Motor driver ICs
2-phase half-wave motor driver
BA6809F / BA6819AF
The BA6809F and BA6819AF are motor drivers designed for 3V and 5V fan motors. Built-in output transistors reduce
the number of external components required. The ICs have an alarm output pin (BA6809F) and Hall output pin
Fan motors
1) Lock detection and rotational speed sensing mechanisms are built in.
2) Alarm output pin (BA6809F) and Hall output pin
Absolute maximum ratings (Ta = 25C)
Recommended operating conditions (Ta = 25C)
3) Built-in thermal shutdown circuit.
4) Operation assured with a supply voltage as low as
5) Compact 8-pin SOP package.
Motor driver ICs
BA6809F / BA6819AF
Block diagram
Pin descriptions
Hall input / output truth table
Motor driver ICs
Input / output circuits
Electrical characteristics (unless otherwise noted, Ta = 25C and VCC = 3V)
BA6809F / BA6819AF
Motor driver ICs
BA6809F / BA6819AF
FCircuit operation
The BA6809F and BA6819AF have motor lock detection
and automatic restart circuits. The timing of lock detection and automatic restart is determined by the external
capacitor connected to the LD pin. The charge time of the
external capacitor is given by :
ton (Charge time)=
toff (Discharge time)=
(Typical value)
VLDCL is the LD-pin clamp voltage
VLDCP is the LD-pin comparator voltage (0.73V),
ILDC is the LD-pin charge current
ILDD is the LD-pin discharge current
C is the capacitance of the LD-pin external capacitor.
For C=0.47µF, for example, the charge and discharge
times are 0.25s (output ON) and 1.31s (output OFF), respectively.
FApplication example
Motor driver ICs
Operation notes
(1) Thermal shutdown circuit
The IC has a built-in thermal shutdown circuit. The is a
temperature difference of 20C (typical) between the
temperatures at which the circuit is activated and deactivated.
The circuit is activated at the temperature of about 175C
(typical), so that all outputs are turned OFF. Normal operation resumes when the circuit is deactivated.
(2) Power dissipation
Power consumed in the IC can be calculated from the following equation :
PC1 is power consumed by the circuit current.
PC2 is the output current consumption.
VOL is the LOW level output voltage of output pins
1 and 2, and IO is the sink current of pins 1 and 2.
PC3 is power consumed by the AL and HO pins.
PC3=VHOL IHO / 2 (BA6819AF)
VALL is the AL-pin LOW level voltage,
IAL is the AL-pin sink current,
VHOL is the HO-pin LOW level voltage,
IHO is the HO-pin sink current.
Make sure that your application does not exceed the allowable power dissipation of the IC.
BA6809F / BA6819AF
Hall amplifier input voltage
The R1 and R2 resistances must be set so as to maintain
the Hall amplifier input bias voltage within the range of 0V
to (VCC*2V) including the signal amplitude.
The Hall device may be affected by power supply noise
due to the PCB conductor pattern. If you have this problem, insert a capacitor C1 as shown in Fig. 5.
If the conductor lines from the Hall device output terminals to the Hall inputs of the IC are particularly long, noise
can be picked up and fed into the inputs. If you have this
problem, insert a capacitor C2 as shown in Fig. 5. Note
that the Hall inputs have no hysteresis in this IC.
Hall current is given by=
where RH is the Hall device impedance.
Motor driver ICs
BA6809F / BA6819AF
External dimensions (Units: mm)