BA6287F [ROHM]
Reversible motor driver; 可逆电机驱动器
| 型号： | BA6287F |
| 厂家： | 
ROHM |
| 描述： | Reversible motor driver |
| 文件： | 总6页 (文件大小：80K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Motor driver ICs
Reversible motor driver
BA6287F
The BA6287F is a reversible-motor driver with a maximum output current of 1.0A. 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.
FApplications
VCRs and audio equipment in general
FFeatures
1) Built-in power saving circuit suppresses the stop
mode current dissipation.
3) Interfaces with TTL devices.
4) Built-in thermal shutdown circuit.
2) Output voltage can be set arbitrarily with the VREF pin.
FAbsolute maximum ratings (Ta = 25_C)
FRecommended operating conditions (Ta = 25_C)
439
Motor driver ICs
BA6287F
FBlock diagram
FPin descriptions
FInput / output circuits
440
Motor driver ICs
BA6287F
FElectrical characteristics (unless otherwise noted, Ta = 25_C, VCC = 9V, VM=9V, VREF = 9V)
FCircuit operation
(1) Input section
(3) Power saving circuit
The four output modes are controlled by two logic inputs.
Current flows from OUT1 to OUT2 when FIN is HIGH and
RIN is LOW, and from OUT2 to OUT1 when RIN is HIGH
and FIN is LOW (refer to the truth table). The input circuit
can be operated by a logic circuit with a current capacity
of 120 X 170µA.
All circuits are turned OFF when the FIN and RIN input pins
are both put to LOW level. This circuit saves power dur-
ing standby mode by leaving the outputs OPEN.
(4) Thermal shutdown circuit
When the thermal shutdown circuit is activated at the
chip temperature of about 175_C (typical), the outputs
are left OPEN. The temperature difference between the
activation and deactivation settings is about 15_C. When
the thermal shutdown circuit is deactivated, the outputs
revert to the status determined by input mode.
Input / output truth table
FApplication example
(2) Output section
Current flows from OUT1 to OUT2 during forward rota-
tion, and from OUT2 to OUT1 during reverse rotation.
The output voltages VOH and VOL are given by :
VOH [V]=VREF*VCE (sat) (PNP)*VBE (NPN)
VOL [V]=VCE (sat) (NPN)
VCE and VBE are functions of the output current (see elec-
trical characteristic curves). The output current can be
set with the VREF pin.
441
Motor driver ICs
BA6287F
FOperation notes
(1) The quality of these products have been carefully
checked; however, use of the products with applied volt-
ages, 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 physi-
cal safety measures.
(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 rat-
ings for the IC are exceeded.
(8) ASO
Make sure that the output current and supply voltage do
not exceed the ASO values.
(2) GND potential
(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.
The potential for pin 1 must be kept lower than the poten-
tials of the 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.
(10) In-rush current
There are no circuits built into these ICs that prevent in-
rush currents. Therefore, it is recommended to place a
current limiting resistor or other physical countermea-
sure.
(4) Back-rush voltage
(11) Factors regarding the thermal, power supply, and
motor conditions
Depending on the ambient conditions, environment, or
motor characteristics, the back-rush voltage may fluctu-
ate. Be sure to confirm that the back-rush voltage will not
adversely affect the operation of the IC.
If the potential of the output pin sways greatly and goes
belowthe 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.
(5) Large current line
Largecurrentsarecarriedbythemotorpowersupplyand
motor ground for these ICs.
(12) HIGH level output voltage setting pin
Ensure that the voltage applied to VREF does not exceed
the voltage on the motor power supply pin or the VCC pin.
(13) The input pins have temperature-dependent char-
acteristics. Take the temperature effect into consider-
ation when using the IC.
Therefore, the layout of the pattern of the PC board and
the constants of certain parameters for external compo-
nents, 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
(14) To eliminate motor noise, connect a capacitor be-
tween OUT1 and GND and between OUT2 and GND. Al-
ternatively, connect a capacitor between OUT1 and
OUT2, and also a diode between OUT1 and GND and
between OUT2 and GND (see Fig. 2).
The power dissipation will fluctuate depending on the
mounting conditions of the IC and the ambient environ-
ment. Make sure to carefully check the thermal design of
the application where these ICs will be used.
442
Motor driver ICs
BA6287F
FElectrical characteristic curves
443
Motor driver ICs
BA6287F
FExternal dimensions (Units: mm)
444
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