Electronic Components Datasheet Search |
|
ADG702BRJZ-500RL71 Datasheet(PDF) 10 Page - Analog Devices |
|
ADG702BRJZ-500RL71 Datasheet(HTML) 10 Page - Analog Devices |
10 / 12 page ADG701/ADG702 Rev. C | Page 10 of 12 APPLICATIONS INFORMATION The ADG701/ADG702 belong to the Analog Devices family of CMOS switches. This series of general-purpose switches has improved switching times, lower on resistance, higher bandwidth, low power consumption, and low leakage currents. ADG701/ADG702 SUPPLY VOLTAGES Functionality of the ADG701/ADG702 extends from 1.8 V to 5.5 V single supply, making the parts ideal for battery-powered instruments, where power efficiency and performance are important design parameters. It is important to note that the supply voltage affects the input signal range, on resistance, and switching times of the part. The effects of the power supplies can be clearly seen in the Typical Performance Characteristics and the Specifications sections. For VDD = 1.8 V operation, RON is typically 40 Ω over the temperature range. BANDWIDTH Figure 18 illustrates the parasitic components that affect the ac performance of CMOS switches (a box surrounds the switch). Additional external capacitances further degrade performance by affecting feedthrough, crosstalk, and system bandwidth. VIN SD RON CDS CD CLOAD RLOAD VOUT Figure 18. Switch Represented by Equivalent Parasitic Components The transfer function that describes the equivalent diagram of the switch ( see Figure 18) is of the form (A)s, shown in the following equation: ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ + + = 1 ) ( 1 ) ( ) ( T T ON DS ON T R C R s C R s R s A where CT = CLOAD + CD + CDS. The signal transfer characteristic is dependent on the switch channel capacitance, CDS. This capacitance creates a frequency zero in the numerator of the transfer function A(s). Because the switch on resistance is small, this zero usually occurs at high frequencies. The bandwidth is a function of the switch output capacitance combined with CDS and the load capacitance. The frequency pole corresponding to these capacitances appears in the denominator of A(s). The dominant effect of the output capacitance, CD, causes the pole breakpoint frequency to occur first. To maximize bandwidth, a switch must have a low input and output capacitance and low on resistance. The on response vs. frequency for the ADG701/ ADG702 can be seen in Figure 10. OFF ISOLATION Off isolation is a measure of the input signal coupled through an off switch to the switch output. The capacitance, CDS, couples the input signal to the output load when the switch is off, as shown in Figure 19. VIN SD CDS CD CLOAD RLOAD VOUT Figure 19. Off Isolation Is Affected by External Load Resistance and Capacitance The larger the value of CDS, the larger the values of feedthrough produced. Figure 9 illustrates the drop in off isolation as a function of frequency. From dc to roughly 1 MHz, the switch shows better than −75 dB isolation. Up to frequencies of 10 MHz, the off isolation remains better than −55 dB. As the frequency increases, more of the input signal is coupled through to the output. Off isolation can be maximized by choosing a switch with the smallest CDS possible. The values of load resistance and capacitance also affect off isolation, because they contribute to the coefficients of the poles and zeros in the transfer function of the switch when open. ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ + + = 1 ) )( ( 1 ) ( ) ( T LOAD DS LOAD T C R s C R s R s A |
Similar Part No. - ADG702BRJZ-500RL71 |
|
Similar Description - ADG702BRJZ-500RL71 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |