Datasheet

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General Description

The DS1089L is a clock generator that produces a

spread spectrum (dithered) square-wave output of fre-

quencies from 130kHz to 66.6MHz. The DS1089L is

shipped from the factory programmed at a specific fre-

quency. The DS1089L is pin-for-pin compatible with the

DS1087L, however, the DS1089L dithers at equal per-

centages above and below the center frequency. The

user still has access to the internal frequency divider,

selectable ±1%, ±2%, ±4%, or ±8% dithered output,

dithering rate, and programmable output power-

down/disable mode through an I

C-compatible pro-

gramming interface. All the device settings are stored

in nonvolatile (NV) EEPROM allowing it to operate in

stand-alone applications. The DS1089L also has

power-down and output-enable control pins for power-

sensitive applications.

Applications

Automotive Infotainment

Printers

Copiers

Computer Peripherals

POS Terminals

Cable Modems

Features

♦ Factory-Programmed Square-Wave Generator

from 33.3MHz to 66.6MHz

♦ Center Frequency Remains Constant Independent

of Dither Percentage

♦ No External Timing Components Required

♦ EMI Reduction

♦ Variable Dither Frequency

♦ User Programmable Down to 130kHz with Divider

(Dependent on Master Oscillator Frequency)

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

Output

♦ Glitchless Output-Enable Control

♦ I

C-Compatible Serial Interface

♦ Nonvolatile Settings

♦ Power-Down Mode

♦ Programmable Output Power-Down/Disable Mode

DS1089L

3.3V Center Spread-Spectrum EconOscillator™

______________________________________________ Maxim Integrated Products 1

Rev 2; 5/06

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.

*See Standard Frequency Options Table.

Ordering Information

Pin Configuration and Typical Operating Circuits appear at end of data sheet.

PART TEMP RANGE PIN-PACKAGE

DS1089LU-yxx* -40°C to +85°C

8 µSOP (118 mil)

Add “/T” for Tape and Reel.

Custom frequencies available, contact factory.

Standard Frequency Options

PART FREQUENCY (MHz) SPREAD (±%) DITHER FREQUENCY

DS1089LU-21G 14.7456 1 f

MOSC

/ 4096

DS1089LU-4CL 18.432 2 f

MOSC

/ 4096

DS1089LU-22F 24.576 1 f

MOSC

/ 2048

DS1089LU-23C 33.3 1 f

MOSC

/ 4096

DS1089LU-450 50.0 2 f

MOSC

/ 4096

DS1089LU-866 66.6 4 f

MOSC

/ 4096

DS1089LU-yxx Fixed up to 66.6 1, 2, 4, or 8 f

MOSC

/ 2048 or 4096 or 8192

EconOscillator is a trademark of Dallas Semiconductor Corp.

Summary of content (12 pages)

PAGE 1
Rev 2; 5/06 3.3V Center Spread-Spectrum EconOscillator™ Features The DS1089L is a clock generator that produces a spread spectrum (dithered) square-wave output of frequencies from 130kHz to 66.6MHz. The DS1089L is shipped from the factory programmed at a specific frequency. The DS1089L is pin-for-pin compatible with the DS1087L, however, the DS1089L dithers at equal percentages above and below the center frequency.
PAGE 2
DS1089L 3.3V Center Spread-Spectrum EconOscillator™ ABSOLUTE MAXIMUM RATINGS Voltage on VCC Relative to Ground.......................-0.5V to +6.0V Voltage on SPRD, PDN, OE, SDA, SCL Relative to Ground* ........................-0.5V to (VCC + 0.5V) Operating Temperature Range ...........................-40°C to +85°C Programming Temperature Range .........................0°C to +70°C Storage Temperature Range .............................-55°C to +125°C Soldering Temperature...................
PAGE 3
.3V Center Spread-Spectrum EconOscillator™ DS1089L MASTER OSCILLATOR CHARACTERISTICS (VCC = +2.7V to +3.6V, TA = -40°C to +85°C) PARAMETER Internal Master Oscillator Frequency Master Oscillator Frequency Tolerance Voltage Frequency Variation Temperature Frequency Variation (Note 4) SYMBOL CONDITION MAX UNITS 33.3 66.6 MHz VCC = 3.3V, TA = +25°C (Notes 2, 10) -0. 5 +0. 5 % TA = +25°C (Note 3) -0.75 +0.75 % TA = 0°C to +85°C -0.75 +0.75 TA = -40°C to 0°C -2.00 +0.
PAGE 4
DS1089L 3.3V Center Spread-Spectrum EconOscillator™ AC ELECTRICAL CHARACTERISTICS—I2C INTERFACE (VCC = +2.7V to +3.6V, TA = -40°C to +85°C, unless otherwise noted. Timing referenced to VIL(MAX) and VIH(MIN).) PARAMETER SYMBOL CONDITIONS TYP UNITS 400 kHz fSCL Bus Free Time Between Stop and Start Conditions tBUF 1.3 µs tHD:STA 0.6 µs Low Period of SCL tLOW 1.3 µs High Period of SCL tHIGH 0.6 Data Hold Time tHD:DAT 0 Data Setup Time tSU:DAT 100 Start Setup Time tSU:STA 0.
PAGE 5
3.3V Center Spread-Spectrum EconOscillator™ ACTIVE SUPPLY CURRENT vs. TEMPERATURE SUPPLY CURRENT (mA) 50MHz 130kHz 33MHz 2 66MHz 7 6 5 4 50MHz 3 10 130kHz 33MHz TA = +25°C, fMOSC = 50MHz, OUTPUT UNLOADED 8 2 DS 1089L toc03 8 6 4 TA = +25°C, OUTPUT UNLOADED 9 DS 1089L toc02 8 66MHz 10 SUPPLY CURRENT (mA) TA = +25°C, OUTPUT UNLOADED DS 1089L toc01 10 SUPPLY CURRENT vs. PRESCALER SUPPLY CURRENT (mA) ACTIVE SUPPLY CURRENT vs. SUPPLY VOLTAGE 6 4 3.6V 3.3V 2.7V 2 1 0 0 2.
PAGE 6
Typical Operating Characteristics (continued) (VCC = 3.3V, TA = +25°C, unless otherwise noted.) 56 66MHz 33MHz DUTY CYCLE (%) 50MHz VCC = 3.3V 54 52 50MHz 54 52 33MHz 50 -10 POWER SPECTRUM (dBm) 66MHz 0 DS 1089L toc08 TA = +25°C 56 58 DS 1089L toc07 58 SPECTRUM COMPARISON (120kHz BW, SAMPLE DETECT) DUTY CYCLE vs. TEMPERATURE 2.7 3.0 3.3 SUPPLY VOLTAGE (V) NO SPREAD -20 -30 -40 ±8% ±4% -50 -60 fMOSC = 50MHz, DITHER RATE = fMOSC / 4096 -80 130kHz 3.
PAGE 7
3.3V Center Spread-Spectrum EconOscillator™ PDN H/W GATED OUTPUT OE DS1089L SDA CONTROL REGISTERS I2C I2C SERIAL ADDRESS INTERFACE BITS OUTPUT CONTROL S/W GATED OUTPUT SCL ADDR J3 J2 OE X WC A2 A1 A0 WRITE EE COMMAND EEPROM WRITE CONTROL FACTORYPROGRAMMED MASTER OSCILLATOR PRESCALER fMOSC DIVIDE BY 1, 2, 4, 8, 16, 32, 64, 128, OR 256 33.3MHz TO 66.
PAGE 8
DS1089L 3.3V Center Spread-Spectrum EconOscillator™ Output Control Dither Percentage Settings Two user control signals control the output. The output enable pin (OE) gates the output buffer and the powerdown pin (PDN) disables the master oscillator and turns off the output for power-sensitive applications. (Note: the power-down command must persist for at least two output frequency cycles plus 10µs for deglitching purposes.
PAGE 9
3.3V Center Spread-Spectrum EconOscillator™ DS1089L When dither is enabled (by selecting a dither frequency setting greater than 0 with SPRD high), the master oscillator frequency is dithered around the center frequency by the selected percentage from the programmed fMOSC (see Figure 2). For example, if fMOSC is programmed to 40MHz (factory setting) and the dither amount is programmed to ±1%, the frequency of fMOSC will dither between 39.6MHz and 40.
PAGE 10
DS1089L 3.3V Center Spread-Spectrum EconOscillator™ bit, the value of the ADDR register is always written immediately to EEPROM. When the WRITE EE command has been received, the contents of the registers are written into the EEPROM, thus locking in the register settings. WRITE EE Command The WRITE EE command is useful in closed-loop applications where the registers are frequently written.
PAGE 11
3.3V Center Spread-Spectrum EconOscillator™ DS1089L SDA tBUF tSP tHD:STA tLOW tR tF SCL tHD:STA STOP tSU:STA tHIGH tSU:DAT START REPEATED START tSU:STO tHD:DAT Figure 5.
PAGE 12
DS1089L 3.3V Center Spread-Spectrum EconOscillator™ Typical Operating Circuits STAND-ALONE MODE PROCESSOR-CONTROLLED MODE VCC DITHERED 130kHz TO 66.6MHz OUTPUT 4.7kΩ OUT SCL DS1089L SDA VCC OUT XTL1/OSC1 2-WIRE INTERFACE VCC SPRD DITHERED 130kHz TO 66.6MHz OUTPUT 4.7kΩ SCL* VCC XTL2/OSC2 N.C. SPRD VCC DS1089L SDA* MICROPROCESSOR VCC PDN VCC PDN GND OE GND OE DECOUPLING CAPACITORS (0.1µF and 0.01µF) DECOUPLING CAPACITORS (0.1µF and 0.