LTC6930-X.XX
1
6930fd
–0.10 0.10
6930 TA01b
–0.05 0.050
FREQUENCY ERROR (%)
70
60
40
20
50
30
10
UNITS
0
TA = 25°C
V+ = 3V
DIV = 0
1045 UNITS
TYPICAL APPLICATION
FEATURES
APPLICATIONS
DESCRIPTION
32.768kHz to 8.192MHz
Precision µPower Oscillators
The LTC
®
6930 series is a family of very low power precision
silicon oscillators with a frequency error less than 0.09%.
For each oscillator, the user can select one of 8 frequen-
cies between 32.768kHz and 8.192MHz. Based on a fixed
master oscillator frequency, internal frequency dividers
between 1 and 128 provide the 8 different frequencies.
The LTC6930 requires no external components other than
power supply bypass capacitors. Requiring only a single
1.7V to 5.5V supply enables operation from a single Li-Ion
cell or 2 AA alkaline cells.
The LTC6930 features a proprietary control architecture
that allows for ultralow power operation while maintaining
industry leading accuracy and jitter specifications. The
exceptionally fast start-up time, combined with the low
power consumption, is ideal for battery operated applica-
tions with frequent power-up cycles.
Any frequency from 32.768kHz to 8.192MHz can be pro-
vided by the factory. Minimum order sizes apply for custom
frequencies. Please consult LTC Marketing for details.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property
of their respective owners. Protected by U.S. Patents, including 6342817, 6614313.
4MHz Micropower Clock Generator
n Frequency Error <0.09% Max at 25°C
n Start-Up Time <110µs at All Frequencies
n 1.7V to 5.5V Single Supply Operation
n 105µA Typical Supply Current at 32kHz, V+ = 3V
n 490µA Typical Supply Current at 8MHz, V+ = 3V
n Typical RMS Period Jitter <0.15% at V+ = 3V
n No External Components to Set Frequency
n 5 Options Cover 32.768kHz to 8.192MHz:
LTC6930-4.19: 4.194304MHz ÷ N
LTC6930-5.00: 5.000000MHz ÷ N
LTC6930-7.37: 7.372800MHz ÷ N
LTC6930-8.00: 8.000000MHz ÷ N
LTC6930-8.19: 8.192000MHz ÷ N
Where N = 1, 2, 4, 8, 16, 32, 64, 128
(N Determined by State of DIVA, DIVB, DIVC Pins)
n –40°C to 125°C Operating Temperature Range
n Tiny 2mm × 3mm DFN or MS8 Package
n Digitally Controlled Oscillator
n Microprocessor Clock
n Power Supply Clock
n Portable and Battery Operated Devices
Typical Frequency Error Distribution
4MHz
0.1µF
6930 TA01a
V+ = 1.7V TO 5.5V
IS = 325µA AT 3VDC
V+
GNDGND
OUT
DIVB
DIVA
DIVC
V+
LTC6930-8.00
LTC6930-X.XX
2
6930fd
ABSOLUTE MAXIMUM RATINGS
Total Supply Voltage
(V+ to GND) ............................................. –0.3V to 6V
Any Input Pin to GND
(DIV Pins) ......................................–0.3V to V+ + 0.3V
Operating Temperature Range (Note 2)
LTC6930C ............................................ –40°C to 85°C
LTC6930I.............................................. –40°C to 85°C
LTC6930H .......................................... –40°C to 125°C
(Note 1)
TOP VIEW
V+
OUT
GND
DIVC
V+
GND
DIVA
DIVB
DCB PACKAGE
8-LEAD (2mm × 3mm) PLASTIC DFN
9
3
4
2
1
6
5
7
8
TJMAX = 125°C, θJA = 64°C/W
EXPOSED PAD (PIN 9) MUST BE SOLDERED TO GND
1
2
3
4
V+
GND
DIVA
DIVB
8
7
6
5
V+
OUT
GND
DIVC
TOP VIEW
MS8 PACKAGE
8-LEAD PLASTIC MSOP
TJMAX = 150°C, θJA = 300°C/W
(SINGLE-LAYER BOARD)
PIN CONFIGURATION
Specified Temperature Range (Note 3)
LTC6930C ................................................ 0°C to 70°C
LTC6930I.............................................. –40°C to 85°C
LTC6930H .......................................... –40°C to 125°C
Storage Temperature Range ................... –65°C to 150°C
Lead Temperature (Soldering, 10 sec) .................. 300°C
ORDER INFORMATION
Lead Free Finish
TAPE AND REEL (MINI) TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC6930CDCB-4.19#TRMPBF LTC6930CDCB-4.19#TRPBF LCKT 8-Lead (2mm × 3mm) Plastic DFN 0°C to 70°C
LTC6930IDCB-4.19#TRMPBF LTC6930IDCB-4.19#TRPBF LCKT 8-Lead (2mm × 3mm) Plastic DFN –40°C to 85°C
LTC6930HDCB-4.19#TRMPBF LTC6930HDCB-4.19#TRPBF LCKT 8-Lead (2mm × 3mm) Plastic DFN –40°C to 125°C
LTC6930CDCB-5.00#TRMPBF LTC6930CDCB-5.00#TRPBF LCKV 8-Lead (2mm × 3mm) Plastic DFN 0°C to 70°C
LTC6930IDCB-5.00#TRMPBF LTC6930IDCB-5.00#TRPBF LCKV 8-Lead (2mm × 3mm) Plastic DFN –40°C to 85°C
LTC6930HDCB-5.00#TRMPBF LTC6930HDCB-5.00#TRPBF LCKV 8-Lead (2mm × 3mm) Plastic DFN –40°C to 125°C
LTC6930CDCB-7.37#TRMPBF LTC6930CDCB-7.37#TRPBF LCKW 8-Lead (2mm × 3mm) Plastic DFN 0°C to 70°C
LTC6930IDCB-7.37#TRMPBF LTC6930IDCB-7.37#TRPBF LCKW 8-Lead (2mm × 3mm) Plastic DFN –40°C to 85°C
LTC6930HDCB-7.37#TRMPBF LTC6930HDCB-7.37#TRPBF LCKW 8-Lead (2mm × 3mm) Plastic DFN –40°C to 125°C
LTC6930CDCB-8.00#TRMPBF LTC6930CDCB-8.00#TRPBF LCKX 8-Lead (2mm × 3mm) Plastic DFN 0°C to 70°C
LTC6930IDCB-8.00#TRMPBF LTC6930IDCB-8.00#TRPBF LCKX 8-Lead (2mm × 3mm) Plastic DFN –40°C to 85°C
LTC6930HDCB-8.00#TRMPBF LTC6930HDCB-8.00#TRPBF LCKX 8-Lead (2mm × 3mm) Plastic DFN –40°C to 125°C
LTC6930CDCB-8.19#TRMPBF LTC6930CDCB-8.19#TRPBF LCKY 8-Lead (2mm × 3mm) Plastic DFN 0°C to 70°C
LTC6930IDCB-8.19#TRMPBF LTC6930IDCB-8.19#TRPBF LCKY 8-Lead (2mm × 3mm) Plastic DFN –40°C to 85°C
LTC6930HDCB-8.19#TRMPBF LTC6930HDCB-8.19#TRPBF LCKY 8-Lead (2mm × 3mm) Plastic DFN –40°C to 125°C
TRM = 500 pieces.
LTC6930-X.XX
3
6930fd
AC ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. Unless otherwise noted, specifications apply over the full range of
operating supply voltage and frequency output: V+ = 1.7V to 5.5V and all DIV settings with CLOAD = 5pF, RLOAD = ∞.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Δfi Initial Frequency Accuracy DIVA = DIVB = DIVC = 0, TA = 25°C, V+ = 3V 0.08 0.09 %
Δf Frequency Accuracy
(Note 4)
V+ = 3V – 3.6V
LTC6930C
LTC6930I
LTC6930H
l
l
l
±0.1
±0.1
±0.1
±0.45
±0.65
±1
%
%
%
V+ = 2V – 3.6V
LTC6930C
LTC6930I
LTC6930H
l
l
l
±0.1
±0.1
±0.1
±0.52
±0.65
±1.1
%
%
%
V+ = 1.7V – 5.5V
LTC6930C
LTC6930I
LTC6930H
l
l
l
±0.1
±0.1
±0.1
±0.8
±0.95
±1.3
%
%
%
Δf/ΔT Frequency Drift Over Temperature MS8 Package
DCB Package
l
l
0.0001
0.001
%/°C
%/°C
Δf/ΔV Frequency Drift Over Supply l0.07 %/V
Long-Term Frequency Stability (Note 5) l30 ppm/√kHr
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC6930CMS8-4.19#PBF LTC6930CMS8-4.19#TRPBF LTCKZ 8-Lead Plastic MSOP 0°C to 70°C
LTC6930IMS8-4.19#PBF LTC6930IMS8-4.19#TRPBF LTCKZ 8-Lead Plastic MSOP –40°C to 85°C
LTC6930HMS8-4.19#PBF LTC6930HMS8-4.19#TRPBF LTCKZ 8-Lead Plastic MSOP –40°C to 125°C
LTC6930CMS8-5.00#PBF LTC6930CMS8-5.00#TRPBF LTCLB 8-Lead Plastic MSOP 0°C to 70°C
LTC6930IMS8-5.00#PBF LTC6930IMS8-5.00#TRPBF LTCLB 8-Lead Plastic MSOP –40°C to 85°C
LTC6930HMS8-5.00#PBF LTC6930HMS8-5.00#TRPBF LTCLB 8-Lead Plastic MSOP –40°C to 125°C
LTC6930CMS8-7.37#PBF LTC6930CMS8-7.37#TRPBF LTCLC 8-Lead Plastic MSOP 0°C to 70°C
LTC6930IMS8-7.37#PBF LTC6930IMS8-7.37#TRPBF LTCLC 8-Lead Plastic MSOP –40°C to 85°C
LTC6930HMS8-7.37#PBF LTC6930HMS8-7.37#TRPBF LTCLC 8-Lead Plastic MSOP –40°C to 125°C
LTC6930CMS8-8.00#PBF LTC6930CMS8-8.00#TRPBF LTCLD 8-Lead Plastic MSOP 0°C to 70°C
LTC6930IMS8-8.00#PBF LTC6930IMS8-8.00#TRPBF LTCLD 8-Lead Plastic MSOP –40°C to 85°C
LTC6930HMS8-8.00#PBF LTC6930HMS8-8.00#TRPBF LTCLD 8-Lead Plastic MSOP –40°C to 125°C
LTC6930CMS8-8.19#PBF LTC6930CMS8-8.19#TRPBF LTCLF 8-Lead Plastic MSOP 0°C to 70°C
LTC6930IMS8-8.19#PBF LTC6930IMS8-8.19#TRPBF LTCLF 8-Lead Plastic MSOP –40°C to 85°C
LTC6930HMS8-8.19#PBF LTC6930HMS8-8.19#TRPBF LTCLF 8-Lead Plastic MSOP –40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.*Temperature grades are identified by a label on the shipping container.
Consult LTC Marketing for information on lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
LTC6930-X.XX
4
6930fd
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. Unless otherwise noted, specifications apply over the full range of
operating supply voltage and frequency output: V+ = 1.7V to 5.5V and all DIV settings with CLOAD = 5pF, RLOAD = ∞.
DC ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VSSupply Voltage Applied Between
V+ and GND
l1.7 5.5 V
IS,DC V+ Combined Supply Current LTC6930-4.19
DIVA = DIVB = DIVC = 0, V+ = 1.7V
DIVA = DIVB = DIVC = 0, V+ = 3V
DIVA = DIVB = DIVC = 0, V+ = 5.5V
DIVA = DIVB = DIVC = 1, V+ = 1.7V
DIVA = DIVB = DIVC = 1, V+ = 3V
DIVA = DIVB = DIVC = 1, V+ = 5.5V
l
l
l
l
l
l
170
260
490
80
105
130
290
420
750
160
190
355
µA
µA
µA
µA
µA
µA
LTC6930-5.00
DIVA = DIVB = DIVC = 0, V+ = 1.7V
DIVA = DIVB = DIVC = 0, V+ = 3V
DIVA = DIVB = DIVC = 0, V+ = 5.5V
DIVA = DIVB = DIVC = 1, V+ = 1.7V
DIVA = DIVB = DIVC = 1, V+ = 3V
DIVA = DIVB = DIVC = 1, V+ = 5.5V
l
l
l
l
l
l
201
307
579
95
124
154
430
570
960
176
212
375
µA
µA
µA
µA
µA
µA
IS,DC V+ Combined Supply Current LTC6930-7.37
DIVA = DIVB = DIVC = 0, V+ = 1.7V
DIVA = DIVB = DIVC = 0, V+ = 3V
DIVA = DIVB = DIVC = 0, V+ = 5.5V
DIVA = DIVB = DIVC = 1, V+ = 1.7V
DIVA = DIVB = DIVC = 1, V+ = 3V
DIVA = DIVB = DIVC = 1, V+ = 5.5V
l
l
l
l
l
l
296
453
853
139
183
226
480
660
1310
220
273
440
µA
µA
µA
µA
µA
µA
LTC6930-8.00
DIVA = DIVB = DIVC = 0, V+ = 1.7V
DIVA = DIVB = DIVC = 0, V+ = 3V
DIVA = DIVB = DIVC = 0, V+ = 5.5V
DIVA = DIVB = DIVC = 1, V+ = 1.7V
DIVA = DIVB = DIVC = 1, V+ = 3V
DIVA = DIVB = DIVC = 1, V+ = 5.5V
l
l
l
l
l
l
321
491
926
151
198
246
520
740
1380
240
295
475
µA
µA
µA
µA
µA
µA
LTC6930-8.19
DIVA = DIVB = DIVC = 0, V+ = 1.7V
DIVA = DIVB = DIVC = 0, V+ = 3V
DIVA = DIVB = DIVC = 0, V+ = 5.5V
DIVA = DIVB = DIVC = 1, V+ = 1.7V
DIVA = DIVB = DIVC = 1, V+ = 3V
DIVA = DIVB = DIVC = 1, V+ = 5.5V
l
l
l
l
l
l
310
500
880
150
190
210
490
760
1400
270
325
540
µA
µA
µA
µA
µA
µA
VIH Minimum High Level Input Voltage,
All Digital Input Pins
l1.25 1.4 V
AC ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. Unless otherwise noted, specifications apply over the full range of
operating supply voltage and frequency output: V+ = 1.7V to 5.5V and all DIV settings with CLOAD = 5pF, RLOAD = ∞.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
RMS Period Jitter DIVA = DIVB = DIVC = 0, V+ = 3V
LTC6930-4.19 (4.194304MHz)
LTC6930-5.00 (5.000000MHz)
LTC6930-7.37 (7.372800MHz)
LTC6930-8.00 (8.000000MHz)
LTC6930-8.19 (8.192000MHz)
320
1.7
225
1.2
180
0.97
130
0.8
130
0.8
ps RMS
nsP-P
ps RMS
nsP-P
ps RMS
nsP-P
ps RMS
nsP-P
ps RMS
nsP-P
LTC6930-X.XX
5
6930fd
The l denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at TA = 25°C. Unless otherwise noted, specifications apply over the full range of operating supply
voltage and frequency output: V+ = 1.7V to 5.5V and fOUT = 32.768kHz to 8.192MHz with CLOAD = 5pF, RLOAD = ∞.
TIMING CHARACTERISTICS
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: LTC6930C is guaranteed functional over the operating range of
–40°C to 85°C.
Note 3: The LTC6930C is guaranteed to meet specified performance from
0°C to 70°C. The LTC6930C is designed, characterized and expected to
meet specified performance from –40°C to 85°C but is not tested or QA
sampled at these temperatures. The LTC6930I is guaranteed to meet
specified performance from –40°C to 85°C. The LTC6930H is guaranteed
to meet specified performance from –40°C to 125°C.
Note 4: Frequency accuracy and frequency drift are defined as deviation
from the nominal frequency or the nominal frequency divided by the
integer set through the DIV pins for each part. The nominal frequency for
the LTC6930 family of parts are defined as follows:
LTC6930-4.19 fNOM = 4.194304MHz
LTC6930-5.00 fNOM = 5.000000MHz
LTC6930-7.37 fNOM = 7.372800MHz
LTC6930-8.00 fNOM = 8.000000MHz
LTC6930-8.19 fNOM = 8.192000MHz
Note 5: Long-term drift of silicon oscillators is primarily due to the
movement of ions and impurities within the silicon and is tested at 30°C
under otherwise nominal operating conditions. Long-term drift is specified
as ppm/√kHr due to the typically non-linear nature of the drift. To calculate
drift for a set time period, translate that time into thousands of hours,
take the square root and multiply by the typical drift number. For instance,
a year is 8.77kHr and would yield a drift of 89ppm at 30ppm/√kHr. Drift
without power applied to the device may be approximated as 1/10th of the
drift with power, or 3ppm/√kHr for a 30ppm/√kHr device.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
trf Output Rise/Fall Time (10% to 90%) V+ = 3V 3 ns
DCY Duty Cycle DIVA = DIVB = DIVC = 0; V+ = 2V to 5.5V
DIVA = DIVB = DIVC = 0
DIVA or DIVB or DIVC ≠ 0
l
l
l
35
35
48
50
50
50
65
70
52
%
%
%
DDIV DIV to FOUT Delay Edge of DIV Signal to 1st Accurate Output Cycle 1 Cycle
DPON Power On Delay V+ > 1.7V to 1st Accurate Output Cycle l110 µs
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. Unless otherwise noted, specifications apply over the full range of
operating supply voltage and frequency output: V+ = 1.7V to 5.5V and all DIV settings with CLOAD = 5pF, RLOAD = ∞.
DC ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VIL Maximum Low Level Input Voltage,
All Digital Input Pins
l0.7 1.25 V
IIN Digital Input Leakage Current, All
Digital Input Pins 0 < VIN < V+l±1 µA
ROUT Output Resistance OUT Pin, V+ = 3V 40 Ω
VOH High Level Output Voltage DIVA = DIVB = DIVC = 0, No Load
V+ = 5.5V
V+ = 3V
V+ = 2V
V+ = 1.7V
l
l
l
5.4
2.9
1.8
5.5
3
2
1.7
V
V
V
V
DIVA = DIVB = DIVC = 0, 1kΩ Load to GND
V+ = 5.5V
V+ = 3V
V+ = 2V
V+ = 1.7V
l
l
l
5
2.6
1.5
5.2
2.7
1.6
1.5
V
V
V
V
VOL Low Level Output Voltage DIVA = DIVB = DIVC = 0, No Load
V+ = 5.5V
V+ = 3V
V+ = 2V
V+ = 1.7V
l
l
l
0
0
0
0
0.1
0.1
0.1
V
V
V
V
DIVA = DIVB = DIVC = 0, 1kΩ Load to V+
V+ = 5.5V
V+ = 3V
V+ = 2V
V+ = 1.7V
l
l
l
0.3
0.3
0.3
0.3
0.7
0.5
0.35
V
V
V
V
LTC6930-X.XX
6
6930fd
6930 G09
40ns/DIV
LTC6930-8.00
CLOAD = 12pF
0.45V/DIV
6930 G08
400kHz/DIV
10dB/DIV
TEMPERATURE (°C)
–45
POWER SUPPLY CURRENT (µA)
4216 G07
5 55 105
700
600
100
200
400
300
500
0
3V, 8.192MHz
1.7V, 32kHz
CLOAD = 5pF
3V, 4.19MHz
LOAD CAPACITANCE (pF)
0
SUPPLY CURRENT (µA)
4216 G05
10 20 30 40 50 60
2000
1000
800
600
200
400
1800
1600
1200
1400
0
LTC6930-8.19
DIV = 1
DIV = 2
DIV = 4
DIV = 8
DIV = 16
DIV = 32
DIV = 64
DIV = 128
V+ = 3V
TA = 25°C
TEMPERATURE (°C)
–45
FREQUENCY ERROR (%)
115125
4216 G02
–25 –5 15 35 55 75 95
0.60
0.40
0.20
0
–0.20
–0.40
–0.60
V+ = 3V
SUPPLY VOLTAGE (V)
1.7
SUPPLY CURRENT (µA)
4216 G06
2.2 2.7 3.2 3.7 4.2 4.7 5.2
1000
900
800
600
700
100
200
400
300
500
0
8.192MHz
DIVIDE = 1
TA = 25°C
4.194MHz
DIV SETTING (LOG)
1 10 100
SUPPLY CURRENT (µA)
600
8.192MHz, 3V
4.194MHz, 1.7V
500
400
300
200
100
0
6930 G04
4.194MHz, 3V
8.192MHz, 1.7V
TA = 25°C
SUPPLY VOLTAGE (V)
1.7
FREQUENCY ERROR (%, NORMALIZED TO 3V)
4216 G01
2.7 3.7 4.7
0.25
0.20
0.15
0.05
0.10
–0.20
–0.15
–0.05
–0.10
0
–0.25
8.19MHz
TA = 25°C
4.19MHz
TEMPERATURE (°C)
–45
115125
4216 G03
–25 –5 15 35 55 75 95
0.40
0.20
0
–0.20
–0.40
–0.60
V+ = 3V
TYPICAL PERFORMANCE CHARACTERISTICS
Typical Supply Current
vs DIV Setting
Typical Supply Current
vs Load Capacitance
Typical Supply Current
vs Supply Voltage
Typical Supply Current
vs Temperature
Typical Output Spectrum, 8MHz
Typical Output Waveform, 8MHz
Typical Frequency Error
vs Supply Voltage
Frequency Error vs Temperature,
MS8 Package
Frequency Error vs Temperature,
DFN Package
LTC6930-X.XX
7
6930fd
PERIOD ERROR (ps)
–450
SAMPLES
4216 G11
–300 –150 0 150 450300
400
300
100
200
0
LTC6930-8.19 V+ = 3V
TA = 25°C
DIVIDE = 1
TIME (HOURS)
0
DELTA FREQUENCY (ppm)
4216 G17
500 1000 1500 2000 30002500
500
400
300
100
200
–400
–300
–100
–200
0
–500
25 PARTS SHOWN
TA = 30°C
6930 G18
400ns/DIV
TIME SINCE POWER APPLIED (µs)
0
FREQUENCY ERROR (%)
4216 G16
50 100 150 200
10
5
–10
–5
–20
–15
–25
0
–30
SUPPLY VOLTAGE (V)
1.7
OUTPUT RISE/FALL TIME (ns)
4216 G13
2.2 2.7 3.2 3.7 4.2 4.7 5.2
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
FALL TIME
RISE TIME
CLOAD = 5pF
TA = 25°C
SUPPLY VOLTAGE (V)
1.7
OUTPUT RESISTANCE (Ω)
4216 G14
2.2 2.7 3.2 3.7 4.2 4.7 5.2
100
90
80
60
70
10
20
40
30
50
0
TA = 25°C
DIV SETTING (LOG)
1 10 100
JITTER (% RMS)
0.16
0.14
0.12
0.10
0.08
0.06
0.04
0.02
0
6930 G12
8.192MHz
4.194MHz
V+ = 3V
TA = 25°C
SUPPLY VOLTAGE (V)
1.7
JITTER (% RMS)
4216 G10
2.2 2.7 3.2 3.7 4.2 4.7 5.2
0.30
0.25
0.20
0.15
0.10
0.05
0
8.192MHz
4.194MHz
TA = 25°C
TYPICAL PERFORMANCE CHARACTERISTICS
Typical Output Rise/Fall Time
vs Supply
Typical Output Resistance
vs Supply Voltage
Typical Output Duty Cycle
vs Supply and Divide Ratio
Typical Frequency Settling
from Power-Up
Typical Frequency Error
vs Time (Long-Term Drift)
Typical Output Waveform
at DIV Pin Change
Typical Jitter vs Supply in
Divide by 1 Mode
Typical Period Jitter Histogram
Typical Jitter vs Divider Setting
SUPPLY VOLTAGE (V)
1.7
DUTY CYCLE (%)
4216 G15
2.2 2.7 3.2 3.7 4.2 4.7 5.2
60
58
56
52
54
42
44
48
46
50
40
4MHz, DIVIDE BY 1
DIVIDE BY >1
8MHz, DIVIDE BY 1
LTC6930-X.XX
8
6930fd
V+ (Pins 1, 8): Positive Supply Pins. Each supply pin
should be bypassed directly to the neighboring GND pin
with a 0.1µF ceramic capacitor, and must be externally
connected to the other V+ pin (see recommended layout).
GND (Pins 2, 6): Ground Pins. Each should be connected
to a low inductance ground plane and must be connected
to the other GND pin and on the DFN package, Pin 9.
DIVA, DIVB, DIVC (Pins 3, 4, 5): Output Prescaler. Se-
lects divide ratio of master oscillator frequency used to
generate the output. See frequency setting Table 1 for
function. These are standard CMOS logic inputs with a
typical threshold of 1.25V
OUT (Pin 7): Oscillator Output. Drives up to 50pF capaci-
tive or 1k resistive load (Refer to Supply Current vs Load
Capacitance in Typical Performance Characteristics sec-
tion). Typical series resistance is less than 80Ω at 1.7V
and less than 40Ω at 3V supply. The output trace should
be isolated as much as possible from Pin 1 and Pin 2.
The OUT pin is held low during start-up, and remains free
from glitches and runt pulses during DIV pin switching.
Exposed Pad (Pin 9, DFN Only): The Exposed Pad must
be soldered to a PCB plane connected to GND.
APPLICATIONS INFORMATION
Theory of Operation
The LTC6930 is an entirely self contained all silicon oscil-
lator which consists of a master oscillator, a control loop
and an output frequency divider. The master oscillator
operates between 4.2MHz and 8.2MHz and is factory
programmed. The master oscillator frequency is accurately
maintained over temperature and environmental extremes
by a proprietary switched capacitor feedback loop.
Each LTC6930 oscillator has an output frequency divider
which is controlled via the DIVA, DIVB and DIVC inputs.
The divider divides the master frequency by 2N, where N
is an integer from 0 to 7 (divider ranges from 1 to 128).
See Table 1 for the full range of frequencies covered by
the LTC6930 family.
The presence of two sets of supply pins and careful internal
layout reduce interference between the oscillator output
and the control loop. This allows the LTC6930 to provide
a clean output frequency with very little deterministic jitter,
even in cases of heavy output loading and noisy operating
environments.
The supply voltage of the LTC6930 is internally regulated
to maintain a very low frequency drift over supply.
Output Driver and Loading
The output of the LTC6930 is a low series resistance 40Ω
CMOS driver with controlled rise/fall times to limit RF
interference and power supply spikes generated by the
output while preserving the ability to drive low impedance
loads. Especially at high frequencies, the capacitive loading
of the output of the LTC6930 may cause the majority of
the power supply dissipation of the part.
The LTC6930 supply current is specified at an output load
of 5pF, which is equivalent to two standard HC logic inputs.
The portion of the power supply current needed to drive
a capacitive load may be calculated as:
ISUPPLY = CLOAD • VSWING • fOSC
where CLOAD is the 5pF load capacitance, VSWING is the
voltage swing, in this case up to 5.5V, and fOSC is the fre-
quency of the oscillator output. Driving a 5.5V swing into a
5pF load at 8MHz takes an average of 220µA. To calculate
the portion of the supply current needed for a 50pF load,
simply substitute 50pF for CLOAD in the same equation:
50pF • 5.5V • 8MHz = 2.2mA
The majority of this power is expended during the rise and
fall time of the output signal, not while it is in a steady
PIN FUNCTIONS
LTC6930-X.XX
9
6930fd
MONTHS
0
DRIFT (%)
40
0.045
0.040
0.035
0.030
0.025
0.020
0.015
0.010
0.005
0
6930 F02
20 8060
10ppm/√kHr
30ppm/√kHr
60ppm/√kHr
APPLICATIONS INFORMATION
state. The 2ns rise and fall times of the LTC6930 mean that
the instantaneous power supply current required during
the rise and fall portions of the waveform is much greater
than the average.
The instantaneous power supply current may be calculated
by a similar formula:
IPEAK =CLOAD •VSWING •1
tr f
where trf is the rise/fall time of the signal. In this case,
14mA spikes are generated by driving 5.5V into a 5pF load.
Power is supplied to the output driver of the LTC6930
from the V+ and GND pins on each side of the output pin
(Pins 6 and 8). Allowances must be made in the design
to provide for output load related supply current spikes,
especially in high accuracy applications. A 0.1µF ceramic
capacitor connected between V+ and GND (Pins 6 and 8)
as close as possible to the device will decouple the rest
of the circuit from spikes caused by powering a capacitive
output load of up to 50pF. See Figure 1.
Start-Up Time
The start-up time of the LTC6930 is typically 50µs from the
time that valid power is applied to the first output pulse.
The output is held low for the first 50µs to prevent any
glitches, runt pulses, or invalid frequency output during
start-up.
Long-Term Drift
Long-term stability of silicon oscillators is specified in
ppm/√kHr, which is typical of other silicon devices such
as operational amplifiers and voltage references. Because
drift in silicon-based oscillators is generated primarily by
movement of ions in the silicon, most of the drift is ac-
complished early in the life of the device and the drift can
be expected to level off in the long term. The ppm/√kHr
unit models this time variant decay. Crystal oscillators
are often specified with drift measured in ppm/year be-
cause their drift mechanism is different. A comparison of
various drift rates over a five year time period is shown
in Figure 2.
When calculating the amount of drift to be expected, it is
important to consider the entire time in the calculation,
because the relationship to time is not linear. The drift for
Figure 2. 5 Year Drift at Various Rates
Switching the DIV Pins
The LTC6930 is designed to quickly and cleanly respond
to the digital inputs. The output will respond to the DIV
pins within a single clock cycle without introducing any
sliver or runt pulses.
6930 F01
OUT
V+
C2
0.1µF
C1
0.1µF
GND
GND
Figure 1. Recommended Layout
LTC6930-X.XX
10
6930fd
APPLICATIONS INFORMATION
Table 1. Frequency Setting and Available Frequencies
÷1 ÷2 ÷4 ÷8 ÷16 ÷32 ÷64 ÷128
DIV Pin Settings
[DIVC][DIVB][DIVA] 000 001 010 011 100 101 110 111
LTC6930-4.19 4.194304MHz 2.097152MHz 1.048576MHz 524.288kHz 262.144kHz 131.072kHz 65.536kHz 32.768kHz
LTC6930-5.00 5.000MHz 2.500MHz 1.250MHz 625.0kHz 312.5kHz 156.25kHz 78.125kHz 39.0625kHz
LTC6930-7.37 7.3728MHz 3.6864MHz 1.8432MHz 921.6kHz 460.8kHz 230.4kHz 115.2kHz 57.6kHz
LTC6930-8.00 8.000MHz 4.000MHz 2.000MHz 1000kHz 500.0kHz 250.0kHz 125.0kHz 62.5kHz
LTC6930-8.19 8.192MHz 4.096MHz 2.048MHz 1024kHz 512.0kHz 256.0kHz 128.0kHz 64.0kHz
5 years is not 5 times the drift for one year. A sample cal-
culation for drift over 5 years at 30ppm/√kHr is as follows:
5 years • 365.25 days/year • 24 hours/day = 43,830
hours = 43.830kHr
√43.830kHr = 6.62√kHr
6.62√kHr • 30ppm/√kHr = 0.0198% over 5 years.
Drift calculations assume that the part is in continuous
operation during the entire time period of the calculation.
The movement of ions which results in drift is usually aided
by electric fields in the operating parts, and the typical drift
spec applies while the part is powered up. Conservative
calculations would use a tenth of the drift specification for
time when power is not applied to the part.
Setting the Frequency
The output frequency of the LTC6930 is chosen from the
values in Table 1 and set using the DIV pins, as noted
in the table. Master oscillator frequency is preset in the
factory, and the DIV pins select an internal binary divider
of up to 128.
For example, if the desired oscillator output frequency
is 2.5MHz, finding 2.5MHz in Table 1 shows that the
LTC6930-5.00 should be ordered, having a master
oscillator frequency of 5MHz, and a DIV value of [001]
should be used. This would equate to grounding DIVC
and DIVB, while connecting DIVA to the positive supply.
Frequencies other than those shown in Table 1 may
be requested.
LTC6930-X.XX
11
6930fd
PACKAGE DESCRIPTION
DCB Package
8-Lead Plastic DFN (2mm × 3mm)
(Reference LTC DWG # 05-08-1718 Rev A)
3.00 ±0.10
(2 SIDES)
2.00 ±0.10
(2 SIDES)
NOTE:
1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE
TOP AND BOTTOM OF PACKAGE
0.40 ± 0.10
BOTTOM VIEW—EXPOSED PAD
0.75 ±0.05
R = 0.115
TYP
R = 0.05
TYP
1.35 REF
1
4
85
PIN 1 BAR
TOP MARK
(SEE NOTE 6)
0.200 REF
0.00 – 0.05
(DCB8) DFN 0106 REV A
0.23 ± 0.05
0.45 BSC
PIN 1 NOTCH
R = 0.20 OR 0.25
× 45° CHAMFER
0.25 ± 0.05
1.35 REF
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED
2.10 ±0.05
0.70 ±0.05
3.50 ±0.05
PACKAGE
OUTLINE
0.45 BSC
1.35 ±0.10
1.35 ±0.05
1.65 ± 0.10
1.65 ± 0.05
LTC6930-X.XX
12
6930fd
PACKAGE DESCRIPTION
MS8 Package
8-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1660 Rev F)
MSOP (MS8) 0307 REV F
0.53 ± 0.152
(.021 ± .006)
SEATING
PLANE
NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
0.18
(.007)
0.254
(.010)
1.10
(.043)
MAX
0.22 – 0.38
(.009 – .015)
TYP
0.1016 ± 0.0508
(.004 ± .002)
0.86
(.034)
REF
0.65
(.0256)
BSC
0° – 6° TYP
DETAIL “A”
DETAIL “A”
GAUGE PLANE
1 2 34
4.90 ± 0.152
(.193 ± .006)
8765
3.00 ± 0.102
(.118 ± .004)
(NOTE 3)
3.00 ± 0.102
(.118 ± .004)
(NOTE 4)
0.52
(.0205)
REF
5.23
(.206)
MIN
3.20 – 3.45
(.126 – .136)
0.889 ± 0.127
(.035 ± .005)
RECOMMENDED SOLDER PAD LAYOUT
0.42 ± 0.038
(.0165 ± .0015)
TYP
0.65
(.0256)
BSC
LTC6930-X.XX
13
6930fd
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
REVISION HISTORY
REV DATE DESCRIPTION PAGE NUMBER
C 1/11 Revised the option for LTC6930-7.37 under Features. 1
D 2/11 Added LTC6930CMS8-4.19 to the Order Information section. 3
(Revision history begins at Rev C)
LTC6930-X.XX
14
6930fd
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
LINEAR TECHNOLOGY CORPORATION 2008
LT 0211 REV D • PRINTED IN USA
RELATED PARTS
TYPICAL APPLICATION
PART NUMBER DESCRIPTION COMMENTS
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LTC6906 Micropower 10kHz to 1MHz ThinSOT Oscillator, Resistor Set 12µA Supply Current at 100kHz, 0.65% Frequency Accuracy
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LTC6908 Multiphase Oscillator with Spread Spectrum Modulation 2 Outputs Shifted by Either 180° or 90°
5V
0.1µF
1 8
2 7
3 6
4 5
VOUT1
VIN1
5V
1µF2k
3.48k
5V
6930 TA02
LTC1569-7
IN+
IN–
GND
V–
OUT
V+
RX
DIV/CLK
0.1µF
1 8
2 7
3 6
4 5
VOUT2
VIN2
5V
1µF2k
3.48k
5V
LTC1569-7
IN+
IN–
GND
V–
OUT
V+
RX
DIV/CLK
0.1µF
1 8
2 7
3 6
4 5
0.1µF
LTC6930-8.192
V+
GND
DIVA
DIVB
DIVA
DIVB
DIVC
V+
OUT
GND
DIVC
FREQUENCY (kHz)
1
GAIN (dB)
0
–20
–40
–60
–80
–100 10 100 1000
32kHzfCUTOFF = 8kHz 128kHz
fOSC
Dual, Matched, Digitally Programmable, Lowpass Filter, 2kHz to 256kHz
Amplitude Response
DIVC, DIVB, DIVA 000 001 010 011 100 101 110 111
fCUTOFF 256kHz 128kHz 64kHz 32kHz 16kHz 8kHz 4kHz 2kHz