Motor Driver SN754410

Discussion in 'Electronics Resources' started by avuzman, Jan 17, 2010.

  1. avuzman

    Thread Starter New Member

    Apr 21, 2008
    I have some question regarding some Data-Sheet parameters of
    Quadruple Half-H Driver p.n:SN754410 Texas Instruments.
    I am planning some hardware for my graduate project,i want to use this Driver with DC Motors.
    1) The PWM pulse generator for motors command must be 0 to 36v or can the max. bias be lower then 36V for proper operation?
    2)Why does values of Icc1 and Icc2 are different according to the D_Sheet table.
    3) Can i use 12v supply for Vcc2 for proper operation,the recommended value in D_Sheet is 24V?
    4)Does the Motors Enable work in positive logic: 3v Motor Enable
    0V Motor Disable
    5)Do i need to add some Load Resistor in the Driver output? i`m planing to use the configuration that described in D_Sheet figure1 test circuit
    6) What is Input clamp voltage?
    Thanks allot.
  2. SgtWookie


    Jul 17, 2007
    Vcc1 is used for the logic supply. It should be in a range of 4.5v to 5.5v for proper operation. The input controls should be at TTL logic levels.
    That is because the control inputs are at TTL levels; Vcc2 can be anywhere from 4.5v to 36v.
    That was for an example circuit. As long as you are within a range of 4.5v to 36v and do not exceed the current and power dissipation limits, you should be OK.
    Your statement agrees with the function table. However, it appears that the inputs do not have current limiting resistors. If you are driving the IC from a MCU, it would be a good idea to use a 270 Ohm to 470 Ohm current limiting resistor between your I/O pins and the inputs to the IC. The inputs are configured as emitter followers, which should mean a low input current - however, adding current limiting protection for your MCU's pins is cheap insurance.
    It depends upon your motor's voltage rating. If you are running it from 12v and your motor is rated for less than about 0.13A at 12v, you may not need them. Note that current will be much higher (perhaps 7x-10x) the motor's rated current when the motor is at stall (stopped or rotor locked) than it is rated for.
    The inputs are clamped to ground in the case that they go more than about 0.5v below ground.