Rainbow Electronics MAX9491 User Manual

General Description

The MAX9491 multipurpose clock generator is ideal for
communication applications. It offers a factory-program­mable PLL output that can be set to almost any frequency,
ranging from 4MHz to 200MHz. The MAX9491 uses a
one-time-programmable (OTP) ROM to program the PLL
output. The MAX9491 also features an integrated volt­age-controlled crystal oscillator (VCXO) that is tuned by a
DC voltage. The VCXO output is used as the PLL input.
The VCXO has a wide ±200ppm (typ) tuning range. The
OTP on the MAX9491 is factory preset, based upon the
customer request. Contact the factory for samples with
preferred frequencies.

The device operates from a 3.3V supply and is speci­fied over the -40°C to +85°C extended temperature
range. The MAX9491 is available in 14-pin TSSOP and
20-pin TQFN (5mm x 5mm) packages.

Applications

Telecommunications

Data Networking Systems

Home Entertainment Centers

SOHO

Features

♦ 5MHz to 35MHz for Crystal-Clock Reference

♦ 5MHz to 50MHz for a Driver Clock Reference

♦ One Fractional-N PLL with Buffered Output

♦ 4MHz to 200MHz Output Frequency Range

♦ Low RMS Jitter PLL (< 13ps) at 197 MHz

♦ Integrated VCXO with ±200ppm Tuning Range

♦ Available in 14-Pin TSSOP and 20-Pin TQFN

Packages

♦ +3.3V Supply

♦ -40°C to +85°C Temperature Range

MAX9491

Factory-Programmable, Single PLL

Clock Generator

________________________________________________________________ Maxim Integrated Products 1

Pin Configurations

19-3942; Rev 0; 1/06

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.

PART

PIN­PACKAGE

PKG

CODE

MAX9491ETP

T2055-5

14 TSSOP U14-2

Ordering Information

*Future product—contact factory for availability.

**EP = Exposed pad.

TEMP RANGE

-40°C to +85°C 20 TQFN-EP**

MAX9491EUD* -40°C to +85°C

DD

I.C.

V

DDA

V

AGND

DD

V

GND

GND

11

5

CLK_OUT

TOP VIEW

X1

I.C.

I.C.

TUNE

GND

1

2

3

4

DD

MAX9491

5

6

7

TSSOP

GND

10

I.C.

9

I.C.

8

7

I.C.

6

I.C.

CLK_OUT

14

X2

13

PD

12

V

DD

11

GNDV

10

I.C.

9

GND

8

I.C.

TOP VIEW

V

DD

X2

X1

I.C.

PD

15 14 13 12

16

17

18

19

20I.C.

MAX9491

1234

TUNE

TQFN (5mm x 5mm)

MAX9491

Factory Programmable Single PLL
Clock Generator

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(VDD= V

DDA

= +3.0V to +3.6V and TA= -40°C to +85°C. Typical values at VDD= V

DDA

= 3.3V, TA= +25°C, unless otherwise noted.)

(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

DDA

to AGND ......................................................-0.3V to +4.0V

All Other Pins to GND ..................................-0.3V to V

DD

+ 0.3V

Short-Circuit Duration

(all LVCMOS outputs)..............................................Continuous

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

Continuous Power Dissipation (T

A

= +70°C)

20-Lead TQFN (derate 21.3mW/°C above +70°C) ....2758mW

14-Pin TSSOP (derate 9.1mW/°C above +70°C) ......796.8mW

Storage Temperature Range .............................-65°C to +150°C

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

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

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

LVCMOS INPUTS (PD, X1 as a reference INPUT CLK)

Input High Level V

Input Low Level V

High-Level Input Current I

Low-Level Input Current I

CLOCK OUTPUT (CLK_OUT)

Output High Level V

Output Low Level V

POWER SUPPLIES

Digital Power-Supply Voltage V

Analog Power-Supply Voltage V

Total Current for Digital and
Analog Supplies

Power-Down Current IDC2 PD = low 60 µA

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

IH

IL

IH

OH

DD

DDA

I

DC

VIN = V

DD

VIN = 0 -20 µA

IL

IOH = -4mA

IOL = 4mA 0.4 V

OL

f

= 45MHz, no load

OUT

= 13MHz

f

IN

2.0 V

0 0.8 V

V

-

DD

0.6

3.0 3.6 V

3.0 3.6 V

10 mA

DD

20 µA

V

V

MAX9491

Factory Programmable Single PLL

Clock Generator

_______________________________________________________________________________________ 3

AC ELECTRICAL CHARACTERISTICS

(VDD= V

DDA

= +3.0V to +3.6V, CL= 10pF and TA= -40°C to +85°C. Typical values are at VDD= V

DDA

= 3.3V, TA= +25°C, unless

otherwise noted.) (Note 2)

Note 1: All parameters are tested at TA= +25°C. Specifications over temperature are guaranteed by design and characterization.
Note 2: Guaranteed by design and characterization; limits are set at ±6 sigma.

OUTPUT CLOCK (CLK_OUT)

Minimum Frequency Range f

Maximum Frequency Range

Clock Rise Time t

Clock Fall Time t

Duty Cycle f

Soft Power-On Time t

Hard Power-On Time t

VCXO CLOCK

Crystal Frequency f

Crystal Accuracy ±30 ppm

Tuning Voltage Range V

VCXO Tuning Range V

TUNE Input Impedance Z

Output CLK Accuracy V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

= 5MHz to 50MHz 4

f

OUT

R

F

PO2

PO1

XTL

TUNE

TUNE

IN

CL < 5pF 133 200

20% to 80% of VDD, f

= 13MHz

f

IN

80% to 20% of VDD, f

= 13MHz

f

IN

= 45MHz, fIN = 13MHz 44 50 56 %

OUT

f

= 45MHz, fIN = 13MHz 14

OUT

f

= 80MHz, fIN = 13MHz 22Output Period Jitter J

OUT

P

f

= 197MHz, fIN = 13MHz 13

OUT

PD from low to high, f
f

= 13MHz, see Figure 2

IN

See Figure 2 15 ms

= 0 to 3V, C1 = C2 = 4pF ±150 ±200 ppm

TUNE

= 1.5V, C1 = C2 = 4pF ±50 ppm

TUNE

OUT

OUT

OUT

= 80MHz,

= 80MHz,

= 45MHz,

1.5 ns

1.3 ns

1ms

27 MHz

03V

95 kΩ

MHz

ps

RMS

MAX9491

Factory Programmable Single PLL
Clock Generator

4 _______________________________________________________________________________________

Typical Operating Characteristics

(VDD= V

DDA

= +3.3V, TA= +25°C, fIN= 13MHz clock, CL= 10pF, 27MHz, unless otherwise noted.)

SUPPLY CURRENT vs. TEMPERATURE

13

fIN = 13MHz

= 45MHz

f

OUT

12

11

10

SUPPLY CURRENT (mA)

9

8

-40 10-15 35 60 85
TEMPERATURE (°C)

JITTER vs. TEMPERATURE

40

fIN = 13MHz

= 45MHz

f

OUT

35

30

25

20

JITTER (ps)

15

10

5

0

-40 10-15 35 60 85
TEMPERATURE (°C)

MAX9491 toc01

MAX9491 toc04

RISE TIME vs. TEMPERATURE

2.2
fIN = 13MHz

= 45MHz

f

OUT

1.8

1.4

1.0

RISE TIME (ns)

0.6

0.2

-40 10-15 35 60 85
TEMPERATURE (°C)

JITTER vs. TEMPERATURE

40

fIN = 13MHz

= 80MHz

f

OUT

32

24

JITTER (ps)

16

8

0

-40 10-15 35 60 85
TEMPERATURE (°C)

MAX9491 toc02

MAX9491 toc05

FALL TIME vs. TEMPERATURE

2.2
fIN = 13MHz

= 45MHz

f

OUT

1.8

1.4

1.0

FALL TIME (ns)

0.6

0.2

-40 10-15 35 60 85
TEMPERATURE (°C)

JITTER vs. TEMPERATURE

40

fIN = 27MHz

= 197MHz

f

OUT

30

20

JITTER (ps)

10

0

-40 10-15 35 60 85
TEMPERATURE (°C)

MAX9491 toc03

MAX9491 toc06

TYPICAL CLK_OUT WAVEFORM AT 45MHz

VDD = V

= 3.0V

DDA

4ns/div

MAX9491 toc07

CLK1
1V/div

TYPICAL CLK_OUT WAVEFORM AT 80MHz

VDD = V

= 3.0V

DDA

4ns/div

MAX9491 toc08

CLK1
1V/div

TYPICAL CLK_OUT WAVEFORM AT 197MHz

VDD = V

= 3.0V

DDA

4ns/div

MAX9491 toc09

CLK1
1V/div