ATMEGA32M1-MU Atmel, ATMEGA32M1-MU Datasheet - Page 251

• Manufacturer Part Number: ATMEGA32M1-MU
• Description: MPU AVR 32K FLASH 20MHZ 32-QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA32M1-MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: CAN, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 11x10b; D/A 1x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of I /o: -

22. ISRC - Current Source
22.1
22.2
22.2.1
8209D–AVR–11/10
Features
Typical applications
LIN Current Source
•
•
The ATmega16M1/32M1/64M1 features a 100µA ±2% 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 recom-
mended. To protect the device against big values, the ADC must be configured with AVcc as
internal reference 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 22-1. 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.
100µA Constant current source
±2% Absolute Accuracy
AREF Internal Circuit
ADC Input
100 uA
AREFEN
AVCC
ISRCEN
ATmega16M1/32M1/64M1
AREF / ISRC
External
Resistor
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