U2796B-MFPG3

U2796B 2-GHz Single-Balanced Mixer Description The U2796B-FP is a 2-GHz down-conversion mixer for telecommunication systems, e.g. cellular radio, CT1, CT2, DECT, PCN, using Atmel Wireless & Microcontrollers’ advanced bipolar UHF technology. The U2796B is well suited for the receiver portion of the RF circuit. Single-balanced structure has been chosen for best noise performance and low current consumption. The IIP3 is programmable. Features Benefits
Supply-voltage range: 2.7 V to 5.5 V
Stand-alone product Electrostatic sensitive device. Observe precautions for handling.
Low current consumption extends talk time
Excellent isolation characteristics
Low current consumption: 3.2 mA without RIP3
3-V operation requires only small space for batteries
IIP3 programmable
Input frequency operating range up to 2 GHz
RF characteristic nearly independent of supply voltage Block Diagram RFI 2 5 IFO 3 4 IFO Mixer BPC Duty cycle control loop Buffer 6,8 7 LOi Voltage regulator 93 7758 e 1 VS Figure 1. Block diagram Ordering Information Extended Type Number Package U2796B-MFP SO8 Tube U2796B-MFPG3 SO8 Taped and reeled Rev. A3, 10-Oct-00 Remarks 1 (10) U2796B Pin Description VS 1 8 GND RFi 2 7 LOi BPC 3 6 GND IFO 4 5 IFO 93 7820 e Figure 2. Pinning Pin Symbol Function 1 VS Supply voltage 2 RF RF input and IIP3 programming port 3 BPC Bypass capacitor 4 IFo IF output 5 IFo IF output 6 GND 7 LOi 8 GND Ground Local oscillator input Ground Absolute Maximum Ratings Parameters Symbol Value Unit Supply voltage Pin 1 VS 6 V Input voltage Pins 2, 3, 4, 5 and 7 Vi 0 to VS V Junction temperature Tj 125 °C Storage temperature Tstg –40 to +125 °C Symbol Value Unit VS 2.7 to 5.5 V Tamb –40 to +85 °C Parameters Symbol Value Unit SO8 RthJA 175 K/W Operating Range Parameters Supply-voltage range Pin 1 Ambient temperature Thermal Resistance Junction ambient Electrical Characteristics Test conditions (unless otherwise specified): VS = 3 V, fLO = 900 MHz; IM = 1.2 mA, Tamb = 25°C. System impedance ZO = 50 Ω Parameters Test conditions / Pin Supply voltage Symbol Min. Pin 1 VS 2.7 Pin 1 IS 2.8 Supply current RIP3 = , Conversion power gain RL = 3 kΩ, RIP3 =  fLO = 900 MHz Figure 4 fLO = 1700 MHz fIF = 45 MHz 2 (10) PGC Typ. 3.2 9 Max. Unit 5.5 V 3.7 mA dB 9 Rev. A3, 10-Oct-00 U2796B Electrical Characteristics (continued) Parameters Test conditions / Pin Symbol LO spurious at RFin PiLO = –10 dBm Figure 5 Pin 7 to 2 ISLORF RF to LO PiRF = –25 dBm Pin 2 to 7 fLO = 900 MHz fLO = 1700 MHz ISRFLO Min. Typ. Max. Unit –35 dBm Isolation Fi Figure 6 30 dB 40 20 Operating frequencies RF frequency Pin 2 RFi 2000 MHz LOin frequency Pin 7 LOi 2000 MHz IFo 300 MHz IFout frequency Pins 4 and 5 Input level RF input (–1 dB comp.) RL = 50 Ω, 3rd-order intercept point PiLO = –10 dBm, RIP3 =  Figure 2 Pin 2 Pin 2 PiRF –15 dBm IIP3 –4 dBm Pin 7 PiLO –6 RF input Pin 2 ZiRF 25 Ω LO input Pin 7 ZiLO 50 Ω Pins 4 and 5 ZoIF PiLO = 0 dBm, RL  3 kΩ fLO = 900 MHz fLO = 1700 MHz NF50 10 kΩ// 0.9 pF 9 dB LO input 0 dBm Impedances IF output Noise figure (DSB) Figure i 7 Voltage standing wave ratio LO Pin 7 12 VSWR- 1.3 2 LO 3.5 8 3.0 5 IIP3 ( dBm ) IM ( mA ) Note: IM = Internal mixer current (see figure 3) 2.5 2.0 2 –1 –4 1.5 1.0 –7 0 400 800 1200 1600 RE (  ) 93 7825 e Figure 3. Mixer current (IM) versus RE Rev. A3, 10-Oct-00 2000 1 93 7827 e 2 3 IM ( mA ) Figure 4. Third-order input intercept IIP3 point versus IM 3 (10) U2796B IFO 5 4 LO buffer 3 LOi 7 IM RFi 2 RE 93 7759 e Figure 5. Mixer circuitry f 1= 958.5 MHz f 1. RF generator Ri = 50 LOi C1 8 7 6 10 dB 5 IFO U2796B 10 dB 10 dB 1 2 –26 dBm 2. RF generator R = 50 i f = 958.55 MHz 2 N Cr RFi Power splitter LO generator Ri = 50 10 dB –10 dBm 3 = 900 MHz LO Spectrum analyzer Hp 70908 A R = 50 i IFO 4 C3 C4 C2 1H RIP3 VS 93 7760 e Figure 6. Test circuit conversion power gain (PGC) and 3rd-order input intercept point (IIP3) 4 (10) Rev. A3, 10-Oct-00 U2796B 93 7761 e LO generator Ri = 50  LOi 10 dB – 10 dBm C1 8 7 6 5 IFO U2796B Spectrum analyzer Ri = 50  C2 1 2 IFO 4 3 C4 C3 10 dB RFi VS Figure 7. Test circuit isolation LO to RF LO generator Ri = 50  Power splitter NWA, E R i = 50  10 dB 10 dB LOi C1 –15 to –5 dBm 8 7 6 5 IF O U2796B 1 2 3 IF O 4 C2 NWA, S R i = 50  C3 C4 –26 dBm 10 dB RF i H 


VS R IP3 93 7762 e Figure 8. Test circuit isolation RF to LO Rev. A3, 10-Oct-00 5 (10) U2796B LO generator R i = 50  LOi C1 8 7 6 5 IFO N Cr Noise figure meter U2796B 1 2 IFO 4 3 C3 C2 Noise source RFi C4 RIP3 VS 93 7763 e Figure 9. Test circuit noise figure Note: 1. The noise floor of the LO generator might influence the noise figure test result. In order to avoid this, either a bandpass or a highpass filter with fc  fIF should be implemented. 2. If IF output network does not provide sufficient suppression of the LO component, a lowpass filter should be inserted to avoid overdriving the noise figure meter. 3. For best noise performance 0 dBm LO power level is required. 6 (10) Rev. A3, 10-Oct-00 U2796B 94 7840 e Figure 10. S11 RF input impedance 94 7841 e Figure 11. S11 LO input impedance Rev. A3, 10-Oct-00 7 (10) U2796B Application Circuit LO i C1 8 7 6 5 IFO 2 IFout Cr U2796B 1 N TR8/1 3 IFO 4 C3 C2 RFi R2 RIP3 C4 VS 93 7765 e Figure 12. Application circuit Recommended Values for the Evaluator C1 and C2 = 150 pF, C3 and C4 = 100 nF. Cr is calculated for resonance with the balun at fIF, or as a highpass filter for fLO. The output balun transformer ratio  = 8:1 for ZO = 50 Ω. R2 increases the IF output level and is calculated from: V (4, MinimalMinimal5) – V S (1) R2
S I S (1 ) For example ,VS (4, 5) = 4 V, VS (1) = 3 V, IS (1) = 2.2 mA R2  470 Ω, where IS (1) is the current consumption without the mixer stage. the impedance of a subsequent filter is 1 k, the capacitive voltage divider may be left out. VS VS L1 L2 The second circuit was dimensioned for approximately 130 MHz and a load resistance of 50 . If, for instance, 8 (10) C2 C1 C2 R 5 4 Application Hint The output transformer at the Pins 4 and 5 can be replaced by LC circuits as shown in figure 13. Compared to transformer, LC circuits save space and are suitable for higher IF frequencies. When applying one of these solutions, it has to be checked whether the requirements on noise figure and gain can be achieved. 95 9632 VS 1 H 10 pF 8.2 pF 220 nH 4 5 RL = 50  39 pF Figure 13. Rev. A3, 10-Oct-00 U2796B Evaluation Board Cx n.c. out C1 C3 RIP3 Cr C2 i 93 7826 e Figure 14. Evaluation board with application circuit Package Information 5.2 4.8 Package SO8 5.00 4.85 Dimensions in mm 3.7 1.4 0.25 0.10 0.4 1.27 6.15 5.85 3.81 8 0.2 3.8 5 technical drawings according to DIN specifications 13034 1 Rev. A3, 10-Oct-00 4 9 (10) U2796B Ozone Depleting Substances Policy Statement It is the policy of Atmel Germany GmbH to 1. Meet all present and future national and international statutory requirements. 2. Regularly and continuously improve the performance of our products, processes, distribution and operating systems with respect to their impact on the health and safety of our employees and the public, as well as their impact on the environment. It is particular concern to control or eliminate releases of those substances into the atmosphere which are known as ozone depleting substances (ODSs). The Montreal Protocol (1987) and its London Amendments (1990) intend to severely restrict the use of ODSs and forbid their use within the next ten years. Various national and international initiatives are pressing for an earlier ban on these substances. Atmel Germany GmbH has been able to use its policy of continuous improvements to eliminate the use of ODSs listed in the following documents. 1. Annex A, B and list of transitional substances of the Montreal Protocol and the London Amendments respectively 2. Class I and II ozone depleting substances in the Clean Air Act Amendments of 1990 by the Environmental Protection Agency (EPA) in the USA 3. Council Decision 88/540/EEC and 91/690/EEC Annex A, B and C (transitional substances) respectively. Atmel Germany GmbH can certify that our semiconductors are not manufactured with ozone depleting substances and do not contain such substances. 2. We reserve the right to make changes to improve technical design and may do so without further notice. Parameters can vary in different applications. All operating parameters must be validated for each customer application by the customer. Should the buyer use Atmel Wireless & Microcontrollers products for any unintended or unauthorized application, the buyer shall indemnify Atmel Wireless & Microcontrollers against all claims, costs, damages, and expenses, arising out of, directly or indirectly, any claim of personal damage, injury or death associated with such unintended or unauthorized use. Data sheets can also be retrieved from the Internet: http://www.atmel–wm.com Atmel Germany GmbH, P.O.B. 3535, D-74025 Heilbronn, Germany Telephone: 49 (0)7131 67 2594, Fax number: 49 (0)7131 67 2423 10 (10) Rev. A3, 10-Oct-00