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LM2904-Q1: amps select

Part Number: LM2904-Q1
Other Parts Discussed in Thread: OPA564-Q1, ALM2403-Q1, ALM2402F-Q1

Could you pls select a suitable product for me? Thanks!


1) Automotive grade dual-channel operational amplifier

2)Single power supply voltage range 5-24V

3) Common mode voltage range VCC+/-0.7V

4) RθJA does not exceed 47℃/W (may be ignored if necessary)

5) Input offset voltage ≤25mV; offset voltage temperature drift not greater than ±50uv/℃; power supply rejection ratio not exceeding ±50uV/V; common mode rejection ratio minimum 52dB

6) The input offset current does not exceed 0.1uA; the input bias current does not exceed 0.1uA;

7) Open loop gain ≥96DB

8) The load capacity of a single channel is not less than 500mA

  • What does "VCC+/-0.7V" mean? That with a 24 V supply, the input voltage range is from 23.3 V to 24.7 V?

    500 mA is quite a lot. The ALM2403-Q1 cannot handle this; the OPA564-Q1 has only one channel and requires at least 7 V.

  • Hi MingKang,

    Could you pls select a suitable product for me?

    It is great that you listed many of the design requirements. The issue is that it is way too detailed and many specifications are too confined. As system requirements, it is good to specify general application requirements (This should be the top level product selection requirements), rather than the specific performance figures (lower level product specifications), which these figures may exclude many good options for the application.     

    Could you tell me what is the power amplifier's application? Are you looking for resolver driver?

    8) The load capacity of a single channel is not less than 500mA

    Per Clements comments, ALM2402F-Q1/ALM2403-Q1 is unable to handle 500mA current load. OPA564-Q1 may do it, but I need to know more about the application. 



  • Thanks Raymond. I would update the application when I got the information. 

  • Hi Mingkang,

    Sure, Please let me know. I can speak to the customer as well, if you think that this will help them to decide. I can communicate via Chinese, if we can exchange the information more effectively.   

    FYI, our ALM2402F-Q1/ALM2403-Q1 resolver drivers are capable to drive the most of the resolvers on the market. When the customer is specifying 500mA/channel in current rating, the system engineers are likely taken into account > 2X current margins in the requirements. Per the detailed design requirements, it is likely that the customer is looking for resolver drivers. 

    The automotive market trend is to toward smaller dimensions and lower driving power in resolver, e.g. EVs. Furthermore, there is a power factor consideration in the resolver load. Once the correction is implemented,  it may lower the power dissipation in the power amplifier and lower the working current to drive the L, C & R complex load.