参数资料
型号: LTC6990CDCB#TRMPBF
厂商: Linear Technology
文件页数: 7/30页
文件大小: 0K
描述: IC OSC SILICON 1MHZ 6DFN
产品培训模块: TimerBlox Family Timing Devices
特色产品: TimerBlox?
标准包装: 1
系列: TimerBlox®
类型: 振荡器 - 硅
频率: 488Hz ~ 1MHz
电源电压: 2.25 V ~ 5.5 V
电流 - 电源: 235µA
工作温度: 0°C ~ 70°C
封装/外壳: 6-WFDFN 裸露焊盘
包装: 标准包装
供应商设备封装: 6-DFN-EP(2x3)
安装类型: 表面贴装
配用: DC1562A-A-ND - BOARD EVAL LTC6990
其它名称: LTC6990CDCB#TRMPBFDKR
LTC6990
15
6990fc
For more information www.linear.com/LTC6990
APPLICATIONS INFORMATION
Start-Up Behavior
When first powered up, the output is high impedance. If
the output is enabled (OE = 1) at the end of the start-up
time, the output will go low for one tMASTER cycle (or half
a tOUT cycle if NDIV < 4) before the first rising edge. If the
output is disabled (OE = 0) at the end of the start-up time,
the output will drop to a low output if the Hi-Z bit = 0, or
simply remain floating if Hi-Z = 1.
Basic Fixed Frequency Operation
The simplest and most accurate method to program the
LTC6990 for fixed frequency operation is to use a single
resistor, RSET, between the SET and GND pins. The design
procedureisasimpletwostepprocess.FirstselecttheNDIV
value and then calculate the value for the RSET resistor.
Alternatively, Linear Technology offers the easy to use
TimerBlox Designer tool to quickly design any LTC6990
based circuit. Download the free TimerBlox Designer
software at www.linear.com/timerblox.
Step 1: Selecting the NDIV Frequency Divider Value
As explained earlier, the voltage on the DIV pin sets the
DIVCODE which determines both the Hi-Z bit and the
NDIV value. For a given output frequency, NDIV should be
selected to be within the following range.
62.5kHz
fOUT
≤ NDIV
1MHz
fOUT
(1a)
To minimize supply current, choose the lowest NDIV value
(generallyrecommended).Forfasterstart-upordecreased
jitter,chooseahigherNDIVsetting.Alternatively,useTable1
as a guide to select the best NDIV value for the given ap-
plication. After choosing the value for NDIV, use Table 1 to
select the proper resistor divider or VDIV/V+ ratio to apply
to the DIV pin.
Step 2: Calculate and Select RSET
The final step is to calculate the correct value for RSET
using the following equation.
RSET =
1MHz 50k
NDIV fOUT
(1b)
Select the standard resistor value closest to the calculated
value.
Example: Design a 20kHz Oscillator with Minimum
Power Consumption
Step 1: Selecting the NDIV Frequency Divider Value
First, choose an NDIV value that meets the requirements
of Equation (1a).
3.125 ≤ NDIV ≤ 50
Potential settings for NDIVinclude4,8,16,and32.NDIV=4
is the best choice, as it minimizes supply current by using
a large RSET resistor. Using Table 1, choose the R1 and R2
values to program DIVCODE to either 2 or 13, depending
on the desired behavior when the output is disabled.
Step 2: Select RSET
Calculate the correct value for RSET using Equation (1b).
RSET =
1MHz 50k
4 20kHz
= 625k
Since 625k is not available as a standard 1% resistor,
substitute 619k if a 0.97% frequency shift is acceptable.
Otherwise, select a parallel or series pair of resistors such
as 309k and 316k to attain a more precise resistance.
相关PDF资料
PDF描述
VE-B5M-MY-S CONVERTER MOD DC/DC 10V 50W
NC7SP157P6X IC MUX ULP 2-INP NONINV SC70-5
VE-B5L-IU-S CONVERTER MOD DC/DC 28V 200W
VE-B5K-IU-S CONVERTER MOD DC/DC 40V 200W
VE-B52-MY-S CONVERTER MOD DC/DC 15V 50W
相关代理商/技术参数
参数描述
LTC6990CDCBTRPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:TimerBlox: Voltage Controlled Silicon Oscillator
LTC6990CDCB-TRPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:TimerBlox: Voltage Controlled Silicon Oscillator
LTC6990CS6#PBF 制造商:Linear Technology 功能描述:TIMERBLOX: VOLTAGE CONTROLLED SILICON OSCILLATOR 制造商:Linear Technology 功能描述:IC VOLTAGE CONTROLLED OSCILLATOR SOT23-6 制造商:Linear Technology 功能描述:IC VOLTAGE CONTROLLED OSCILLATOR SOT23-6; Operating Mode:-; Frequency:2MHz; Supply Voltage Min:2.25V; Supply Voltage Max:5.5V; Digital IC Case Style:SOT-23; No. of Pins:6; Clock External Input:Yes; Operating Temperature Min:0C ;RoHS Compliant: Yes
LTC6990CS6#TRMPBF 功能描述:IC OSC SILICON 1MHZ TSOT23-6 RoHS:是 类别:集成电路 (IC) >> 时钟/计时 - 可编程计时器和振荡器 系列:TimerBlox® 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
LTC6990CS6#TRPBF 功能描述:IC OSC SILICON 1MHZ TSOT23-6 RoHS:是 类别:集成电路 (IC) >> 时钟/计时 - 可编程计时器和振荡器 系列:TimerBlox® 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