MAX4357ECD+D Maxim Integrated Products, MAX4357ECD+D Datasheet - Page 32

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

Specifications of MAX4357ECD+D

• 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
• Other names: MAX4357ECD+; MAX4357ECD+

driven externally, the analog output buffers are latched
into a high-impedance state. After RESET is released,
the output buffers remain disabled. The outputs may be
enabled by sending a new 112-bit data word or a 16-bit
individual output address word. A reset is initiated from
any of three sources. RESET can be driven low by
external circuitry to initiate a reset, or RESET can be
pulled low by internal circuitry during power-up (power-
on reset) or thermal shutdown.
Since driving RESET low only clears the output-buffer-
enable bit in the matrix control latches, RESET can be
used to disable all outputs simultaneously. If no new
data has been loaded into the 112-bit Complete Matrix
Mode register, a single UPDATE restores the previous
matrix control settings.
The power-on reset ensures all output buffers are in a
disabled state when power is initially applied. A V
voltage comparator generates the power-on reset.
When the voltage at V
on-reset comparator pulls RESET low via internal cir-
cuitry. As the digital-supply voltage ramps up crossing
2.5V, the MAX4357 holds RESET low for 40ns (typ).
Connecting a small capacitor from RESET to DGND
extends the power-on-reset delay. (see the RESET
Delay vs. RESET Capacitance graph in the Typical
Operating Characteristics) .
32 x 16 Nonblocking Video Crosspoint Switch
with I/O Buffers
32
Table 2. 16-Bit Serial Control Word Bit Assignments (Mode 0: Individual Output
Address Mode)
15 (MSB)
0 (LSB)
______________________________________________________________________________________
BIT
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Output Address B3
Output Address B2
Output Address B1
Output Address B0
Input Address 4
Input Address 3
Input Address 2
Input Address 1
Input Address 0
IC Address A3
IC Address A2
IC Address A1
IC Address A0
Output Enable
DD
Gain Set
NAME
is less than 2.5V, the power-
X
Power-On Reset
Don’t care
MSB of selected chip address
MSB of selected chip address
MSB of selected chip address
LSB of selected chip address
MSB of output buffer address
MSB of output buffer address
MSB of output buffer address
LSB of output buffer address
Enable bit for output, 0 = disable, 1 = enable
Gain select for output buffer, 0 = gain of +1V/V, 1 = gain of +2V/V
MSB of input channel select address
MSB of input channel select address
MSB of input channel select address
MSB of input channel select address
LSB of input channel select address
DD
The MAX4357 features thermal shutdown protection
with temperature hysteresis. When the die temperature
exceeds 150°C, the MAX4357 pulls RESET low, dis-
abling the output buffer. When the die cools by 20°C,
the RESET pulldown is deasserted, and output buffers
remain disabled until the device is programmed again.
The MAX4357 can be easily used to create larger
switching matrices. The number of ICs required to
implement the matrix is a function of the number of
input channels, the number of outputs required, and
whether the array needs to be nonblocking.
The most straightforward technique for implementing
nonblocking matrices is to arrange the building blocks
in a grid. The inputs connect to each vertical bank of
devices in parallel with the other banks. The outputs of
each building block in a vertical column connect
together in a wired-OR configuration. Figure 6 shows a
128-input, 32-output, nonblocking array using eight
MAX4357 crosspoint devices.
Building Large Video-Switching Systems
FUNCTION
Applications Information
Thermal Shutdown