SOM Power
Your carrier card should provide:
• The SOM main power supply (+5V power rail).
• The V
CCO
power rails for the programmable logic (PL) HPIO and HDIO banks on the K26
SOM.
• Optionally, the carrier card can supply an external battery power to the V
CC_BATT
pin for real-
time clock (RTC) battery backup power.
SOM Connector Power Pins
The following table lists all power rails required for the proper operation of the K26 SOM. The
carrier card designed for your application should provide these power rails based on the required
peripheral I/O voltage. These supplies must be intentionally sequenced as outlined in the
Table 9: SOM Power Rails
Power Rail
Name
Supported Voltage Range
Maximum
Current
Description
V
CC_SOM
5V (4.75V – 5.25V) 50 mV p-p
maximum noise
4A
Main power input to the SOM. Supplies power to
on-board power regulators.
V
CC_BATT
1.50V
External battery input for the RTC
V
CCO_HPA
1.00V – 1.80V
1.0A
Voltage rail for HPIO bank 66
V
CCO_HPB
1.00V – 1.80V
1.0A
Voltage rail for HPIO bank 65
V
CCO_HPC
1.00V – 1.80V
1.0A
Voltage rail for HPIO bank 64
V
CCO_HDA
1.20V – 3.30V
1.0A
Voltage rail for HDIO bank 45
V
CCO_HDB
1.20V – 3.30V
1.0A
Voltage rail for HDIO bank 43
V
CCO_HDC
1.20V – 3.30V
1.0A
Voltage rail for HDIO bank 44
For the selected I/O type, the supply voltage tolerance at the SOM connector must be within
+3%/–2%. For example:
• If an HPIO bank is configured for the LVDS (1.8V) standard, the V
CCO
at the SOM connector
pin must be within 1.764V–1.854V.
• If an HDIO bank is configured for the LVDS_25 standard, the V
CCO
at the SOM connector pin
must be within 2.450V–2.575V.
Chapter 2: Electrical Design Considerations
UG1091 (v1.0) April 20, 2021
Carrier Card Design for Kria SOM
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