8-Channel Latchable Multiplexers

8

_______________________________________________________________________________________

PROTECTION

V-

Sn

S1

D

V+

CLK

RESET

4-WIDE LATCH

RS

PROTECTION

WR

PROTECTION

A_

PROTECTION

LEVEL SHIFT

DECODE

EN

Figure 8. Simplified Internal Structure

_______________________Applications

Operation with Supply Voltages

Other Than ±15V

Maxim guarantees the DG528/DG529 for operation

from ±4.5V to ±20V supplies. The switching delays

increase by about a factor of two at ±5V, and break-

before-make action is preserved.

The DG528/DG529 can operate with a single +5V to

+30V supply as well as asymmetrical power supplies

like +15V and -5V. The digital threshold will remain

approximately 1.6V above the GND pin, and the analog

total voltage difference between V+ and V-. Connect V-

to 0V when operating with a +5V to +30V single supply.

Digital Interface Levels

The typical digital threshold of both the address lines

and EN is 1.6V with a temperature coefficient of

approximately -3mV/°C, ensuring compatibility with TTL

logic over the temperature range. The digital threshold

is relatively independent of the power-supply voltages,

going from a typical 1.6V when V+ is 15V to 1.5V typi-

cal with V+ = 5V. Therefore, Maxim’s DG528/DG529

operate with standard TTL logic levels, even with ±5V

power supplies. In all cases, EN’s threshold is the same

as the other logic inputs and is referenced to GND.

The digital inputs can also be driven with CMOS logic

levels swinging from either V+ to V- or from V+ to GND.

The digital input current is just a few nanoamps of leak-

age at all input-voltage levels with a guaranteed maxi-

mum of 1µA. The digital inputs are protected from ESD

by a 30V zener diode between the input and V+ and

can be driven ±2V beyond the supplies without draw-

ing excessive current.