msx532 Fairchild Semiconductor, msx532 Datasheet - Page 34

• Manufacturer Part Number: msx532
• Description: 532 Port Digital Crosspoint Switch With Lvttl I/o S
• Manufacturer: Fairchild Semiconductor

www.fairchildsemi.com
Package Thermal Characteristics
Thermal performance values are based on simulation data
Power Consumption
There are three components to consider when calculating power for the MSX Family of devices:
1. Steady State Component:
2. Connection Component:
3. Output Drive Component:
Glossary
Array Side: The signal and connections between the Cros-
spoint Array and the I/O Buffer.
Bus Repeater: A circuit operation of the I/O Buffer that
enables the MSX device to pass data in both directions on
an I/O device pin. The I/O Buffer is placed in a disabled
output state to the pin and to the Crosspoint array. A forced
LOW on either side of the I/O Buffer will be transmitted to
the other side of the I/O Buffer and held until the forced
LOW is changed to a force HIGH. At the change of the
forcing input, the I/O Buffer will force the other side to a fol-
lowing high state and drive a high level out for a period of
time. After the period of time, the I/O Buffer will return to
the disabled state.
Bypass: A JTAG instruction that connects the previous
chip to the next chip through a one bit data register to
speed up programming of other chips in a JTAG chain of
devices.
Clock: Four device corner inputs used to gate data into
registers in the I/O Buffer. The Corner inputs serve two
sides of the MSX. This provides two choices for each I/O
Buffer register in and register out. The neighbor input can
also be used as register clock and the clocks can be
inverted.
Control Register: A programmable register used to con-
trol various functions in programming and other circuit set-
tings.
This element equals 252 mW.
This element equals 0.006 mW x Mb/s x connections.
This element equals 0.013 mW x number of outputs x Mb/s x capacitive load (pF).
Package
Power Consumption
The following examples shows the total power consumption as determined by the above formula:
Example 1
Using the MSX532 with 10 Mb/s into a 10pF load with 266 inputs connected to 266 outputs:
Power Consumption
Example 2
Using the MSX532 with 150 Mb/s into a 10pF load with 266 inputs connected to 266 outputs:
Power Consumption
TBGA
All
Bits
programmed
Pin Count
792
Steady State Component
252 mW + (0.006 x Mb/s x #connections) + (0.013 x Mb/s x #outputs x Cload)
252 mW + (0.006 x 10 x 266) + (0.013 x 266 x 10 x 10)
252 mW
252 mW + (0.006 x 150 x 266) + (0.013 x 266 x 150 x 10)
252 mW
in
TABLE 12. Package Thermal Characteristics
the
JC
0.4
( C/W)
+
+
JTAG
16 mW
239.4 mW
Mode.
JA
Still Air
7.58
( C/W)
34
Connection Component
+
RapidConfigure Enable bit can be set with a high level on
the RCE pin during a reset of the circuits.
Crosspoint: A single cell containing two N Channel tran-
sistors and two RAM bits. The RAM bits are connected in a
master-slave configuration to provide an update for pro-
gramming and changing program information all at once.
Each cell contains both an X and Y reset to remove all
ports connected to an addressed port in a single program
cycle.
Crosspoint Array: An array of Crosspoint used to connect
any port to any other port or any combination of other ports.
The array has all redundant cell removed; there is a single
Crosspoint cell for each port to port connection. The
reduced cell count is folded to provide a square array. The
array has a diagonal line where the cells are rotated.
Data Bit Lines: A pair of signal lines used to write into and
read out of Crosspoint Cells. The lines are pre-charged
before a read and one is pulled LOW for a write.
Device ID: A 32-bit register in the MSX device with a wired
identification. The ID consists of a given number for the
device and a revision history field. The identification is
shifted out during JTAG reset and the DEVICE ID instruc-
tion in JTAG mode. The ID for the MSX devices is
0x0000A89F.
+
346 mW
5187 mW
200 Ifpm
JA
6.00
( C/W)
= 0.614 Watts
Output Drive Component.
= 5.68 Watts
300 Ifpm
JA
5.66
( C/W)
500 Ifpm
JA
5.26
( C/W)