max5165lecmt Maxim Integrated Products, Inc., max5165lecmt Datasheet - Page 8

• Manufacturer Part Number: max5165lecmt
• Description: Max5165 32-channel Sample/hold Amplifier With A Single Multiplexed Input
• Manufacturer: Maxim Integrated Products, Inc.

The MAX5165 clamps the output between two external-
ly applied reference voltages. Internal diodes connect
all outputs to the clamping voltages, restricting the out-
put voltage to:
When the clamping voltage exceeds the maximum out-
put voltage, the maximum output voltage will be the lim-
iting factor. To disable output clamping, connect CH to
V
the maximum output voltage range. The clamping
diodes allow the MAX5165 to be used with other
devices requiring restricted input voltages.
Acquisition time (t
MAX5165 must remain in sample mode for the hold
capacitor to acquire an accurate sample. The hold-
mode settling time (t
for the output voltage to settle to its final value. Aperture
delay (t
the input from the hold capacitor. The inhibit pulse
width (t
remain in hold mode while the address is changed. The
data setup time (t
must be maintained before the address becomes valid.
The data hold time (t
address must be maintained after mode select has
gone from low to high (Figure 2).
32-Channel Sample/Hold Amplifier
with a Single Multiplexed Input
Figure 2. Timing Performance
8
DD
_______________________________________________________________________________________
and C
AP
PW
) is the time interval required to disconnect
L
) is the amount of time the MAX5165 must
V
CH
to V
+ 0.7V ≤ V
SS
DS
to set the clamping voltages beyond
) is the amount of time an address
H
AQ
DH
) is the amount of time necessary
ADDRESS
OUTPUT
(A0–A2)
SELECT
) is the amount of time that an
) is the amount of time the
MODE
INPUT
OUT_
Timing Definitions
≤ V
CL
Output Clamp
- 0.7V
t
AQ
t
H
t
PW
The MAX5165 contains four separate 1-to-8 multiplex-
ers and individual mode selectors for each multiplexer.
Configure the device to sample only one channel at a
time or up to four channels (with the same address, see
Table 1) simultaneously. When sampling one channel
at a time, use an external 2-to-4 decoder (with active-
low outputs) to reduce the number of digital control
lines from seven to five (Figure 3).
Individually control the four mode/multiplexer-select
pins to simultaneously sample on four channels, the
same channel for each multiplexer (Figure 4). Each
mode-select pin controls sampling on one of the 1-to-8
multiplexers, while the 3-bit address selects one of the
eight channels on all the multiplexers (Tables 1, 2).
Setting any combination of the mode-select pins low
enables sampling on the addressed channels for the
selected multiplexers.
Simultaneously sampling two or more channels reduces
offset voltage but increases acquisition time. Multiply
the single-channel acquisition time by the number of
channels sampling.
t
t
AP
DH
__________Applications Information
HOLD STEP
t
DS
Single vs. Simultaneous Sampling
Control-Line Reduction