ATA6623-EK Atmel, ATA6623-EK Datasheet - Page 3

• Manufacturer Part Number: ATA6623-EK
• Description: BOARD DEMO LIN SBC FOR ATA6623
• Manufacturer: Atmel

Specifications of ATA6623-EK

• Main Purpose: Interface, LIN
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: ATA6623
• Primary Attributes: LIN-SBC (System-Basis-Chip) Transceiver, LIN 2.0, Voltage Regulator
• Secondary Attributes: 4 Power Modes: Pre-Normal, Normal, Sleep, Silent, 8-SOIC
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

2.3
2.3.1
2.3.2
2.3.3
2.4
4969B–AUTO–03/11
LIN Interface (LIN, TXD and RXD)
Undervoltage Reset Output (NRES)
Bus Pin (LIN)
Input Pin (TXD)
Output Pin (RXD)
A low-side driver with internal current limitation and thermal shutdown and 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. There is the possibility of
additionally mounting the two extra components diode D2 (LL4148) in series with resistor R1
(1k ) on the board at their designated placeholders, necessary when using the development
board for a LIN master application.
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
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 structure with typ. 5k resistance to VCC and is short circuit
protected.
In the Atmel
the VCC voltage falls below the undervoltage threshold, NRES switches to LOW after a
debounce time of approximately 2µs. The implemented undervoltage delay keeps NRES at a
low level for approximately 10ms after VCC reaches its nominal value.
In the Atmel ATA6623 and Atmel ATA6625, the Reset output is an open-drain output imple-
mented using a single MOS transistor which is switched on in the case of a VCC undervoltage.
In order to pull up the output of the Atmel ATA6623/25, an external resistor connected to VCC
is necessary. Space for this resistor (R2) is available on the development board .
If a reset occurs (NRES is low), the circuit switches to pre-normal mode.
®
ATA6620, the Reset output is a push-pull stage supplied by the VCC voltage. If
DOM
> 20 ms, the LIN bus driver is switched to the recessive state.
Atmel ATA6620/23/25
3