PCA8553 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2015. All rights reserved.
Product data sheet Rev. 2 — 27 March 2015 24 of 56
NXP Semiconductors
PCA8553
Automotive 40 × 4 LCD segment driver
9.3 Backplane and segment outputs
9.3.1 Backplane outputs
The LCD drive section includes four backplane outputs COM0 to COM3, which must be
directly connected to the LCD. The backplane output signals are generated in accordance
with the selected LCD drive mode. If less than four backplane outputs are required, the
unused outputs can be left open-circuit.
• In 1:3 multiplex drive mode, COM3 carries the same signal as COM1, therefore these
two outputs can be tied together to give enhanced drive capabilities
• In 1:2 multiplex drive mode, COM0 and COM2, respectively, COM1 and COM3 all
carry the same signals and may also be paired to increase the drive capabilities
• In static drive mode, the same signal is carried by all four backplane outputs and they
can be connected in parallel for very high drive requirements
9.3.2 Segment outputs
The LCD drive section includes 40 segment outputs SEG0 to SEG39, which must be
directly connected to the LCD. The segment output signals are generated in accordance
with the multiplexed backplane signals and with data residing in the display registers.
When less than 39 segment outputs are required, the unused segment outputs must be
left open-circuit.
