MAX4550CAI+T Maxim Integrated Products, MAX4550CAI+T Datasheet - Page 10

• Manufacturer Part Number: MAX4550CAI+T
• Description: IC CROSSPOINT SWITCH DUAL 28SSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX4550CAI+T

• Function: Audio/Video Crosspoint Switch
• Circuit: 2 x 4:2
• On-state Resistance: 100 Ohm
• Voltage Supply Source: Single, Dual Supply
• Voltage - Supply, Single/dual (±): 2.7 V ~ 5.5 V, ±2.7 V ~ 5.5 V
• Current - Supply: 7µA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 28-SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Serially Controlled, Dual 4x2, Clickless
Audio/Video Analog Crosspoint Switches
The MAX4550/MAX4570 are serial-interface, program-
mable, dual 4x2 audio/video crosspoint switches. Each
device contains two independent 4x2 crosspoint
switches, controlled through the on-chip serial inter-
face. The MAX4550 uses a 2-wire I
communications protocol, while the MAX4570 uses a
3-wire SPI/QSPI/MICROWIRE-compatible serial com-
munications protocol.
These ICs include four controllable auxiliary outputs,
each capable of sourcing 1mA or sinking 12mA. Also
included are four selectable bias-resistor networks (one
for each output) for use with AC-coupled input signals.
Both devices operate with either ±5V dual supplies or a
single +5V supply, and are optimized for use in the
audio frequency range to 20kHz and at video frequen-
cies up to 4MHz. They feature 80Ω on-resistance, 10Ω
on-resistance matching between channels, 5Ω on-
resistance flatness, and as low as 0.004% total harmon-
ic distortion.
The MAX4550/MAX4570 offer better than -110dB of
audio off-isolation, -95dB of audio crosstalk, -78dB of
video off-isolation, and -54dB of video crosstalk
(4MHz). The SA and SB (shunt) inputs further improve
off-isolation, allowing for the addition of external shunt
capacitors or the connection of outputs to AC grounds.
These devices feature a clickless operation mode for
noiseless audio switching. Clickless or standard switch-
ing mode is selectable for each individual output using
the serial interface.
__________ Applications Information
The MAX4550/MAX4570 are divided into five functional
blocks: the control-logic block, two switch-matrix
blocks, the bias-resistor block, and the auxiliary-output
block (see Functional Diagram ). The control-logic block
accepts commands via the serial interface and uses
those commands to control the four remaining blocks.
The devices are programmed through their serial inter-
face with a command byte followed by a data byte.
Each bit of the command byte selects one of the func-
tional blocks to be controlled by the subsequent data
byte. The data byte sets the state of the selected
block(s). For the two switch-matrix blocks, the data
byte sets the switch state. For the bias-resistor block,
the data byte controls which bias network is active. For
the auxiliary-output block, the data byte programs the
state of the four auxiliary outputs (see Functional
Diagram ).
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Command-Byte and Data-Byte
Detailed Description
2
C-compatible serial
Programming
A logic “1” in any bit position of the data byte makes
that function active, while a logic “0” makes it inactive.
Tables 1–4 describe the command byte and the corre-
sponding data byte. For example, if bit C4 of the com-
mand byte is set, the subsequent data byte programs
the state of the auxiliary outputs. If bits D0 and D2 of
the subsequent data byte are set, Q0 and Q2 outputs
are set high. If more than one bit of the command byte
is set, the data byte programs all of the corresponding
blocks. This operation is useful, for instance, to simulta-
neously set both switch matrices to the same configura-
tion. Any block that is not selected in the command
byte remains unchanged.
Table 1. Command-Byte Format
Table 2. COM Data-Byte Format
(C0, C1, C2, C3 = “1”)
BIT
D7
D6
D5
D4
D3
D2
D1
D0
BIT
C7
C6
C5
C4
C3
C2
C1
C0
Don’t care
Don’t care
Don’t care
Controls the switch connected to S_ ;
1 = close switch, 0 = open switch.
Controls the switch connected to NO4_ ;
1 = close switch, 0 = open switch.
Controls the switch connected to NO3_ ;
1 = close switch, 0 = open switch.
Controls the switch connected to NO2_ ;
1 = close switch, 0 = open switch.
Controls the switch connected to NO1_ ;
1 = close switch, 0 = open switch.
Don’t care
Don’t care
BIAS/MODE
AUX
COM2B
COM1B
COM2A
COM1A
DESCRIPTION
REGISTER