MAX4357ECD+TD Maxim Integrated Products, MAX4357ECD+TD Datasheet - Page 30

• Manufacturer Part Number: MAX4357ECD+TD
• Description: IC VIDEO CROSSPOINT SWIT 128TQFP
• Manufacturer: Maxim Integrated Products

Specifications of MAX4357ECD+TD

• Function: Video Crosspoint Switch
• Circuit: 1 x 32:16
• Voltage Supply Source: Single, Dual Supply
• Voltage - Supply, Single/dual (±): 5V, ± 3 V ~ 5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 128-TQFP, 128-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

32 x 16 Nonblocking Video Crosspoint Switch
with I/O Buffers
The MAX4357 offers 32 analog input channels. Each
input is buffered before the crosspoint matrix switch,
allowing one input to cross-connect up to 16 outputs.
The input buffers are voltage feedback amplifiers with
high-input impedance and low-input bias current. This
allows the use of very simple input clamp circuits.
The MAX4357 has 512 individual T-switches making a
32
nonblocking, which means that any input may be rout-
ed to any output. The switch matrix programming is
output referred. Each output may be connected to any
one of the 32 analog inputs. Any one input can be rout-
ed to all 16 outputs with no signal degradation.
The digital interface consists of the following pins: DIN,
DOUT, SCLK, AOUT, UPDATE, CE, A3–A0, MODE, and
RESET. DIN is the serial-data input, DOUT is the serial-
data output.
Table 1. Operation Truth Table
30
Note: "X" = Don’t Care
CE
1
0
0
0
0
X

______________________________________________________________________________________
16 switch matrix. The switching matrix is 100%
UPDATE
X
1
0
1
0
X
SCLK
X
↓
X
↓
X
X
DIN
D
D
D
X
X
X
i
i
i
Digital Interface
Switch Matrix
Analog Inputs
DOUT
D
i-112
D
D
X
X
X
i
i
MODE
X
1
1
0
0
X
AOUT
SCLK is the serial-data clock which clocks data into the
data input registers (Figure 3). Data at DIN is loaded in
at each falling edge of SCLK. DOUT is the data shifted
out of the 112-bit Complete Matrix Mode register (Mode
= 1). DIN passes directly to DOUT when in Individual
Output Address Mode (Mode = 0).
The falling edge of UPDATE latches the data and pro-
grams the matrix. When using Individual Output
Address Mode, the address recognition output AOUT
drives low when control-word bits D14 to D11 match
the address programming inputs (A3–A0) and UPDATE
is low (Table 1). Table 1 is the operation truth table.
The MAX4357 offers two programming modes:
Individual Output Address Mode and Complete Matrix
Mode. These two distinct programming modes are
selected by toggling a single MODE pin high or low.
Both modes operate with the same physical board lay-
out. This flexibility allows initial programming of the IC
by daisy-chaining and sending one long data word
while still being able to immediately address and
update individual outputs in the matrix.
X
1
1
1
0
X
RESET
1
1
1
1
1
0
No change in logic.
Data at DIN is clocked on negative edge of
SCLK into 112-bit Complete Matrix Mode
register. DOUT supplies original data in
112 SCLK pulses later.
Data in serial 112-bit Complete Matrix
Mode register is transferred into parallel
latches, which control the switching matrix.
Data at DIN is routed to Individual Output
Address Mode shift register. DIN is also
connected directly to DOUT so that all
devices on the serial bus may be
addressed in parallel.
4-bit chip address A3–A0 is compared to
D14–D11. If equal, remaining 11 bits in
Individual Output Address Mode register
are decoded, allowing reprogramming for
a single output. AOUT signals successful
individual matrix update.
Asynchronous reset. All outputs are
disabled. Other logic remains unchanged.
Programming the Matrix
OPERATION/COMMENTS