参数资料
型号: LTC6900CS5#TR
厂商: Linear Technology
文件页数: 12/12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
9
6900fa
APPLICATIONS INFORMATION
A Ground Referenced Voltage Controlled Oscillator
The LTC6900 output frequency can also be programmed by
steering current in or out of the SET pin, as conceptually
shown in Figure 8. This technique can degrade accuracy
as the ratio of (V+ – VSET) / IRES is no longer uniquely
dependent of the value of RSET, as shown in the LTC6900
Block Diagram. This loss of accuracy will become noticeable
when the magnitude of IPROG is comparable to IRES. The
frequency variation of the LTC6900 is still monotonic.
Figure 9 shows how to implement the concept shown in
Figure 8 by connecting a second resistor, RIN, between the
SET pin and a ground referenced voltage source, VIN.
For a given power supply voltage in Figure 9, the output
frequency of the LTC6900 is a function of VIN, RIN, RSET
and (V+ – VSET) = VRES:
fOSC =
10MHz
N
20k
RIN RSET
1
+
VIN V+
()
VRES
1
+
RIN
RSET
(1)
When VIN = V+, the output frequency of the LTC6900 as-
sumes the highest value and it is set by the parallel com-
bination of RIN and RSET. Also note, the output frequency,
fOSC, is independent of the value of VRES = (V+ – VSET) so
the accuracy of fOSC is within the data sheet limits.
When VIN is less than V+, and expecially when VIN ap-
proaches the ground potential, the oscillator frequency,
fOSC, assumes its lowest value and its accuracy is affected
by the change of VRES = (V+ – VSET). At 25°C VRES varies
by ±8%, assuming the variation of V+ is ±5%. The tem-
perature coefcient of VRES is 0.02%/°C.
By manipulating the algebraic relation for fOSC above, a
simple algorithm can be derived to set the values of external
resistors RSET and RIN, as shown in Figure 9.
1. Choose the desired value of the maximum oscillator
frequency, fOSC(MAX), occurring at maximum input
voltage VIN(MAX) ≤ V+.
2. Set the desired value of the minimum oscillator fre-
quency, fOSC(MIN), occurring at minimum input voltage
VIN(MIN) ≥ 0.
3. Choose VRES = 1.1 and calculate the ratio of RIN/RSET
from the following:
RIN
RSET
=
VIN(MAX) V+
() fOSC(MAX)
fOSC(MIN)
VIN(MIN) V
+
()
VRES
fOSC(MAX)
()
fOSC(MIN)
1
1
(2)
Figure 7
V+
1
2
RSET1
RSET2
3
S1
5
V+
6900 F07
4
GND
LTC6900
3V OR 5V
SET
OUT
DIV
÷10
÷100
÷1
fOSC = 10MHz
OR
()
20k
N RSET1
fOSC = 10MHz
()
20k
N RSET1//RSET2
Figure 8. Concept for Programming via Current Steering
Figure 9. Implementation of Concept Shown in Figure 8
V+
1
2
RSET
IPR
3
5
5V
V+
6900 F08
4
GND
LTC6900
0.1μF
OPEN
SET
OUT
DIV
÷10
÷100
÷1
IRES
V+
1
2
RSET
VRES
RIN
VIN
3
5
5V
V+
6900 F09
4
GND
LTC6900
0.1μF
fOSC
OPEN
SET
OUT
DIV
÷10
÷100
÷1
+
+
相关PDF资料
PDF描述
MS3450L20-16SY CONN RCPT 9POS WALL MNT W/SCKT
MAX188CCWP+T IC ADC 12BIT SERIAL 20-SOIC
MS3450L20-16SX CONN RCPT 9POS WALL MNT W/SCKT
MS3450L20-16SW CONN RCPT 9POS WALL MNT W/SCKT
V375A8M300BL CONVERTER MOD DC/DC 8V 300W
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