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General Description

The DS1086 EconOscillator™ is a programmable clock

generator that produces a spread-spectrum (dithered)

square-wave output of frequencies from 260kHz to

133MHz. The selectable dithered output reduces radi-

ated-emission peaks by dithering the frequency 2% or

4% below the programmed frequency. The DS1086 has

a power-down mode and an output-enable control for

power-sensitive applications. All the device settings are

stored in nonvolatile (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 260kHz to

133MHz

♦ 2% or 4% Selectable Dithered Output

♦ Glitchless Output-Enable Control

♦ 2-Wire Serial Interface

♦ Nonvolatile Settings

♦ 5V Supply

♦ No External Timing Components Required

♦ Power-Down Mode

♦ 10kHz Master Frequency Step Size

♦ EMI Reduction

DS1086

DS1086 Spread-Spectrum EconOscillator

______________________________________________ Maxim Integrated Products 1

PDN

OEGND

SCL

SDASPRD

OUT

µSOP/SO

TOP VIEW

DS1086

Pin Configuration

Ordering Information

DS1086

XTL1/OSC1

MICRO-

PROCESSOR

XTL2/OSC2

DITHERED 260kHz TO

133MHz OUTPUT

DECOUPLING CAPACITORS

(0.1µF and 0.01µF)

*SDA AND SCL CAN BE CONNECTED DIRECTLY HIGH IF THE DS1086 NEVER NEEDS

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

SPRD

OUT

GND

N.C.

SCL*

SDA*

PDN

Typical Operating Circuit

Rev 1; 9/03

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.

*Future Product

PART PIN-PACKAGE

DS1086U* 8 µSOP (118mil)

DS1086Z 8 SO (150mil)

EconOscillator is a trademark of Dallas Semiconductor.

Summary of content (14 pages)

PAGE 1
Rev 1; 9/03 DS1086 Spread-Spectrum EconOscillator The DS1086 EconOscillator™ is a programmable clock generator that produces a spread-spectrum (dithered) square-wave output of frequencies from 260kHz to 133MHz. The selectable dithered output reduces radiated-emission peaks by dithering the frequency 2% or 4% below the programmed frequency. The DS1086 has a power-down mode and an output-enable control for power-sensitive applications.
PAGE 2
DS1086 DS1086 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 (See Note 1).......-0.5 to (VCC + 0.5V) Note 1: Operating Temperature Range...............................0°C to +70°C Storage Temperature Range .............................-55°C to +125°C Soldering Temperature ..................See IPC/JEDEC J-STD-020A This voltage must not exceed 6.0V.
PAGE 3
DS1086 Spread-Spectrum EconOscillator DS1086 MASTER OSCILLATOR CHARACTERISTICS (VCC = 5V ±5%, TA = 0°C to +70°C.) PARAMETER Master Oscillator Range Default Master Oscillator Frequency SYMBOL fOSC CONDITION (Note 2) MIN TYP 66 f0 MAX UNITS 133 MHz 97.1 MHz Master Oscillator Frequency Tolerance ∆f0 f0 VCC = 5V, TA = +25°C (Notes 3,17) Default frequency (f0) -0.75 +0.75 DAC step size -0.75 +0.
PAGE 4
DS1086 DS1086 Spread-Spectrum EconOscillator AC ELECTRICAL CHARACTERISTICS (VCC = 5V ±5%, TA = 0°C to +70°C.) PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS 1 Period 0.2 1 ms 0.1 0.5 ms Frequency Stable After Prescaler Change Frequency Stable After DAC or Offset Change Power-Up Time (Note 9) tpor + tstab (Note 10) Enable of OUT After Exiting Power-Down Mode tstab 500 µs OUT High-Z After Entering Power-Down Mode tpdn 0.
PAGE 5
DS1086 Spread-Spectrum EconOscillator (VCC = 5V ±5%, TA = 0°C to +70°C.) PARAMETER Setup Time for STOP SYMBOL tSU:STO Capacitive Load for Each Bus Line CB NV Write-Cycle Time tWR Input Capacitance Note 1: Note 2: Note 3: Note 4: Note 5: Note 6: Note 7: Note 8: Note 9: Note 10: Note 11: Note 12: Note 13: Note 14: Note 15: Note 16: Note 17: CI CONDITION MIN Fast mode 0.6 Standard mode 4.0 TYP MAX UNITS µs (Note 16) 5 400 pF 10 ms pF All voltages are referenced to ground.
PAGE 6
Typical Operating Characteristics (VCC = 5.0V, TA = 25°C, unless otherwise noted) SUPPLY CURRENT vs. VOLTAGE 18 18 19 18 16 15 14 17 CURRENT (mA) CURRENT (mA) 16 15 14 16 15 13 13 12 12 12 11 11 11 10 10 10 20 30 40 50 60 4.85 4.95 5.05 5.15 5.25 0 100 150 200 250 VOLTAGE (V) PRESCALER SUPPLY CURRENT vs. PRESCALER SUPPLY CURRENT vs. TEMPERATURE WITH OE = 0 SUPPLY CURRENT vs.
PAGE 7
DS1086 Spread-Spectrum EconOscillator PIN NAME 1 OUT Oscillator Output FUNCTION 2 SPRD Dither Enable. When the pin is high, the dither is enabled. When the pin is low, the dither is disabled. 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 8
DS1086 DS1086 Spread-Spectrum EconOscillator Table 1. Register Summary REGISTER ADDR MSB PRESCALER DAC HIGH DAC LOW OFFSET ADDR RANGE WRITE EE 02h 08h 09h 0Eh 0Dh 37h 3Fh X1 b9 b1 X1 X1 XX BINARY X1 b8 b0 X1 X1 XX XX b7 X0 X1 X1 XX J0 P3 b6 b5 X0 X0 b4 b3 X1 WC b4 b3 NO DATA P2 b4 X0 b2 A2 b2 P1 b3 X0 b1 A1 b1 LSB FACTORY DEFAULT ACCESS P0 b2 X0 b0 A0 b0 11100000b 01111101b 00000000b 111- ----b 11110000b xxx- - - - - b R/W R/W R/W R/W R/W R — — X0 = Don’t care, reads as zero.
PAGE 9
DS1086 Spread-Spectrum EconOscillator DS1086 VCC SDA SCL 2-WIRE INTERFACE EEPROM CONTROL REGISTERS DS1086 DAC OFFSET DAC ADDR RANGE PRESCALER FREQUENCY CONTROL VOLTAGE 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.
PAGE 10
DS1086 DS1086 Spread-Spectrum EconOscillator ADDR Register The A0, A1, A2 bits determine the 2-wire slave address. The WC bit determines if the EEPROM is to be written to after register contents have been changed. If WC = 0 (default), EEPROM is written automatically after a WRITE EE command. If WC = 1, the EEPROM is only written when the WRITE EE command is issued. In applications where the register contents are frequently written, the WC bit should be set to 1.
PAGE 11
DS1086 Spread-Spectrum EconOscillator The expected output frequency is not exactly equal to the desired frequency of 11.0592MHz. The difference is 450Hz. In terms of percentage, Equation 6 shows that the expected error is 0.004%. The expected error assumes typical values and does not include deviations from the typical as specified in the electrical tables.
PAGE 12
DS1086 DS1086 Spread-Spectrum EconOscillator MSB LSB 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 Since the expected output frequency is equal to the desired frequency, the calculated error is 0%.
PAGE 13
DS1086 Spread-Spectrum EconOscillator also the beginning of the next serial transfer, the bus is not released. 2) SCL and SDA cannot be left floating when they are not used. If the DS1086 never needs to be programmed incircuit, including during production testing, SDA and SCL can be tied high. The SPRD pin must be tied either high or low. Data transfer from a slave transmitter to a master receiver. The first byte (the slave address) is transmitted by the master. The slave then returns an acknowledge bit.
PAGE 14
DS1086 DS1086 Spread-Spectrum EconOscillator TYPICAL 2-WIRE WRITE TRANSACTION MSB START 1 LSB 0 1 1 A2* A1* A0* R/W DEVICE ADDRESS DEVICE IDENTIFIER MSB SLAVE ACK b7 READ/ WRITE b5 b4 b3 B0h START 1 0 1 1 0 0 0 0 b2 b1 b0 SLAVE ACK b7 LSB b6 COMMAND/REGISTER ADDRESS EXAMPLE 2-WIRE TRANSACTIONS (WHEN A0, A1, AND A2 ARE ZERO) B0h 0Eh SLAVE SLAVE A) SINGLE BYTE WRITE START 1 0 1 1 0 0 0 0 ACK 0 0 0 0 1 1 1 0 ACK -WRITE OFFSET REGISTER B) SINGLE BYTE READ -READ OFFSET REGISTER MSB LSB