Rainbow Electronics DS1094L User Manual
General Description
The DS1094L is a silicon oscillator that generates four
multiphase, spread-spectrum, square-wave outputs.
Frequencies between 2MHz and 31.25kHz can be output in either two, three, or four-phase mode. The internal master oscillator can be dithered by either 0, 2, 4,
or 8% to reduce the amount of peak spectral energy at
the fundamental and harmonic clock frequencies. This
significantly reduces the amount of electromagnetic
interference (EMI) radiation that is generated at the system level. The DS1094L is ideally suited as a clock generator for switched-mode power supplies. The outputs
generated by the DS1094L are used by DC-DC circuitry to efficiently shift voltages either up or down. The
DS1094L can be programmed using the I2C™-compatible, 2-wire serial interface to select the output frequency, number of clock phases, and dither rate, or
optionally it can be shipped from the factory custom
programmed.
Applications
Switch-Mode Power Supplies
Servers
Printers
Automotive Telematics and Infotainment
Features
♦ EconOscillator™ with Two, Three, or Four Phase
Outputs
♦ Ideally Suited as the Clock Generator for Switch-
Mode Power Supplies
♦ Output Frequencies Programmable from 2MHz to
31.25kHz
♦ Dithered Output Significantly Reduces EMI
Emissions
♦ No External Timing Components Required
♦ Nonvolatile (NV) Configuration Settings
♦ User-Programmable—Factory Programmed
Options Available
♦ Operating Temperature Range: -40°C to +85°C
DS1094L
Multiphase Spread-Spectrum EconOscillator
______________________________________________ Maxim Integrated Products 1
OUT4
OUT3GND
1
2
87SCL
SDAOUT2
V
CC
OUT1
µSOP
TOP VIEW
3
4
6
5
DS1094L
Pin Configuration
Ordering Information
V
OUT
V
IN
PHASE 1
PHASE 2
PHASE 3
DC-DC
STEP-DOWN
CONVERTER
OUT1
OUT2
OUT3
OUT4
GND
SCL
SDA
V
CC
V
CC
DS1094L
R
PULLUP
THREE-PHASE
EXAMPLE WITH
DITHERED CLOCKS TO
REDUCE EMI
DC-DC
STEP-DOWN
CONVERTER
DC-DC
STEP-DOWN
CONVERTER
Typical Operating Circuit
Rev 1; 5/04
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
DS1094LU -40°C to +85°C 8 µSOP
EconOscillator is a trademark of Dallas Semiconductor.
I
2
C is a trademark of Philips Corp. Purchase of I2C components of Maxim Integrated Products, Inc., or one of its sublicensed Associated Companies, conveys a license under the
Philips I
2
C Patent Rights to use these components in an I2C
system, provided that the system conforms to the I
2
C Standard
Specification as defined by Philips.
DS1094L
Multiphase Spread-Spectrum EconOscillator
2 _____________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
RECOMMENDED DC OPERATING CONDITIONS
(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.
Voltage Range on VCC, SDA, and SCL
Relative to Ground.............................................-0.5V to +6.0V
Operating Temperature Range ...........................-40°C to +85°C
EEPROM Programming Temperature Range .........0°C to +70°C
Storage Temperature Range .............................-55°C to +125°C
Soldering Temperature .......................................See IPC/JEDEC
J-STD-020A Specification
PARAMETER
CONDITIONS
UNITS
Supply Voltage V
CC
(Note 1) 3.0 3.6 V
Input Logic 1 (SDA, SCL) V
IH
0.7 x
V
CC
+
0.3
V
Input Logic 0 (SDA, SCL) V
IL
+0.3 x
V
DC ELECTRICAL CHARACTERISTICS
(VCC= +3.0 to 3.6V, TA= -40°C to +85°C, unless otherwise noted.)
PARAMETER
CONDITIONS
UNITS
Active Supply Current I
CC
CL = 15pF per output, SDA = SCL = V
CC
1.4 3 mA
High-Level Output Voltage
(OUT1-4)
V
OH
IOH = -4mA; VCC = min 2.4 V
Low-Level Output Voltage
(OUT1-4)
V
OL
IOL = 3.5mA 0.4 V
3mA sink current 0.4
Low-Level Output Voltage (SDA)
V
OL
6mA sink current 0.6
V
High-Level Input Current
(SDA, SCL)
I
IH
VIH = V
CC
µA
Low-Level Input Current
(SDA, SCL)
I
IL
VIL = 0.0V
µA
SYMBOL
MIN TYP MAX
V
CC
SYMBOL
-0.3
MIN TYP MAX
-1.0
V
CC
+1.0
DS1094L
Multiphase Spread-Spectrum EconOscillator
_____________________________________________________________________ 3
AC ELECTRICAL CHARACTERISTICS
(VCC= +3.0V to 3.6V, TA= -40°C to +85°C, unless otherwise noted.)
PARAMETER
CONDITIONS
UNITS
Master Oscillator Frequency f
MOSC
12
MHz
Output Frequency Tolerance ∆f
OUT
VCC = 3.3V,
T
A
= +25°C (Note 8)
%
Voltage Frequency Variation ∆f
OUT
TA = +25°C (Note 2)
%
0 to +70°C
Temperature Frequency Variation
∆f
OUT
-40°C to +85°C
%
DAC Step Size
%
Peak-to-Peak Jitter (3σ) P1:P0 = 11 (Note 3) 8 %
Load Capacitance C
L
15 50 pF
2 Phase 50
3 Phase
Output Duty Cycle (Note 4)
4 Phase 50
%
Power-Up Time
t
POR
+
t
STAB
(Note 5) 0.1 0.5 ms
AC ELECTRICAL CHARACTERISTICS (See Figure 3)
(VCC= +3.0V to 3.6V, TA= -40°C to +85°C, unless otherwise noted. Timing referenced to V
IL(MAX)
and V
IH(MIN)
.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
SCL Clock Frequency f
SCL
(Note 6) 0 400 kHz
Bus Free Time Between Stop and
Start Conditions
t
BUF
1.3 µs
Hold Time (Repeated) Start
Condition
0.6 µs
Low Period of SCL t
LOW
1.3 µs
High Period of SCL t
HIGH
0.6 µs
Data Hold Time
0 0.9 µs
Data Setup Time
ns
Start Setup time t
SU:STA
0.6 µs
SDA and SCL Rise Time t
R
(Note 7)
20 +
300 ns
SDA and SCL Fall Time t
F
(Note 7)
20 +
300 ns
Stop Setup Time
0.6 µs
SDA and SCL Capacitive
Loading
C
B
(Note 7) 400 pF
EEPROM Write Time t
WR
510ms
Input Capacitance C
I
5pF
SYMBOL
VCC = 3.3V (Note 2)
MIN TYP MAX
-2.5 +2.5
-0.5 +0.5
-1.1 +1.1
-2.5 +1.1
-0.75 +0.75
33.3
t
HD:STA
t
HD:DAT
t
SU:DAT
t
SU:STO
100
0.1C
0.1C
B
B
SUPPLY CURRENT vs. SUPPLY VOLTAGE
f
OUT
= 1MHz, 2φ MODE
DS1094L toc01
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
3.453.303.15
0.75
1.00
1.25
1.50
0.50
3.00 3.60
TA = +85°C
TA = +25°C
TA = -40°C
SUPPLY CURRENT vs. FREQUENCY
V
CC
= 3.3V, 2φ MODE
DS1094L toc02
f
OUT
(MHz)
SUPPLY CURRENT (mA)
1.00
0.5
1.5
1.0
2.0
2.5
0
0.1 10.00
DUTY CYCLE vs. SUPPLY VOLTAGE
f
OUT
= 2MHz, 2φ MODE
DS1094L toc03
SUPPLY VOLTAGE (V)
DUTY CYCLE (%)
3.453.303.15
50.25
50.50
50.75
51.00
50.00
3.00 3.60
TA = +85°C
TA = +25°C
TA = -40°C
Typical Operating Characteristics
(VCC= +3.3V, TA = +25°C, unless otherwise noted.)
DS1094L
Multiphase Spread-Spectrum EconOscillator
4 _____________________________________________________________________
NONVOLATILE MEMORY CHARACTERISTICS
(VCC= +3.0V to 3.6V, unless otherwise noted.)
PARAMETER
CONDITIONS
UNITS
EEPROM Writes +70°C (Note 4)
Note 1: All voltages referenced to ground.
Note 2: This is the change observed in output frequency due to changes in temperature or voltage.
Note 3: This is a percentage of the output period. Parameter is characterized but not production tested. This can be varied from
2%, 4%, or 8%.
Note 4: This parameter is guaranteed by design.
Note 5: This indicates the time between power-up and the outputs becoming active. An on-chip delay is intentionally introduced to
allow the oscillator to stabilize. t
STAB
is equivalent to approximately 64 f
MOSC
cycles and, hence, will depend on the pro-
grammed clock frequency.
Note 6: Timing shown is for fast-mode (400kHz) operation. This device is also backward compatible with I
2
C standard-mode timing.
Note 7: CB—total capacitance of one bus line in picofarads.
Note 8: 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.
SYMBOL
MIN TYP MAX
10,000
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