PCA8537 View Datasheet(PDF) - NXP Semiconductors.

Part Name

Description

Manufacturer

PCA8537

Automotive LCD driver for multiplex rates up to 1:8

NXP Semiconductors. 

NXP Semiconductors

PCA8537

Automotive LCD driver for multiplex rates up to 1:8

If the internal charge pump is enabled, then the internal oscillator starts and is used to run

the charge pump. An external oscillator can still be applied for driving the display

waveforms.

The duty cycle of the output clock provided on the CLK pin is not always 50 : 50. Table 18

on page 13 shows the expected duty cycle for each of the chosen frame frequencies.

8.1.3.3 External clock

In applications where an external clock must be applied to the PCA8537, bit OSC (see

Table 8) must be set logic 1. In this case, pin CLK becomes an input.

The CLK signal is a signal that is fed into the VDD1 domain. Therefore it must have an

amplitude equal to the VDD1 voltage supplied to the chip and be referenced to VSS.

The clock frequency (fclk) determines the LCD frame frequency.

Remark: If an external clock is used then this clock signal must always be supplied to the

device. Removing the clock can freeze the LCD in a DC state. Removal of the clock is

possible when following the correct procedures (see Figure 11 on page 21 and Figure 12

on page 22).

8.1.4 Command: Charge-pump-ctrl

The Charge-pump-ctrl command enables or disables the internal VLCD generation and

controls the charge pump voltage multiplier setting.

Table 9. Charge-pump-ctrl - charge pump control command bit description

For further information, see Table 12 on page 11 and Section 8.4.3 on page 26.

Bit

Symbol

Binary value Description

7 to 2 -

1100 00

fixed value

1

CPE

charge pump switch

0[1]

charge pump disabled;

no internal VLCD generation;

external supply of VLCD

1

charge pump enabled

0

CPC

charge pump voltage multiplier setting

0[1]

VLCD = 2  VDD2

1

VLCD = 3  VDD2

[1] Default value.

PCA8537

Product data sheet

All information provided in this document is subject to legal disclaimers.

Rev. 2 — 7 April 2015

© NXP Semiconductors N.V. 2015. All rights reserved.

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