November 2006

P2040B

rev 0.2

LCD Panel EMI Reduction IC

3 of 8

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

P2040B

CLKIN

CP0

SR0

SSON#

CP1

ModOUT

1

2

3

4

5

6

7

8

+3.3V

Digital control for SS

enable or disable

0.1 µF

Modulation 65MHz signal

with +/- 1.56% Deviation

and Modulation Rate of

101.54 KHz. This signal is

connected back to the

Spread Spectrum input

Pin (SSIN) of the

Graphics Accelerator.

65MHz from Graphics

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: P2040B is designed for high resolution flat panel applications and is able to support panel frequencies from

30MHz to 100MHz. For a 65MHz pixel clock frequency, a spreading selection of CP0 = 0,CP1=1 and SR0=1 gives a

percentage deviation of +/-1.56% (see Table 1). This results in frequency on ModOUT being swept from 64.5MHz to

65.5MHz. This particular example given here is a common EMI reduction method for notebook LCD panel and has already

been implemented by most of the leading OEM and mobile graphic accelerator manufacturers.

Application Schematic for Mobile LCD Graphics Controllers

Absolute Maximum Ratings

Symbol

Parameter

Rating

Unit

Voltage on any pin with respect to Ground

-0.5 to +4.6

V

Storage temperature

-65 to +125

°C

Operating temperature

-40 to +85

°C

Max. Soldering Temperature (10 sec)

260

°C

Junction Temperature

150

°C

Static Discharge Voltage

(As per JEDEC STD22- A114-B)

2

KV

Note: These are stress ratings only and are not implied for functional use. Exposure to absolute maximum ratings for prolonged periods of time may affect

device reliability.