參數(shù)資料
型號: LM3814MX-1.0/NOPB
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 電源管理
英文描述: 2-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8
封裝: 0.150 INCH, PLASTIC, SOP-8
文件頁數(shù): 2/14頁
文件大小: 711K
代理商: LM3814MX-1.0/NOPB
Product Operation
The current is sampled by the delta-sigma modulator, as
illustrated in Figure 6. The pulse density output of the delta-
sigma modulator is digitally filtered. The digital output is then
compared to the output of a digital ramp generator. This
produces a PWM output. The duty cycle of the PWM output
is proportional to the amount of current flowing. A duty cycle
of 50% indicates zero current flow. If the current is flowing in
positive direction, the duty cycle will be greater than 50%.
Conversely, the duty cycle will be less than 50% for currents
flowing in the negative direction. A duty cycle of 95.5%
(4.5%) indicates the current is at I
MAX (IMAX). The IC can
sense currents from I
MAX to +IMAX. Options for IMAX are 1A
or 10A. The sense current is given by:
I
SENSE = 2.2 (D0.5)(IMAX)
where D is the duty cycle of the PWM waveform, and I
MAX is
the full scale current (1A or 10A). Similarly, the duty cycle is
given by:
D=[I
SENSE/(2.2 IMAX)] + 0.5
For quick reference, see the Conversion Tables in Table 1
The user should note that, while the LM3814-7.0/
LM3815-7.0 will read 10A full scale, it is rated for 10A
operation for a duration of no more than 200 msec, and
7A operation continuously.
In this IC, the current is averaged over 6 msec time slots.
Hence, momentary current surges of less than 6 msec are
tolerated.
This is a sampled data system which requires an anti-
aliasing filter, provided by the filter capacitor.
The delta-sigma modulator converts the sensed current to
the digital domain. This allows digital filtering, and provides
immunity to current and noise spikes. This type of filtering
would be difficult or impossible to accomplish on an IC with
analog components.
When ordering, the user has to specify whether the part is
being used for low-side or high-side sense. The user also
needs to specify the full scale value. See the Ordering
Information table for details.
10101310
FIGURE 6. Functional block diagram of LM3814 and LM3815
LM3814/LM3815
www.national.com
10
相關PDF資料
PDF描述
LM3815MX-1.0/NOPB 2-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8
LM3814M-1.0/NOPB 2-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8
LM3815MX-7.0/NOPB 2-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8
LM3814M-7.0/NOPB 2-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8
LM3814X-1.0 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8
相關代理商/技術參數(shù)
參數(shù)描述
LM3814MX-7.0 功能描述:IC CURRENT GAUGE 6% 8SOIC RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)流/電流管理 系列:- 產(chǎn)品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:50 系列:- 功能:電流開關 檢測方法:- 精確度:±10% 輸入電壓:1.7 V ~ 5.5 V 電流 - 輸出:600mA 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:10-UFQFN 供應商設備封裝:10-UTQFN(1.4x1.8) 包裝:管件
LM3815 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Fast Current Gauge IC with Ultra Low Loss Sense Element and PWM Output
LM3815M-1.0 制造商:Texas Instruments 功能描述:
LM3815M-1.0/NOPB 功能描述:IC CURRENT GAUGE PREC 8-SOIC RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)流/電流管理 系列:- 產(chǎn)品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:50 系列:- 功能:電流開關 檢測方法:- 精確度:±10% 輸入電壓:1.7 V ~ 5.5 V 電流 - 輸出:600mA 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:10-UFQFN 供應商設備封裝:10-UTQFN(1.4x1.8) 包裝:管件
LM3815M-7.0 制造商:Texas Instruments 功能描述: