Fault-Protected Analog Multiplexer with Latch

MAX368/369 are 8 channel single-ended ( 1 of 8) and 4 channel differential (2 of 8) fault-protected multiplexers with on-chip data latches. Using a series N-channel. P-channel, N-channel structure, these multiplexers provide significantly improved fault protection over previous devices. If power to the multiplexers is removed while input voltages are still applied, all channels urn off, allowing only a few nanoamperes of leakage current to flow in the inputs. This not only protects the multiplexer and the circuitry connected to the output, but also protects the sensors or signal sources which drive the multiplexer inputs.

When an overvoltage signal of up to ±35V is applied to an analog input of a Maxim fault-protected multiplexer, that input channel turns off. If the overvoltage is applied to an on channel. the multiplexer output is clamped to less than its power supply voltage, thereby protecting sensitive circuitry that may be connected to the multiplexer output.

All channel selection and control inputs are fully compatible with both TTL and CMOS logic levels. In addition, break-before-make switch operation is guaranteed and typical power dissipation is less than 7 milliwatts. which makes the MAX 368/369 ideally suited for portable equipment usage.

APPLICATIONS

* Data Acquisition Systems

* Industrial Process Control Systems

* Avionics Test Equipment

* Signal Routing Between Systems

* Computer Controlled Analog Data Logging

* All Switches Off with Power Supplies Off

* Overvoltage Protection up to ±35V

* Only Nanoamperes of Input Current under All Fault Conditions

* Latch-Up Proof Construction