Power supply

The card can operate as stand alone devide, or plugged into a uTCA crate.

While working standalone payload power (12 V) is supplied through Molex Connector (39-28-1043) - J5. The pinout is shown below. 3.3 V management power, used to supply Managment CPU, is derived from payload power in this case. Managment CPU then enables power converters which convert 12 V to lower voltages needed by the board.

../_images/power_conn.svg

Power connector

When the card is mounted on top of the MCH, both 12 V payload power and 3.3 V management power is supplied through daughterboard connector. First, management power is supplied to the Managment CPU, which can negotiate enabling payload power with the MCH if hotswap handle is pushed in. After payload power is enabled, then Managment CPU enables power converters which convert 12 V to lower voltages needed by the board.

Note

Currently MCH that was tested (NAT MCH v3.5) always enables payload power.

Simplified power map is in figure below. All onboard voltages (exept P3V3_MP) can be enabled by Managment CPU. There are two types of power distributors, LDOs and LTM chip - quad channel digital Pulse Width Modulated (PWM) step down (buck) controller. These power supplies require no configuration besides enabling. LTM chip and all LDOs have connected Power Good outputs which Managment CPU reads to check if all power buses have the correct voltage.

Note

Please note that power consumption heavily depends on FPGA configuration.

  • Input voltage range: 10.8-13.2 [V]

  • The board needs active cooling. Approx. 20CFM in 20 C air.

../_images/power_map.svg

Power supply block schematic

Name

Voltage [V]

Maximum predicted current [A]

Current limit [A]

P0V95

0.95

12.0

20

P1V0

1.0

3.0

4

P1V2

1.2

0.6

1

P1V5

1.5

3.1

4

P1V8

1.8

3.7

4

P3V3

3.3

3.8

4

P3V3_MP

3.3

0.35

0.5

P5V0

5.0

0.9

2

Power up sequence

../_images/power_sequence.svg

Power up sequence is controlled entirely by the Managment CPU (apart from managent power). Sequence presented above is programmed into Managment CPU and is done according to various on-board chip requirements. Power down sequence is done in reverse.

Exar power converter

Metlino has pads for an alternative module with Exar power converter. Exar power converter was used in Sayma AMC v1.0 but had problems with voltage stability. For documentation on Exar and its configuration please consult v1.0 documentation.