Dennis, your divider have inherent flaw :) It basically have just 1:10 range unless relays are used.
Input of ADC or multiplexer CD74HC4051 will act as clamp for 1:10 tap, rendering higher ranges of your circuit useless at voltages exceeding 10*(VCC…
Our two schematics use a different approach. My resistor divider is always the same, only the used tap is different. This ensures a constant input impedance. For my approach I would use a multiplexer like the CD74HC4051 (or a similar type with lower leakage…
Teroa,
The SN74HC4851 doesn't sepecify the break before make time in the datasheet so TI cannot gauruntee there won't be an cross conduction between channels when the "old" channel turned OFF before the next is activated? You need to search for a…
I think the voltage drop is mostly due to the Ron change with Vin. This can be seen in the datasheet Ron plot.
I believe that a better part would be CD74HC4051 since this part has much lower Ron.
Hi Sho Ogane ,
CD74HC4351 should be able to perform over 140Mhz.
alternatively , you can also consider CD74HC4051 devices which are rated above 140Mhz fmax.
Hi Benjamin,
With 3.3V supply above the min recommended operating conditions for the part , it will work. Any input from 0 to 3.3V can pass through the switch with 3.3Vcc .
consider using sn74LV4051A or sn74HC4851 or CD74hc4051 devices which work…
Hi Alex
There should not be a short between Vss and Vee. If you are measuring with an Ohmeter you may see some amount of resistance in one direction but if you reverse the probes you should see an open. This could be cause by the protection diodes…
Other Parts Discussed in Thread: UCD9248 , UCD7242 , CD74HC4051 I have a design with two UCD9248 devices, controlling in total eight rails. All the rails uses UCD7242 drivers, in either single or dual phase configuration. The design works fine, with the…
