参数资料
型号: LTC1799IS5#TRMPBF
厂商: Linear Technology
文件页数: 12/14页
文件大小: 0K
描述: IC OSC SILICON 33MHZ TSOT23-5
产品目录绘图: TSOT23-5 Series Top
标准包装: 1
类型: 振荡器 - 硅
频率: 1kHz ~ 33MHz
电源电压: 2.7 V ~ 5.5 V
电流 - 电源: 7mA
工作温度: -40°C ~ 85°C
封装/外壳: SOT-23-5 细型,TSOT-23-5
包装: 标准包装
供应商设备封装: TSOT-23-5
安装类型: 表面贴装
产品目录页面: 1715 (CN2011-ZH PDF)
其它名称: LTC1799IS5#TRMPBFDKR
LTC1799
7
1799fc
applicaTions inForMaTion
Figure 3. Current Controlled Oscillator
Figure 4. Voltage Controlled Oscillator
ALTERNATIVE METHODS OF SETTING THE OUTPUT
FREqUENCY OF THE LTC1799
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 program-
mable current source and in the expression for fOSC, the
resistor RSET is replaced by the ratio of 1.13V/ICONTROL.
As already explained in the “Theory of Operation,” the
voltage difference between V+ and SET is approximately
1.13V, therefore, the Figure 3 circuit is less accurate than
if a resistor controls the oscillator frequency.
Figure4showstheLTC1799configuredasaVCO.Avoltage
source is connected in series with an external 10k 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.
SELECTING THE DIVIDER SETTING AND RESISTOR
The LTC1799’s master oscillator has a frequency range
spanning0.1MHzto33MHz.However,accuracymaysuffer
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 = 10k, N = 100, master oscilla-
tor = 10MHz or RSET = 100k, N = 10, master oscillator =
1MHz. The RSET = 100k 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 < 10kΩ), the
LTC1799 may suffer 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
correspondencebetweenoscillationperiodandresistance,
a simple equation relates resistance with frequency.
RSET =10k
10MHz
N fOSC
, N =
100
10
1
(RSETMIN = 3k (5V Supply), 5k (3V Supply),
RSETMAX = 1M)
Any resistor, RSET, tolerance adds to the inaccuracy of
the oscillator, fOSC.
V+
1
2
3
5
400kHz TO 21MHz
(APPROXIMATE, SEE TEXT)
V+
0.1F
ICONTROL
5A TO 200A
1799 F03
4
GND
N = 1
LTC1799
SET
OUT
DIV
10MHz
N
OSC
ICONTROL
ICONTROL EXPRESSED IN (A)
10k
1.13V
V+
1
2
3
5
V+
0.1F
RSET
10k
VCONTROL
0V TO 1.13V
1799 F04
4
GND
N = 1
LTC1799
SET
OUT
DIV
+–
10MHz
N
OSC
1 –
VCONTROL
1.13V
10k
RSET
(
)
相关PDF资料
PDF描述
V28A36M200BF CONVERTER MOD DC/DC 36V 200W
VE-B14-IU-S CONVERTER MOD DC/DC 48V 200W
NC7SZ66P5X IC BUS SWITCH SPST SGL LV SC70-5
D38999/26JH55JA CONN PLUG 55POS STRAIGHT W/SCKT
LTC6900IS5#TRMPBF IC OSC SILICON 20MHZ TSOT23-5
相关代理商/技术参数
参数描述
LTC1821-1ACGW 功能描述:IC D/A CONV 16BIT PRECISE 36SSOP RoHS:否 类别:集成电路 (IC) >> 数据采集 - 数模转换器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:1,000 系列:- 设置时间:1µs 位数:8 数据接口:串行 转换器数目:8 电压电源:双 ± 功率耗散(最大):941mW 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:24-SOIC(0.295",7.50mm 宽) 供应商设备封装:24-SOIC W 包装:带卷 (TR) 输出数目和类型:8 电压,单极 采样率(每秒):*
LTC1821-1ACGW#PBF 功能描述:IC D/A CONV 16BIT PRECISE 36SSOP RoHS:是 类别:集成电路 (IC) >> 数据采集 - 数模转换器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:1,000 系列:- 设置时间:1µs 位数:8 数据接口:串行 转换器数目:8 电压电源:双 ± 功率耗散(最大):941mW 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:24-SOIC(0.295",7.50mm 宽) 供应商设备封装:24-SOIC W 包装:带卷 (TR) 输出数目和类型:8 电压,单极 采样率(每秒):*
LTC1821-1ACGW#TR 功能描述:IC D/A CONV 16BIT PRECISE 36SSOP RoHS:否 类别:集成电路 (IC) >> 数据采集 - 数模转换器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:1,000 系列:- 设置时间:1µs 位数:8 数据接口:串行 转换器数目:8 电压电源:双 ± 功率耗散(最大):941mW 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:24-SOIC(0.295",7.50mm 宽) 供应商设备封装:24-SOIC W 包装:带卷 (TR) 输出数目和类型:8 电压,单极 采样率(每秒):*
LTC1821-1ACGW#TRPBF 功能描述:IC D/A CONV 16BIT PRECISE 36SSOP RoHS:是 类别:集成电路 (IC) >> 数据采集 - 数模转换器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:1,000 系列:- 设置时间:1µs 位数:8 数据接口:串行 转换器数目:8 电压电源:双 ± 功率耗散(最大):941mW 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:24-SOIC(0.295",7.50mm 宽) 供应商设备封装:24-SOIC W 包装:带卷 (TR) 输出数目和类型:8 电压,单极 采样率(每秒):*
LTC1821-1AIGW 功能描述:IC D/A CONV 16BIT PRECISE 36SSOP RoHS:否 类别:集成电路 (IC) >> 数据采集 - 数模转换器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:1,000 系列:- 设置时间:1µs 位数:8 数据接口:串行 转换器数目:8 电压电源:双 ± 功率耗散(最大):941mW 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:24-SOIC(0.295",7.50mm 宽) 供应商设备封装:24-SOIC W 包装:带卷 (TR) 输出数目和类型:8 电压,单极 采样率(每秒):*