to the package as possible. This location will be at the lowest impedance point, which will minimize the sensitivity of the performance to the loading of the shunt L-R branches. The IF inputs are tied to the emitters of the double-balanced mixer transistors, as shown in Figure 2. These pins are internally biased to a common mode voltage of 570mV. The optimum DC current in the mixer core is approximately 50mA per side, and is set by the external resistors, R1 and R2. The inductors and resistors must be able to handle the anticipated current and power dissipation. For best LO leakage performance the board layout must be symmetrical and the input resistors should be well matched (0.1% tolerance is recommended). Capacitors C1 and C2 are used to cancel out the parasitic series inductance of the IF transformer. They also provide DC isolation between the IF ports to prevent unwanted interactions that can affect the LO to RF leakage performance. The differential input resistance to the mixer is approximately 10Ω, as indicated in Table 1. The package and external inductances (TL1 and TL2) are used along with R1 IF INPUT LT5579 T1 4:1 C1 L1 50mA TL1 3 IF+ 570mV 2k C9 C2 VCC C3 2k TL2 4 L2 IF– 570mV 50mA 5579 F02 R2 Figure 2. IF Input with External Matching 5579f 12 LT5579 APPLICATIONS INFORMATION C9 to step the impedance up to about 12.5Ω. At lower frequencies additional series inductance may be required between the IF ports and C9. The position of C9 may vary with the IF frequency due to the different series inductance requirements. The 4:1 impedance ratio of transformer T1 completes the transformation to 50 ohms. Table 1 lists the differential IF input impedances and reflection coefficients for several frequencies. Table 1. IF Input Differential Impedance FREQUENCY (MHz) IF INPUT IMPEDANCE 70 REFLECTION COEFFICIENT The purpose of capacitor C3 is to improve the LO-RF leakage in some applications. This relatively small-valued capacitor has little effect on the impedance match in most cases. This capacitor should typically be located close to the IC, however, there may be cases where re-positioning the capacitor may improve performance. The measured return loss of the IF input is shown in Figure 3 for application frequencies of 70MHz, 240MHz and 456MHz. Component values are listed in Table 2. (For 70MHz matching details, refer to Figure 8.) MAG ANGLE 8.8+j1.3 0.70 177 140 8.7+j2.3 0.70 175 170 9.0+j2.8 0.70 174 140 190 8.9+j3.0 0.70 173 240 9.0+j4.0 0.70 170 380 9.7+j4.9 0.68 168 450 10.0+j5.2 0.67 167 750 10.8+j9.4 0.65 158 1000 11.8+j13.8 0.64 148 Table 2. IF Input Component Values FREQUENCY C1, C2 (MHz) (pF) C9 (pF) C3 (pF) L1, L2 R1, R2 MATCH BW (nH) (Ω) (at 12dB RL) 1000 120 (1) 100 9.1 <50 to 158 240 82 33 (1) 40 11 174 to 263 450 33 33 (1) 40 11 330 to 505 Note: (1) Depends on RF, (2) T1 = M/A-Com MABAES0061 0 RETURN LOSS (dB) –5 –10 –15 c –20 a b –25 0 100 200 300 400 500 600 700 800 FREQUENCY (MHz) 5579 F03 Figure 3. IF Input Return Loss with 70MHz (a), 240MHz (b) and 456MHz (c) Matching 5579f 13 LT5579 APPLICATIONS INFORMATION LO Input Interface The simplified schematic for the single-ended LO input port is shown in Figure 4. An internal transformer provides a broadband impedance match and performs single-ended to differential conversion. An internal capacitor also aids in impedance matching and provides DC isolation to the primary transformer winding. The transformer secondary feeds the differential limiting amplifier stages that drive the mixer core. The measured return loss of the LO input port is shown in Figure 5 for an LO input power of –1dBm. The impedance match is acceptable from about 1.1GHz to beyond 4GHz, with a minimum return loss across this range of about 9dB at 2300MHz. If desired, the return loss can be improved below 1.1GHz by external components as shown in Figure 4. The return loss can also be improved by reducing the LO drive level, though performance will degrade if the level is too low. Table 3. Single-Ended LO Input Impedance (at Pin 22, No External Match) FREQUENCY (MHz) INPUT IMPEDANCE REFLECTION COEFFICIENT MAG ANGLE 750 63.3||– j30.5 0.68 –125 1000 20.3||– j1120 0.42 –179 1500 78.4||– j1250 0.22 –7.7 1900 79.1||– j113 0.34 –65.2 2000 74.7||– j96.3 0.35 –74.7 2150 66.8||– j81.5 0.36 –87.0 2400 53.8||– j69.8 0.35 –105 3050 33.7||– j115 0.26 –148 3150 33.0||– j146 0.24 –154 4000 43.9||+ j173 0.15 –123 0 VCC –5 L6 22 LO C13 VBIAS 5579 F04 Figure 4. LO Input Circuit RETURN LOSS (dB) LO INPUT EXTERNAL MATCHING FOR LOW FREQUENCY ONLY While external matching of the LO input is not required for frequencies above 1.1GHz, external matching should be used for lower LO frequencies for best performance. Table 3 lists the input impedance and reflection coefficient vs frequency for the LO input for use in such cases. –10 –15 –20 –25 500 1000 1500 2000 2500 3000 3500 4000 FREQUENCY (MHz) 5579 F05 Figure 5. LO Input Return Loss 5579f 14 LT5579 APPLICATIONS INFORMATION RF Output Interface The RF output interface is shown in Figure 6. An internal RF transformer reduces the mixer core output impedance to simplify matching of the RF output pin. A center tap in the transformer provides the DC connection to the mixer core and the transformer provides DC isolation to the RF output. The RF pin is internally grounded through the secondary winding of the transformer, thus a DC voltage should not be applied to this pin. While the LT5579 performs best at frequencies above 1500MHz, the part can be used down to 900MHz. The internal RF transformer is not optimized for these lower frequencies, thus the gain and impedance matching bandwidth will decrease due to the low transformer inductance. The impedance data for the RF output, listed in Table 4, can be used to develop matching networks for different frequencies or load impedances. Figure 7 illustrates the output return loss performance for several applications. The component values and approximate matching bandwidths are listed in Table 5. Table 4. Single-Ended RF Output Impedance (at Pin 15, No External Matching) FREQUENCY (MHz) RF OUTPUT IMPEDANCE 1250 11.0+j42.7 1750 1950 REFLECTION COEFFICIENT MAG ANGLE 0.78 97.4 55.6+j83.4 0.62 47.8 119+j62.4 0.52 21.9 2150 116–j21.0 0.42 –10.4 2300 73.7–j37.7 0.34 –40.9 2600 35.2–j21.5 0.30 –110 3600 21.9+j17.8 0.45 134 Table 5. RF Output Component Values FREQUENCY (MHz) C8 (pF) L3 (nH) MATCH BW (at 12dB RL) 1650 1.5 6.8 1630 to 1770 1750 1.2 6.8 1725 to 1870 1950 1 4.7 1840 to 2020 2140 0.45 3.9 2035 to 2285 2600 0.45 1.8 2260 to 2780* 3600 0.7 0Ω 3170 to 4100* *10dB Return Loss bandwidth DC and RF Grounding 0 –5 RETURN LOSS (dB) The LT5579 relies on the back side ground for both RF and thermal performance. The Exposed Pad must be soldered to the low impedance topside ground plane of the board. Several vias should connect the topside ground to other ground layers to aid in thermal dissipation. –10 –15 c LT5579 –20 L3 15 C8 RF 50Ω d –25 1500 a b 2000 3000 3500 2500 FREQUENCY (MHz) 4000 5579 F07 8 9 10 11 5579 F06 Figure 7. RF Output Return Loss with 1750MHz (a), 2140MHz (b), 2600MHz (c) and 3600MHz (d) Matching VCC Figure 6. RF Output Circuit 5579f 15 LT5579 TYPICAL APPLICATIONS The following examples illustrate the implementation and performance of the LT5579 in different frequency configurations. These circuits were evaluated using the circuit board shown in Figure 12. 1650MHz Application In this case, the LT5579 was evaluated while tuned for an IF of 70MHz and an RF output of 1650MHz. The matching configuration is shown in Figure 8. Input capacitors are used only as DC blocks in this application. The 4.7nH inductors and the 120pF capacitor transform the input impedance of the IC up to approximately 12.5Ω. The relatively low input frequency demanded the use of 4.7nH chip inductors instead of short transmission lines. Closer to the IC input, 47pF capacitors were used instead of a single differential capacitor (C3 in Figure 1), because it was found that the addition of common mode capacitance improved the high side LO performance in this application. The value of these 47pF capacitors was selected to resonate with the 100nH inductors at 70MHz. Note that adding common mode capacitance does not improve performance with all frequency configurations. 9.1Ω 47pF MABAES0061 1nF 4:1 100nH LO 4.7nH 6.8nH IF 70MHz 120pF RF 1650MHz 4.7nH 1.5pF 1nF 5579 F08 47pF 100nH 9.1Ω Figure 8. IF Input Tuned for 70MHz 5579f 16 LT5579 TYPICAL APPLICATIONS The RF port impedance match was realized with C8 = 1.5pF and L3 = 6.8nH. The optimum impedance match was purposefully shifted high in order to achieve better OIP3 performance at the desired frequency. Figure 9 shows the measured conversion gain and OIP3 as a function of RF output frequency. As mentioned above, the output impedance match is shifted towards the high side of the band, and this is evidenced by the positive slope of the gain. The single sideband noise figure across the frequency range is also shown. Curves for both high side and low side LO cases are shown. In this particular application, the low side OIP3 outperforms the high side case. In this example, a high side LO was used to convert the IF input signal at 240MHz to 1950MHz at the RF output. The RF port impedance match was realized with C8 = 1pF and L3 = 4.7nH. As in the 1650MHz case, it was found that tuning the output match slightly high in frequency gave better OIP3 results at the desired frequency. The input match for 240MHz operation is the same as described in the test circuit of Figure 1. The measured 1950MHz performance is plotted in Figure 10 for both low side and high side LO drive. With this matching configuration, the low side LO case outperforms the high side LO. The gain, noise figure (SSB) and OIP3 are plotted as a function of RF output frequency. OIP3 35 30 25 20 15 TA = 25°C fIF = 70MHz PIF = –5dBm/TONE PLO = –1dBm 10 LOW SIDE LO HIGH SIDE LO SSB NF 5 GAIN 0 –5 1550 GAIN (dB), NF (dB), OIP3 (dBm) GAIN (dB), NF (dB), OIP3 (dBm) 35 1950MHz Application OIP3 30 25 20 15 TA = 25°C fIF = 240MHz PIF = –5dBm/TONE PLO = –1dBm LOW SIDE LO HIGH SIDE LO SSB NF 10 5 GAIN 1650 1600 1700 RF OUTPUT FREQUENCY (MHz) 1750 5579 F09 Figure 9. Gain, Noise Figure and OIP3 vs RF Frequency with 70MHz IF and 1650MHz RF 0 1800 1850 1900 1950 2000 RF OUTPUT FREQUENCY (MHz) 2050 5579 F10 Figure 10. Gain, Noise Figure and OIP3 vs RF Frequency for the 1950MHz Application 5579f 17 LT5579 TYPICAL APPLICATIONS 2140MHz with Low Side LO The LT5579 was fully characterized with an RF output of 2140MHz and a high side LO. The part also works well when driven with low side LO, however, the performance benefited from the addition of common mode capacitance to the IF input match. A 10pF capacitor to ground was added to each IF pin. These capacitors were attached near inductors L1 and L2. The measured performance is shown in Figure 11. GAIN (dB), NF (dBm), OIP3 (dBm) 30 OIP3 25 20 15 TA = 25°C fIF = 240MHz PIF = –5dBm/TONE PLO = –1dBm fRF = fIF + fLO SSB NF 10 5 0 2000 GAIN 2050 2100 2150 2200 2250 RF OUTPUT FREQUENCY (MHz) 2300 5579 F11 Figure 11. Measured Performance when Tuned for 240MHz IF, 2140MHz RF and Low Side LO Figure 12. LT5579 Evaluation Board (DC1233A) 5579f 18 LT5579 PACKAGE DESCRIPTION UH Package 24-Lead Plastic QFN (5mm × 5mm) (Reference LTC DWG # 05-08-1747 Rev Ø) 0.75 ±0.05 5.40 ±0.05 3.90 ±0.05 3.20 ± 0.05 3.25 REF 3.20 ± 0.05 PACKAGE OUTLINE 0.30 ± 0.05 0.65 BSC RECOMMENDED SOLDER PAD LAYOUT APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 5.00 ± 0.10 R = 0.05 TYP 0.75 ± 0.05 BOTTOM VIEW—EXPOSED PAD R = 0.115 TYP 23 0.00 – 0.05 PIN 1 NOTCH R = 0.30 TYP OR 0.35 s 45° CHAMFER 24 0.55 ± 0.10 PIN 1 TOP MARK (NOTE 6) 1 2 3.20 ± 0.10 5.00 ± 0.10 3.25 REF 3.20 ± 0.10 (UH24) QFN 1206 REV Ø 0.200 REF NOTE: 1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.20mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE 0.30 ± 0.05 0.65 BSC 5579f 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. 19 LT5579 RELATED PARTS PART NUMBER Infrastructure LT5514 DESCRIPTION COMMENTS Ultralow Distortion, IF Amplifier/ADC Driver with Digitally Controlled Gain 40MHz to 900MHz Quadrature Demodulator 1.5GHz to 2.4GHz High Linearity Direct Quadrature Modulator 850MHz Bandwidth, 47dBm OIP3 at 100MHz, 10.5dB to 33dB Gain Control Range LT5519 0.7GHz to 1.4GHz High Linearity Upconverting Mixer 17.1dBm IIP3 at 1GHz, Integrated RF Output Transformer with 50Ω Matching, Single-Ended LO and RF Ports Operation LT5520 1.3GHz to 2.3GHz High Linearity Upconverting Mixer LT5521 10MHz to 3700MHz High Linearity Upconverting Mixer 400MHz to 2.7GHz High Signal Level Downconverting Mixer 15.9dBm IIP3 at 1.9GHz, Integrated RF Output Transformer with 50Ω Matching, Single-Ended LO and RF Ports Operation 24.2dBm IIP3 at 1.95GHz, NF = 12.5dB, 3.15V to 5.25V Supply, Single-Ended LO Port Operation LT5517 LT5518 LT5522 LT5524 LT5525 LT5526 LT5527 LT5528 Low Power, Low Distortion ADC Driver with Digitally Programmable Gain High Linearity, Low Power Downconverting Mixer High Linearity, Low Power Downconverting Mixer 400MHz to 3.7GHz High Signal Level Downconverting Mixer 1.5GHz to 2.4GHz High Linearity Direct Quadrature Modulator 21dBm IIP3, Integrated LO Quadrature Generator 22.8dBm OIP3 at 2GHz, –158.2dBm/Hz Noise Floor, 50Ω Single-Ended RF and LO Ports, 4-Channel W-CDMA ACPR = –64dBc at 2.14GHz 4.5V to 5.25V Supply, 25dBm IIP3 at 900MHz, NF = 12.5dB, 50Ω Single-Ended RF and LO Ports 450MHz Bandwidth, 40dBm OIP3, 4.5dB to 27dB Gain Control Single-Ended 50Ω RF and LO Ports, 17.6dBm IIP3 at 1900MHz, ICC = 28mA 3V to 5.3V Supply, 16.5dBm IIP3, 100kHz to 2GHz RF, NF = 11dB, ICC = 28mA, –65dBm LO-RF Leakage IIP3 = 23.5dBm and NF = 12.5dBm at 1900MHz, 4.5V to 5.25V Supply, ICC = 78mA, Conversion Gain = 2dB 21.8dBm OIP3 at 2GHz, –159.3dBm/Hz Noise Floor, 50Ω, 0.5VDC Baseband Interface, 4-Channel W-CDMA ACPR = –66dBc at 2.14GHz LT5557 400MHz to 3.8GHz 3.3V Downconverting Mixer IIP3 = 23.5dBm at 3.6GHz, NF = 15.4dB, Conversion Gain = 1.7dB, 3.3V Supply at 82mA, Single-Ended RF and LO Inputs LT5558 600MHz to 1100MHz High Linearity Direct 22.4dBm OIP3 at 900MHz, –158dBm/Hz Noise Floor, 3kΩ, 2.1VDC Baseband Quadrature Modulator Interface, 3-Ch CDMA2000 ACPR = –70.4dBc at 900MHz LT5560 Ultra-Low Power Active Mixer 10mA Supply Current, 10dBm IIP3, 10dB NF, Usable as Up- or Down-Converter. LT5568 700MHz to 1050MHz High Linearity Direct 22.9dBm OIP3 at 850MHz, –160.3dBm/Hz Noise Floor, 50Ω, 0.5VDC Baseband Quadrature Modulator Interface, 3-Ch CDMA2000 ACPR = –71.4dBc at 850MHz LT5572 1.5GHz to 2.5GHz High Linearity Direct 21.6dBm OIP3 at 2GHz, –158.6dBm/Hz Noise Floor, High-Ohmic 0.5VDC Baseband Quadrature Modulator Interface, 4-Ch W-CDMA ACPR = –67.7dBc at 2.14GHz LT5575 700MHz to 2.7GHz Direct Conversion I/Q Integrated Baluns, 28dBm IIP3, 13dBm P1dB, 0.03dB I/Q Amplitude Match, Demodulator 0.4° Phase Match RF Power Detectors LTC®5505 RF Power Detectors with >40dB Dynamic Range 300MHz to 3GHz, Temperature Compensated, 2.7V to 6V Supply LTC5507 100kHz to 1000MHz RF Power Detector 100kHz to 1GHz, Temperature Compensated, 2.7V to 6V Supply LTC5508 300MHz to 7GHz RF Power Detector 44dB Dynamic Range, Temperature Compensated, SC70 Package LTC5509 300MHz to 3GHz RF Power Detector 36dB Dynamic Range, Low Power Consumption, SC70 Package LTC5530 300MHz to 7GHz Precision RF Power Detector Precision VOUT Offset Control, Shutdown, Adjustable Gain LTC5531 300MHz to 7GHz Precision RF Power Detector Precision VOUT Offset Control, Shutdown, Adjustable Offset LTC5532 300MHz to 7GHz Precision RF Power Detector Precision VOUT Offset Control, Adjustable Gain and Offset LT5534 50MHz to 3GHz Log RF Power Detector with ±1dB Output Variation over Temperature, 38ns Response Time, Log Linear 60dB Dynamic Range Response LTC5536 Precision 600MHz to 7GHz RF Power Detector 25ns Response Time, Comparator Reference Input, Latch Enable Input, with Fast Comparator Output –26dBm to +12dBm Input Range LT5537 Wide Dynamic Range Log RF/IF Detector Low Frequency to 1GHz, 83dB Log Linear Dynamic Range LT5570 2.7GHz Mean-Squared Detector ±0.5dB Accuracy Over Temperature and >50dB Dynamic Range, Fast 500ns Rise Time 5579f 20 Linear Technology Corporation LT 0108 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2008