Rainbow Electronics MAX9486 User Manual

General Description

The MAX9486 low-cost, high-performance clock syn­thesizer with an 8kHz input reference clock provides six
buffered LVTTL clock outputs at 35.328MHz. The clock
synthesizer can be used to generate the clocks for T1,
E1, T3, E3, and xDSL.

The MAX9486 has two phase-lock loops (PLLs). The
first PLL uses a voltage-controlled crystal oscillator
(VCXO). The second PLL is a frequency multiplier. With
the two PLLs, the MAX9486 generates the output fre­quency at 35.328MHz. In addition, this device gener­ates a jitter-suppressed 8kHz output that provides a
better source for the reference clock relay.

The MAX9486 is available in a 24-pin TSSOP package
and operates over the extended operating temperature
range of -40°C to +85°C and a single +3V to +3.6V
power-supply range.

Applications

Telecom Equipment Using T1, E1, T3, E3, and
ISDN Protocols

xDSL Equipment in CO with Interface to the
Telecom Protocols

Features

♦ 8kHz Input Reference CLK

♦ High-Jitter Rejection on the Reference CLK

♦ Synthesizer Locks to the 8kHz Reference with a

±200ppm Range

♦ Output Frequency: 35.328MHz

♦ Six Buffered LVTTL Low-Jitter Outputs

♦ One 8kHz Reference CLK Relay Output

♦ +3.3V Supply Operation

♦ 24-Pin TSSOP Package

MAX9486

8kHz Reference Clock Synthesizer

with Multiple Outputs at 35.328MHz

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

19-3345; Rev 0; 8/04

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

EVALUATION KIT

AVAILABLE

PART TEMP RANGE PIN-PACKAGE

MAX9486EUG -40°C to +85°C 24 TSSOP

24

23

22

21

20

19

18

17

1

2

3

4

5

6

7

8

CLK1

GND

CLK2

V

DD

V

DDP

REIN

REO

TOP VIEW

CLK3

V

DD

GND

CLK4X2

V

DD

X1

GNDP

16

15

14

13

9

10

11

12

V

DD

CLK5

GND

CLK6SETI

LP1

LP2

GND

TSSOP

MAX9486

SHDN

Pin Configuration

MAX9486

CLK2

X1

CLK1

V

DDP

GNDP

X2

REO

CLK6

CLK5

CLK4

CLK3

GND

V

DD

LP1 LP2

REIN

R

SET

R

1

C

1

C

2

SETI

V

DD

SHDN

Typical Application Circuit

MAX9486

8kHz Reference Clock Synthesizer
with Multiple Outputs at 35.328MHz

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(VDD= V

DDP

= +3.0V to +3.6V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at VDD= V

DDP

= +3.3V, TA=

+25°C.) (Note 1)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

VDDto GND...........................................................-0.3V to +4.0V

V

DDP

to GNDP.......................................................-0.3V to +4.0V

SHDN, REO, REIN, X1, X2, CLK_ to GND ...-0.3V to (VDD+ 0.3V)

LP1, SETI to GNDP.....................................-0.3V to (V

DD

+ 0.3V)
LP2 Internally Connected to GNDP

Short-Circuit Duration of Outputs ...............................Continuous

Continuous Power Dissipation (T

A

= +70°C)

24-Pin TSSOP (derate 12.2mW/°C above +70°C) .......976mW

Operating Temperature Range ...........................-40°C to +85°C

Maximum Junction Temperature .....................................+150°C

Storage Temperature Range .............................-60°C to +150°C

ESD Rating (Human Body Model) .......................................±2kV

Lead Temperature (soldering, 10s) .................................+300°C

PARAMETER

CONDITIONS

UNITS

DIGITAL INPUTS (REIN,

SHDN

)

Input High Logic Level V

IH

2.0 V

Input Low Logic Level V

IL

0.8 V

Input-Current High Level I

IH

VIN = V

DD

20 µA

Input-Current Low Level I

IL

VIN = 0 -20 µA

DIGITAL OUTPUT CLOCKS (CLK1–CLK6, REO)

Output High Logic Level V

OH

IOH = -4mA

V

Output Low Logic Level V

OL

IOL = 4mA 0.4 V

POWER SUPPLY (VDD, V

DDP

)

Power-Supply Range V

DD

3.0 3.6 V

PLL Power-Supply Range V

DDP

3.0 3.6 V

Power-Supply Current

(Note 2) 13 25 mA

Shutdown Supply Current I

SHDN

830µA

SYMBOL

MIN TYP MAX

VDD -

0.6V

IDD + I

DDP

MAX9486

8kHz Reference Clock Synthesizer

with Multiple Outputs at 35.328MHz

_______________________________________________________________________________________ 3

Note 1: Specifications are 100% tested at TA= +25°C. Specifications over temperature are guaranteed by design and characterization.
Note 2: No load on clock outputs.
Note 3: Guaranteed by design.

Note 4: Crystal loading capacitance is 14pF.

AC ELECTRICAL CHARACTERISTICS

(VDD= V

DDP

= +3.0V to +3.6V, CL= 20pF, TA= -40°C to +85°C, unless otherwise noted. Typical values are at VDD= V

DDP

= +3.3V,

T

A

= +25°C.) (Note 3)

PARAMETER

CONDITIONS

UNITS

DIGITAL OUTPUT CLOCKS (CLK1–CLK6)

Frequency Range f

OUT

MHz

Clock Rise Time T

R1

20% to 80% V

DD

1.8 ns

Clock Fall Time T

F1

80% to 20% V

DD

1.8 ns

Duty Cycle 40 50 60 %

Period Jitter J

PP1

Peak-to-peak

ps

Output Skew t

S

Peak-to-peak

ps

REFERENCE CLOCK OUTPUT (REO)

Frequency f

REF

8 kHz

Clock Rise Time T

R2

1.8 ns

Clock Fall Time T

F2

1.8 ns

Duty Cycle 40 50 60 %

VCXO

Crystal Frequency f

XTL

MHz

Crystal Accuracy

Including frequency accuracy and
temperature range

ppm

VCXO Pulling Range (Note 4)

ppm

Input Reference CLK Pulse Width

t

W

Measured at high or low states 10 ns

SYMBOL

MIN TYP MAX

35.328

120

185

17.664

±25

-200 +200