LTC6905-XXX Series
Supply Voltage (V +) to GND ........................–0.3V to 6V DIV –0.3V to (V + + 0.3V)OE to GND .....................................–0.3V to (V + + 0.3V)Output Short-Circuit Duration (Note 6)........... Indefinite Operating Temperature Range (Note 8)
LTC6905C ..........................................–40°C to 85°.–40°C to 85°C LTC6905H ........................................–40°C to 125°C Specified Temperature Range (Note 8)
LTC6905C ...............................................0°C to 70°.–40°C to 85°C LTC6905H ........................................–40°C to 125°C Storage –65°C to 150°C Lead Temperature (Soldering, 10 c)..................300°C
ORDER PART NUMBER T JMAX = 125°C, θJA = 150°C/W
LTC6905CS5-133LTC6905IS5-133LTC6905HS5-133LTC6905CS5-100LTC6905IS5-100LTC6905HS5-100LTC6905CS5-96LTC6905IS5-96LTC6905HS5-96LTC6905CS5-80LTC6905IS5-80LTC6905HS5-80
(Note 1)
TOP VIEW
S5 PACKAGE著名的诗
5-LEAD PLASTIC SOT-23123
V +GND OE 54OUT
DIV S5 PART MARKING*
LTBPM
ABSOLUTE AXI U RATI GS
W W W风景旅游区
U PACKAGE/ORDER I FOR ATIO
U U W
*The temperature grade is identified by a label on the shipping container.
The ● denotes the specifications which apply over the full specified
temperature range, otherwi specifications are at T A = 25°C or as noted. OE = DIV = V +, V + = 2.7V to 3.6V, R L = 15k, C L = 5pF, unless otherwi noted. All voltages are with respect to GND.
电影主题音乐SYMBOL PARAMETER
CONDITIONS MIN
TYP MAX UNITS
∆f
Frequency Accuracy (Notes 2, 7)
LTC6905C-XXX
T A = 25°C, V + = 3V ±0.5
±1.0%0°C < T A < 70°C ●
±1.5%LTC6905I-XXX 25°C < T A < 85°C ±1.8%–40°C < T A < 85°C ●
±2.9%LTC6905H-XXX
25°C < T A < 125°C ±2.3%–40°C < T A < 125°C ●
±2.9
%V + = 5V
±1.5
%∆f/∆T Freq Drift Over Temp (Note 2)●
±20ppm/°C ∆f/∆V
Freq Drift Over Supply (Notes 2, 7)V + = 2.7V to 3.6V
0.5%/V Timing Jitter (Note 3)
0.8%Long-Term Stability of Output Frequency 300
ppm/√kHr
Duty Cycle
●47.55052.5%V +
Operating Supply Range
●
2.7
泳鹅5.5
科普征文V
ELECTRICAL CHARACTERISTICS
LTBPK
LTBPJ
LTBPH
LTC6905-XXX Series
6905xf
The ● denotes the specifications which apply over the full specified
temperature range, otherwi specifications are at T A = 25°C or as noted. OE = DIV = V +, V + = 2.7V to 3.6V, R L = 15k, C L = 5pF, unless otherwi noted. All voltages are with respect to GND.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CONDITIONS
MIN TYP MAX UNITS I S
Power Supply Current
DIV = V + (÷ 1), V + = 3.6V LTC6905-133●1015mA LTC6905-100●812mA LTC6905-96●812mA LTC6905-80●711mA DIV = 0 (÷ 4), V + = 3.6V LTC6905-133●58mA LTC6905-100●47mA LTC6905-96●47mA LTC6905-80
●
3.5
6mA V IH High Level DIV or OE Pins Input Voltage ● V + – 0.15V V IL Low Level DIV or OE Pins Input Voltage ●
0.2
V I DIV DIV Input Current (Note 4)DIV = V +V + = 5.5V ● 15 40
µA DIV = 0V V + = 5.5V ●
–40
–11µA I OE OE Input Current (Note 4)OE = V +V + = 5.5V 15µA OE = 0V V + = 5.5V –11
µA V OH
High Level Output Voltage (Note 4)
V + = 5.5V I OH = –1mA ● 5.25 5.45V I OH = –4mA ● 5.20 5.30V V + = 2.7V
I OH = –1mA ● 2.5 2.6V I OH = –4mA ● 2.3
2.5V
V OL
Low Level Output Voltage (Note 4)
V + = 5.5V I OL = 1mA ●0.050.25V I OL = 4mA ●0.20.3V V + = 2.7V
I OL = 1mA ●0.10.3V I OL = 4mA
●
0.40.5
V t r , t f
OUT Ri/Fall Time (Note 5)
0.5
ns
Note 1: Absolute Maximum Ratings are tho values beyond which the life of the device may be impaired.
Note 2: Frequency accuracy is tested with DIV = V + (÷1). 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 bad 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 ri and fall times are measured between the 10% and 90% power supply levels.
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 LTC6905 is optimized for the performance with a 3V power supply voltage. Refer to Typical Performance Characteristics curves in this data sheet for additional information regarding the LTC6905 voltage coefficient, especially between 4.5V and 5.5V.
Plea consult LTC Marketing for parts optimized for 5V operation.
Note 8: The LTC6905C-XXX is guaranteed functional over the operating temperature range and 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 the temperatures. The LTC6905I-XXX is guaranteed to meet specified performance from –40°C to 85°C.读书分享会流程
LTC6905-XXX Series
LTC6905-80 Output Operating at 20MHz, V S = 3V
LTC6905-133 Output Operating at 133MHz, V S = 3V
R OUT vs V +
Jitter vs Frequency
SUPPLY VOLTAGE (V)
2.5
0O U T P U T R E S I S T A N C E (Ω)
5152025 4.5456905x G04
10 3.53
5
4 5.5
3035
40
FREQUENCY (MHz)
00
J I T T E R (%)
0.200.60÷4
÷2
÷1
0.80
1.0040
801001806905x G05
0.40
20601201401601.20TYPICAL PERFOR A CE CHARACTERISTICS
U W
Frequency vs Temperature
TEMPERATURE (°C)
–40–1.0
P E R C E N T A G E E R R O R
(%)
–0.8
–0.4–0.201.00.40
40606905x G08
–0.60.60.8
0.2–20
2080100120Supply Current vs Frequency
FREQUENCY (MHz)
S U P P L Y C U R R E N T (m A )
101214200
6905x G01
8
60250
100
北京烤鸭制作方法
15041816Frequency Error vs Supply Voltage
SUPPLY VOLTAGE (V)
2.5
–0.50
F R E Q U E N C Y
E
R R O R (%)
O 0.501.001.502.503
3.54
4.56905x G09
5
5.5
2.00
0.75V/DIV
10ns/DIV
6905x G06
0.75V/DIV
2.5ns/DIV
6905x G07
LTC6905-XXX Series
APPLICATIO S I FOR ATIO
W U
U
U START-UP TIME
The start-up and ttling time to within 1% of the final frequency is typically 100µs.MAXIMUM OUTPUT LOAD
The LTC6905 output (Pin 5) can drive a capacitive load (C LOAD ) of 5pF or more. Performance driving a C LOAD greater than 5pF depends on the oscillator’s frequency (f OSC ) and output resistance (R OUT ). The output ri time or fall time due to R OUT and C LOAD is equal to 2.2 • R OUT •C LOAD (from 10% to 90% of the ri or fall transition). If the total output ri time plus fall time is arbitrarily specified to be equal to or less than 20% of the oscillator’s period (1/f OSC ), then the maximum output C LOAD in picofarads (pF)should be equal to or less than [45454/(R OUT • f OSC )](R OUT in ohms and f OSC in MHz).
Example: An LTC6905-100 is operating with a 3V power supply and is t for a f OSC = 50MHz.
R OUT with V + = 3V is 27Ω (using the R OUT vs V + graph in the Typical Performance Characteristics).
The maximum output C LOAD 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 Elec-trical Characteristics. With a V + equal to 5.5V and 4mA output current, the minimum high level output voltage is 5.2V and the lowest resistive load Pin 5 can drive is 1.30k (5.2V/4mA). With a V + equal to 2.7V and 4mA output current, the minimum high level output voltage is 2.4V and the lowest resistive load Pin 5 can drive is 600Ω (2.4V/4mA).FREQUENCY ACCURACY AND POWER SUPPLY NOISE The frequency accuracy of the LTC6905 may be affected when its power supply generates noi with frequency contents equal to f MO /64 or its multiples. f MO is the
highest frequency for an LTC6905-XXX which is with DIV = V + (÷1). This is also the frequency indicated in the part number (i.e., LTC6905-100, f MO = 100MHz). f MO /64is the master oscillator control loop frequency. For ex-ample, if the LTC6905-80 with a master oscillator fre-quency of 80MHz is powered by a switching regulator,
then the oscillator frequency may show an additional error if the switching frequency is 1.4MHz (80MHz/64).The magnitude of this effect is heavily dependent on supply bypass and routing.JITTER AND POWER SUPPLY NOISE
If the LTC6905 is powered by a supply that has frequency content equal to the output frequency then the output jitter may increa. In addition, power supply ripple in excess of 20mV at any frequency may increa jitter.
Higher divide ratios will result in lower percentage jitter.For example, jitter percentage of the LTC6905-80 operat-ing at 20MHz is lower than for the same part operating at 80MHz. Plea consult the Jitter vs Frequency graph showing jitter at various divider ratios.LTC6905 SUGGESTED CRITICAL COMPONENT LAYOUT
In order to provide the specified performance, it is re-quired that the supply bypass capacitor be plac
老公礼物ed as clo as possible to the LTC6905. The following additional rules should be followed for best performance:
1)The bypass capacitor must be placed as clo 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.
2)If a ground plane is ud, the connection of the LTC6905to the ground plane should be as clo as possible to the LTC6905 GND pin and should be compod of multiple,high current capacity vias.
Figure 2. LTC6905 Suggested Critical Component Layout
