MAX5168
Input Drive Requirements
The input of the MAX5168 feeds the inputs of 32 high-
impedance buffers. These buffers are what charge the
sample/hold capacitor through the multiplexer switch
resistance. The bias current of a selected buffer is
10µA, and this feeds into the 10pF input capacitance.
Figure 5 shows an equivalent input circuit. The bias cur-
rents of the other 31 sample and holds are very small in
comparison to the bias current of the selected channel.
Powering the MAX5168
The MAX5168 does not require a special power-up
sequence to avoid latchup. The device requires three
separate supply voltages for operation. However, when
one or two of the voltages are not available, DC-DC
charge-pump (switched-capacitor) converters provide
a simple, efficient solution. The MAX860 provides volt-
age doubling or inversion, ideal for conversions from
+5V to +10V or from +5V to -5V.
Chip Information
TRANSISTOR COUNT: 6961
32-Channel Sample/Hold Amplifier
with a Single Multiplexed Input
10 ______________________________________________________________________________________
