CD4055B: Display Driver interface query

Prabhavathy Namasivayam

Part Number: CD4055B

I am using CD4055BM instead of 74HC4511D,653. I don't need the level shifter function, hence VEE is connected to VSS through 10K. Unused Display Frequency IN (pin1) and Display Frequency OUT (Pin6) should be connected to GND? Please review my schematics and give your input on design recommendations for CDM4055BM IC.

over 3 years ago

0 Clemens Ladisch over 3 years ago

Guru 317750 points

VEE is a power supply and must have a low-impedance connection. Just connect it directly to VSS.

Unused output should be left open.

All inputs must have a valid voltage. For active-high outputs, the DF input must be low.

0 Prabhavathy Namasivayam over 3 years ago in reply to Clemens Ladisch

Prodigy 10 points

VEE directly shorted to GND - OK. Since I am not using the DF function. DF pin6 input should connect to Pulldown and DF pin 1 should be left open? Right

+1 Clemens Ladisch over 3 years ago in reply to Prabhavathy Namasivayam

Guru 317750 points

You can connect the DF input directly to GND.

0 Albert Xu1 over 3 years ago in reply to Prabhavathy Namasivayam

TI__Mastermind 39285 points

Hi Prabhavathy,

VEE should be connected directly to VSS, and DF pin 6 can be connected directly to GND. You don't need a pulldown.

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CD4055B: Display Driver interface query