For more information www.linear.com/LTC6990 APPLICATIONS INFORMATION Start-Up Behavio" />
參數(shù)資料
型號: LTC6990IS6#TRPBF
廠商: Linear Technology
文件頁數(shù): 7/30頁
文件大小: 0K
描述: IC OSC SILICON 1MHZ TSOT23-6
產(chǎn)品培訓模塊: TimerBlox Family Timing Devices
特色產(chǎn)品: TimerBlox?
標準包裝: 2,500
系列: TimerBlox®
類型: 振蕩器 - 硅
頻率: 488Hz ~ 1MHz
電源電壓: 2.25 V ~ 5.5 V
電流 - 電源: 235µA
工作溫度: -40°C ~ 85°C
封裝/外殼: SOT-23-6 細型,TSOT-23-6
包裝: 帶卷 (TR)
供應商設備封裝: TSOT-23-6
安裝類型: 表面貼裝
配用: DC1562A-A-ND - BOARD EVAL LTC6990
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.
相關PDF資料
PDF描述
LTC6992HDCB-1#TRMPBF IC OSC SILICON 1MHZ 6-DFN
LTC6990HDCB#TRMPBF IC OSC SILICON 1MHZ 6DFN
V375B12M300BL CONVERTER MOD DC/DC 12V 300W
V375B12M300BF3 CONVERTER MOD DC/DC 12V 300W
V375A8M300BF2 CONVERTER MOD DC/DC 8V 300W
相關代理商/技術參數(shù)
參數(shù)描述
LTC6990MPS6#PBF 制造商:Linear Technology 功能描述:SC-Timing, Cut Tape VCO with Confirgurable Gain and Voltage Range, MP
LTC6990MPS6#TRMPBF 功能描述:IC VCO CONFIG GAIN/VOLT TSOT23-6 RoHS:是 類別:集成電路 (IC) >> 時鐘/計時 - 可編程計時器和振蕩器 系列:TimerBlox® 產(chǎn)品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:45 系列:- 類型:溫度 - 補償晶體振蕩器(TCXO) 計數(shù):- 頻率:25MHz 電源電壓:3.135 V ~ 3.465 V 電流 - 電源:1.5mA 工作溫度:-40°C ~ 85°C 封裝/外殼:16-SOIC(0.295",7.50mm 寬) 包裝:管件 供應商設備封裝:16-SOIC W 安裝類型:表面貼裝
LTC6990MPS6#TRPBF 功能描述:IC VCO CONFIG GAIN/VOLT TSOT23-6 RoHS:是 類別:集成電路 (IC) >> 時鐘/計時 - 可編程計時器和振蕩器 系列:TimerBlox® 產(chǎn)品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:45 系列:- 類型:溫度 - 補償晶體振蕩器(TCXO) 計數(shù):- 頻率:25MHz 電源電壓:3.135 V ~ 3.465 V 電流 - 電源:1.5mA 工作溫度:-40°C ~ 85°C 封裝/外殼:16-SOIC(0.295",7.50mm 寬) 包裝:管件 供應商設備封裝:16-SOIC W 安裝類型:表面貼裝
LTC6991 制造商:LINER 制造商全稱:Linear Technology 功能描述:TimerBlox: Resettable, Low Frequency Oscillator
LTC6991CDCB#TRMPBF 功能描述:IC OSC SILICON 977HZ 6-DFN RoHS:是 類別:集成電路 (IC) >> 時鐘/計時 - 可編程計時器和振蕩器 系列:TimerBlox® 標準包裝:3,000 系列:- 類型:振蕩器 - 晶體 計數(shù):- 頻率:- 電源電壓:2.3 V ~ 5.5 V 電流 - 電源:1.07mA 工作溫度:-30°C ~ 80°C 封裝/外殼:SOT-665 包裝:帶卷 (TR) 供應商設備封裝:SS迷你型-5D 安裝類型:表面貼裝 其它名稱:AN8955SSMTXLTR