Peak EMI Reducing Solution

2 of 8

rev 0.7

December 2004

ASM3P2853A

Pin Configuration

Pin Description

Pin Name

Type

Description

XIN

I

Connection to crystal or external reference frequency input. This pin has dual

functions. It can be connected either to an external crystal or an external

reference clock.

XOUT

O

Connection to crystal. If using an external reference clock, this pin must be left

unconnected.

P

Power supply for the analog and digital blocks

P

Ground to entire chip.

PWDNB

I

Power-down control pin. Pull low to enable the power-down mode. Connect to

VDD, if not used.

SSONB

I

Digital logic input used to enable spread spectrum function (Active LOW).

Spread spectrum is enabled when LOW, disabled when HIGH.

USB Clock

O

Clock output -1 (48 MHz unmodulated)

50 MHz

O

Clock output -2 (50 MHz modulated)

50 MHz

XOUT

XIN

VDD

8

7

6

5

1

2

3

4

ASM3P2853A

PWDNB

SSONB

USB Clock