ATA6834-DK Atmel, ATA6834-DK Datasheet - Page 6

• Manufacturer Part Number: ATA6834-DK
• Description: BOARD BLDC MOTOR CTRL ATA6833/34
• Manufacturer: Atmel
• Type: MOSFET & Power Driverr

Specifications of ATA6834-DK

• Main Purpose: Power Management, Motor Control
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: ATA6833 / ATA6834, ATmega32M1
• Primary Attributes: 3-Ph BLDC, IC with FET Driver, LIN Transceiver, Volt Regulator, Watchdog
• Secondary Attributes: LCD with Touch Screen on MCU Controller Board
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4. System Basis Chip ATA6833/ATA6834
4.1
4.2
6
Cooling Area Design
Ground Area Design
BLDC Motor Control Kit with ATA6833/ATA6834
The ATA6833/ATA6834 is designed specifically for automotive applications that require
high-power BLDC motors. The six high current gate drivers are capable of driving a wide
range of n-channel power MOSFETs. To guarantee steady operation down to crank pulse, a
two-stage charge pump provides the voltages to drive the external MOSFETs. Direct control of
each gate output allows running the BLDC in different commutation shapes.
Diagnostic outputs immediately indicate short-to-battery, short-to-ground, battery over/under-
voltage conditions, charge pump failure and overtemperature prewarning. A dead time control
protection feature is also available
The SBC (System Basis Chip) enables designs with reduced component lists and limited PCB
space. The ATA6833/ATA6834 includes a Voltage Regulator, LIN transceiver and Window
Watchdog.
The driver IC ATA6833/ATA6834 is housed in a QFN package. QFN package is suitable for
power package due to the exposed die pad; however, ensure the heat slug is completely sol-
dered to the PCB.
To reduce thermal resistance, vias down to the soldering layer are necessary. A sufficient
ground plane has to be placed on the soldering layer to get rid of the thermal energy.
A via diameter of 0.3 mm to 0.4 mm and a spacing of 1 mm to 1.5 mm has proven to be most
suitable. Some care should be taken of the copper area’s planarity; in particular, avoid solder
bumps arising at the thermal vias.
The common ground reference point of the BLDC ECU (electronic control unit) is located
under the ATA6833/ATA6834. On the one side there is the Power Ground Plane, from the
ECU power input to the half-bridge foot point. On the other side there is the Digital Ground
Plane, including all the circuitry around the Gate Driver SBC. It’s reference point is the die pad
of the ATA6833/ATA6834.
The exposed die pad must be soldered completely. Through vias, the exposed die pad should
be connected with the ground layer. The two ground pins GND (11) and PGND (43) should be
connected directly to the die pad.
The N.C. pins (9, 10, 12, 14, 37, 45) are connected internally to the die pad and should also be
connected to GND.
The ATA6833/ATA6834 has a lot of regulation loops. To get good EMC performance, the
loops should be as short as possible.
The input capacitor at VBAT 100 nF and larger electrolytic capacitor should be connected
directly to the die pad of the ATA6833/ATA6834.
The ground of the VINT capacitor should be connected in star formation directly to the die pad
as well the VMODE pin depending on the VCC output voltage.
The ground of the logic part should be separated and also connected in star-formation directly
to the die pad. This is the complete microcontroller circuitry.
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