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tpic6a595 and tpic6a596

Other Parts Discussed in Thread: TPIC6A596, TPIC6A595

Hello! Pls, tell me when is tpic6a596 used? In which cases?
Is it better than tpic6a595?

  • Hello Denis,

    These two devices are very similar. One is not necessarily better than the other.

    Note the following difference:
    TPIC6A595 - When SRCLR is low, the input shift register is cleared.
    TPIC6A596 - When SRCLR is low, all registers in the device are cleared.

    Note this difference in the Logic Diagram of the datasheets where the TPIC6A595 has the CLR connected only to the input registers.

  • Hi Michael! Thank you for your answer.
    In datasheet of TPIC6A596 I found the following feature: Enhanced Cascading for Multiple Stages.
    Could you pls describe it?

    Which are advantages of TPIC6A596 Cascading over TPIC6A595 Cascading?

  • Denis,

    Yes, of course. This is also another difference between the parts, sorry to overlook this.
    Both devices have the ability to be cascaded from this shift register to other devices or shift registers at the SEROUT output.

    Specifically the advantage is described in the datasheet as follows for the TPIC6A596:
    The serial output (SER OUT) is clocked out of the device on the falling edge of SRCK to provide additional hold time for cascaded applications. This will provide improved performance for applications where clock signals may be skewed, devices are not located near one another, or the system must tolerate electromagnetic interference

    The TPIC6A596 has an additional D flip flop (at the bottom of the Logic Diagram by SEROUT) to enable this.

  • Michael,

    ye, I read it but I am not clear why cascading is enhanced using falling edge of SRCK. I think using of rising edge of SRCK is the same.

    Could you pls provide timing diagrams for tpic6a595 and tpic6a596 like this:

    After that I think I can understand it fully.


  • Michael, perhaps I get it.

    Pls check the following diagram. Am I right?

  • Denis,

    That is correct. The additional D flip flop and inverted clock cause this half clock cycle delay so that the serial out is on the falling edge of the input clock as opposed to the rising edge.

  • Hi Michael! Thank you for your answer.

    Several questions about tpic6a596:

    1. Can tpic6a596 manage solenoids, each 48V, 240mA? Will it work stable?

    2. Has tpic6a596 flyback current protection for inductive load? Don't I need use additional diode near solenoid for protection?

    3.  Which value of voltage drop is in tpic6a596 for full load (8 solenoids 48V, 240mA) and temperature 25°C ?

  • Denis,

    1. If you refer to Figure 8 in the datasheet, it shows that if all 8 outputs are conducting simultaneously then they can each have a current up to 350mA when VCC = 5V and Ta = 25C. Please note that the device will heat up under these conditions, limiting the maximum current, so proper heatsinking is recommended as this is a lot of continuous current.

    2. The datasheet states: "The device contains a built-in voltage clamp on the outputs for inductive transient protection"

    This protection is achieved internally through the use of a zener diode to ground. Refer to the graphic labelled "Typical of all drain outputs" in the schematic section of the datasheet.

    3. Please refer to Figure 10: "Static Drain-Source On-State Resistance vs Drain Current" in the datasheet.

    This figure provides the Rds(on) value of the FET and therefore you can calculate the voltage drop based on the current.


  • Michael,

    1. you are talking about logical voltage VCC=5V, but I ask about solenoid voltage 48V. Solenoids will be connected to 48V and create current 240mA and be managed by TPIC6A596. So, can TPIC6A596 work with 48V and 240mA in each Drain pin ?
  • Denis,

    That plot refers to the maximum current for each of the FETs. It shows that each FET can handle 350mA when they are all on continuously. The VCC is just a condition.
    Each FET is 50V tolerant, but that is an absolute maximum, so I would recommend making sure the 48V is stable and doesn't increase much.

  • Michael,

    after solenoid will be disconnected from 48V, high voltage (may be more 50V ?) will be flyback. So, perhaps additional diode is needed near so powerfull solenoid, how do you think? Or TPIC6A596 has perfect protection for it?