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DS1086L

3.3V Spread-Spectrum EconOscillator

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

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

General Description

The DS1086L EconOscillator™ is a 3.3V programmable

clock generator that produces a spread-spectrum

(dithered) square-wave output of frequencies from

130kHz to 66.6MHz. The selectable dithered output

reduces radiated-emission peaks by dithering the fre-

quency 0.5%,1%, 2%, 4%, or 8% below the pro-

grammed frequency. The DS1086L has a power-down

mode and an output-enable control for power-sensitive

applications. All the device settings are stored in non-

volatile (NV) EEPROM memory allowing it to operate in

stand-alone applications.

Applications

Printers

Copiers

PCs

Computer Peripherals

Cell Phones

Cable Modems

Features

♦ User-Programmable Square-Wave Generator

♦ Frequencies Programmable from 130kHz to

66.6MHz

♦ 0.5%, 1%, 2%, 4%, or 8% Selectable Dithered

Output

♦ Adjustable Dither Rate

♦ Glitchless Output-Enable Control

♦ 2-Wire Serial Interface

♦ Nonvolatile Settings

♦ 2.7V to 3.6V Supply

♦ No External Timing Components Required

♦ Power-Down Mode

♦ 5kHz Master Frequency Step Size

♦ EMI Reduction

♦ Industrial Temperature Range: -40°C to +85°C

PDN

OEGND

SCL

SDASPRD

OUT

SOP

TOP VIEW

DS1086L

Pin Configuration

Ordering Information

XTL1/OSC1

μP

XTL2/OSC2

DITHERED 130kHz TO

66.6MHz OUTPUT

DECOUPLING CAPACITORS

(0.1μF and 0.01μF)

*SDA AND SCL CAN BE CONNECTED DIRECTLY HIGH IF THE DS1086L NEVER NEEDS

TO BE PROGRAMMED IN-CIRCUIT, INCLUDING DURING PRODUCTION TESTING.

SPRD

OUT

GND

N.C.

SCL*

SDA*

PDN

DS1086L

Typical Operating Circuit

19-6226; Rev 2; 3/12

PART

TEMP RANGE

PIN-PACKAGE

DS1086LU

-40°C to +85°C

8 μSOP (118 mils)

DS1086LU+

-40°C to +85°C

8 μSOP (118 mils)

EconOscillator is a trademark of Maxim Integrated Products, Inc.

Note: Contact the factory for custom settings.

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

Summary of content (17 pages)

PAGE 1
DS1086L 3.3V Spread-Spectrum EconOscillator General Description The DS1086L EconOscillator™ is a 3.3V programmable clock generator that produces a spread-spectrum (dithered) square-wave output of frequencies from 130kHz to 66.6MHz. The selectable dithered output reduces radiated-emission peaks by dithering the frequency 0.5%,1%, 2%, 4%, or 8% below the programmed frequency. The DS1086L has a power-down mode and an output-enable control for power-sensitive applications.
PAGE 2
DS1086L 3.3V Spread-Spectrum EconOscillator ABSOLUTE MAXIMUM RATINGS Voltage Range on VCC Relative to Ground ..........-0.5V to +6.0V Voltage Range on SPRD, PDN, OE, SDA, and SCL Relative to Ground* ..................................-0.5 to (VCC + 0.5V) Continuous Power Dissipation (TA = +70°C) μSOP (derate 4.5mW/°C above +70°C)........................362mW Operating Temperature Range ...........................-40°C to +85°C Programming Temperature Range .........................
PAGE 3
DS1086L 3.3V Spread-Spectrum EconOscillator MASTER OSCILLATOR CHARACTERISTICS (VCC = 2.7V to 3.6V, TA = -40°C to +85°C.) PARAMETER Master Oscillator Frequency Default Master Oscillator Frequency SYMBOL fOSC f0 CONDITIONS (Note 2) MIN TYP 33.3 Factory-programmed default MAX 66.6 48.65 Δf0 f0 VCC = 3.3V, TA = +25°C (Notes 3,17) Default frequency (f0) -0.5 +0.5 DAC step size -0.5 +0.5 Voltage Frequency Variation ΔfV f0 Over voltage range, TA = +25°C (Note 4) Default frequency -0.75 +0.
PAGE 4
DS1086L 3.3V Spread-Spectrum EconOscillator AC ELECTRICAL CHARACTERISTICS (VCC = 2.7V to 3.6V, TA = -40°C to +85°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 1 period 0.1 1 ms 0.1 0.
PAGE 5
DS1086L 3.3V Spread-Spectrum EconOscillator AC ELECTRICAL CHARACTERISTICS—2-WIRE INTERFACE (continued) (VCC = 2.7V to 3.6V, TA = -40°C to +85°C.) PARAMETER Setup Time for STOP SYMBOL tSU:STO Capacitive Load for Each Bus Line CB EEPROM Write Cycle Time tWR Input Capacitance CONDITIONS MIN Fast mode 0.6 Standard mode 4.0 TYP UNITS μs (Note 16) CI MAX 400 pF 10 ms 5 pF NONVOLATILE MEMORY CHARACTERISTICS (VCC = 2.7V to 3.
PAGE 6
DS1086L 3.3V Spread-Spectrum EconOscillator Typical Operating Characteristics (VCC = 3.3V, TA = 25°C, unless otherwise noted.) SUPPLY CURRENT vs. MASTER OSCILLATOR FREQUENCY 5 4 4.7pF LOAD 3 fO = 50MHz 6 fO = 33.3MHz 5 PRESCALER = 1 15pF LOAD 4 2 PRESCALER = 1 10 35 60 MASTER OSCILLATOR FREQUENCY PERCENT CHANGE vs. TEMPERATURE 0 fO = 50MHz -0.2 fO = 33.3MHz -0.4 fO = 33.3MHz -0.25 -0.50 fO = 50MHz -0.75 fO = 66MHz -0.5 3.0 3.3 54 3.6 fO = 66MHz 53 52 fO = 50MHz fO = 33.
PAGE 7
DS1086L 3.3V Spread-Spectrum EconOscillator Typical Operating Characteristics (continued) (VCC = 3.3V, TA = 25°C, unless otherwise noted.) POWER-DOWN CURRENT vs. SUPPLY VOLTAGE 1.6 1.5 1.4 1.3 1.2 1.62 1.1 1.60 1.58 1.56 1.54 1.52 1.50 1.48 1.46 1.44 1.0 3.0 3.3 -40 3.6 -15 10 35 TEMPERATURE (°C) SUPPLY CURRENT WITH OUTPUT DISABLED vs. SUPPLY VOLTAGE SUPPLY CURRENT WITH OUTPUT DISABLED vs. TEMPERATURE 2.7 DS1086L toc10 4.0 3.5 2.6 SUPPLY CURRENT (mA) 3.0 2.5 2.0 1.5 1.0 85 2.5 2.4 2.
PAGE 8
DS1086L 3.3V Spread-Spectrum EconOscillator Pin Description PIN NAME FUNCTION 1 OUT 2 SPRD Oscillator Output. The output frequency is determined by the OFFSET, DAC, and prescaler registers. 3 VCC Power Supply 4 GND Ground 5 OE Output Enable. When the pin is high, the output buffer is enabled. When the pin is low, the output is disabled but the master oscillator is still on. 6 PDN Power-Down. When the pin is high, the master oscillator is enabled.
PAGE 9
DS1086L 3.3V Spread-Spectrum EconOscillator VCC VCC SDA SCL 2-WIRE INTERFACE DS1086L EEPROM CONTROL REGISTERS DAC DAC OFFSET ADDR RANGE FREQUENCY CONTROL VOLTAGE PRESCALER VOLTAGE-CONTROLLED OSCILLATOR PDN MASTER OSCILLATOR OUTPUT DITHER CONTROL PRESCALER BY 1, 2, 4...256 OUT OE SPRD GND TRIANGLE WAVE GENERATOR DITHER SIGNAL Figure 3. Block Diagram Detailed Description A block diagram of the DS1086L is shown in Figure 3. The internal master oscillator generates a square wave with a 33.
PAGE 10
DS1086L 3.3V Spread-Spectrum EconOscillator Table 1.
PAGE 11
DS1086L 3.3V Spread-Spectrum EconOscillator JS2 to JS0: Jitter Percentage. These three bits select the amount of jitter in percent. The SPRD pin must be a logic high for the jitter to be enabled. Bit combinations not shown are reserved. JS2 JS1 JS0 JITTER % 0 0 0 0.5 0 0 1 1 0 1 0 2 1 0 0 4 1 1 1 8 ADDR (0Dh) Lo/HiZ: Output Low or High-Z. This bit determines the state of the output pin when the device is in powerdown mode or when the output is disabled.
PAGE 12
DS1086L 3.3V Spread-Spectrum EconOscillator Example Frequency Calculations Example #1: Calculate the register values needed to generate a desired output frequency of 11.0592MHz. Since the desired frequency is not within the valid master oscillator range of 33.3MHz to 66.6MHz, the prescaler must be used. Valid prescaler values are 2x where x equals 0 to 8 (and x is the value that is programmed into the P3 to P0 bits of the PRESCALER register).
PAGE 13
DS1086L 3.3V Spread-Spectrum EconOscillator SDA MSB SLAVE ADDRESS R/W DIRECTION BIT ACKNOWLEDGEMENT SIGNAL FROM RECEIVER ACKNOWLEDGEMENT SIGNAL FROM RECEIVER SCL 1 2 6 7 8 9 1 2 3–7 8 ACK START CONDITION 9 ACK REPEATED IF MORE BYTES ARE TRANSFERRED STOP CONDITION OR REPEATED START CONDITION Figure 4. 2-Wire Data Transfer Protocol The expected output frequency is not exactly equal to the desired frequency of 11.0592MHz. The difference is 450Hz.
PAGE 14
DS1086L 3.3V Spread-Spectrum EconOscillator LSB MSB 1 1 A1 A0 R/W DEVICE ADDRESS REA D/W DEVICE IDENTIFIER A2 IT 0 RIT EB 1 Figure 5. Slave Address SDA tBUF tHD:STA tLOW tR tSP tF SCL tHD:STA STOP tSU:STA tHIGH tSU:DAT START REPEATED START tSU:STO tHD:DAT Figure 6. 2-Wire AC Characteristics _______2-Wire Serial Port Operation 2-Wire Serial Data Bus The DS1086L communicates through a 2-wire serial interface.
PAGE 15
DS1086L 3.3V Spread-Spectrum EconOscillator data bytes transferred between START and STOP conditions is not limited, and is determined by the master device. The information is transferred byte-wise and each receiver acknowledges with a ninth bit. Within the bus specifications a standard mode (100kHz clock rate) and a fast mode (400kHz clock rate) are defined. The DS1086L works in both modes.
PAGE 16
DS1086L 3.
PAGE 17
DS1086L 3.3V Spread-Spectrum EconOscillator Revision History PAGES CHANGED REVISION NUMBER REVISION DATE 0 11/03 Initial release 1 9/07 Updated Table 2 10 2 3/12 Updated the Ordering Information, Absolute Maximum Ratings, and Package Information DESCRIPTION 1, 2, 16 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.