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Updated Oct 27, 2013 by rijadsul...@gmail.com

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LM340-N

Description

The LM340-N monolithic 3-terminal positive voltage regulator employs internal current limiting, thermal shutdown and safe-area compensation, making then essentially indestructible. If adequate heat sinking is provided, they can deliver over 1.0A output current. They are intended as fixed voltage regulators in a wide range of applications including local (on card) regulation for noise and distribution problems associated with single-point regulation. In addition to use as fixed voltage regulators, this device can be used with external components to obtain adjustable output voltages and currents.

Features of LM340-N

  • Standard 3-Terminal Positive Regulator
  • Fixed 5V output voltage
  • Max output current 1A
  • Min input voltage 7.5V
  • Load regulation 50mV
  • Line regulation 50mV
  • Requires a capacitor on input of 0.22uF
  • Optional capacitor on output of 0.1uF
  • For a 9V source and 5V load, Efficiency of 55.56%

Fixed Output Regulator

SOT-223 package top view

MC7800 (Alternative)

Description

These voltage regulators are monolithic integrated circuits designed as fixed voltage regulators for a wide variety of applications, including local, on card regulation. These regulators employ internal current limiting, thermal shutdown, and safe area compensation. With adequate heat sinking they can deliver output currents in excess of 1.0 A. Although designed primarily as a fixed voltage regulator, these devices can be used with external components to obtain adjustable voltages and currents.

Features of MC7800

  • Standard 3-Terminal Positive Regulator
  • Fixed 5V output voltage
  • Max output current 1A
  • Min input voltage 7V
  • No External Components Required
  • Load regulation 100mV
  • Line regulation 100mV
  • Input voltage max 35V
  • Similar in price and availability as LM-340
  • About a dollar a piece for both
  • Same efficiency

LM2675

Description

The LM2675 series of regulators are monolithic integrated circuits built with a LMDMOS process. These regulators provide all the active functions for a step-down (buck) switching regulator, capable of driving a 1A load current with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5.0V, 12V, and an adjustable output version.

Features of LM2675

  • Efficiency up to 96%
  • Available in 8-pin SOIC
  • Requires Only 5 External Components
  • Min input voltage 8V
  • Max input voltage 40V
  • Output voltage 5V
  • Output current 1A
  • Switching frequency 260kHz

Switching regulator Vs. Linear regulator

A linear regulator regulates either output voltage or current by dissipating the excess electric power in the form of heat, and hence its maximum power efficiency is voltage-out/voltage-in since the voltage difference is wasted. In contrast, a switching regulator regulates output voltage by switching ideal storage elements, like inductors and capacitors, into and out of different electrical configurations. Ideal switching elements have no resistance when closed and carry no current when open, and so the regulators can theoretically operate with 100% efficiency. The main advantage switching regulators is greater efficiency because the switching transistor dissipates little power when it is outside of its active region. Other advantages include lower heat generation due to higher efficiency. Disadvantages include greater complexity, the generation of high-amplitude, high-frequency energy that the low-pass filter must block to avoid electromagnetic interference, a ripple voltage at the switching frequency, and the harmonic frequencies thereof. Switching regulators are also more expensive. 3-4 dollars a piece

Typical application

Connection diagram

TLV1117-33CDCYR

Description

The TLV1117 is a positive low-dropout voltage regulator designed to provide up to 800 mA of output current. All internal circuitry is designed to operate down to 1-V input-to-output differential. Dropout voltage is specified at a maximum of 1.3 V at 800 mA, decreasing at lower load currents. The TLV1117 is designed to be stable with tantalum and aluminum electrolytic output capacitors having an ESR between 0.2 Ω and 10 Ω. Unlike pnp-type regulators, in which up to 10% of the output current is wasted as quiescent current, the quiescent current of the TLV1117 flows into the load, increasing efficiency. The TLV1117C device is characterized for operation over the virtual junction temperature range of 0°C to 125°C, and the TLV1117I device is characterized for operation over the virtual junction temperature range of –40°C to 125°

Features of TLV1117-33CDCYR

  • Standard 3-Termial Positive Regulator
  • Fixed output voltage 3.3V
  • Max output current 800mA
  • Min input voltage 4.7V
  • SOT-223 package
  • For a 9V source and a 3.3V load, Efficiency of 36.67%

SOT-223 package

uA78M33C (Alternative)

Description

This Series of fixed-voltage integrated-circuit voltage regulators is designed for a wide range of applications. These Applications include on-card regulation for elimination of noise and distribution problems associated with single-point regulation. Each of these regulators can deliver up to 500 mA of output current. The Internal current- limiting and thermal-shutdown features of these regulators essentially make them immune to overload. In addition to use as fixed-voltage regulators, these devices can be used with external components to obtain adjustable output voltages and currents and also as the power-pass element in precision regulators.

Features of uA78M33C

  • Max input voltage 25V
  • Fixed output voltage 3.3V
  • Max output current 500mA
  • Min input voltage 5.3V
  • SOT-223 4 package
  • Load regulation 100mV
  • Line regulation 100mV
  • Same efficiency and price range as TLV1117-33CDCYR

U9VL-J-P 9V Li battery

Description

It’s a 9V disposable battery.

Features of U9VL-J-P 9V Li battery

  • Average voltage 9V
  • Max continuous current 150mA
  • Nominal capacity 1200mA
  • Battery life at max continuous discharge of 8 hours
  • Pulse capability 1050mA
  • Max continuous power 1350mW

UBBL21 10.8V Li Battery (Alternative)

Description

Lithium ion rechargeable battery pack

Features of UBBL21 10.8V Li battery

  • Li-ion battery pack
  • Output voltage 10.8V
  • Nominal capacity 2.4Ah
  • Rechargeable
  • Wire style termination
  • 3 batteries to the pack

U9VL-J-P battery (Alternative)

Description

Nickel metal hydride battery pack consisting of eight, 1.2V cells.

Features of U9VL-J-P battery

  • Nickel Metal Hydride
  • Output voltage 9.6V
  • Nominal capacity 1.15Ah
  • Rechargeable
  • Solder tab termination
  • Battery cell size 4/5 AA
  • Discharge capacity 1150mAh
  • Max current discharge 240mA

Block Diagram

Plan B

In case of regulator failure:

  • There will be a 5.3V Zener diode on the 5V line
  • There will be a 3.6V Zener diode on the 3.3V line
  • Use different 5V and 3.3V regulators with different design characteristics

In case of current shortage

  • Use additional batteries in parallel as needed

Parts List

  • 4 - TLV1117 3.3V Voltage regulator
  • 4 - LM340-N 5V voltage regulator
  • 4 - U9VL-J-P 9V battery
  • 4 - VJ....W1BC 0.22uF capacitor
  • 2 - VJ....W1BC 0.1uF capacitor
  • 2 - PLVA6xxA 5.6V Zener diode
  • 4 - BZX84 3.6V Zener diode

References

  • 1. Discrete Semiconductors, “BZX84 series Voltage regulator diodes,” BZX84-A3V6,215 Datasheet, Apr. 2003.
  • 2. Discrete Semiconductors, “PLVA6xxA series Low-voltage avalanche regulator diodes,” PLVA6xxA datasheet, May 1999.
  • 3. On Semiconductor, “MC7800, MC7800A, MC7800AE, NCV7800,” MC7800 datasheet, May 2013.
  • 4. Texas Instruments, “ADJUSTABLE AND FIXED LOW-DROPOUT VOLTAGE REGULATOR,” TLV1117 Datasheet, Dec. 2004April 2013.
  • 5. Texas Instruments, “LM340-N/LM78XX Series 3-Terminal Positive Regulators,” LM340-N datasheet, April 2013.
  • 6. Texas Instruments, “LM2675 SIMPLE SWITCHER ® Power Converter High Efficiency 1A Step-Down Voltage Regulator,” LM2675 datasheet, June 2005.
  • 7. UltraLife, “U9VL-J-P Technical Datasheet,” U9VL-J-P datasheet, Mar. 2013.
  • 8. Vishay, “Surface Mount Multilayer Ceramic Chip Capacitors for Commodity Applications,” VJ....W1BC datasheet, Mar. 2013.
  • 9. Texas Instruments, “POSITIVE-VOLTAGEREGULATORS,” uA78M00 datasheet, May 2013.
  • 10. Panasonic, “NICKEL METAL HYDRIDE BATTERIES: INDIVIDUAL DATA SHEET,” HHR120AA datasheet, Aug. 2005.

All performance graphs and passive component specifications can be found in their respective datasheets listed in the references section.

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