RF2368

Preliminary RF2368 DCS/PCS 2.7V LOW NOISE AMPLIFIER 4 Typical Applications • DCS Handsets • PCS Handsets • General Purpose Amplification • Commercial and Consumer Systems Product Description The RF2368 is a DCS/PCS low noise amplifier with bypass switch designed for use as a front-end for DCS1800/PCS1900 applications. The LNA is a two-stage amplifier with bypass switch. This amplifier has low noise figure and high linearity in both high gain and bypass/low gain mode. 0.365 2.80 3.00 0.650 2.60 3.00 3°MAX 0°MIN 1.44 1.04 0.127 *When Pin 1 is in upper left, text reads downward (as shown). 0.35 0.55 Optimum Technology Matching® Applied Si BJT Si Bi-CMOS ü Package Style: SOT 8 Lead GaAs HBT SiGe HBT GaAs MESFET Si CMOS Features • Low Noise and High Intercept Point • Power Down Control • Switchable Gain BIAS 1 GND 2 IN 3 GND1 4 Control Logic 8 SELECT 7 OUT 6 GND2 5 VCC Ordering Information RF2368 RF2368 PCBA DCS/PCS 2.7V Low Noise Amplifier Fully Assembled Evaluation Board Functional Block Diagram RF Micro Devices, Inc. 7625 Thorndike Road Greensboro, NC 27409, USA Tel (336) 664 1233 Fax (336) 664 0454 http://www.rfmd.com Rev A0 010503 4-199 GENERAL PURPOSE AMPLIFIERS 1.59 1.61 0.15 0.05 4 TEXT* RF2368 Absolute Maximum Ratings Parameter Supply Voltage Input RF Level Storage Temperature Preliminary Rating -0.5 to +6.0 +10 -40 to +150 Unit VDC dBm °C Caution! ESD sensitive device. RF Micro Devices believes the furnished information is correct and accurate at the time of this printing. However, RF Micro Devices reserves the right to make changes to its products without notice. RF Micro Devices does not assume responsibility for the use of the described product(s). Parameter Operating Range Overall Frequency Range Supply Voltage (VCC) Power Down Voltage (VBIAS) Logic Control Voltage Level Operating Ambient Temperature Input Impedance Output Impedance Specification Min. Typ. Max. 1800 2.7 2.7 0 -40 2000 2.86 2.86 2.86 +85 Unit MHz V V V °C Ω Ω Condition 4 GENERAL PURPOSE AMPLIFIERS 2.78 2.78 VCC1, VCC2 BIAS SELECT 50 50 1850MHz Performance High Gain Mode Gain Gain Variation Over Temperature Range Gain Variation Over Frequency Band Current Consumption Noise Figure Reverse Isolation Input IP3 Input P1dB 17 18 19 +0.5 +0.5 9.0 1.6 20 +1.0 -10 9.5 1.7 dB dB dB mA dB dB dBm dB T = 25°C, RF=1850MHz, VCC =BIAS=2.78V, SELECT=0V, ZIN =ZO =50 Ω ICC +IBIAS 15 0.0 -13 1850MHz Performance Bypass Mode Gain Gain Reduction Power Down Current Input IP3 Input P1dB 21 12 +5 -4.5 22.5 15.0 +8 24 10 dB dBc µA dBm dB T = 25°C, RF=1850MHz, VCC =2.78V, SELECT=2.7V, ZIN =ZO =50 Ω 1960MHz Performance High Gain Mode Gain Gain Variation Over Temperature Range Gain Variation Over Frequency Band Current Consumption Noise Figure Reverse Isolation Input IP3 Input P1dB 15.5 16.5 17.5 +0.5 +0.5 9.0 1.6 20 +2 -10 9.5 1.7 dB dB dB mA dB dB dBm dB T = 25°C, RF=1960MHz, VCC =BIAS=2.78V, SELECT=0V, ZIN =ZO =50 Ω ICC +IBIAS 15 +1 -13 1960MHz Performance Bypass Mode Gain Gain Reduction Power Down Current Input IP3 Input P1dB 20 14.0 +5 -5 21.5 17.0 +8 23 10 dB dBc µA dBm dB T = 25°C, RF=1960MHz, VCC =2.78V, SELECT=2.7V, ZIN =ZO =50 Ω 4-200 Rev A0 010503 Preliminary Pin 1 Function BIAS Description BIAS is set to the supply voltage at high gain mode. For bypass mode see “Application Notes”. RF2368 Interface Schematic BIAS 2 3 GND IN DCS1800/PCS1900 RF input pin. To Bias Circuit RF IN VCC1 4 GND1 4 GND1 LNA1 emittance inductance. Total inductance is comprised of package+bondwire+L2 on PCB. 5 VCC Open collector for first stage LNA of DCS1800/PCS1900. It must be biased to VCC through a choke or matching inductor. VCC1 GND1 6 GND2 LNA2 emittance inductance. Total inductance is comprised of package+bondwire+L4 on PCB. 7 OUT DCS1800 Amplifier Output pin. This pin is an open-collector output. It must be biased to VCC through a choke or matching inductor. This pin is typically matched to 50 Ω with a shunt bias/matching inductor and series blocking/matching capacitor. Refer to application schematics. RF OUT GND2 8 SELECT This pin selects high gain. Select < 0.8V, high gain. Select > 1.8V, low gain. SELECT Rev A0 010503 4-201 GENERAL PURPOSE AMPLIFIERS RF2368 Application Notes Preliminary Bypass Mode Configurations The RF2368 may be placed into either high gain or bypass mode via the GAIN SELECT pin (pin 8). The high gain state is selected by asserting the GAIN SELECT pin to a voltage level of less than 0.8V. For Bypass operation, there are two possible methods for placing the RF2368 into this low gain state. The table below shows the two possible Bypass configurations. Bypass Mode Possibilities Gain Select 2.7 2.7 BIAS (V) 0 2.7 VCC1 and VCC2 (V) 2.78 2.78 Current (mA) 1.4 2.2 4 GENERAL PURPOSE AMPLIFIERS For both Bypass configurations, the GAIN SELECT pin must be placed at a level greater than or equal to 1.8V. The difference between the Bypass possibilities is determined by the specific application's ability to change the voltage of the BIAS pin (pin 1) independently of the VCC supply voltage. The advantage of the ability to assert the power down pin to 0V when in Bypass mode is shown by the decreased current draw when in this Bypass configuration. BIAS Pin Resistor The BIAS pin (pin1) of the RF2368 should be maintained at 2.7V to 2.86V for proper high gain operation. This voltage range ensures the correct bias current will be present at the BIAS pin of the device. However, an external series resistor may be used to allow various operating voltages at this pin (see R1 of the evaluation board schematic). The required value for this resistor may be roughly calculated by using the operating input voltage to the BIAS pin, the desired voltage at the device, and the typical current consumption for the BIAS pin, along with Ohm's law. For example, assume the design will supply 5.0V to the BIAS pin of the device, but the biasing circuitry internal to the RF2368 requires 2.78V typical, and the BIAS current is known to typically be 0.25mA, then the required value for R1 would be found as follows. 5.0 V – 2.78 V ------------------------------- = 8.88 k Ω 0.25 mA 4-202 Rev A0 010503 Preliminary Application Schematic SELECT VCC2 100 pF RF2368 10 nF 0.1 µF 0Ω BIAS 0.1 uF 33 nF RFIN 8.2 nH 2.7 nH 3.9 nH 10 kΩ 3 4 6 5 1 2 Control Logic 8 7 1.5 nH 10 kΩ 3.9 nH 0.8 pF RF OUT 4 GENERAL PURPOSE AMPLIFIERS 10 nF 100 pF VCC1 Rev A0 010503 4-203 RF2368 (Download Bill of Materials from www.rfmd.com.) P1 P1-1 1 2 P1-3 3 HDR_3 BIAS GND SELECT P2-3 P2-1 P2 1 2 3 HDR_3 VCC2 GND VCC1 C6 100 pF C8 0.1 µF 1 C1 0.1 uF J1 RF IN 50 Ω µstrip 3 L1 8.2 nH C2 33 nF L2 2.7 nH 4 6 5 L3 3.9 nH L4 1.5 nH 2 Control Logic 8 7 L5 3.9 nH R3 10 kΩ C5 0.8 pF SELECT VCC2 C7 10 nF Preliminary Evaluation Board Schematic - PCS/DCS 4 GENERAL PURPOSE AMPLIFIERS BIAS R1 0Ω 50 Ω µstrip J2 RF OUT 2368310, rev. 2 R2 10 kΩ C4 100 pF C3 10 nF VCC1 4-204 Rev A0 010503 Preliminary Evaluation Board Layout Board Size 1” x 1” Board Thickness 0.032”, Board Material FR-4 RF2368 4 GENERAL PURPOSE AMPLIFIERS Rev A0 010503 4-205 RF2368 High Gain Mode Input Impedance (S11) 1.0 6 0. Preliminary High Gain Mode Output Impedance (S22) 1.0 0.6 Swp Max 4GHz 2. 0 Swp Max 4GHz 2. 0 0.8 0.8 0 3. 3.0 GHz 10.0 10.0 0.2 0.4 0.6 0.8 1.0 2.0 3.0 4.0 5.0 0.2 0.4 0.6 0.8 1.0 2.0 3.0 2.0 GHz 100 MHz GENERAL PURPOSE AMPLIFIERS 1.5 GHz - 4 0. .4 -0 .0 -2 -0 .6 -0.8 -1.0 -0. 6 Swp Min 0.01GHz -0.8 .0 -2 Swp Min 0.01GHz Bypass Mode Input Impedance (S11) 1.0 0.6 Bypass Mode Output Impedance (S22) 1.0 0.6 Swp Max 4GHz 2. 0 -1.0 Swp Max 4GHz 2. 0 0.8 0 3. 3.5 GHz 0.8 0 3. 10.0 10.0 0.2 0.4 0.6 0.8 1.0 2.0 3.0 4.0 5.0 0.2 0.4 0.6 0.8 1.0 2.0 3.0 4.0 5.0 0 0 10.0 3.7 GHz 2.0 GHz .4 -0 3.0 GHz .4 -0 .0 -2 -0. 6 2.5 GHz -0.8 -0. 6 Swp Min 0.01GHz -0.8 .0 -2 -1.0 S-Parameter Conditions: All plots shown were taken at VCC =2.78V and Ambient Temperature=25°C. Note: All S11 and S22 plots shown were taken from an RF2368 while on a 2368310 evaluation board. The data was captured without the external input or output tuning components in place, and the reference points at the RF IN and RF OUT pins of the device. 4-206 -1.0 Rev A0 010503 -3 .0 -3 .0 1.0 GHz Swp Min 0.01GHz -4. 0 -5.0 -4. 0 -5.0 -0.2 1.5 GHz -0.2 3.0 GHz -10.0 0.2 4.0 5.0 2.0 GHz 10.0 -4. 0 -5.0 -3 .0 0. 4 -10.0 -4 .0 -5. 0 2 -0. 1.0 GHz -0.2 4.0 5.0 -10.0 -10.0 4 2.0 GHz 4.0 5.0 0 0 10.0 1.0 GHz 0.2 0 4. 5.0 0. 4 1.0 GHz -3 .0 0. 4 0 3. 4.0 5.0 0. 4 0.2 10.0 0.2