LINER LTC6905HS5

LTC6905
17MHz to 170MHz
Resistor Set SOT-23 Oscillator
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FEATURES
DESCRIPTIO
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The LTC®6905 precision, programmable silicon oscillator
is easy to use and occupies very little board space. It
requires only a single resistor to set the output frequency
from 17MHz to 170MHz with a typical frequency error of
0.5% or less.
■
■
■
■
■
■
■
■
■
■
■
One External Resistor Sets the Frequency
Fast Start-Up Time: 100µs Typical
Frequency Range: 17MHz to 170MHz
Frequency Error ±0.5% Typ 17MHz to 170MHz
(TA = 0°C to 70°C, Over All Settings)
±20ppm/°C Temperature Stability
Rise Time: 0.5ns, CL = 5pF
Timing Jitter: 50ps at 170MHz
50% ±2.5% Duty Cycle
6mA Typical Supply Current, fOSC = 100MHz
CMOS Output Drives 500Ω Load (VS = 3V)
Operates from a Single 2.7V to 5.5V Supply
Low Profile (1mm) ThinSOTTM Package
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APPLICATIO S
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The LTC6905 operates with a single 2.7V to 5.5V power
supply and provides a rail-to-rail, 50% duty cycle square
wave output. The CMOS output driver ensures fast rise/fall
times and rail-to-rail switching. Operation is simple: A
single resistor, RSET, between 10K to 25K is used to set the
frequency, and an internal three-state divider (DIV input)
allows for division of the master clock by 1, 2 or 4,
providing three frequencies for each RSET value.
The LTC6905 features a proprietary feedback loop that
linearizes the relationship between RSET and frequency,
eliminating the need for tables to calculate frequency. The
oscillator can be easily programmed using the simple
formula outlined below:
High Frequency Precision Oscillator
High Speed Data Bus Clock
Fixed Crystal Oscillator Replacement
Ceramic Oscillator Replacement
, LTC and LT are registered trademarks of Linear Technology Corporation. ThinSOT is a
trademark of Linear Technology Corporation. All other trademarks are the property of their
respective owners. Protected by U.S. Patents, including 6614313, 6342817.
fOSC
⎧1, DIV Pin = V +
⎛ 168.5MHz • 10kΩ
⎞ 1
⎪
=⎜
+ 1.5MHz⎟ • , N = ⎨2, DIV Pin = Open
⎝
⎠ N
RSET
⎪4, DIV Pin = GND
⎩
For higher accuracy, fixed frequency versions that include
an internal frequency-setting resistor, see the LTC6905XXX Series datasheet.
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TYPICAL APPLICATIO
Typical Distribution of Frequency Error, TA = 25°C
60
50
Basic Connection
V+ = 3V
RSET = 12k
DIV = 1
5V
1
0.1µF
10k ≤ RSET ≤ 25k
2
3
OUT
V+
LTC6905
5
5V
GND
SET
UNITS
40
17.225MHz ≤ fOSC ≤ 170MHz
30
20
÷1
DIV
6905 TA01
4
÷2
OPEN
10
÷4
0
–0.5
–0.3
–0.1
0.1
% ERROR
0.3
0.5
6905 TA02
NOTE: RESISTOR, RSET, TOLERANCE WILL ADD
TO THE FREQUENCY ERROR
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LTC6905
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ABSOLUTE
RATI GS
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PACKAGE/ORDER I FOR ATIO
(Note 1)
Supply Voltage (V +) to GND ........................– 0.3V to 6V
DIV to GND .................................... – 0.3V to (V + + 0.3V)
SET to GND ................................... – 0.3V to (V + + 0.3V)
Output Short-Circuit Duration (Note 6) ........... Indefinite
Operating Temperature Range (Note 7)
LTC6905C, I ....................................... – 40°C to 85°C
LTC6905H ........................................ – 40°C to 125°C
Specified Temperature Range (Note 8)
LTC6905C ............................................... 0°C to 70°C
LTC6905I .............................................–40°C to 85°C
LTC6905H .........................................–40°C to 125°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER PART NUMBER
LTC6905CS5
LTC6905IS5
LTC6905HS5
TOP VIEW
V+
5 OUT
1
GND 2
SET 3
4 DIV
S5 PART MARKING
S5 PACKAGE
5-LEAD PLASTIC SOT-23
LTBJC
TJMAX = 125°C, θJA = 150°C/W
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full specified
temperature range, otherwise specifications are at TA = 25°C or as noted. V+ = 2.7V to 5.5V, RL = 15k, CL = 5pF, Pin 4 = V+ unless
otherwise noted. All voltages are with respect to GND.
SYMBOL
∆f
RSET
PARAMETER
Frequency Accuracy (Notes 2, 9)
CONDITIONS
MIN
V+ = 2.7V, 17.225MHz < f < 170MHz
V+ = 5V, 17.225MHz < f < 170MHz
LTC6905CS5
V+ = 2.7V, 17.225MHz < f < 170MHz
V+ = 5V, 17.225MHz < f < 170MHz
LTC6905HS5 (25°C ≤ T ≤ 125°C),
LTC6905IS5 (25°C ≤ T ≤ 85°C)
V+ = 2.7V, 17.225MHz < f < 170MHz
V+ = 5V, 17.225MHz < f < 170MHz
LTC6905HS5 (–40°C ≤ T ≤ 125°C),
LTC6905IS5 (–40°C ≤ T ≤ 85°C)
V+ = 2.7V, 17.225MHz < f < 170MHz
V+ = 5V, 17.225MHz < f < 170MHz
TYP
MAX
UNITS
±0.5
±1.4
±2.2
%
%
±1.7
±2.5
%
%
±1.9
±2.9
%
%
±3.5
±3.5
%
%
25
kΩ
●
●
●
●
Frequency-Setting Resistor Range
10
Maximum Frequency
Pin 4 = V +, N = 1
fMIN
Minimum Frequency
Pin 4 = 0V, N = 4
∆f/∆T
Freq Drift Over Temp (Note 2)
RSET = 10k
●
±20
ppm/°C
∆f/∆V
Freq Drift Over Supply (Notes 2, 9)
V+ = 2.7V to 5.5V, RSET = 10k
●
0.5
%/V
fMAX
170
17.225
MHz
Timing Jitter (Note 3)
0.8
%
Long-Term Stability of Output Frequency
300
ppm/√kHr
Duty Cycle
V+
Operating Supply Range
IS
Power Supply Current
VIH
MHz
High Level DIV Input Voltage
●
47.5
●
2.7
50
52.5
%-
5.5
V
RSET = 10k, N = 1, RL = ∞,
fOSC = 170MHz, CL = 5pF
V + = 5.5V
V + = 2.7V
●
●
14
7
20
12
mA
mA
RSET = 20k, N = 4, RL = ∞,
fOSC = 21.44MHz, CL = 5pF
V + = 5.5V
V + = 2.7V
●
●
5
3
7
5
mA
mA
● V+ – 0.15
V
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LTC6905
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full specified
temperature range, otherwise specifications are at TA = 25°C or as noted. V+ = 2.7V to 5.5V, RL= 15k, CL = 5pF, Pin 4 = V+ unless
otherwise noted. All voltages are with respect to GND.
SYMBOL
PARAMETER
VIL
Low Level DIV Input Voltage
IDIV
DIV Input Current (Note 4)
Pin 4 = V +
Pin 4 = 0V
High Level Output Voltage (Note 4)
V+
VOH
VOL
CONDITIONS
OUT Rise/Fall Time (Note 5)
VSET
Voltage at RSET Pin
TYP
●
Low Level Output Voltage (Note 4)
tr, tf
MIN
V + = 5.5V
V + = 5.5V
●
●
– 40
15
– 11
MAX
UNITS
0.2
V
40
µA
µA
= 5.5V
IOH = – 1mA
IOH = – 4mA
●
●
5.25
5.20
5.45
5.30
V
V
V + = 2.7V
IOH = – 1mA
IOH = – 4mA
●
●
2.5
2.4
2.6
2.4
V
V
V + = 5.5V
IOL = 1mA
IOL = 4mA
●
●
0.05
0.2
0.25
0.3
V
V
V + = 2.7V
IOL = 1mA
IOL = 4mA
●
●
0.1
0.4
0.3
0.5
V
V
0.5
V+ = 5.5V
V+ = 2.7V
●
●
Note 1: Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.
Note 2: Frequency accuracy is defined as the deviation from the fOSC
equation. Accuracy is tested with DIV = V+, N = 1 and other divide ratios
are guaranteed by design.
Note 3: Jitter is the ratio of the peak-to-peak distribution of the period to
the mean of the period. This specification is based on characterization and
is not 100% tested.
Note 4: To conform with the Logic IC Standard convention, current out of
a pin is arbitrarily given as a negative value.
Note 5: Output rise and fall times are measured between the 10% and
90% power supply levels.
4.27
1.61
4.5
1.7
ns
4.73
1.79
V
V
Note 6: A heat sink may be required to keep the junction temperature
below the absolute maximum when the output is shorted indefinitely.
Note 7: The LTC6905C is guaranteed functional over the operating
temperature range.
Note 8: The LTC6905 is guaranteed to meet specified performance from
0°C to 70°C. The LTC6905C-XXX 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 LTC6905I-XXX is guaranteed to meet
specified performance from –40°C to 85°C.
Note 9: The LTC6905 is optimized for the performance with a 3V power
supply voltage. Please consult LTC Marketing for parts optimized for 5V
operation.
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TYPICAL PERFOR A CE CHARACTERISTICS
Supply Current vs Frequency
5.5V
2.7V
FREQUENCY ERROR (%)
÷1
12
10
÷2
8
÷1
÷4
6
÷2
4
1.20
0.40
14
÷4
0.20
0
–0.20
–0.40
–0.60
2
0
Frequency Error vs Supply Voltage
1.40
FREQUENCY ERROR (%)
16
SUPPLY CURRENT (mA)
Frequency Error vs RSET
0.60
18
50
100
150
200
10
12
14
16
18
RSET (kΩ)
FREQUENCY (MHz)
6905 G01
0.60
0.40
0.20
0
–0.20
–0.80
0
1.00
0.80
20
22
24
6905 G02
–0.40
2.5
3
3.5
4
4.5
SUPPLY VOLTAGE (V)
5
5.5
6905 G03
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LTC6905
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TYPICAL PERFOR A CE CHARACTERISTICS
ROUT vs V+
Jitter vs Frequency
45
Frequency vs Temperature
1.0
1.20
0.8
40
30
÷2
PERCENTAGE ERROR (%)
÷4
35
÷1
0.80
JITTER (%)
OUTPUT RESISTANCE (Ω)
1.00
25
20
0.60
0.40
15
10
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
0.20
5
–0.8
0
2.5
3
3.5
4
4.5
SUPPLY VOLTAGE (V)
5
5.5
0
0
20
40
60 80 100 120 140 160 180
FREQUENCY (MHz)
6905 G04
–1.0
–40 –20
0
20 40 60 80 100 120
TEMPERATURE (°C)
6905 G08
6905 G05
LTC6905 Output Operating at
17.5MHz, VS = 3V
LTC6905 Output Operating at
170MHz, VS = 3V
1V/DIV
1V/DIV
12.5ns/DIV
6905 G06
1ns/DIV
6905 G07
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PI FU CTIO S
V+ (Pin 1): Voltage Supply (2.7V ≤ V+ ≤ 5.5V). This supply
must be kept free from noise and ripple. It should be
bypassed directly to the GND (Pin 2) with a 0.1µF capacitor
or higher.
GND (Pin 2): Ground. Should be tied to a ground plane for
best performance.
SET (Pin 3): Frequency-Setting Resistor Input. The value
of the resistor connected between this pin and V+ determines the oscillator frequency. The voltage on this pin is
held by the LTC6905 to approximately 1V below the V+
voltage. For best performance, use a precision metal film
resistor with a value between 10k and 25k and limit the
capacitance on this pin to less than 10pF.
DIV (Pin 4): Divider-Setting Input. This three-state input
selects among three divider settings, determining the value
of N in the frequency equation. Pin 4 should be tied to V+
for the ÷1 setting, the highest frequency range. Floating Pin
4 divides the master oscillator by 2. Pin 4 should be tied to
GND for the ÷4 setting, the lowest frequency range. To detect
a floating DIV pin, the LTC6905 attempts to pull the pin
toward midsupply. This is realized with two internal current
sources, one tied to V + and Pin 4 and the other one tied to
ground and Pin 4. Therefore, driving the DIV pin high requires sourcing approximately 15µA. Likewise, driving DIV
low requires sinking 15µA. When Pin 4 is floated, it should
be bypassed by a 1nF capacitor to ground or it should be
surrounded by a ground shield to prevent excessive coupling from other PCB traces.
OUT (Pin 5): Oscillator Output. This pin can drive 5kΩ
and/or 5pF loads. For larger loads, refer to the Applications
Information section.
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LTC6905
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BLOCK DIAGRA
1
VRES = 1V ±5%
(V+ – VSET)
V+
PROGRAMMABLE
DIVIDER
(÷1, 2 OR 4)
+
RSET
GAIN = 1
IRES
3
SET
fOSC =
fMO
N
OUT
5
MASTER OSCILLATOR
V+
DIVIDER
SELECT
–
15µA
+
–
2 GND
–
VBIAS
DIV
THREE-STATE
INPUT DETECT
IRES
+
4
15µA
GND
6905 BD
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THEORY OF OPERATIO
A resistor RSET, connected between the V+ and SET pins,
“locks together” the voltage (V + – VSET) and current, IRES,
variation. This provides the LTC6905’s high precision. The
master oscillation frequency reduces to:
168.5MHz • 10kΩ
f MO =
+ 1.5MHz
RSET
To extend the output frequency range, the master oscillator signal is divided by 1, 2 or 4 before driving OUT (Pin
5). The LTC6905 is optimized for use with resistors
between 10k and 25k, corresponding to oscillator frequencies between 17.225MHz and 170MHz. The divideby value is determined by the state of the DIV input
(Pin 4). Tie DIV to V+ or drive it to within 0.4V of V+ to
select ÷1. This is the highest frequency range, with the
master output frequency passed directly to OUT. The DIV
pin may be floated or driven to midsupply to select ÷2, the
intermediate frequency range. The lowest frequency range,
÷4, is selected by tying DIV to GND or driving it below
0.5V. Figure 1 shows the relationship between R SET,
divider setting and output frequency, including the overlapping frequencies.
30
25
÷4 ÷2
RSET (Ω)
As shown in the Block Diagram, the LTC6905’s master
oscillator is controlled by the ratio of the voltage between
the V+ and SET pins and the current entering the SET pin
(IRES). The voltage on the SET pin is forced to approximately 1V below V+ by the PMOS transistor and its gate
bias voltage.
÷1
20
15
10
5
10
110
60
160
OUTPUT FREQUENCY (MHz)
6905 F01
Figure 1. RSET vs Output Frequency
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LTC6905
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APPLICATIO S I FOR ATIO
SELECTING THE DIVIDER SETTING AND RESISTOR
The LTC6905’s master oscillator has a frequency range
spanning 68.9MHz to 170MHz. A programmable divider
extends the frequency range from 17.225MHz to 170MHz.
Table 1 describes the recommended frequencies for each
divider setting. Note that the ranges overlap; at some
frequencies there are two divider/resistor combinations
that result in the same frequency. Choosing a higher
divider setting will result in less jitter at the expense of
slightly higher supply current.
Table 1. Frequency Range vs Divider Setting
DIVIDER SETTING
÷1
⇒
DIV (Pin 4) = V+
÷2
⇒
DIV (Pin 4) = Floating
÷4
⇒
DIV (Pin 4) = GND
FREQUENCY RANGE
68.9MHz to 170MHz
34.45MHz to 85MHz
17.225MHz to 43MHz
After choosing the proper divider setting, determine the
correct frequency-setting resistor. Because of the linear
correspondence between oscillation period and resistance, a simple equation relates resistance with frequency.
⎧⎪1
⎛ 168.5MHz ⎞
•⎜
,
N
=
⎨2
⎟
⎝ fOSC – 1.5MHz ⎠
⎪⎩4
(RSETMIN = 10k, RSETMAX = 25k)
RSET =
10k
N
Any resistor, RSET, tolerance adds to the inaccuracy of the
oscillator, fOSC.
START-UP TIME
The start-up time and settling time to within 1% of the final
frequency is typically 100µs.
MAXIMUM OUTPUT LOAD
The LTC6905 output (Pin 5) can drive a capacitive load
(CLOAD) of 5pF or more. Driving a CLOAD greater than 5pF
depends on the oscillator’s frequency (fOSC) and output
resistance (ROUT). The output rise time or fall time due to
ROUT and CLOAD is equal to 2.2 • ROUT • CLOAD (from 10%
to 90% of the rise or fall transition). If the total output rise
time plus fall time is arbitrarily specified to be equal to or
less than 20% of the oscillator’s period (1/fOSC), then the
maximum output CLOAD in picofarads (pF) should be equal
to or less than [45454/(ROUT • fOSC)] (ROUT in ohms and
fOSC in MHz).
Example: An LTC6905 is operating with a 3V power supply
and is set for a fOSC = 50MHz.
ROUT with V+ = 3V is 27Ω (using the ROUT vs V+ graph in
the Typical Performance Characteristics).
The maximum output CLOAD should be equal to or less
than [45454/(27 • 50)] = 33.6pF.
The lowest resistive load Pin 5 can drive can be calculated
using the minimum high level output voltage in the Electrical Characteristics. With a V+ equal to 5.5V and 4mA
output current, the minimum high level output voltage is
5V and the lowest resistive load Pin 5 can drive is 1.25k
(5V/4mA). With a V+ equal to 2.7V and 4mA output
current, the minimum high level output voltage is 1.9V and
the lowest resistive load Pin 5 can drive is 475Ω (1.9V/4mA).
FREQUENCY ACCURACY AND POWER SUPPLY NOISE
The frequency accuracy of the LTC6905 may be affected
when its power supply generates noise with frequency
contents equal to fMO/64 or its multiples (fMO is the internal
LTC6905 master oscillator frequency before the divider
and fMO/64 is the master oscillator control loop frequency). If for example, the master oscillator frequency is
set equal to 80MHz and the LTC6905 is powered by a
switching regulator, then the oscillator frequency may
show an additional error if the switching frequency is
1.4MHz (80MHz/64).
JITTER AND POWER SUPPLY NOISE
If the LTC6905 is powered by a supply that has frequency
contents equal to the output frequency then the oscillators
jitter may increase. In addition, power supply ripple in
excess of 20mV at any frequency may increase jitter.
JITTER AND DIVIDE RATIO
At a given output frequency, a higher master oscillator
frequency and a higher divide ratio will result in lower jitter
and higher power supply dissipation. Indeterminate jitter
percentage will decrease by a factor of slightly less than
the square root of the divider ratio, while determinate jitter
will not be similarly attenuated. Please consult the specification tables and Jitter vs Frequency graph showing jitter
at various divider ratios.
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LTC6905
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APPLICATIO S I FOR ATIO
JITTER AND STRAY CAPACITANCE ON THE SET PIN
(PIN 3)
2) The resistor RSET should be placed as close as possible
to the LTC6905, and the connection of RSET to VCC
should be closely shared with the bypass capacitor. The
resistor RSET may be placed on the opposite side of the
board from the LTC6905, directly underneath the bypass capacitor.
The stray capacitance on the SET pin (Pin 3) should be
limited to 10pF or less to avoid increased jitter or unstable
oscillation.
3) If a ground plane is used, the connection of the LTC6905
to the ground plane should be as close as possible to the
LTC6905 GND pin and should be composed of multiple,
high current capacity vias.
LTC6905 SUGGESTED CRITICAL COMPONENT
LAYOUT
In order to provide the specified performance, it is required that the frequency setting resistor RSET and the
supply bypass capacitor be placed as close as possible to
the LTC6905. The following additional rules should be
followed for best performance:
R
C
1) The bypass capacitor must be placed as close as
possible to the LTC6905, and no vias should be placed
between the capacitor and the LTC6905. The bypass
capacitor must be on the same side of the circuit board
as the LTC6905.
LTC6905
6905 F02
Figure 2. LTC6905 Suggested Critical Component Layout
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PACKAGE DESCRIPTIO
S5 Package
5-Lead Plastic TSOT-23
(Reference LTC DWG # 05-08-1635)
0.62
MAX
0.95
REF
2.90 BSC
(NOTE 4)
1.22 REF
3.85 MAX 2.62 REF
1.4 MIN
2.80 BSC
1.50 – 1.75
(NOTE 4)
PIN ONE
RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR
0.30 – 0.45 TYP
5 PLCS (NOTE 3)
0.95 BSC
0.80 – 0.90
0.20 BSC
0.01 – 0.10
1.00 MAX
DATUM ‘A’
0.30 – 0.50 REF
0.09 – 0.20
(NOTE 3)
NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DRAWING NOT TO SCALE
3. DIMENSIONS ARE INCLUSIVE OF PLATING
4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
5. MOLD FLASH SHALL NOT EXCEED 0.254mm
6. JEDEC PACKAGE REFERENCE IS MO-193
1.90 BSC
S5 TSOT-23 0302
6905fa
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
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LTC6905
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APPLICATIO S I FOR ATIO
ALTERNATIVE METHODS OF SETTING THE OUTPUT
FREQUENCY OF THE LTC6905
Figure 3 shows a method to control the frequency of the
LTC6905 using a current source. RSET, in this case, sets a
maximum frequency according to the regular expression
for fOSC. The current source will subtract current from the
SET pin to lower the frequency.
The LTC6905 may be programmed by any method that
sources a current into the SET pin (Pin 3). The accuracy of
the programming is best with a simple resistor because
the LTC6905 takes into account both the voltage at the SET
pin and the current into the SET pin when generating the
output frequency. Since the voltage at the SET pin can vary
by as much as 5%, setting the frequency using a current
rather than a resistor will result in as much as 5% additional inaccuracy in the output frequency.
V+
1
0.1µF
RSET
10k
2
3
OUT
V+
LTC6905
SET
ICNTRL
0µA TO 60µA
DIV
⎤
⎡
⎡ V + – VSET
⎤
– ICNTRL ⎥
⎢ 168.5MHz • 10kΩ • ⎢
⎥
RSET
1⎢
⎣
⎦
fOSC =
+ 1.5MHz⎥
+
⎢
⎥
N
V – VSET
⎢
⎥
⎢⎣
⎥⎦
5
fOSC
69.8MHz TO 170MHz
GND
V+
N=1
4
ICNTRL Frequency ≤ 100kHz
Example (Figure 3): VSET = (V+ – 1V), RSET = 10k, N = 1
6905 F03
[
fOSC = 168.5MHz • (1 – 10kΩ • ICNTRL ) + 1.5MHz
Figure 3. Current Controlled Oscillator
V + = 3V
1
0.1µF
RSET
10k
3
RCNTRL
33.2k
+
–
2
V+
OUT
LTC6905
DIV
fOSC
69.8MHz TO 170MHz
4
]
⎤
⎡
⎡ V + – VSET VSET – VCNTRL ⎤
–
⎢ 168.5MHz • 10kΩ • ⎢
⎥
⎥
RCNTRL ⎦
1
⎣ RSET
fOSC = ⎢
+ 1.5MHz⎥
+
⎢
⎥
N
V – VSET
⎢
⎥
⎢⎣
⎥⎦
5
GND
SET
Figure 4 shows a method for controlling the frequency of
the LTC6905 using a voltage source. In this case, RSET sets
a constant current into the SET pin, and RCNTRL will subtract from this current in order to change the frequency.
Increasing VCNTRL will increase the output frequency.
VCNTRL Frequency ≤ 100kHz
V+
N=1
Example (Figure 4): VSET = (V+ – 1V), RSET = 10k, RCNTRL = 33.2k,
N = 1, V+ = 3V
6905 F04
VCNTRL
0V TO 2V
⎤
⎡
2V – VCNTRL ⎤
⎡ 1
–
fOSC = ⎢168.5MHz • 10kΩ • ⎢
+ 1.5MHz⎥
⎥
33.2kΩ ⎦
⎣ 10kΩ
⎣
⎦
Figure 4. Voltage Controlled Oscillator
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LTC1799
LTC6900
LTC6902
LTC6903/LTC6904
LTC6905-XXX Series
LTC6906
1kHz to 33MHz ThinSOT Oscillator
1kHz to 20MHz ThinSOT Oscillator
Multiphase Oscillator with Spread Spectrum Modulation
1kHz to 68MHz Serial Port Programmable Oscillator
Fixed Frequency LTC6905
Micropower, 10kHz to 1MHz Resistor Set ThinSOT Oscillator
Single Output, High Frequency Operation
Single Output Lower Power
2-, 3- or 4-Phase Outputs
3-Wire or I2CTM Programmable
High Accuracy, No External Resistor
Ultralow Power, Resistor Sets Frequency
I2C is a trademark of Philips Electronics N.V.
8
6905fa
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