![Inrevium TB-FMCL-MIPI Скачать руководство пользователя страница 15](http://html1.mh-extra.com/html/inrevium/tb-fmcl-mipi/tb-fmcl-mipi_hardware-user-manual_2065190015.webp)
TB-FMCL-MIPI Hardware User Manual
15
Rev.3.01
7.3. LDO regulators
There are two Texas Instruments TPS74701 LDO regulators that are used to support the MIPI PHY
devices. The 1.2V regulator will need to supply up to 30mA to two PHY devices core supply in full
operation, and the 2.5V regulator will supply up to 60mA to two PHY devices IO supply in full operation.
In addition to the PHYs, the 2.5V regulator may also see an additional 72mA maximum loading from all
MIPI GPIO and 4.5mA maximum loading from MIPI I2C pullups if 2.5V is selected as the IO voltage
option for all the MIPI GPIO and I2C ports. Note that the TPS74701 requires a bias voltage of 1.3V
greater than the
output
voltage, thus the 2.5V regulator requires a bias input of at least 3.8V. Since
there is no 5V rail available, the bias input is generated by a zener diode from the FMC 12V power. The
zener regulation system draws 4.6mA (typ) to account for Bias current variation while still providing
sufficient reverse zener current to establish a stable voltage of approximately 4.3V.
The regulators each provide a Power-Good output; these open-collector outputs are tied together and
used as the control for the shared 2.5V and 1.2V LED indicator D4.
7.4. LED Power Indicators
A series of six green LEDs are located in a row on Side 2 (solder side) so they are visible when the card
is installed on an FMC carrier. The LEDs indicate the presence of the various supply rails, and under
normal conditions, all six LEDs should be lit when the card is powered-up. The following diagram of the
solder side displays the row of LEDs and their meaning:
1
2
V
0
3
V
3
3
V
3
_
V
A
U
X
2
V
5
&
1
V
2
V
A
D
J
V
U
S
E
R
Figure 7-3 Power LEDs Identification
8. MIPI PHY Device to FMC Interface
8.1. PHY Device Overview
The PHY devices are produced by Meticom GmbH in both Receiver (MC20901) and Transmitter
(MC20902) versions. The devices draw very little power in operation and do not require any special
cooling considerations. The Meticom chip pinouts are designed to be mirrored between the Transmitter
(DSI) device, and Receiver (CSI-2) device. This permits a direct top-bottom PCB placement of the two
types while maintaining a fixed order and polarity of the MIPI differential pairs running to the connector.
This avoids signal integrity measures that would otherwise be needed in layout design to support the
dual CSI-2 or dual DSI assembly options.
8.2. HS Mode Interface
The FMC HS interface to the PHY devices consists of five differential pairs per MIPI port, totaling 10 IO
pins each. These signals are termed by Meticom as LVDS HS(0-4) and are the high-speed data
connection that carries MIPI payload data at up to Gb/s speeds. Typically, four lanes are assigned as