7. INTERNAL STRUCTURE
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7 Internal structure
This section gives an overview of the internal structure of a Vision 312 device.
7.1 Temperature sensors
To allow monitoring of the internal temperature, the Vision 312 device is equipped with two temperature
sensors. One measures the ambient air temperature within the housing (PCBA sensor). The other sensor
is integrated in the i.MX6 CPU to measure the core temperature (on-die sensor).
7.1.1 Characteristics
Symbol
Parameter
Note
Min
Max
Unit
T
op
Measure temperature range
-40
+125
○
C
T
PCBA, acy
PCBA sensor temperature accuracy
at -25
○
C to 100
○
C
-2
+2
K
T
PCBA, acy
PCBA sensor temperature accuracy
at -55
○
C to 125
○
C
-3
+3
K
T
on-die, acy
On-die sensor accuracy
1
-7
+7
K
7.2 Speaker
A loudspeaker is mounted within the Vision 312 housing. It is activated via software.
7.2.1 Characteristics
Symbol
Parameter
Min
Max
Unit
SPL
Sound pressure level, 0.5 m distance, from freely mounted
housing
t.b.d.
dBA
7.3 Real-time clock (RTC)
The Vision 312 device includes a real-time clock with a backup power system. When the device is con-
nected to the vehicle’s battery via the main connector’s (C1) BAT+ pin, the real-time clock is supplied by
the vehicle’s battery regardless of whether the device is operational or not.
If the BAT+ pin is disconnected, the real-time clock is supplied by an internal super-capacitor. The super-
capacitor provides approximately 14 days of backup time, if fully charged. The capacitor is charged to 90%
after 2 hours, and fully charged after 5 hours. It is charging if the BAT+ pin is connected to the vehicle’s
battery.
© TTControl GmbH 2020. All rights reserved.
Confidential and Proprietary Information
31
Document Number:
D-156-G-02-001
