October 2003

P2160

rev E

High Frequency LCD Panel EMI Reduction IC

3 of 9

Notice: The information in this document is subject to change without notice.

Table-1 Modulation Selection

FS0

MRA

SR0

Frequency Range

Spread Range

Modulation Rate

0

0

0

40-80MHz

+/- 0.5%

(Fin/40) * 34.72 KHz

0

0

1

40-80MHz

+/- 1.0%

(Fin/40) * 34.72 KHz

0

1

0

40-80MHz

+/- 0.5%

(Fin/40) * 20.83 KHz

0

1

1

40-80MHz

+/- 1.0%

(Fin/40) * 20.83 KHz

1

0

0

80-166MHz

+/- 0.5%

(Fin/80) * 34.72 KHz

1

0

1

80-166MHz

+/- 1.00%

(Fin/80) * 34.72 KHz

1

1

0

80-166MHz

+/- 0.5%

(Fin/80) * 20.83 KHz

1

1

1

80-166MHz

+/- 1.00%

(Fin/80) * 20.83 KHz

Spread Spectrum Selection

Table 1 illustrates the possible spread spectrum options. The optimal setting should minimize system EMI to the

fullest without affecting system performance. The spreading is described as a percentage deviation of the center

frequency (Note: the center frequency is the frequency of the external reference input on CLKIN, Pin 1).

Example: P2160 is designed for high-resolution flat panel applications and is able to support UXGA (1600 X

1200) flat panel that operates on 162 MHz (Fin) clock speed. A spreading selection of FS0=1, SR0=1 and

modulation rate selection MRA=1, enables input frequency range from 80 ~ 166 MHz and provides a

percentage deviation of +/-1.00% (see Table 1) of the input frequency (Fin). This results in frequency on

ModOUT being swept from 160.38 MHz to 163.62 MHz at a modulation rate of 42.18 KHz (162 MHz/80 MHz X

20.83KHz). This particular example (see below figure) given here is a common EMI reduction method for

notebook and LCD monitor manufacturers and has already been implemented by most of the leading OEM and

mobile graphic accelerator manufacturers.

Application Schematic for Mobile LCD Graphics Controllers