Os motores de busca de Datasheet de Componentes eletrônicos |
|
ISL54048 Folha de dados(PDF) 7 Page - Intersil Corporation |
|
ISL54048 Folha de dados(HTML) 7 Page - Intersil Corporation |
7 / 12 page 7 FN6469.0 March 20, 2007 Detailed Description The ISL54048 and ISL54049 are bidirectional, dual single pole/single throw (SPST) analog switches that offer precise switching capability from a single 1.65V to 4.5V supply with low on-resistance (0.29 Ω) and high speed operation (tON = 40ns, tOFF = 20ns). The devices are especially well suited for portable battery powered equipment due to their low operating supply voltage (1.65V), low power consumption (4.5µW max), low leakage currents (195nA max) and the tiny µTQFN package. The ultra low ON-resistance and rON flatness provide very low insertion loss and distortion to applications that require signal reproduction. Supply Sequencing and Overvoltage Protection With any CMOS device, proper power supply sequencing is required to protect the device from excessive input currents which might permanently damage the IC. All I/O pins contain ESD protection diodes from the pin to V+ and to GND (see Figure 7). To prevent forward biasing these diodes, V+ must be applied before any input signals, and the input signal voltages must remain between V+ and GND. If these conditions cannot be guaranteed, then precautions must be implemented to prohibit the current and voltage at the logic pin and signal pins from exceeding the maximum ratings of the switch. The following two methods can be used to provided additional protection to limit the current in the event that the voltage at a signal pin or logic pin goes below ground or above the V+ rail. Logic inputs can be protected by adding a 1k Ω resistor in series with the logic input (see Figure 7). The resistor limits the input current below the threshold that produces permanent damage, and the sub-microamp input current produces an insignificant voltage drop during normal operation. This method is not acceptable for the signal path inputs. Adding a series resistor to the switch input defeats the purpose of using a low rON switch. Connecting schottky diodes to the signal pins (as shown in Figure 7) will shunt the fault current to the supply or to ground thereby protecting the switch. These schottky diodes must be sized to handle the expected fault current. Power-Supply Considerations The ISL54048 and ISL54049 construction is typical of most single supply CMOS analog switches, in that they have two supply pins: V+ and GND. V+ and GND drive the internal CMOS switches and set their analog voltage limits. Unlike switches with a 4V maximum supply voltage, the ISL54048 and ISL54049 4.7V maximum supply voltage provides plenty of room for the 10% tolerance of 4.3V supplies, as well as room for overshoot and noise spikes. The minimum recommended supply voltage is 1.65V. It is important to note that the input signal range, switching times, and ON-resistance degrade at lower supply voltages. Refer to “Electrical Specifications” on page 3 and the Typical Performance Curves on page 8 for details. FIGURE 5. CROSSTALK TEST CIRCUIT FIGURE 6. CAPACITANCE TEST CIRCUIT Test Circuits and Waveforms (Continued) 0V or V+ ANALYZER V+ C SIGNAL GENERATOR RL GND IN1 COM 50 Ω N.C. COM Signal direction through switch is reversed, worst case values are recorded. Repeat test for all switches. NX1 OR NX2 NX1 OR NX2 V+ C GND COM IN IMPEDANCE ANALYZER 0V or V+ Repeat test for all switches. NX1 OR NX2 FIGURE 7. OVERVOLTAGE PROTECTION GND VCOM VNX V+ INX OPTIONAL PROTECTION RESISTOR OPTIONAL SCHOTTKY DIODE OPTIONAL SCHOTTKY DIODE ISL54048, ISL54049 |
Nº de peça semelhante - ISL54048 |
|
Descrição semelhante - ISL54048 |
|
|
Ligação URL |
Privacy Policy |
ALLDATASHEETPT.COM |
ALLDATASHEET é útil para você? [ DONATE ] |
Sobre Alldatasheet | Publicidade | Contato conosco | Privacy Policy | roca de Link | Lista de Fabricantes 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 |