• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 78 subscribers
  • Views 726 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

MSP430 LCD Driver without resistor dividers

Jaden Ghylin102047
Expert 1140 points
Other Parts Discussed in Thread: MSP430F412

I'm looking for an MSP430 with 4-8k flash, 1-2k RAM and an LCD driver that does not require the use of external resistor dividers.  This is a very power sensitive application that cannot afford the power lost through a resistive divider, like that required by MSP430F412.  Lowest power part available would be preferred.  Built-in cap sense would be preferred as well.

Does something like this exist?

-Jaden

  • 0
    Guru 227245 points

    The resistor dividers are IIRC required for the different voltage levels that are necessary for multiplexed display. If you don't use multiplexing, you should be able to go without.

    Cap sense is IIRC only available on the G2 series MSPs, which do not have an LCD controller. But maybe one of the latest MSPs ha both and I missed it.

    YOu can use the device selector on the TI website for finding a proper MSP.

  • 0 in reply to Jens-Michael Gross
    Expert 1140 points

    Thanks for the input.  Some competing manufacturers use charge pumps to produce these voltages which greatly reduces the current required.  I was wondering if this is planned for MSP430s.

    -Jaden

  • 0 in reply to Jaden Ghylin102047
    Expert 1140 points

    There are currently 71 segments in the display, and plan to go higher.  That’s a lot of pins for a small piece of glass, not to mention there are very few LCD drivers that have 70+ pins for driving LCD’s.   Muxing is necessary.

    -Jaden

  • 0 in reply to Jaden Ghylin102047
    Guru 227245 points

    Jaden Ghylin102047 said:
    Some competing manufacturers use charge pumps to produce these voltages which greatly reduces the current required.

    The resistors are not directly used for the voltages, but rather as inputs to the BIAS generator which has a charge pump. (LCD_A to LCD_C module). So they generate the voltage reference only, not the actual supply voltage. Only the original LCD module used them as direct source for the voltage multiplexer.
    Separate charge pumps would be way more ineffective.

**Attention** This is a public forum