DataSheet.es    


PDF LM317M Data sheet ( Hoja de datos )

Número de pieza LM317M
Descripción MEDIUM CURRENT 1.2 TO 37V ADJUSTABLE VOLTAGE REGULATOR
Fabricantes STMicroelectronics 
Logotipo STMicroelectronics Logotipo

LM317M Voltage Regulator


1. Adjustable Voltage Regulator - TI






Hay una vista previa y un enlace de descarga de LM317M (archivo pdf) en la parte inferior de esta página.


Total 11 Páginas

No Preview Available ! LM317M Hoja de datos, Descripción, Manual

LM217M
LM317M
MEDIUM CURRENT
1.2 TO 37V ADJUSTABLE VOLTAGE REGULATOR
s OUTPUT VOLTAGE RANGE : 1.2 TO 37V
s OUTPUT CURRENT IN EXCESS OF 500 mA
s LINE REGULATION TYP. 0.01%
s LOAD REGULATION TYP. 0.1%
s THERMAL OVERLOAD PROTECTION
s SHORT CIRCUIT PROTECTION
s OUTPUT TRANSISTOR SAFE AREA
COMPENSATION
s FLOATING OPERATION FOR HIGH
VOLTAGE APPLICATIONS
DESCRIPTION
The LM217M/LM317M are monolithic integrated
circuits in TO-220, DPAK, SOT-82 and SOT-194
packages intended for use as positive adjustable
voltage regulators.
They are designed to supply until 500 mA of load
current with an output voltage adjustable over a
1.2 to 37V range.
The nominal output voltage is selected by means
of only a resistive divider, making the device
exceptionally easy to use and eliminating the
stocking of many fixed regulators.
SCHEMATIC DIAGRAM
TO-220
SOT-82
DPAK
TO-252
SOT-194
September 1997
1/11

1 page




LM317M pdf
LM217M/LM317M
APPLICATION INFORMATION
The LM317M provides an internal reference
voltage of 1.25V between the output and
adjustments terminals. This is used to set a
constant current flow across an external resistor
divider (see fig. 3), giving an output voltage VO of:
VO = VREF (1 + RR21) + IADJ R2
The device was designed to minimize the term
IADJ (100µA max) and to maintain it very constant
with line and load changes. Usually, the error
term IADJR2 can be neglected. To obtain the
previous requirement, all the regulator quiescent
current is returned to the output terminal,
imposing a minimum load current condition. If the
load is insufficient, the output voltage will rise.
Since the LM317M is a floating regulator and
”sees” only the input-to-outputdifferential voltage,
supplies of very high voltage with respect to
ground can be regulated as long as the maximum
input-to-output differential is not exceeded.
Furthermore, programmable regulator are easily
obtainable and, by connecting a fixed resistor
between the adjustment and output, the device
can be used as a precision current regulator.
In order to optimise the load regulation, the
current set resistor R1 (see fig. 3) should be tied
as close as possible to the regulator, while the
ground terminal of R2 should be near the ground
of the load to provide remote ground sensing.
EXTERNAL CAPACITORS (Fig.5)
Normally no capacitors are needed unless the
device is situated far from the input filter
capacitors; in which case an input bypass is
needed.
A 0.1µF disc or 1µF tantalium input bypass
capacitor (CI) is recommended to reduce the
sensitivity to input line impedance.
The adjustment terminal may be bypassed to
ground to improve ripple rejection. This capacitor
(Cadj) prevents ripple from being amplified as the
output voltage is increased. A 10µF capacitor
should improve ripple rejection about 80dB at
120Hz an a 10V application.
Although the LM317M is stable with no output
capacitance like any feedback circuit, certain
values of external capacitance can cause
excessive ringing. An output capacitance (CO) in
the form of a 1µF tantalium or 25µF aluminium
electrolytic capacitor on the output swamps this
effect and insures stability.
PROTECTION DIODES (Fig.5)
When external capacitors are used with any IC
regulator it is sometimes necessary to add
protection diodes to prevent the capacitors from
discharging through low current points into the
regulator.
Figure 5 show the LM317M with the
recommended protection diodes for output
voltages in excess of 25V or high capacitance
values (C3 > 25µF, C2 > 10µF). Diode D1
prevents C3 from discharging through the IC
during an input short-circuit. The combination of
diodes D1 and D2 prevents C2 from discarging
through the regulator during an input or output
short-circuit.
START-UP BLOCK
It’s not guaranteed the Re-Boot of the device
when the junction temperature is over 85 oC.
5/11

5 Page





LM317M arduino
LM217M/LM317M
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsability for the
consequences of use of such information nor for any infringement of patents or other rights of third parties which may results from its use. No
license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned
in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied.
SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express
written approval of SGS-THOMSON Microelectonics.
© 1997 SGS-THOMSON Microelectronics - Printed in Italy - All Rights Reserved
SGS-THOMSON Microelectronics GROUP OF COMPANIES
Australia - Brazil - Canada - China - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands -
Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A
.
11/11

11 Page







PáginasTotal 11 Páginas
PDF Descargar[ Datasheet LM317M.PDF ]




Hoja de datos destacado

Número de piezaDescripciónFabricantes
LM317Adjustable Voltage RegulatorInchange Semiconductor
Inchange Semiconductor
LM317THREE.TERMINAL ADJUSTABLE POSITIVE VOLTAGE REGULATORON Semiconductor
ON Semiconductor
LM3173-TERMINAL ADJUSTABLE REGULATORSWing Shing Computer Components
Wing Shing Computer Components
LM3171.2V TO 37V VOLTAGE REGULATORSTMicroelectronics
STMicroelectronics

Número de piezaDescripciónFabricantes
SLA6805M

High Voltage 3 phase Motor Driver IC.

Sanken
Sanken
SDC1742

12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters.

Analog Devices
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,
permitiéndote verlos en linea o descargarlos en PDF.


DataSheet.es    |   2020   |  Privacy Policy  |  Contacto  |  Buscar