|
|
PDF LM3822 Data sheet ( Hoja de datos )
| Número de pieza | LM3822 | |
| Descripción | Precision Current Gauge IC with Internal Zero Ohm Sense Element and PWM Output | |
| Fabricantes | National Semiconductor | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LM3822 (archivo pdf) en la parte inferior de esta página. Total 12 Páginas | ||
|
No Preview Available !
July 2000
LM3822
Precision Current Gauge IC with Internal Zero Ohm
Sense Element and PWM Output
General Description
The LM3822 Current Gauge provides easy to use precision
current measurement with virtually zero insertion loss (typi-
cally 0.003Ω). The LM3822 is used for high-side sensing.
A Delta Sigma analog to digital converter is incorporated to
precisely measure the current and to provide a current aver-
aging function. Current is averaged over 50 msec time peri-
ods in order to provide immunity to current spikes. The ICs
have a pulse-width modulated (PWM) output which indicates
the current magnitude and direction. The shutdown pin can
be used to inhibit false triggering during start-up, or to enter
a low quiescent current mode.
The LM3822 is factory-set in two different current options.
The sense range is −1.0A to +1.0A or −2.0A to +2.0A. The
sampling interval for this part is 50ms. If faster sampling is
desired, please refer to the data sheet for the part number
LM3824.
Key Specifications
n Ultra low insertion loss (typically 0.003Ω)
n 2V to 5.5V supply range
n ±2% accuracy at room temperature for the 1A device
(includes accuracy of the internal sense element)
n Low quiescent current in shutdown mode (typically
1.8 µA)
n 50 msec sampling interval
n In MSOP-8 Package
Features
n No external sense element required
n PWM output indicates the current magnitude and
direction
n PWM output is easily interfaced with microprocessors
and controllers
n Precision ∆Σ current-sense technique
n Low temperature sensitivity
n Internal filtering rejects false trips
n Internal Power-On-Reset (POR)
n DC Offset is less than 1 mA for 1A part
Applications
n Battery charge/discharge gauge
n Motion control diagnostics
n Power supply load monitoring and management
n Resettable smart fuse
Connection Diagram
DS101249-1
Top View
LM3822 for High-Side Sensing
© 2000 National Semiconductor Corporation DS101249
www.national.com
1 page  
Typical Performance Characteristics Supply bypass capacitor is 0.1 µF and filter capacitor is 0.1 µF.
Measured Current vs Actual Current
(LM3822-1.0)
Measured Current vs Actual Current
(LM3822-2.0)
DS101249-24
PWM Frequency vs Supply Voltage
PWM Frequency vs Temperature
DS101249-25
DS101249-33
Operating Current vs Supply Voltage
DS101249-23
Shutdown Current vs Supply Voltage
DS101249-18
5
DS101249-20
www.national.com
5 Page 
Timing Diagram
DS101249-11
Duty cycle of the PWM waveform during any sampling interval indicates the current magnitude (average) and direction during the previous sampling interval.
FIGURE 6. Typical Timing Diagram for Mostly Positive Current
11 www.national.com
11 Page | ||
| Páginas | Total 12 Páginas | |
| PDF Descargar | [ Datasheet LM3822.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LM382 | Low Noise Dual Preamplifier | National Semiconductor |
| LM3820 | AM RADIO SYSTEM | National Semiconductor |
| LM3822 | Precision Current Gauge IC with Internal Zero Ohm Sense Element and PWM Output | National Semiconductor |
| LM3822 | LM3822 Precision Current Gauge IC w/Inter Zero Ohm Sense Element PWM Output (Rev. C) |  Texas Instruments |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |