CDC582

3.3V PHASELOCK LOOP CLOCK DRIVER

WITH DIFFERENTIAL LVPECL CLOCK INPUTS

SCAS446B − JULY 1994 − REVISED FEBRUARY 1996

7

POST OFFICE BOX 655303

POST OFFICE BOX 1443

timing requirements over recommended ranges of supply voltage and operating free-air

temperature

MIN

MAX

UNIT

fclock

Clock frequency

VCO is operating at four times the CLKIN/CLKIN frequency

25

50

MHz

fclock

Clock frequency

VCO is operating at double the CLKIN/CLKIN frequency

50

100

MHz

Input clock duty cycle

40%

60%

After SEL1, SEL0

50

Stabilization time†

After OE

↓

50

µs

Stabilization time

After power up

50

µs

† Time required for the integrated PLL circuit to obtain phase lock of its feedback signal to its reference signal. For phase lock to be obtained, a

fixed-frequency, fixed-phase reference signal must be present at CLKIN. Until phase lock is obtained, the specifications for propagation delay

and skew parameters given in the switching characteristics table are not applicable.

switching characteristics over recommended ranges of supply voltage and operating free-air

PARAMETER

FROM

(INPUT)

TO

(OUTPUT)

MIN

MAX

UNIT

Duty cycle

Y

45%

55%

fmax

100

MHz

Jitter(pk-pk)

CLKIN

↑

Y

↑

200

ps

tphase error‡

CLKIN

↑

Y

↑

−500

500

ps

tsk(o)‡

Y

0.5

ns

tsk(pr)‡

Y

1

ns

tr

1.4

ns

tf

1.4

ns

‡ The propagation delay, tphase error, is dependent on the feedback path from any output to the FBIN. The tphase error, tsk(o), and tsk(pr)

specifications are only valid for equal loading of all outputs.

NOTE 4: The specifications for parameters in this table are applicable only after any appropriate stabilization time has elapsed.

PARAMETER MEASUREMENT INFORMATION

From Output

Under Test

LOAD CIRCUIT FOR OUTPUTS

tphase error

2 V

2.4 V

1.6 V

VOH

VOL

CLKIN

0.8 V

2 V

tr

tf

0.8 V

2 V

500

Ω

CL = 30 pf

(see Note A)

VOLTAGE WAVEFORMS

PROPAGATION DELAY TIMES

Output

1.5 V

CLKIN

2 V

NOTES: A. CL includes probe and jig capacitance.

B. The outputs are measured one at a time with one transition per measurement.

C. All input pulses are supplied by generators having the following characteristics: PRR

≤ 10 MHz, ZO = 50 Ω, tr ≤ 2.5 ns, tf ≤ 2.5 ns.

Figure 1. Load Circuit and Voltage Waveforms