NT6862 View Datasheet(PDF) - Novatek Microelectronics

Part Name

Description

Manufacturer

NT6862

8-Bit Microcontroller for Monitor

Novatek Microelectronics 

NT6862-5xxxx

9. PWM DACs (Pulse Width Modulation D/A Converters)

There are 13 PWM D/A converters with 8-bit resolution in NT6862. All of these D/A (DAC0 - DAC12) converters are open-

drain output structure with an external 5V applied maximum. DAC0 – DAC6 are dedicated PWM channels, and DAC7 -

DAC12 are shared with I/O pins. Those shared PWM channels are activated by clearing the correspondent control bits in the

ENDAC control register ($000F). When users write '0' into one of the enable control bits, its correspondent I/O pin will be

switched to PWM output pin.

The PWM refresh rate is 62.5KHz operating on 8MHz system clock. There are 13 readable DACH registers corresponding to

13 PWM channels ($0030 - $003D). Each PWM output pulse width is programmable by setting the 8 bit digital to the

corresponding DACH registers. When these DACH registers are set to 00H, the DAC will output LOW (GND level) and every

1 bit addition will add 62.5ns pulse width. After reset, all DAC outputs are set to 80H (1/2 duty output). Please refer to Figure

9.1 for the detailed timing diagram of PWM D/A output.

8MHz Fosc

PWM value : 255 0

1

2

3

00

01

02

03

m-1

m

255 0

1

m

255(FF)

Figure 9.1. The DAC Output Timing Diagram and Wave Table

15

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