Microchip Technology SA5 Series, User Manual

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MAC-SA5X User’s Guide
DS50002938A-page 12
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2019 Microchip Technology Inc.
output with an externally applied 1PPS reference signal. The PPS input is
selected via digital interface. Default input is PPS0-IN.
1.2.3 Output Connections
• 10 MHz RF Output: One CMOS output is available on pin 3.
• 1PPS Output: A single differential LVDS 1PPS output is available on pins
J1-17, 19.
• Built-In Test Equipment (BITE): An active-low CMOS output on pin 6 signifies
that the MAC has achieved atomic lock.
• Alarm Output: An active-low CMOS output on pin J1-20 indicates if an alarm
condition is present. The user can read the Alarm bits through the USB/Serial
interface to determine which alarm was triggered.
1.2.4 Power and Ground Connections
The MAC is not equipped with a power switch. DC power is applied on pin 5 with
ground pins located on pins 2 and 4. If the J1 connector is used, pins J1-8, J1-9, and
J1-15 should be grounded. Remaining pins should remain as “No Connect” (NC)
unless indicated otherwise in
Figure 1-3 . If J1 connector is unused, all pins should
remain as “No Connect”.
Recommendation: It is recommended to tie ground (Pin 4) to same node as the
baseplate ground Pin 2.
1.3 FUNCTIONAL DESCRIPTION
Communication Ports
These ports can be used to configure the MAC with Microchip’s C3 software com-
mands using a terminal or a computer with terminal emulation software. The default
settings for the serial port are:
• Baud = 57.6K
• Data Bits = 8 bits
• Parity = None
• Stop bits = 1
• Flow Control = None
Commands allow the user to:
• Turn Analog tuning on or off
• Digitally adjust the output frequency
• Configure 1PPS Disciplining settings
• Query the MAC’s health/lock/alarm status
• Configure the Time of Day
Analog Tuning Input
Analog tuning is a means of steering the MAC's output frequency by applying a DC tun-
ing voltage to Pin 1. This is useful for legacy applications where digital frequency steer-
ing is not possible.
1PPS Inputs
The MAC offers two selectable 1PPS inputs for use in steering the output RF (and
1PPS Output, simultaneously). PPS_Input_0 (pins J1-5,7) and PPS_Input_1 (pin
J1-1,3) are selectable with the
PpsSource
parameter. Their 1PPS Disciplining set-