MAX4111/MAX4121/MAX4221
330MHz Buffered Video Switches/
Crosspoint Building Blocks
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7
_______________Detailed Description
The MAX4111/MAX4121/MAX4221 video switches are
manufactured with Maxim’s proprietary, ultra-high fre-
quency, complementary bipolar process that yields
high bandwidth and low capacitance. Make-before-
break switching is used to reduce noise and glitches,
even when switching from part to part in large arrays.
The input buffers provide a constant high input imped-
ance, and prevent the make-before-break action from
feeding back to the input.
The design of the switching mechanism limits the
inevitable glitch to less than 13mVp-p. In addition, the
glitch pulse is positive to avoid confusion with negative
sync pulses.
Unity-gain buffers isolate other inputs from the switch-
ing action of large multiplex arrays. These buffers can
drive 5k
resistive loads. In addition, these devices
drive capacitive loads without oscillation. Load capaci-
tance is limited only by system bandwidth require-
ments.
The MAX4111/MAX4121/MAX4221 do not contain
buffer latches. The digital inputs are transparent.
______________________________________________________________Pin Description
MAX4221
MAX4121
MAX4111
15, 16
11, 13
9, 10
—
14
12
—
6, 8
—
1, 3
—
2, 4, 5, 7
PIN
—
8
7
5
6
—
2, 4
—
1
3
Logic Inputs. Channel Selection Bits for OUT0 of the dual 2x1 (MAX4221). See
Table 3.
SEL1,
SEL0
—
Signal Outputs
OUT1,
OUT0
—
Logic Inputs. Channel Selection Bits for OUT1 of the dual 2x1 (MAX4221).
See Table 3.
SEL3,
SEL2
—
Logic Input. Output Enable for the 1x1, 2x1 switches. A logic high on this
pin enables the output. A logic low causes the output to assume a high-
impedance state, and reduces supply current.
EN
8
Positive Power-Supply Voltage. Connect to +5V. Decouple to power ground.
VCC
7
Negative Power-Supply Voltage. Connect to -5V. Decouple to power ground.
VEE
5
Signal Output
OUT
6
Signal Inputs for the dual 2x1 switch
IN2, IN3
—
Signal Input
IN
2
Signal Input
IN0, IN1
—
No Connect—not internally connected
N.C.
4
Logic Input. Channel Selection Bit for the 2x1. See Table 2.
A0
—
Analog (signal) ground. Since inputs are isolated by these grounds, GND
should be as noise-free as possible.
GND
1, 3
FUNCTION
NAME
