Rainbow Electronics 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
PDN
OEGND
1
2
87SCL
SDASPRD
V
CC
OUT
µSOP (118 mils)
TOP VIEW
3
4
6
5
DS1087L
Pin Configuration
Ordering Information
Rev 0; 7/03
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.
PART TEMP RANGE PIN-PACKAGE
DS1087LU-yxx -40°C to +85°C
8 µSOP (118 mils)
EconOscillator is a trademark of Dallas Semiconductor.
Typical Operating Circuits appear at end of data sheet.
Standard Frequency Options
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
Custom frequencies and over 20 standard frequencies available, contact factory.
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.
PARAMETER
SYMBOL
CONDITION
MIN
TYP
MAX
UNITS
Supply Voltage V
CC
(Note 1) 2.7 3.6 V
High-Level Input Voltage
(SDA, SCL, SPRD, PDN, OE)
V
IH
0.7 x
V
CC
+
0.3
V
Low-Level Input Voltage
(SDA, SCL, SPRD, PDN, OE)
V
IL
0.3 x
V
DC ELECTRICAL CHARACTERISTICS
(VCC= 2.7V to 3.6V, TA= -40°C to +85°C.)
PARAMETER
CONDITION
UNITS
V
OH
IOH = -4mA, VCC = min 2.4 V
V
OL
IOL = 4mA 0.4 V
V
OL1
3mA sink current 0 0.4
V
OL2
6mA sink current 0 0.6
V
High-Level Input Current I
IH
VCC = 3.6V 1 µA
Low-Level Input Current I
IL
VIL = 0 -1 µA
Supply Current (Active) I
CC
CL = 15pF (output at f0)15mA
Standby Current (Power-Down) I
CCQ
Power-down mode 5 µA
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.
V
CC
High-Level Output Voltage (OUT)
Low-Level Output Voltage (OUT)
Low-Level Output Voltage (SDA)
SYMBOL
-0.3
MIN TYP MAX
V
CC
DS1087L
3.3V Spread-Spectrum EconOscillator
_____________________________________________________________________ 3
MASTER OSCILLATOR CHARACTERISTICS
(VCC= 2.7V to 3.6V, TA= -40°C to +85°C.)
PARAMETER
CONDITION
UNITS
Master Oscillator Range
Available
f
0
MHz
Master Oscillator Frequency
Tolerance
∆
f
0
f
0
VCC = 3.3V, TA = +25°C (Note 2)
%
Voltage Frequency
Variation
∆
f
V
f
0
Over voltage range, TA = +25°C (Note 3)
%
Temperature Frequency Variation
∆
f
T
f
0
0°C to +70°C, VCC = 3.3V (Note 4)
%
Temperature Frequency Variation
∆
f
T
f
0
-40°C to +85°C, VCC = 3.3V (Note 4)
%
Prescaler bit J0 = 1 (Note 5) 2
Dither Frequency Range
Prescaler bit J0 = 0 (Note 5) 4
%
Dither Rate
Hz
AC ELECTRICAL CHARACTERISTICS
(VCC= 2.7V to 3.6V, TA= -40°C to +85°C.)
PARAMETER
SYMBOL
CONDITION
MIN
TYP
MAX
UNITS
Frequency Stable After
PRESCALER Change
1
period
Power-Up Time
t
POR
+
t
STAB
(Note 6) 0.1 0.5 ms
Enable of OUT After Exiting
Power-Down Mode
t
STAB
500 µs
OUT Disabled After Entering
Power-Down Mode
t
PDN
1ms
Load Capacitance C
L
(Note 7) 15 50 pF
Output Duty Cycle (OUT) TA = +25°C 45 55 %
SYMBOL
MIN TYP MAX
33.3 66.6
-0.5 +0.5
-0.75 +0.75
-0.5 +0.5
-1.5 +0.5
f0 / 2048
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.)
PARAMETER
SYMBOL
CONDITION
MIN
TYP
MAX
UNITS
Fast mode (Note 8) 400
SCL Clock Frequency f
SCL
Standard mode (Note 8) 100
kHz
Fast mode (Note 8)
Bus Free Time Between a STOP
and START Condition
t
BUF
Standard mode (Note 8) 4.7
µs
Fast mode (Notes 8 and 9) 0.6
Hold Time (repeated) START
Condition
Standard mode (Notes 8 and 9) 4.0
µs
Fast mode (Note 8) 1.3
LOW Period of SCL t
LOW
Standard mode (Note 8) 4.7
µs
Fast mode (Note 8) 0.6
HIGH Period of SCL t
HIGH
Standard mode (Note 8) 4.0
µs
Fast mode 0.6
Setup Time for a Repeated
START
t
SU:STA
Standard mode 4.7
µs
Fast mode (Notes 8, 10, and 11) 0 0.9
Data Hold Time
Standard mode (Notes 8, 10, and 11) 0 0.9
µs
Fast mode (Note 8)
Data Setup Time
Standard mode (Note 8)
ns
Fast mode (Note 12)
300
Rise Time of Both SDA and SCL
Signals
t
R
Standard mode (Note 12)
ns
Fast mode (Note 12)
300
Fall Time of Both SDA and SCL
Signals
t
F
Standard mode (Note 12)
ns
Fast mode 0.6
Setup Time for STOP
Standard mode 4.0
µs
Capacitive Load for Each Bus
C
B
(Note 12) 400 pF
NV Write Cycle Time t
WR
10 ms
Input Capacitance C
I
5pF
NONVOLATILE MEMORY CHARACTERISTICS
(VCC= 2.7V to 3.6V)
PARAMETER
SYMBOL
CONDITION
MIN
TYP
MAX
UNITS
Writes +70°C
1.3
t
HD:STA
t
HD:DAT
t
SU:DAT
t
SU:STO
100
250
20 + 0.1C
20 + 0.1C
20 + 0.1C
20 + 0.1C
10,000
B
B
B
B
1000
1000
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