MAX4359/MAX4360/MAX4456
Low-Cost 4x4, 8x4, 8x8
Video Crosspoint Switches
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Power-On RESET
The MAX4359/MAX4360/MAX4456 have an internal
power-on reset (POR) circuit that remains low for 5µs
after power is applied. POR also remains low if the total
supply voltage is less than 4V. The POR disables all
buffer outputs at power-up, but the switch matrix is
not preset to any initial condition. The desired switch
state should be programmed before the buffer outputs
are enabled.
Digital Interface
The desired switch state can be loaded in a parallel-
interface mode or serial-interface mode (Table 3 and
Figures 4, 5, 6). All action associated with the WR line
occurs on its rising edge. The same is true for the
LATCH line if EDGE/LEVEL is high. Otherwise, the sec-
ond-rank registers update while LATCH is low (when
EDGE/LEVEL is low). WR is logically ANDed with CE
and CE (when present) to allow active-high or active-
low chip enable.
6-Bit Parallel-Interface Mode
(MAX4359/MAX4360)
In the MAX4359/MAX4360’s parallel-interface mode
(SER/PAR = GND), the six data bits specify an output
channel (A1, A0) and the input channel to which it con-
nects (D3–D0). This data is loaded on the rising edge
of WR. The input channels are selected by codes 0000
through 0111 (D3–D0) for the MAX4360, and codes
0000 through 0011 (D3–D0) for the MAX4359. Note that
the MAX4359 does not use codes 0100 through 0111.
The eight codes 1000 through 1111 control other func-
tions, as listed in Table 1.
7-Bit Parallel-Interface Mode (MAX4456)
In the MAX4456’s parallel-interface mode (SER/PAR =
GND), the seven data bits specify an output channel
(A2, A1, A0) and the input channel to which it connects
(D3–D0). This data is loaded on the rising edge of WR.
The input channels are selected by codes 0000
through 0111 (D3–D0) for the MAX4456. The remaining
eight codes 1000 through 1111 control other functions,
as listed in Table 1.
16-Bit Serial-Interface Mode
(MAX4359/MAX4360)
In serial mode (SER/PAR = V
CC
), all first-rank registers
are loaded with data, making it unnecessary to specify
an output address (A1, A0). The input data format is
D3–D0, starting with OUT0 and ending with OUT3 for
16 total bits. For the MAX4360, only codes 0000
through 1010 are valid. For the MAX4359, only the
codes 0000 through 0011 and codes 1000 through
1010 are valid. Code 1010 disables a buffer, while
code 1001 enables it. After data is shifted into the 16-
bit first-rank register, it is transferred to the second rank
by LATCH (Table 2), which updates the switches.
Table 1. Parallel-Interface Mode Functions
For the MAX4359, unused codes.0100 and 0111
Do not use these codes in the parallel-interface mode. These codes are for the serial-
interface mode only.
1001 and 1010
Send a pulse to the 2nd-rank registers to load them with the contents of the 1st-rank
registers. When latch is held high, this “software-LATCH” command performs the same
function as pulsing LATCH low.
1111
Turn on all buffers, and restore the connected channels.1110
Turn off all buffers, and leave 2nd-rank registers unchanged.1101
Turn on the buffer selected by A2–A0 (MAX4456) or A1–A0 (MAX4359/MAX4360, and
restore the previously connected channel.
1100
Shut off the buffer selected by A2–A0 (MAX4456) or A1–A0 (MAX4359/MAX4360) and
retain 2nd-rank registers contents.
1011
Connect the buffer selected by A2–A0 (MAX4456) or A1–A0 (MAX4359/MAX4360) to
DGND. Note, if the buffer output is on, its output is its offset voltage.
1000
Connect the buffer selected by A2–A0 (MAX4456) or A1–A0 (MAX4359/MAX4360) to the
input channel selected by D3–D0.
0000 to 0111
FUNCTIOND3–D0A2, A1, A0
Selects
Output
Buffer
