MAXIM DS1087L User Manual
General Description
The DS1087L is a clock generator that produces a
spread-spectrum (dithered) square-wave output of frequencies from 130kHz to 66.6MHz. The DS1087L is
shipped from the factory programmed at a specific frequency and spread-spectrum percentage. The user still
has access to an internal frequency divider, selectable
2% or 4% dithered output, and programmable output
power-down/disable mode through a 2-wire programming interface. All the device settings are stored in nonvolatile (NV) EEPROM allowing it to operate in
stand-alone applications. The DS1087L has powerdown and output-enable control pins for power-sensitive applications.
Applications
Printers
Copiers
PCs
Computer Peripherals
Cell Phones
Cable Modems
Features
♦ Factory Programmed Square-Wave Generator
from 130kHz to 66.6MHz
♦ No External Timing Components Required
♦ EMI Reduction
♦ 2.7V to 3.6V Supply
♦ User Programmable Down to 130kHz with Divider
(Dependent on Master Oscillator Frequency)
♦ 2% or 4% Selectable Dithered Output
♦ Glitchless Output-Enable Control
♦ 2-Wire Serial Interface
♦ Nonvolatile Settings
♦ Power-Down Mode
♦ Programmable Output Power-Down/Disable Mode
DS1087L
3.3V Spread-Spectrum EconOscillator
______________________________________________ Maxim Integrated Products 1
Pin Configuration
Ordering Information
Rev 1; 11/03
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.
EconOscillator is a trademark of Dallas Semiconductor.
Typical Operating Circuits appear at end of data sheet.
Standard Frequency Options
Custom frequencies and over 20 standard frequencies available, contact factory.
PART TEMP RANGE PIN-PACKAGE
DS1087LU-yxx -40°C to +85°C 8 µSOP (118 mils)
PART FREQUENCY (MHz) SPREAD (%)
DS1087LU-202 2.0480 2
DS1087LU-402 2.0480 4
DS1087LU-210 10.0 2
DS1087LU-216 16.6 2
DS1087LU-266 66.6 2
DS1087LU-466 66.6 4
DS1087LU-yxx Fixed up to 66.6 2 or 4
TOP VIEW
OUT
V
CC
1
2
DS1087L
3
4
µSOP (118 mils)
87SCL
SDASPRD
PDN
6
OEGND
5
DS1087L
3.3V Spread-Spectrum EconOscillator
2 _____________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
RECOMMENDED DC OPERATING CONDITIONS
(VCC= 2.7V to 3.6V, TA= -40°C to +85°C.)
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.
DC ELECTRICAL CHARACTERISTICS
(VCC= 2.7V to 3.6V, TA= -40°C to +85°C.)
Voltage Range on VCCRelative to Ground ..........-0.5V to +6.0V
Voltage Range on SPRD, PDN, OE, SDA, SCL
Relative to Ground* ................................-0.5V to (V
CC
+ 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 ..................See IPC/JEDEC J-STD-020A
*This voltage must not exceed 6.0V.
PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS
Supply Voltage V
High-Level Input Voltage
(SDA, SCL, SPRD, PDN, OE)
Low-Level Input Voltage
(SDA, SCL, SPRD, PDN, OE)
CC
V
V
(Note 1) 2.7 3.6 V
IH
IL
0.7 x
V
CC
-0.3
V
CC
0.3
0.3 x
V
+
CC
V
V
PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS
High-Level Output Voltage (OUT) V
Low-Level Output Voltage (OUT) V
Low-Level Output Voltage (SDA)
High-Level Input Current I
Low-Level Input Current I
Supply Current (Active) I
Standby Current (Power-Down) I
V
OL1
V
OL2
CC
CCQ
OH
OL
IH
IL
IOH = -4mA, VCC = min 2.4 V
IOL = 4mA 0.4 V
3mA sink current 0 0.4
6mA sink current 0 0.6
VCC = 3.6V 1 µA
VIL = 0 -1 µA
CL = 15pF (output at f0)15mA
Power-down mode 5 µA
V
DS1087L
3.3V Spread-Spectrum EconOscillator
_____________________________________________________________________ 3
MASTER OSCILLATOR CHARACTERISTICS
(VCC= 2.7V to 3.6V, TA= -40°C to +85°C.)
AC ELECTRICAL CHARACTERISTICS
(VCC= 2.7V to 3.6V, TA= -40°C to +85°C.)
PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS
Master Oscillator Range
Available
Master Oscillator Frequency
Tolerance
Voltage Frequency
Variation
Temperature Frequency Variation
Temperature Frequency Variation
Dither Frequency Range
Dither Rate f0 / 4096 Hz
f
0
∆ f
0
f
∆ f
f
∆
f
∆
f
VCC = 3.3V, TA = +25°C (Notes 2, 13) -0.5 +0.5 %
0
V
Over voltage range, TA = +25°C (Note 3) -0.75 +0.75 %
0
f
T
0°C to +70°C, VCC = 3.3V (Note 4) -0.5 +0.5 %
0
f
T
-40°C to +85°C, VCC = 3.3V (Note 4) -1.5 +0.5 %
0
Prescaler bit J0 = 1 (Note 5) 2
Prescaler bit J0 = 0 (Note 5) 4
33.3 66.6 MHz
%
PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS
Frequency Stable After
PRESCALER Change
+
t
Power-Up Time
Enable of OUT After Exiting
Power-Down Mode
OUT Disabled After Entering
Power-Down Mode
Load Capacitance C
Output Duty Cycle (OUT) TA = +25°C 45 55 %
POR
t
STAB
t
STAB
t
PDN
(Note 6) 0.1 0.5 ms
(Note 7) 15 50 pF
L
1 period
500 µs
1ms
DS1087L
3.3V Spread-Spectrum EconOscillator
4 _____________________________________________________________________
AC ELECTRICAL CHARACTERISTICS—2-WIRE INTERFACE
(VCC= 2.7V to 3.6V, TA= 0°C to +70°C.)
NONVOLATILE MEMORY CHARACTERISTICS
(VCC= 2.7V to 3.6V)
PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS
SCL Clock Frequency f
Bus Free Time Between a STOP
and START Condition
Hold Time (repeated) START
Condition
LOW Period of SCL t
HIGH Period of SCL t
Setup Time for a Repeated
START
Data Hold Time t
Data Setup Time t
Rise Time of Both SDA and SCL
Signals
Fall Time of Both SDA and SCL
Signals
Setup Time for STOP t
Capacitive Load for Each Bus
NV Write Cycle Time t
Input Capacitance C
SCL
t
BUF
t
HD:STA
LOW
HIGH
t
SU:STA
HD:DAT
SU:DAT
t
t
SU:STO
C
WR
Fast mode (Note 8) 400
Standard mode (Note 8) 100
Fast mode (Note 8) 1.3
Standard mode (Note 8) 4.7
Fast mode (Notes 8 and 9) 0.6
Standard mode (Notes 8 and 9) 4.0
Fast mode (Note 8) 1.3
Standard mode (Note 8) 4.7
Fast mode (Note 8) 0.6
Standard mode (Note 8) 4.0
Fast mode 0.6
Standard mode 4.7
Fast mode (Notes 8, 10, and 11) 0 0.9
Standard mode (Notes 8, 10, and 11) 0 0.9
Fast mode (Note 8) 100
Standard mode (Note 8) 250
Fast mode (Note 12) 20 + 0.1C
R
Standard mode (Note 12) 20 + 0.1C
Fast mode (Note 12) 20 + 0.1C
F
Standard mode (Note 12) 20 + 0.1C
Fast mode 0.6
Standard mode 4.0
(Note 12) 400 pF
B
I
kHz
µs
µs
µs
µs
µs
µs
ns
B
B
B
B
5pF
300
1000
300
1000
10 ms
ns
ns
µs
PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS
Writes +70°C 10,000
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