PCA2117DUGSSLASHDA datasheet(35/107 Pages) NXP

35 / 107 page

PCA2117

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Product data sheet

Rev. 4 — 8 April 2015

35 of 107

NXP Semiconductors

PCA2117

Automotive LCD driver for character displays

2. Static voltages across the liquid crystal display can build up when the external LCD

supply voltage (VLCD) is on while the IC supply voltage (VDD1 and VDD2) is off, or the

other way round. This may cause unwanted display artifacts. To avoid such artifacts,

external VLCD, VDD1, and VDD2 must be applied or removed together.

3. A clock signal must always be supplied to the device when the device is active.

Removing the clock may freeze the LCD in a DC state, which is not suitable for the

liquid crystal. Disable the display first and then remove the clock signal afterwards.

8.3 Possible display configurations

The PCA2117 is a versatile peripheral device designed to interface between any

microcontroller to a wide variety of character displays (see Figure 14 and Figure 15).

The host microcontroller maintains the communication channel with the PCA2117. The

only other connections required to complete the system are the power supplies (VDD1,

VDD2, and VSS1 to VSS3), the VLCD pins (VLCDOUT, VLCDSENSE, VLCDIN), the

external capacitors, and the LCD panel selected for the application. The appropriate

biasing voltages for the multiplexed LCD waveforms are generated internally.

External capacitors of 100 nF minimum are required on each of the pins VDD1 and VDD2.

If they are connected to the same power supply (not recommended if VLCD is generated

internally), a capacitor of 300 nF minimum is required.

VSS1 to VSS3 have to be connected to the same ground supply.

Fig 14. Connecting PCA2117 with a 2

 20 character LCD

Fig 15. Connecting PCA2117 with a 1

 40 character LCD

PCA2117DUGS/DA Datasheet(PDF) 35 Page - NXP Semiconductors