Rohm BA6417F Reversible motor driver Datasheet

Motor driver ICs
Reversible motor driver
BA6289F / BA6417F
The BA6289F and BA6417F are reversible-motor drivers, with an output current of 600mA for the former and 1A for the
latter. Two logic inputs allow four output modes: forward, reverse, stop (idling), and brake. A built-in power saving circuit
suppresses current consumption when the motor is in stop mode.
Applications
Compact, low-current DC motors and portable equipment such as camcorders
Features
1) Two logic inputs allow four output modes: forward, reverse, stop (idling), and brake.
2) Built-in power saving circuit suppresses the stop
mode current dissipation.
3) Output voltage can be set arbitrarily with the Vref pin.
4) Interfaces with TTL devices.
5) Built-in thermal shutdown circuit turns off all circuits
when high IC junction temperature is detected.
Absolute maximum ratings (Ta = 25C)
Recommended operating conditions
453
Motor driver ICs
Block diagram
Pin descriptions
454
BA6289F / BA6417F
Motor driver ICs
BA6289F / BA6417F
Electrical characteristics of BA6289F (unless otherwise noted, Ta = 25C, VCC = 6V, VM = 6V)
455
Motor driver ICs
BA6289F / BA6417F
Electrical characteristics of BA6417F (unless otherwise noted, Ta = 25C, VCC = 6V, VM = 6V)
Input / output truth table
456
Motor driver ICs
BA6289F / BA6417F
Input / output circuits
Operation notes
(1) The quality of these products have been carefully
checked; however, use of the products with applied voltages, operating temperatures, or other parameters that
exceed the absolute maximum rating given may result in
the damage of the IC and the product it is used in. If the
IC is damaged, the short mode and open modes cannot
be specified, so if the IC is to be used in applications
where parameters may exceed the absolute maximum
ratings, then be sure to incorporate fuses, or other physical safety measures.
(2) GND potential
The potential for pin 8 must be kept lower than the potensials ofthe other pins regardless of the circumstances.
(3) Input pins
Voltage should never be applied to the input pins when
the VCC voltage is not applied to the IC. Similarly, when
VCC is applied, the voltage on each input pin should be
less than VCC and within the guaranteed range for the
electrical characteristics.
(4) Back-rush voltage
Depending on the ambient conditions, environment, or
motor characteristics, the back-rush voltage may fluctuate. Be sure to confirm that the back-rush voltage will not
adversely affect the operation of the IC.
(5) Large current line
Large currents are carried by the motor power supply and
motor ground for these ICs.
Therefore, the layout of the pattern of the PC board and
the constants of certain parameters for external components, such as the capacitor between the power supply
and ground, may cause this large output current to flow
back to the input pins, resulting in output oscillation or
other malfunctions. To prevent this, make sure that the
PC board layout and external circuit constants cause no
problems with the characteristics of these ICs.
(6) Power dissipation
The power dissipation will fluctuate depending on the
mounting conditions of the IC and the ambient environment. Make sure to carefully check the thermal design of
the application where these ICs will be used.
(7) Power consumption
The power consumption by the IC varies widely with the
power supply voltage and the output current. Give full
consideration to the power dissipation rating and the
thermal resistance data and transient thermal resistance
data, to provide a thermal design so that none of the ratings for the IC are exceeded.
(8) ASO
Make sure that the output current and supply voltage do
not exceed the ASO values.
(9) Precautions for input mode switching
To ensure reliability, it is recommended that the mode
switching for the motor pass once through the open
mode.
457
Motor driver ICs
(10) In-rush current
There are no circuits built into these ICs that prevent inrush currents. Therefore, it is recommended to place a
current limiting resistor or other physical countermeasure.
(11) Factors regarding the thermal, power supply, and
motor conditions
If the potential of the output pin sways greatly and goes
below the potential of ground, the operation of the IC may
malfunction or be adversely affected. In such a case,
place a diode between the output and ground, or other
measure, to prevent this.
(12) HIGH level output voltage setting pin
The output voltage can be varied by controlling the Vref
voltage :
VOH=Vref+VBE (PNP)–VBE (NPN)+(VOUT–Vref offset)
The voltage applied to the Vref pin should not exceed the
motor supply voltage (pin 2) or the VCC voltage. The Vref
input range over which the HIGH level output voltage can
be controlled according to the above equation is between
0V and (VCC–VSAT–VBE).
The output may oscillate if the Vref voltage is controlled by
a low-impedance circuit. Set the voltage by either providing an impedance of about 10kΩ or connecting a capacitor between the Vref and GND pins. Because the optimum
impedance and capacitance values depend on such factors as the type of motor, the PCB pattern, and the load
current, the values must be determined separately for
each application.
(13) Thermal shutdown circuit
When the thermal shutdown circuit is activated at the IC
junction temperature of about 175C (typical), all driver
outputs are turned OFF. There is a temperature difference of about 15C (typical) between the temperatures
at which the circuit is activated and deactivated.
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BA6289F / BA6417F
(13) The input pins (pins 4 and 5 have temperature dependent characteristics. Take the temperature effect into
consideration when using the IC.
(14) To eliminate motor noise, connect a capacitor between OUT1 (pin 1) and GND and between OUT2 (pin 7)
and GND. Alternatively, connect a capacitor between
OUT1 and OUT2, and also a diode between OUT1 and
GND and between OUT2 and GND.
Motor driver ICs
BA6289F / BA6417F
Application example
459
Motor driver ICs
Electrical characteristic curves
460
BA6289F / BA6417F
Motor driver ICs
BA6289F / BA6417F
External dimensions (Units: mm)
461
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