ATA6622-EK Atmel, ATA6622-EK Datasheet - Page 6

• Manufacturer Part Number: ATA6622-EK
• Description: BOARD DEMO LIN SBC FOR ATA6622
• Manufacturer: Atmel

Specifications of ATA6622-EK

• Main Purpose: Interface, LIN
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: ATA6622
• Primary Attributes: LIN-SBC (System-Basis-Chip) Transceiver, LIN 2.0, Voltage Regulator, Window Watchdog
• Secondary Attributes: 4 Power Modes: Pre-Normal, Normal, Sleep, Silent, 20-QFN
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

2.4
2.4.1
2.4.2
2.4.3
2.5
2.6
6
LIN Interface (LIN, TXD and RXD)
Temp Pin (TEMP) (Atmel ATA6621 Only)
Mode and TM Input Pins (MODE and TM)
Atmel ATA6621/22/24/26
Bus Pin (LIN)
Input Pin (TXD)
Output Pin (RXD)
A low-side driver with internal current limitation and thermal shutdown as well as an internal
pull-up resistor in compliance with the LIN specification 2.0 is implemented. LIN receiver
thresholds are compatible with the LIN protocol specification.
At the LIN pin there is a 220-pF capacitor to ground on the board. Additionally, when using the
development board for a LIN master application, there is the opportunity to mount the two nec-
essary extra components diode D2 (LL4148) in series with resistor R1 (1k ) on the board at
their designated placeholders.
In Normal Mode this pin is the microcontroller interface to control the state of the LIN output.
TXD must be pulled to ground in order to have the LIN bus low. If TXD is high, the LIN output
transistor is turned off and the bus is in the recessive state, pulled up by the internal resistor. If
TXD is low, the LIN output transistor is turned on and the bus is in the dominant state.
An internal timer prevents the bus line from being driven permanently in the dominant state. If
TXD is forced to low longer than t
state. This time-out function is disabled in the Atmel ATA6626.
This pin reports the state of the LIN bus to the microcontroller. LIN high (recessive state) is
reported by a high level at RXD, LIN low (dominant state) is reported by a low level at RXD.
The output has an internal pull-up resistor with typ. 5k to VCC. The output is short-circuit
protected.
Besides the internal temperature monitoring of the voltage regulator, an additional sensor
measures the junction temperature and provides a linearized voltage at the TEMP pin.
Together with the analog functions of the microcontroller (for example, the analog comparator
and/or the analog-to-digital converter), this enables the application to detect overload condi-
tions. Further actions in order to prevent the IC from damage can be implemented.
The TM input is only used for Atmel
directly to GND. The Mode input is pulled to GND by the 4.7-k resistor R1 and therefore the
watchdog is active in the normal operation mode. Especially during the early development
phase it can be helpful to have the possibility to deactivate the watchdog in order to debug the
application program without disturbing RESETS caused by the watchdog. Therefore the
watchdog can be switched off by connecting the MODE pin to VCC externally.
DOM
> 20ms, the LIN bus driver is switched to the recessive
®
internal-testing purposes and therefore connected
4970B–AUTO–03/11