General Description
The DS1087L is a clock generator that produces a
spread-spectrum (dithered) square-wave output of fre-
quencies from 130kHz to 66.6MHz. The DS1087L is
shipped from the factory programmed at a specific fre-
quency 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 program-
ming interface. All the device settings are stored in non-
volatile (NV) EEPROM allowing it to operate in
stand-alone applications. The DS1087L has power-
down and output-enable control pins for power-sensi-
tive 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
OE
GND
1
2
8
7
SCL
SDA
SPRD
V
CC
OUT
µSOP (118 mils)
TOP VIEW
3
4
6
5
DS1087L
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.
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 avail-
able, contact factory.
DS1087L
3.3V Spread-Spectrum EconOscillator
2
_____________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
RECOMMENDED DC OPERATING CONDITIONS
(V
CC
= 2.7V to 3.6V, T
A
= -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
V
CC
+
0.3
V
Low-Level Input Voltage
(SDA, SCL, SPRD,
PDN, OE)
V
IL
-0.3
0.3 x
V
CC
V
DC ELECTRICAL CHARACTERISTICS
(V
CC
= 2.7V to 3.6V, T
A
= -40°C to +85°C.)
PARAMETER
SYMBOL
CONDITION
MIN
TYP
MAX
UNITS
High-Level Output Voltage (OUT)
V
OH
I
OH
= -4mA, V
CC
= min
2.4
V
Low-Level Output Voltage (OUT)
V
OL
I
OL
= 4mA
0.4
V
V
OL1
3mA sink current
0
0.4
Low-Level Output Voltage (SDA)
V
OL2
6mA sink current
0
0.6
V
High-Level Input Current
I
IH
V
CC
= 3.6V
1
µA
Low-Level Input Current
I
IL
V
IL
= 0
-1
µA
Supply Current (Active)
I
CC
C
L
= 15pF (output at f
0
)
15
mA
Standby Current (Power-Down)
I
CCQ
Power-down mode
5
µA
Voltage Range on V
CC
Relative 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.
DS1087L
3.3V Spread-Spectrum EconOscillator
_____________________________________________________________________
3
MASTER OSCILLATOR CHARACTERISTICS
(V
CC
= 2.7V to 3.6V, T
A
= -40°C to +85°C.)
PARAMETER
SYMBOL
CONDITION
MIN
TYP
MAX
UNITS
Master Oscillator Range
Available
f
0
33.3
66.6
MHz
Master Oscillator Frequency
Tolerance
f
0
f
0
V
CC
= 3.3V, TA = +25
°C (Notes 2, 13)
-0.5
+0.5
%
Voltage Frequency
Variation
f
V
f
0
Over voltage range, T
A
= +25
°C (Note 3)
-0.75
+0.75
%
Temperature Frequency Variation
f
T
f
0
0°C to +70°C, V
CC
= 3.3V (Note 4)
-0.5
+0.5
%
Temperature Frequency Variation
f
T
f
0
-40°C to +85°C, V
CC
= 3.3V (Note 4)
-1.5
+0.5
%
Prescaler bit J0 = 1 (Note 5)
2
Dither Frequency Range
Prescaler bit J0 = 0 (Note 5)
4
%
Dither Rate
f
0
/ 4096
Hz
AC ELECTRICAL CHARACTERISTICS
(V
CC
= 2.7V to 3.6V, T
A
= -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
1
ms
Load Capacitance
C
L
(Note 7)
15
50
pF
Output Duty Cycle (OUT)
T
A
= +25°C
45
55
%
DS1087L
3.3V Spread-Spectrum EconOscillator
4
_____________________________________________________________________
AC ELECTRICAL CHARACTERISTICS--2-WIRE INTERFACE
(V
CC
= 2.7V to 3.6V, T
A
= 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)
1.3
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
t
HD:STA
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
t
HD:DAT
Standard mode (Notes 8, 10, and 11)
0
0.9
µs
Fast mode (Note 8)
100
Data Setup Time
t
SU:DAT
Standard mode (Note 8)
250
ns
Fast mode (Note 12)
20 + 0.1C
B
300
Rise Time of Both SDA and SCL
Signals
t
R
Standard mode (Note 12)
20 + 0.1C
B
1000
ns
Fast mode (Note 12)
20 + 0.1C
B
300
Fall Time of Both SDA and SCL
Signals
t
F
Standard mode (Note 12)
20 + 0.1C
B
1000
ns
Fast mode
0.6
Setup Time for STOP
t
SU:STO
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
5
pF
NONVOLATILE MEMORY CHARACTERISTICS
(V
CC
= 2.7V to 3.6V)
PARAMETER
SYMBOL
CONDITION
MIN
TYP
MAX
UNITS
Writes
+70°C
10,000
DS1087L
3.3V Spread-Spectrum EconOscillator
_____________________________________________________________________
5
Note 1:
All voltages are referenced to ground.
Note 2:
This is the absolute accuracy of the master oscillator frequency at the default settings.
Note 3:
This is the change that is observed in master oscillator frequency with changes in voltage from nominal voltage at
T
A
= +25°C.
Note 4:
This is the percentage frequency change from the +25°C frequency due to temperature at V
CC
= 3.3V.
Note 5:
The dither deviation of the master oscillator frequency is unidirectional and lower than the undithered frequency.
Note 6:
This indicates the time elapsed between power-up and the output becoming active. An on-chip delay is intentionally
introduced to allow the oscillator to stabilize. t
stab
is equivalent to approximately 512 master clock cycles and depends
on the programmed master oscillator frequency.
Note 7:
Output voltage swings may be impaired at high frequencies combined with high output loading.
Note 8:
A fast-mode device can be used in a standard-mode system, but the requirement t
SU:DAT
> 250ns must then be met. This
is automatically the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch
the LOW period of the SCL signal, it must output the next data bit to the SDA line at least t
R MAX
+ t
SU:DAT
= 1000ns +
250ns = 1250ns before the SCL line is released.
Note 9:
After this period, the first clock pulse is generated.
Note 10:
A device must internally provide a hold time of at least 300ns for the SDA signal (referred to as the V
IH MIN
of the SCL sig-
nal) to bridge the undefined region of the falling edge of SCL.
Note 11:
The maximum t
HD:DAT
need only be met if the device does not stretch the LOW period (t
LOW
) of the SCL signal.
Note 12:
C
B
--total capacitance of one bus line, timing referenced to 0.9 x V
CC
and 0.1 x V
CC
.
Note 13:
Typical frequency shift due to aging is ±0.5%. Aging stressing includes Level 1 moisture reflow preconditioning (24hr
+125°C bake, 168hr 85°C/85%RH moisture soak, and 3 solder reflow passes +240 +0/-5°C peak) followed by 1000hr
max V
CC
biased 125°C HTOL, 1000 temperature cycles at -55°C to +125°C, and 168hr 121°C/2 ATM Steam/Unbiased
Autoclave.
Typical Operating Characteristics
(V
CC
= 3.3V, T
A
= +25°C, unless otherwise noted.)
ACTIVE SUPPLY CURRENT
vs. TEMPERATURE
DS1087L toc01
TEMPERATURE (
°C)
CURRENT (mA)
80
70
60
50
40
30
20
10
0
-10
-20
-30
5.5
6.0
6.5
7.0
7.5
5.0
-40
90
V
CC
= 3.3V
FREQUENCY = 66.6MHz
OE = PDN = V
CC
15pF LOAD
8.2pF LOAD
4.7pF LOAD
UNLOADED
VOLTAGE (V)
3.5
3.4
2.8 2.9 3.0
3.2
3.1
3.3
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
0
2.7
3.6
ACTIVE SUPPLY CURRENT
vs. VOLTAGE
DS1087L toc02
CURRENT (mA)
FREQUENCY = 66.6MHz
OUTPUT UNLOADED
OE = PDN = V
CC
SUPPLY CURRENT vs. PRESCALER
DS1087L toc03
PRESCALER (DECIMAL)
100
10
1
1000
1
2
3
4
5
6
7
0
CURRENT (mA)
OUTPUT UNLOADED
3.6V
3.3V
2.7V
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