ATA6830-PKHW Atmel, ATA6830-PKHW Datasheet - Page 6

• Manufacturer Part Number: ATA6830-PKHW
• Description: Motor / Motion / Ignition Controllers & Drivers IC Automotive for Headlamp Adjustment
• Manufacturer: Atmel
• Type: 2 Phase Stepper Motor Driverr

Specifications of ATA6830-PKHW

• Product: Stepper Motor Controllers / Drivers
• Operating Supply Voltage: 7 V to 20 V
• Supply Current: 7 mA
• Mounting Style: SMD/SMT
• Package / Case: QFN-28
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

3.3
Figure 3-3.
3.4
6
Stepping Motor Driver
Data Communication
ATA6830
Stepper Motor Control
Reset
Clk
H-bridge Driver Stage
Figure 3-3
PMOS power transistors. An external shunt is used for measuring the current flowing through
the motor coil. Additional comparators and current sensing circuitry is integrated for error
detection.
The circuit receives all commands for the stepping motor via a single wire bus. In idle mode the
bus pin is pulled up by an internal current source near to VBAT voltage. During the transmission
the external transmitter has to pull down the bus level to send information about data and clock
timing. The used baud rate has to be about 2400 baud. Because of oscillator tolerances a syn-
chronization sequence has to be sent at the beginning of data transfer.
Figure 3-4 on page 7
sequences for adjusting the internal bit time. Later on during data transfer every 1-0-1-0
sequence coming up randomly is used for resynchronization. Thus all tolerances that occur dur-
ing operation will be eliminated.
To obtain a synchronization of up to 15% oscillator tolerance the pattern has to be sent at least 4
times.
shows the diagram of one H-bridge driver stage. It consists of two NMOS and two
SM1x
Driver Logic
VBAT
shows the pattern used for this sequence. The circuit uses the 1-0-1-0
SRx
Shunt
SM2x
Vref
Error Signals
Temperature
Temperature
Shutdown
Warning
Temp. Shutdown
Temp. Warning
4575D–BCD–09/05