beautypg.com

Aes3 input, Power supply – Grass Valley 8920MUX User Manual

Page 43

background image

8920MUX Instruction Manual

43

Functional Description

CPU

The CPU embedded processor provides the interface between the user and
all the processing logic inside 8920MUX, as well as communication
between a host processor and the 8920MUX.

The CPU also contains:

FLASH memory – stores data for FPGA programming and configura-
tion,

Address decoder,

Address Latch,

Extended address register for FLASH memory,

EEPROM – Stores calibration and user setup data,

Network interface, and

ISP voltage regulator

AES3 Input

The 8920MUX board has two audio inputs that can be configured to be
either AES3, 110 ohm balanced with rear connector adapter, or two AES3id,
75 ohm unbalanced coax BNC connectors. Refer to

Figure 4 on page 11

.

The audio input signal passes through the AES3 input processor and
re-clocker before it is multiplexed.

Power Supply

From the external source +12V, the on-board supply provides +5 V, -5 V and
+3.3 V for the 8920MUX. The power supply uses a monolithic switching
power supply operating in Buck mode. Buck mode switching regulators
are used to generate a lower voltage from higher voltage input. If the
supply ever activates its protective crow bar diode, a high current will be
developed and the input fuse, F1 will blow.