MPC992

MOTOROLA

TIMING SOLUTIONS

BR1333 — REV 5

4

DC CHARACTERISTICS (TA = 0° to 70°C, VCC = 3.3V ±5%)

Symbol

Characteristic

Min

Typ

Max

Unit

Condition

VIH

Input HIGH Voltage

PECL_CLK1

Other

2.15

2.0

2.4

VCC

V

VCC = 3.3V

VIL

Input LOW Voltage

PECL_CLK1

Other

1.5

0

1.8

0.8

V

VCC = 3.3V

VOH

Output HIGH Voltage1

1.8

2.4

V

VCC = 3.3V

VOL

Output LOW Voltage1

1.2

1.7

V

VCC = 3.3V

IIN

Input Current

–120

120

µA

ICCI

Maximum Quiescent Supply Current

130

150

mA

ICCA

Maximum PLL Supply Current

15

20

mA

1. DC levels will vary 1:1 with VCC.

AC CHARACTERISTICS (TA = 0° to 70°C, VCC = 3.3V ±5%)

Symbol

Characteristic

Min

Typ

Max

Unit

Condition

tr, tf

Output Rise/Fall Time

200

850

ps

20% to 80%

tpw1

Output Duty Cycle

49

51

%

tpw2

SYNC Output Duty Cycle

0.95

1.05

%

PCLK Period

fref

Input Reference Frequency

Xtal

FREF

10

Note 2

20

Note 2

MHz

tos

Output-to-Output Skew

Qa, Qb

Qa (–) to SYNC (+)

100

300

ps

fVCO

PLL VCO Lock Range

200

400

440

750

MHz

VCO_SEL = 1

VCO_SEL = 0

fmax

Maximum Output Frequency

Qa (

÷2)

Qa,Qb (

÷4)

Qb (

÷6)

Qb (

÷10)

375

187.5

125

75

MHz

Note 1

tjitter

Cycle–to–Cycle Jitter (Peak–to–Peak)

±25

±50

ps

Note 3

tlock

Maximum PLL Lock Time

10

ms

1. At 400MHz the output swing will be less than the nominal value.

2. ECLK and XTAL input reference limited by the feedback divide and the guaranteed VCO lock range.

3. Guaranteed by characterization.

APPLICATIONS INFORMATION

Using the On–Board Crystal Oscillator

The MPC992 features an on–board crystal oscillator to

allow for seed clock generation as well as final distribution.

The on–board oscillator is completely self contained so that

the only external component required is the crystal. As the

oscillator is somewhat sensitive to loading on its inputs the

user is advised to mount the crystal as close to the MPC992

as possible to avoid any board level parasitics. To facilitate

co–location surface mount crystals are recommended, but

not required.

The oscillator circuit is a series resonant circuit as

opposed to the more common parallel resonant circuit, this

eliminates the need for large on–board capacitors. Because

the design is a series resonant design, for optimum

frequency accuracy a series resonant crystal should be used

(see specification table below). Unfortunately most off the

shelf crystals are characterized in a parallel resonant mode.

However a parallel resonant crystal is physically no different

than a series resonant crystal, a parallel resonant crystal is

simply a crystal which has been characterized in its parallel

resonant mode. Therefore in the majority of cases a parallel

specified crystal can be used with the MPC992 with just a

minor frequency error due to the actual series resonant

frequency of the parallel resonant specified crystal. Typically