参数资料
| 型号： | LTC6900CS5#TR |
| 厂商： | Linear Technology |
| 文件页数： | 10/12页 |
| 文件大小： | 0K |
| 描述： | IC OSC SILICON 20MHZ TSOT23-5 |
| 标准包装： | 2,500 |
| 类型： | 振荡器 - 硅 |
| 频率： | 1kHz ~ 20MHz |
| 电源电压： | 2.7 V ~ 5.5 V |
| 电流 - 电源： | 920µA |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | SOT-23-5 细型，TSOT-23-5 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | TSOT-23-5 |
| 安装类型： | 表面贴装 |
| 其它名称： | LTC6900CS5#TR-ND LTC6900CS5TR |
LTC6900
7
6900fa
APPLICATIONS INFORMATION
SELECTING THE DIVIDER SETTING AND RESISTOR
The LTC6900’s master oscillator has a frequency range
spanning 0.1MHz to 20MHz. However, accuracy may suffer
if the master oscillator is operated at greater than 10MHz
with a supply voltage lower than 4V. A programmable
divider extends the frequency range to greater than three
decades. Table 1 describes the recommended frequencies
for each divider setting. Note that the ranges overlap; at
some frequencies there are two divider/resistor combina-
tions that result in the desired frequency.
In general, any given oscillator frequency (fOSC) should
be obtained using the lowest master oscillator frequency.
Lower master oscillator frequencies use less power and
are more accurate. For instance, fOSC = 100kHz can be
obtained by either RSET = 20k, N = 100, master oscillator =
10MHz or RSET = 200k, N = 10, master oscillator = 1MHz.
The RSET = 200k approach is preferred for lower power
and better accuracy.
Table 1. Frequency Range vs Divider Setting
DIVIDER SETTING
FREQUENCY RANGE
÷1
DIV (Pin 4) = GND
> 500kHz*
÷10
DIV (Pin 4) = Floating
50kHz to 1MHz
÷100
DIV (Pin 4) = V+
< 100kHz
*At master oscillator frequencies greater than 10MHz (RSET < 20kΩ),
the LTC6900 may experience reduced accuracy with a supply voltage
less than 4V.
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.
RSET = 20k
10MHz
N fOSC
, N =
100
10
1
(RSETMIN = 10k, RSETMAX = 2M)
Any resistor, RSET, tolerance adds to the inaccuracy of the
oscillator, fOSC.
ALTERNATIVE METHODS OF SETTING THE OUTPUT
FREQUENCY OF THE LTC6900
The oscillator may be programmed by any method that
sources a current into the SET pin (Pin 3). The circuit in
Figure 3 sets the oscillator frequency using a programmable
current source and in the expression for fOSC, the resistor
RSET is replaced by the ratio of 1.1V/ICONTROL. As already
explained in the Operation section, the voltage difference
between V + and SET is approximately 1.1V, therefore, the
Figure 3 circuit is less accurate than if a resistor controls
the oscillator frequency.
Figure 4 shows the LTC6900 congured as a VCO. A voltage
source is connected in series with an external 20k resis-
tor. The output frequency, fOSC, will vary with VCONTROL,
that is the voltage source connected between V+ and the
SET pin. Again, this circuit decouples the relationship
between the input current and the voltage between V+
and SET; the frequency accuracy will be degraded. The
oscillator frequency, however, will monotonically increase
with decreasing VCONTROL.
Figure 3. Current Controlled Oscillator
Figure 4. Voltage Controlled Oscillator
V+
1
2
3
5
182kHz TO 18MHz (TYPICALLY ±8%)
V+
0.1μF
ICONTROL
1μA TO 100μA
6900 F03
4
GND
N = 1
LTC6900
SET
OUT
DIV
10MHz
N
OSC
ICONTROL
ICONTROL EXPRESSED IN (A)
20kΩ
1.1V
V+
1
2
3
5
V+
0.1μF
RSET
20k
VCONTROL
0V TO 1.1V
6900 F04
4
GND
N = 1
LTC6900
SET
OUT
DIV
+
–
10MHz
N
OSC
1 –
VCONTROL
1.1V
20k
RSET
()
TYPICAL fOSC ACCURACY
±0.5%, VCONTROL = 0V
±8%, VCONTROL = 0.5V
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相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC6900CS5TRMPBF | 制造商:Linear Technology 功能描述:Programmable oscillator,1K-20MHz |
| LTC6900IS5 | 制造商:Linear Technology 功能描述:Silicon Oscillator 5-Pin TSOT-23 制造商:Linear Technology 功能描述:LOW POWER, 1KHZ TO 20MHZ RESISTOR SET SOT-23 OSCILLATOR |
| LTC6900IS5#PBF | 制造商:Linear Technology 功能描述:LOW POWER, 1KHZ TO 20MHZ RESISTOR SET SOT-23 OSCILLATOR 制造商:Linear Technology 功能描述:OSCILLATOR 1KHZ TO 20MHZ SOT-23-5 制造商:Linear Technology 功能描述:OSCILLATOR, 1KHZ TO 20MHZ, SOT-23-5 制造商:Linear Technology 功能描述:SC-Timing, Cut Tape Low Power 1kHz - 20MHz Prec. Oscillator ;RoHS Compliant: Yes |
| LTC6900IS5#TR | 功能描述:IC OSC SILICON 20MHZ TSOT23-5 RoHS:否 类别:集成电路 (IC) >> 时钟/计时 - 可编程计时器和振荡器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:45 系列:- 类型:温度 - 补偿晶体振荡器（TCXO） 计数:- 频率:25MHz 电源电压:3.135 V ~ 3.465 V 电流 - 电源:1.5mA 工作温度:-40°C ~ 85°C 封装/外壳:16-SOIC（0.295"，7.50mm 宽） 包装:管件 供应商设备封装:16-SOIC W 安装类型:表面贴装 |
| LTC6900IS5#TRM | 功能描述:IC OSC SILICON 20MHZ TSOT23-5 RoHS:否 类别:集成电路 (IC) >> 时钟/计时 - 可编程计时器和振荡器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:45 系列:- 类型:温度 - 补偿晶体振荡器（TCXO） 计数:- 频率:25MHz 电源电压:3.135 V ~ 3.465 V 电流 - 电源:1.5mA 工作温度:-40°C ~ 85°C 封装/外壳:16-SOIC（0.295"，7.50mm 宽） 包装:管件 供应商设备封装:16-SOIC W 安装类型:表面贴装 |
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