attiny167-esxz ATMEL Corporation, attiny167-esxz Datasheet - Page 180

• Manufacturer Part Number: attiny167-esxz
• Description: 8-bit Avr 8-bit Microcontroller Microcontroller With 16k Bytes In-system Programmable Flash And Lin Controller
• Manufacturer: ATMEL Corporation

16. ISRC - Current Source
16.1
16.2
16.2.1
180
Features
Typical applications
ATtiny167
LIN Current Source
•
•
The ATtiny167 features a 100µA ±6% Current Source. After RESET or up on request, the
current is flowing through an external resistor. The voltage can be measured on the dedicated
pin shared with the ADC. Using a resistor in serie with a ≤0.5% tolerance is recommended. To
protect the device against big values, the ADC must be configured with AVcc as internal refer-
ence to perform the first measurement. Afterwards, another internal reference can be chosen
according to the previous measured value to refine the result.
When ISRCEN bit is set, the ISRC pin sources 100µA. Otherwise this pin keeps its initial
function.
Figure 16-1. Current Source Block Diagram
During the configuration of a LIN node in a cluster, it may be necessary to attribute dynamically
an unique physical address to every cluster node. The way to do it is not described in the LIN
protocol.
The Current Source offers an excellent solution to associate a physical address to the applica-
tion supported by the LIN node. A full dynamic node configuration can be used to set-up the LIN
nodes in a cluster.
ATtiny167 proposes to have an external resistor used in conjunction with the Current Source.
The device measures the voltage to the boundaries of the resistance via the Analog to Digital
converter. The resulting voltage defines the physical address that the communication handler
will use when the node will participate in LIN communication.
100µA Constant current source
± 6% Absolute Accuracy
ADC Input
100 uA
AVCC
ISRCEN
ADCn/ ISRC
External
Resistor
7728A–AUTO–07/08