MAX382/MAX384
Low-Voltage, 8-Channel/Dual 4-Channel
Multiplexers with Latchable Inputs
10 ______________________________________________________________________________________
V
GEN
GND WR
C
L
100pF
V
OUT
-5V
V-
V+
R
GEN
V
OUT
EN
ON
OFF
OFF
∆V
OUT
∆V
OUT
IS THE MEASURED VOLTAGE ERROR DUE TO
CHARGE INJECTION. THE CHARGE IN COULOMBS IS Q = C
L
x ∆V
O
+5V
N0_
IN
+2.4V
3V
A0, A1, (A2)
COM
RS
MAX382
MAX384
Figure 7. Charge Injection (V
CTE
)
GND
WR
35pF
V
OUT
-5V
V-
V+
V
O
V
OUT
+3V
+1.5V
0V
RS
t
OFF
(RS)
50%
0.8V
O
+5V
EN
RS
1k
+5V
A0, A1,
(A2)
N01–
N08
COM, COMB
LOGIC
INPUT
N01+2.4V
MAX382
Figure 6. Reset Turn-Off Time (t
OFF(RS)
)
Operation with Supply Voltages
Other than ±5V
Using supply voltages less than ±5V reduces the analog
signal range. The MAX382/MAX384 muxes operate with
±3V to ±8V bipolar supplies or with a +2.7V to +16.5V
single supply. Connect V- to GND when operating with a
single supply. Both devices can also operate with unbal-
anced supplies, such as +10V and -5V. The
Typical
Operating Characteristics
graphs show typical on-resis-
tance with ±3V, ±5V, +3V and +5V supplies. (Switching
times increase by a factor of two or more for operation at
+5V or below.)
Overvoltage Protection
Proper power-supply sequencing is recommended for
all CMOS devices. Do not exceed the absolute maxi-
mum ratings, because stresses beyond the listed rat-
ings can cause permanent damage to the devices.
Always sequence V+ on first, then V-, followed by the
logic inputs, NO, or COM. If power-supply sequencing
is not possible, add two small signal diodes (D1, D2) in
series with supply pins for overvoltage protection
(Figure 8). Adding diodes reduces the analog signal
range to one diode drop below V+ and one diode drop
above V-, but does not affect the devices’ low switch
resistance and low leakage characteristics. Device
operation is unchanged, and the difference between V+
and V- should not exceed 17V. These protection diodes
are not recommended when using a single supply.
