LT6600-2.5
PI FU CTIO S
IN
–
and IN
+
(Pins 1, 8):
Input Pins. Signals can be applied
to either or both input pins through identical external
resistors, R
IN
. The DC gain from differential inputs to the
differential outputs is 1580Ω/R
IN
.
V
OCM
(Pin 2):
Is the DC Common Mode Reference Voltage
for the 2nd Filter Stage. Its value programs the common
mode voltage of the differential output of the filter. Pin 2 is
a high impedance input, which can be driven from an
external voltage reference, or Pin 2 can be tied to Pin 7 on
the PC board. Pin 2 should be bypassed with a 0.01µF
ceramic capacitor unless it is connected to a ground plane.
V
+
and V
–
(Pins 3, 6):
Power Supply Pins. For a single
3.3V or 5V supply (Pin 6 grounded) a quality 0.1µF
ceramic bypass capacitor is required from the positive
supply pin (Pin 3) to the negative supply pin (Pin 6). The
bypass should be as close as possible to the IC. For dual
supply applications, bypass Pin 3 to ground and Pin 6 to
ground with a quality 0.1µF ceramic capacitor.
OUT
+
and OUT
–
(Pins 4, 5):
Output Pins. Pins 4 and 5 are
the filter differential outputs. Each pin can drive a 100Ω
and/or 50pF load to AC ground.
V
MID
(Pin 7):
The V
MID
pin is internally biased at mid-
supply, see block diagram. For single supply operation,
the V
MID
pin should be bypassed with a quality 0.01µF
ceramic capacitor to Pin 6. For dual supply operation, Pin
7 can be bypassed or connected to a high quality DC
ground. A ground plane should be used. A poor ground
will increase noise and distortion. Pin 7 sets the output
common mode voltage of the 1st stage of the filter. It has
a 5.5kΩ impedance, and it can be overridden with an
external low impedance voltage source.
4
U
U
U
660025i
LINER [ LINEAR TECHNOLOGY ]
