Single pole double throw (SPDT) switch

Transcription

1 NE/SA63 DESCRIPTION The NE63 is a wideband RF switch fabricated in BiCMOS technology and incorporating on-chip CMOS/TTL compatible drivers. Its primary function is to switch signals in the frequency range DC - GHz from one 5Ω channel to another. The switch is activated by a CMOS/TTL compatible signal applied to the enable channel pin (ENCH). The extremely low current consumption makes the NE/SA63 ideal for portable applications. The excellent isolation and low loss makes this a suitable replacement for PIN diodes. The NE/SA63 is available in an 8-pin dual in-line plastic package and an 8-pin SO (surface mounted miniature) package. FEATURES Wideband (DC - GHz) Low through loss ( typical at 2MHz) Unused input is terminated internally in 5Ω Excellent overload capability ( gain compression point +8m at 3MHz) Low DC power (7µA from supply) Fast switching (2ns typical) Good isolation (off channel isolation 6 at MHz) PIN CONFIGURATION D and N Packages V DD GND INPUT ENCH 8 OUT 2 7 AC GND 3 6 GND 4 5 OUT 2 Low distortion (IP 3 intercept +33m) Good 5Ω match (return loss 8 at 4MHz) Full ESD protection Bidirectional operation APPLICATIONS Digital transceiver front-end switch Antenna switch Filter selection Video switch FSK transmitter ORDERING INFORMATION DESCRIPTION TEMPERATURE RANGE ORDER CODE DWG # 8-Pin Plastic Dual In-Line Package (DIP) to 7 C NE63N 44B 8-Pin Plastic Small Outline (SO) package (Surface-mount) to 7 C NE63D 74C 8-Pin Plastic Dual In-Line Package (DIP) -4 to +85 C SA63N 44B 8-Pin Plastic Small Outline (SO) package (Surface-mount) -4 to +85 C SA63D 74C BLOCK DIAGRAM INPUT/OUTPUT OUTPUT/INPUT OUTPUT/INPUT ENCH RECOMMENDED OPERATING CONDITIONS SYMBOL PARAMETER RATING UNITS V DD Supply voltage 3. to 5. V T A T J Operating ambient temperature range NE Grade SA Grade Operating junction temperature range NE Grade SA Grade to +7-4 to +85 to +9-4 to +5 C C C C October,

2 NE/SA63 EQUIVALENT CIRCUIT + V DD 8 OUT 2kΩ CONTROL LOGIC 5Ω 7 2 AC BYPASS 5Ω 6 INPUT 3 2kΩ ENCH 4 5 OUT 2 ABSOLUTE MAXIMUM RATINGS SYMBOL PARAMETER RATING UNITS V DD Supply voltage -.5 to +5.5 V Power dissipation, T A = 25 o C (still air) P D 8-Pin Plastic DIP 8-Pin Plastic SO T JMAX Maximum operating junction temperature 5 C P MAX Maximum power input/output +2 m T STG Storage temperature range -65 to +5 C NOTES:. Maximum dissipation is determined by the operating ambient temperature and the thermal resistance, θ JA : 8-Pin DIP: θ JA = 8 C/W 8-Pin SO: θ JA = 58 C/W 6 78 mw mw DC ELECTRICAL CHARACTERISTICS V DD = +, T A = 25 C; unless otherwise stated. LIMITS SYMBOL PARAMETER TEST CONDITIONS NE/SA63 UNITS MIN TYP MAX I DD Supply current µa V T TTL/CMOS logic threshold voltage V V IH Logic level Enable channel 2. V DD V V IL Logic level Enable channel V I IL ENCH input current ENCH =. - µa I IH ENCH input current ENCH = 2. - µa NOTE:. The ENCH input must be connected to a valid Logic Level for proper operation of the NE/SA63. October,

3 NE/SA63 AC ELECTRICAL CHARACTERISTICS - D PACKAGE V DD = +, T A = 25 C; unless otherwise stated. LIMITS SYMBOL PARAMETER TEST CONDITIONS NE/SA63 UNITS MIN TYP MAX S 2, S 2 Insertion loss (ON channel) DC - MHz 5MHz 9MHz S 2, S 2 Isolation (OFF channel) 2 MHz 5MHz MHz 9MHz S, S 22 S, S 22 Return loss (ON channel) Return loss (OFF channel) DC - 4MHz 9MHz DC - 4MHz 9MHz t D Switching speed (on-off delay) 5% TTL to 9/% RF 2 ns t r, t f Switching speeds (on-off rise/fall time) 9%/% to %/9% RF 5 ns Switching transients 65 mv P-P P - gain compression DC - GHz +8 m IP 3 Third-order intermodulation intercept MHz +33 m IP 2 Second-order intermodulation intercept MHz +52 m NF Noise figure (Z O = 5Ω ) MHz 9MHz NOTE:. All measurements include the effects of the D package NE/SA63 Evaluation Board (see Figure B). Measurement system impedance is 5Ω. 2. The placement of the AC bypass capacitor is critical to achieve these specifications. See the applications section for more details AC ELECTRICAL CHARACTERISTICS - N PACKAGE V DD = +, T A = 25 C; all other characteristics similar to the D-Package, unless otherwise stated. LIMITS SYMBOL PARAMETER TEST CONDITIONS NE/SA63 UNITS MIN TYP MAX S 2, S 2 Insertion loss (ON channel) DC - MHz 5MHz 9MHz S 2, S 2 Isolation (OFF channel) MHz MHz 5MHz 9MHz NF Noise figure (Z O = 5Ω ) MHz 9MHz NOTE:. All measurements include the effects of the N package NE/SA63 Evaluation Board (see Figure C). Measurement system impedance is 5Ω APPLICATIONS The typical applications schematic and printed circuit board layout of the NE/SA63 evaluation board is shown in Figure. The layout of the board is simple, but a few cautions need to be observed. The input and output traces should be 5Ω. The placement of the AC bypass capacitor is extremely critical if a symmetric isolation between the two channels is desired. The trace from Pin 7 should be drawn back towards the package and then be routed downwards. The capacitor should be placed straight down as close to the device as practical. For better isolation between the two channels at higher frequencies, it is also advisable to run the two output/input traces at an angle. This also minimizes any inductive coupling between the two traces. The power supply bypass capacitor should be placed close to the device. Figure 7 shows the frequency response of the NE/SA63. The loss matching between the two channels is excellent to.2ghz as shown in Figure. October, 99 27

4 NE/SA63.µF V DD + GND D and N Packages AC GND.µF.µF OUT INPUT.µF ENCH GND.µF OUT 2 a. NE/SA Evaluation Board Schematic b. NE/SA63 D-Package Board Layout 63N 7/9 c. NE/SA63 N-Package Board Layout Figure. October, 99 27

5 NE/SA63 The isolation and matching of the two channels over frequency is shown in Figures 2 and 4, respectively. The NE63 is a very versatile part and can be used in many applications. Figure 2 shows a block diagram of a typical Digital RF transceiver front-end. In this application the NE63 replaces the duplexer which is typically very bulky and lossy. Due to the low power consumption of the device, it is ideally suited for handheld applications such as in CT2 cordless telephones. The NE63 can also be used to generate Amplitude Shift Keying (ASK) or On-Off Keying (OOK) and Frequency Shift Keying (FSK) signals for digital RF communications systems. Block diagrams for these applications are shown in Figures 3 and 4, respectively. For applications that require a higher isolation at GHz than obtained from a single NE63, several NE63s can be cascaded as shown in Figure 5. The cascaded configuration will have a higher loss but greater than 35 of isolation at GHz and greater than 5MHz can be obtained from this configuration. By modifying the enable control, an RF multiplexer/ de-multiplexer or antenna selector can be constructed. The simplicity of NE63 coupled with its ease of use and high performance lends itself to many innovative applications. The NE/SA63 switch terminates the OFF channel in 5Ω. The 5Ω resistor is internal and is in series with the external AC bypass capacitor. Matching to impedances other than 5Ω can be achieved by adding a resistor in series with the AC bypass capacitor (e.g., 25Ω additional to match to a 75Ω environment). NE52 NE62A IF OUT NE63 MICRO CONTROLLER KEYPAD & DISPLAY Tx/Rx NE52 VCO MODULATION A TYPICAL TDMA/DIGITAL RF TRANSCEIVER SYSTEM FRONT-END Figure 2. ASK OUTPUT OUT/IN NE63 NE63 OSCILLATOR ENABLE CH 5Ω IN/OUT NE63 TTL DATA AMPLITUDE SHIFT KEYING (ASK) GENERATOR NE63 Figure 3. OUT2/IN2 f NE63 FSK OUTPUT ENABLE Figure 5. ENABLE CH f 2 TTL DATA FREQUENCY SHIFT KEYING (FSK) GENERATOR Figure 4. October,

6 NE/SA C C SUPPLY CURRENT ( µ A) C SUPPLY VOLTAGE (V) Figure 6. Supply Current vs. V DD and Temperature Figure 7. Loss vs. Frequency and V DD for D-Package CH2 8 V DD = 2 2 Figure 8. Loss vs. Frequency and V DD for D-Package -Expanded Detail- Figure 9. Loss Matching vs. Frequency for N-Package (DIP) October,

7 NE/SA63-4 C C C CH V DD = V DD = 2 Figure. Loss Matching vs. Frequency; CH vs. CH2 for D-Pakage Figure. Loss vs. Frequency and Temperature for D-Package CH Figure 2. Isolation vs. Frequency and V DD for D-Package 7 8 V DD = 2 Figure 3. Isolation Matching vs. Frequency for N-Package (DIP) October,

8 NE/SA CH2 S () 5 6 CH V DD = + 2 Figure 4. Isolation Matching vs. Frequency; CH vs. CH2 for D-Package Figure 5. Input Match On-Channel vs. Frequency and V DD S 22 () 5 S 22 () 5 CH: CH: 2 2 CH2: 25 V DD = Figure 6. Output Match On-Channel vs. Frequency Figure 7. OFF-Channel Match vs. Frequency and V DD October,

9 NE/SA S 22 () C +25 C P - (m) C V DD = Figure 8. OFF Channel Match vs. Frequency and Temperature Figure 9. P - vs. Frequency and V DD IP2 4 Z O = 5Ω INTERCEPT POINT (m) IP3 NOISE FIGURE () SUPPLY VOLTAGE (V) 2 Figure 2. Intercept Points vs.v Figure 2. Noise Figure vs. Frequency and DD V DD for D-Package October,

10 NE/SA63 ENCH (Pin4) OUT (Pin 8) Figure 22. Switching Speed; f IN = MHz at -6m, V DD = October,