ATA6844-DK Atmel, ATA6844-DK Datasheet - Page 5

• Manufacturer Part Number: ATA6844-DK
• Description: Power Management IC Development Tools BLDC Motor Drvr Brd
• Manufacturer: Atmel
• Type: Motor / Motion Controllers & Driversr

Specifications of ATA6844-DK

• Rohs: yes
• Product: Development Kits
• Tool Is For Evaluation Of: ATA6844, ATmega32M1, ATmega32U2
• Input Voltage: 3.3 V, 5 V, 12 V
• Description/function: Atmel ATA6844-DK BLDC Motor Control Kit
• Interface Type: LIN, UART, USB
• Factory Pack Quantity: 1

4. BLDC Motor Position Feedback
5. The Atmel System Basis Gate Driver ATA6843/ATA6844
5.1
9236A–AUTO–08/11
Cooling Area Design
The Atmel
back EMF feedback. The position feedback source can be selected by the jumpers J1, J2, and
J3.
The supplied firmware applies the back EMF feedback method as rotor position feedback.
Connecting Hall sensors to the application board is thus unnecessary. X5 pins 4 - 8 can be left
open.
Please refer to the Atmel application note “AVR928: Scalar Sensorless Methods to Drive
BLDC Motors” for more detailed theoretical information about back EMF.
The Atmel ATA6844 is designed for automotive applications requiring high-current BLDC
motors. The six gate drivers are capable of driving a wide range of n-channel power MOS-
FETs. To guarantee steady operation down to crank pulse, a double charge pump provides
the voltages for driving the external MOSFETs. Overvoltage lockout at 32V opens a wide
operating range beyond what is required for jump starts. Direct control of each gate output
allows the BLDC to be run in all different commutation shapes.
Diagnostic outputs immediately indicate instances of a short to battery or short to ground, pos-
sible at short circuit levels operated externally via the SCREF pin. Battery over-/undervoltage
conditions or charge pump failure are also indicated and instantaneously switch off the gate
driver outputs. In case of overtemperature, advance warning is indicated to drive into emer-
gency position or reduce power dissipation.
The COAST input pin acts as an emergency stop function. Applying this pin switches the out-
puts off instantaneously.
Dead time control is a protection feature. The CC (cross conduction) timer can be adjusted to
the switch on/off requirements of different external N-channel MOSFETs.
The Atmel ATA6844 includes a voltage regulator, LIN transceiver and window watchdog. The
SBC (System Basis Chip) capability of the Atmel ATA6844’s enables designs with a reduced
component list and limited PCB space.
The Atmel ATA6844 driver IC is housed in a QFN package. The QFN package is highly suit-
able for a power package because of the exposed die pad. The head slug must be completely
soldered to the PCB in order to take advantage of this feature.
To reduce thermal resistance, vias are necessary down to the soldering layer. A suitable
ground plane has to be placed on the soldering layer to dissipate thermal energy.
A via diameter of 0.3mm to 0.4mm and a spacing of 1mm to 1.5mm has proven to be the most
suitable. Some care should be taken about the planarity of the copper area; special care
should be taken to avoid all solder bumps at the thermal vias.
®
ATA6844-DK hardware offers the option not only of Hall sensor feedback but also
Atmel ATA6843/ATA6844
5