0.5kHz-125MHz MHz to KHz Programmable Clock

T M

47745 Fremont Blvd., Fremont, California 94538 Tel (510) 492-0990 Fax (510) 492-0991 www.phaselink.com Rev 2/23/07 Page 3

FUNCTIONAL DESCRIPTION

PL611s-18 is a highly featured, very flexible, advanced programmable PLL design for high performance, low-

power, small form-factor applications. The PL611s-18 accepts a crystal input of 10MHz to 50MHz or a reference

clock input of 1MHz to 125MHz and is capable of producing two outputs up to 125MHz. This flexible design allows

and/or CLK1. Some of the design features of the PL611s-18 are mentioned below:

PLL Programming

The PLL in the PL611s-18 is fully programmable.

The PLL is equipped with an 5-bit input frequency

divider (R-Counter), and an 8-bit VCO frequency

feedback loop divider (M-Counter). The output of

the PLL is transferred to a 14-bit post VCO divider

(P-Counter). The output frequency is determined by

Clock Output (CLK0)

CLK0 is the main clock output. The PL611s-18 can

also be programmed to provide a second clock

output, CLK1, on the programmable I/O pin (see

OE/PDB/FSEL/CLK1 pin description below). The

output of CLK0 can be configured as the PLL output

programmed to Low Drive (4mA), Standard Drive

(8mA) or High Drive (16mA). The maximum output

frequency is 125MHz.

Clock Output (CLK1)

The CLK1 feature allows the PL611s-18 to have an

additional clock output. This output can be

programmed to one of the following:

CLK0

CLK0 / 2

Output Enable (OE)

The Output Enable feature allows the user to enable

and disable the clock output(s) by toggling the OE

pin. The OE pin incorporates a 60k

pull up resistor

giving a default condition of logic “1”. Pulling the OE

pin low “0” will tri-state the output buffers.

Power-Down Control (PDB)

The Power Down (PDB) feature allows the user to put

the PL611s-18 into “Sleep Mode”. When activated

(logic ‘0’), PDB ‘Disables the PLL, the oscillator

circuitry, counters, and all other active circuitry and

tri-state the output buffers. In Power Down mode the

IC consumes <5 A of power. The PDB pin

incorporates a 60k

pull up resistor giving a default

condition of logic “1”.

Frequency Select (FSEL)

The Frequency Select (FSEL) feature allows the

PL611s-18 to switch between two pre-programmed

outputs allowing the device “On the Fly” frequency

switching. The FSEL pin incorporates a 60k

pull up

resistor giving a default condition of logic “1”.

Programmable CLoad

The PL611s-18 is equipped with programmable S-

Caps to allow the Cload to be tuned from 8pF to

12pF.