MCP654 MICROCHIP [Microchip Technology], MCP654 Datasheet - Page 24

• Manufacturer Part Number: MCP654
• Description: 50 MHz, 6 mA Op Amps with mCal
• Manufacturer: MICROCHIP [Microchip Technology]

MCP651/2/4/5/9
When the V
divider generates a V
which is near the center of the input common mode
voltage range. It is recommended that an external
capacitor from V
noise immunity.
When the V
source, which is within its specified range, the op amp
will have its input offset voltage calibrated at that com-
mon mode input voltage. Make sure that V
its specified range.
It is possible to use an external resistor voltage divider
to modify V
at the V
parallel equivalent of R
smaller than 100 kΩ to minimize differences in match-
ing and temperature drift between the internal and
external resistors. Again, make sure that V
its specified range.
FIGURE 4-2:
Resistors.
For instance, a design goal to set V
V
R
within its range for any V
enough to 0V for ground based applications.
4.2
4.2.1
The input devices are designed to not exhibit phase
inversion when the input pins exceed the supply
voltages.
exceeding both supplies with no phase inversion.
4.2.2
The ESD protection on the inputs can be depicted as
shown in
protect the input transistors, and to minimize input bias
current (I
when they try to go more than one diode drop below
V
DS22146B-page 24
DD
SS
2
= 1.00 kΩ and C
. They also clamp any voltages that go too far
= 2.5V
CAL
Input
B
C
). The input ESD diodes clamp the inputs
Figure
CM_INT
Figure 2-41
1
PHASE REVERSAL
INPUT VOLTAGE AND CURRENT
LIMITS
CAL
CAL
pin looks like 100 kΩ tied to V
could
R
R
pin is left open, the internal resistor
CAL
pin is driven by an external voltage
; see
4-3. This structure was chosen to
1
2
V
V
DD
SS
1
to ground be added to improve
be
CM_INT
Setting V
= 100 nF. This will keep V
Figure
1
V
shows
met
CAL
and R
DD
4-2. The internal circuitry
of approximately V
, and should be close
CM
with:
2
CM_INT
an
MCP65X
should be much
with External
input
R
= 0.1V when
CAL
CAL
1
= 24.3 kΩ,
DD
is within
is within
/3. The
voltage
DD
CAL
/3,
above V
allow normal operation, and low enough to bypass
quick ESD events within the specified limits.
FIGURE 4-3:
Structures.
In order to prevent damage and/or improper operation
of these amplifiers, the circuit must limit the currents
(and voltages) at the input pins (see Section 1.1
“Absolute Maximum Ratings †”).
the recommended approach to protecting these inputs.
The internal ESD diodes prevent the input pins (V
and V
resistors R
of the input pins. Diodes D
pins (V
dump any currents onto V
shown, resistors R
through D
FIGURE 4-4:
Inputs.
It is also possible to connect the diodes to the left of the
resistor R
the diodes D
mechanism. The resistors then serve as in-rush current
limiters; the DC current into the input pins (V
V
IN
–) should be very small.
V
V
V
V
V
IN
IN
DD
IN
SS
1
2
–) from going too far below ground, and the
DD
+
+ and V
R
R
1
1
1
; their breakdown voltage is high enough to
1
2
Bond
Bond
Bond
and D
and R
Pad
Pad
Pad
and R
>
>
1
R
R
and D
V
V
1
2
D
SS
SS
IN
1
2
2
2
–) from going too far above V
.
. In this case, the currents through
– (minimum expected V
– (minimum expected V
limit the possible current drawn out
1
2
need to be limited by some other
Simplified Analog Input ESD
and R
Protecting the Analog
© 2011 Microchip Technology Inc.
Stage
Input
D
2
DD
2 mA
2 mA
1
V
and D
2
. When implemented as
DD
MCP65X
also limit the current
2
Figure 4-4
prevent the input
Bond
Pad
V
1
2
)
)
OUT
V
IN
IN
DD
shows
–
+ and
, and
IN
+