DS1080LU+A00 - Maxim Integrated

General Description

The DS1080L is a low-jitter, crystal-based clock gener-

ator with an integrated phase-locked loop (PLL) to gen-

erate spread-spectrum clock outputs from 16MHz to

134MHz. The device is pin-programmable to select the

clock multiplier rate as well as the dither magnitude.

The DS1080L has a spread-spectrum disable mode

and a power-down mode to conserve power.

Applications

Automotive

Cable Modems

Cell Phones

Computer Peripherals

Copiers

Infotainment

PCs

Printers

Features

Generates Spread-Spectrum Clocks from 16MHz

to 134MHz

Selectable Clock Multiplier Rates of 1x, 2x, and 4x

Center Spread-Spectrum Dithering

Selectable Spread-Spectrum Modulation

Magnitudes of ±0.5%, ±1.0%, and ±1.5%

Spread-Spectrum Disable Mode

Low Cycle-to-Cycle Jitter

Power-Down Mode with High-Impedance Output

Low Power Consumption

3.0V to 3.6V Single-Supply Operation

-40°C to +125°C Temperature Operation

Small 8-Lead µSOP Package

Spread-Spectrum Crystal Multiplier

DS1080L

For pricing, delivery, and ordering information, please contact Maxim Direct at

1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.

SSO

PDNSMSEL

VCC

GND

CMSEL

µSOP

TOP VIEW

DS1080L

Pin Configuration

19-4997; Rev 5; 3/13

Denotes a lead(Pb)-free/RoHS-compliant package.

/V denotes an automotive qualified part.

T = Tape and reel.

Ordering Information

PART TEMP RANGE PIN-PACKAGE

DS1080LU+ -40°C to +125°C 8 µSOP

DS1080LU/V+ -40°C to +125°C 8 µSOP

DS1080LU/V+T -40°C to +125°C 8 µSOP

DS1080LU+T -40°C to +125°C 8 µSOP

Spread-Spectrum Crystal Multiplier

2 Maxim Integrated

DS1080L

ABSOLUTE MAXIMUM RATINGS

RECOMMENDED OPERATING CONDITIONS

(TA= -40°C to +125°C, unless otherwise noted.)

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.

Voltage on VCC Relative to GND...........................-0.3V to +4.3V

Voltage on Any Lead Relative

to GND .................-0.3V to (VCC + 0.3V), not to exceed +4.3V

Continuous Power Dissipation (TA= +70°C)

µSOP (derate 4.5mW/°C above +70°C).......................362mW

Operating Temperature Range .........................-40°C to +125°C

Storage Temperature Range .............................-55°C to +125°C

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

Soldering Temperature (reflow) .......................................+260°C

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Supply Voltage VCC (Note 1) 3.0 3.6 V

Input Logic 1 VIH 0.8 x

VCC

VCC +

0.3 V

Input Logic 0 VIL VGND -

0.3

0.2 x

VCC V

Input Logic Open IIF 0V < VIN < VCC (Note 2) ±1 µA

Input Leakage IIL 0V < VIN < VCC (Note 3) ±80 µA

fSSO < 67MHz 15

67MHz  fSSO < 101MHz 10

SSO Load CSSO

101MHz  fSSO < 134MHz 7

Crystal or Clock Input

Frequency fIN 16.0 33.4 MHz

Crystal ESR XESR 90 

Clock Input Duty Cycle FINDC 40 60 %

Crystal Parallel Load

Capacitance CL (Note 4) 18 pF

DC ELECTRICAL CHARACTERISTICS

(VCC = +3.0V to +3.6V, TA= -40°C to +125°C, unless otherwise noted.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Supply Current ICC1 CSSO = 15pF, SSO = 16MHz 15 mA

Power-Down Current ICCQ PDN = GND, all input pins open 200 µA

Output Leakage (SSO) IOZ PDN = GND -1 +1 µA

Low-Level Output Voltage

(SSO) VOL IOL = 4mA 0.4 V

High-Level Output Voltage

(SSO) VOH IOH = -4mA 2.4 V

Input Capacitance (X1/X2) CIN (Note 5) 5 pF

Spread-Spectrum Crystal Multiplier

Maxim Integrated 3

DS1080L

AC ELECTRICAL CHARACTERISTICS

(VCC = +3.0 to +3.6V, TA= -40°C to +125°C, unless otherwise noted.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Measured at VCC/2, CMSEL = 0 or open 40 60

SSO Duty Cycle SSODC Measured at VCC/2, CMSEL = 1 30 70 %

Rise Time tR(Note 6) 1.6 ns

Fall Time tF(Note 6) 1.6 ns

Peak Cycle-to-Cycle Jitter tJfSSO = 16MHz, TA= -40 to +85°C,

10,000 cycles (Note 5) 75 ps

16MHz 20

Power-Up Time tPOR PDN pin (Note 7) 33.4MHz 11 ms

Power-Down Time tPDN PDN pin (Notes 8 and 9) 100 ns

Dither Rate fDITHER (Note 9) fIN/992

Note 1: All voltages referenced to ground.

Note 2: Maximum source/sink current applied to input to be considered an open. Typical voltage range between 0.4 x VCC and 0.55

x VCC.

Note 3: Applicable to pins CMSEL, SMSEL, and PDN.

Note 4: See information about CL1 and CL2 in the

Applications Information

section at the end of the data sheet.

Note 5: Not production tested.

Note 6: For 7pF load.

Note 7: Time between PDN deasserted to output active.

Note 8: Time between PDN asserted to output high impedance.

Note 9: Guaranteed by design.

Spread-Spectrum Crystal Multiplier

Typical Operating Characteristics

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

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

DS1080L toc01

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

3.43.2

3.0

AT 16MHz

CMSEL = 1x

SUPPLY CURRENT vs. TEMPERATURE

DS1080L toc02

TEMPERATURE (°C)

SUPPLY CURRENT (mA)

1106010

-40

AT 16MHz

CMSEL = 1x

SUPPLY CURRENT vs. FREQUENCY

DS1080L toc03

FREQUENCY (MHz)

SUPPLY CURRENT (mA)

312621

AT 16MHz

CMSEL = 1x

PDN SUPPLY CURRENT

vs. TEMPERATURE

DS1080L toc04

TEMPERATURE (°C)

PDN SUPPLY CURRENT (mA)

1106010

0.01

0.02

0.03

0.04

0.05

0.06

-40

AT 16MHz

CMSEL = 1x

DUTY CYCLE vs. TEMPERATURE

DS1080L toc05

TEMPERATURE (°C)

DUTY CYCLE (%)

1106010

-40

AT 16MHz

DUTY CYCLE vs. SUPPLY VOLTAGE

DS1080L toc06

SUPPLY VOLTAGE (V)

DUTY CYCLE (%)

3.43.2

3.0 3.6

AT 16MHz

FREQUENCY SPECTRUM AT 133.3MHz

DS1080L toc07

OUTPUT FREQUENCY (MHz)

ATTENUATION (dB)

135.3133.3131.3

-60

-55

-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

-65

129.3 137.3

±1% DITHER

±0.5% DITHER

±2%

DITHER

NO DITHER

AT 133.3MHz

4 Maxim Integrated

DS1080L

Spread-Spectrum Crystal Multiplier

CRYSTAL

OSCILLATOR

1x/2x/4x CLOCK MULTIPLYING

PLL WITH SPREAD SPECTRUM

CONFIGURATION DECODE

AND CONTROL

VCC

GND

NOTE: SEE INFORMATION ABOUT CL1 AND CL2 IN THE APPLICATIONS INFORMATION SECTION AT THE END OF THE DATA SHEET.

PDN

SSO

CMSEL

SMSEL

16MHz

33.4MHz

fSSO = 16MHz

134MHz

CL1 CL2

fIN

fSSO

DS1080L

Block Diagram

Pin Description

PIN NAME FUNCTION

1 X1 Crystal Drive/Clock Input. A crystal with the proper loading capacitors is connected across X1 and X2.

Instead of a crystal, a clock can be applied at the X1 input.

2 GND Signal Ground

3 CMSEL

Clock Multiplier Select. Tri-level digital input.

0 = 1x

Open = 2x

1 = 4x

4 SMSEL

Spread-Spectrum Magnitude Select. Tri-level digital input.

0 = ±0.5%

Open = ±1.0%

1 = ±1.5%

5PDN

Power-Down/Spread-Spectrum Disable. Tri-level digital input.

0 = Power-Down/SSO Three-Stated

Open = Power-Up/Spread Spectrum Disabled

1 = Power-Up/Spread Spectrum Enabled

6 SSO Spread-Spectrum Clock Multiplier Output. Outputs a 1x, 2x, or 4x spread-spectrum version of the crystal

or clock applied at the X1/X2 pins.

7 VCC Supply Voltage

8 X2 Crystal Drive Output. A crystal with the proper loading capacitors is connected across X1 and X2.

If a clock is connected to X1, then X2 should be left open circuit.

Maxim Integrated 5

DS1080L

Spread-Spectrum Crystal Multiplier

6 Maxim Integrated

DS1080L

Detailed Description

The DS1080L is a crystal multiplier with center spread-

spectrum capability. A 16MHz to 33.4MHz crystal is

connected to the X1 and X2 pins. Alternately, a 16MHz

to 33.4MHz clock can be applied to X1 in place of the

crystal. In such applications, X2 would be left open cir-

cuit. Using the CMSEL input, the user selects whether

the attached crystal or input clock is multiplied by 1, 2,

or 4. The DS1080L is capable of generating spread-

spectrum clocks from 16MHz to 134MHz.

The PLL can dither the output clock about its center fre-

quency at a user-selectable magnitude. Using the

SMSEL input, the user selects the dither magnitude.

The PDN input can be used to place the device into a

low-power standby mode where the SSO output is tri-

stated. If the PDN pin is open, the SSO output is active

but the spread-spectrum dithering is disabled. The

spread-spectrum dither rate is fixed at fIN / 992 to keep

the dither rate above the audio frequency range. On

power-up, the output clock (SSO) remains three-stated

until the PLL reaches a stable frequency (fSSO) and

dither (fDITHER).

Applications Information

Crystal Selection

The DS1080L requires a parallel resonating crystal

operating in the fundamental mode, with an ESR of less

than 90!. The crystal should be placed very close to

the device to minimize excessive loading due to para-

sitic capacitances.

Oscillator Input

When driving the DS1080L using an external oscillator

clock, consider the input (X1) to be high impedance.

Crystal Capacitor Selection

The load capacitors CL1 and CL2 are selected based

on the crystal specifications (from the data sheet of the

crystal used). The crystal parallel load capacitance is

calculated as follows:

For the DS1080L use CL1 = CL2 = CLX.

In this case, the equation then reduces to:

where CL1 = CL2 = CLX.

Equation 2 is used to calculate the values of CL1 and

CL2 based on values on CLand CIN noted in the data

sheet electrical specifications.

Power-Supply Decoupling

To achieve best results, it is highly recommended that

a decoupling capacitor is used on the IC power-supply

pins. Typical values of decoupling capacitors are

0.001µF and 0.1µF. Use a high-quality, ceramic, sur-

face-mount capacitor, and mount it as close as possi-

ble to the VCC and GND pins of the IC to minimize lead

inductance.

CCC

LLX IN Equati

= +

2oon

CC x C

C C C

LL L

L L IN

=++

1 2

Equation1

+1.5%

+1.0%

+0.5%

-0.5%

-1.0%

-1.5%

DITHER CYCLE RATE = fDITHER = fIN/992

fSSO

Figure 1. Spread-Spectrum Frequency Modulation

Spread-Spectrum Crystal Multiplier

Maxim Integrated 7

DS1080L

Layout Considerations

As noted earlier, the crystal should be placed very

close to the device to minimize excessive loading due

to parasitic capacitances. Care should also be taken to

minimize loading on pins that could be open as a pro-

gramming option (SMSEL and CMSEL). Coupling on

inputs due to clocks should be minimized.

NOTE: IN THE ABOVE CONFIGURATION WITH PDN CONNECTED TO VCC, SMSEL CONNECTED TO GND

AND CMSEL OPEN, THE DEVICE IS IN NORMAL OPERATION WITH 2x CLOCK MULTIPLICATION, AND

SPREAD-SPECTRUM MAGNITUDE OF ±0.5%.

fSSO

VCC

SSO

PDN

CRYSTAL

CL1 CL2

DECOUPLING

CAPACITOR

GND

CMSEL

SMSEL

DS1080L

Typical Operating Circuit

Package Information

For the latest package outline information and land patterns

(footprints), go to www.maximintegrated.com/packages. Note

that a “+”, “#”, or “-” in the package code indicates RoHS status

only. Package drawings may show a different suffix character,

but the drawing pertains to the package regardless of RoHS status.

PACKAGE

TYPE

PACKAGE

CODE

OUTLINE

NO.

LAND

PATTERN NO.

8 µSOP U8+1 21-0036 90-0092

Spread-Spectrum Crystal Multiplier

DS1080L

Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent

licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and

max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.

Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000

Revision History

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

0 11/05 Initial release —

1 3/06 Changed VIHMIN from 0.7V x VCC to 0.08V x VCC and VILMAX from 0.3 x VCC to 0.2V x VCC

in the Recommended Operating Conditions table 2

2 10/09 Changed the part number in the Ordering Information table 1

3 10/11 Updated the Ordering Information table and Absolute Maximum Ratings section; added the

land pattern no. to the Package Information table 1, 2, 7

4 5/12 Clarified SSODC conditions and split limits based upon CMSEL input state 3

5 3/13

Updated the voltage ranges in the Absolute Maximum Ratings; changed the supply current

parameter from 13mA (max) to 15mA (max) in the DC Electrical Characteristics table;

changed the dither rate parameter from fIN/1024 to fIN/992 in the AC Electrical

Characteristics table; updated all graphs in the Typical Operating Characteristics section

2, 3, 4