Spannung regle ich mit einem LM358 und dem anderen Kanal des DACs. Als konstante Last hab ich einen LM334 verbaut. Ein TC7660 gibt mir die negative Spannung am LM358 welcher die Spannung regelt, damit ich hier auch wirklich auf die Referenzsspannung des LM317 runterkomme (aus dem LM358 kommen dann 0,0V
inverter amplifier's output current to a ±200 mA level while maintaining a full ±12V output swing. The LM334 current sources are used to bias complementary emitter-followers. The 200Ω resistors and D1-D4 diodes associated with the LM334s provide temperature compensation for the current sources, while the
einzelnen Signalen..... Bei 3V wird es eng mit der [[Konstantstromquelle]] + LED. Ok, der gute, alte LM334 könnte passen, der braucht nur 0,8V. >> Was hat das mit der Spannung deiner Signale zu tun? Die LEDs müssen doch >> nicht damit versorgt werden. Eine konstante 5V Versorgung, >> Vorwiderstände
Standardschaltung meinst du? Kannst du denn eine KSQ empfehlen? Ich habe im Forum geschaut und viele haben vom LM334 (für 1mA) abgeraten oder einen großen Schaltungsaufwand betrieben.
liegt also 25 GradC daneben, Effekte durch Differenzverstarkerschaltung ignoriert) und Abweichung LM334 (ein Temperatursensor, keine Konstantstromquelle auch nicht wirklich mit der Zusatzbeschaltung) zu MCP4821 interne 2.048 Referenz mit +/-40mV) durch nachträgliche Kalibrierung behandelt werden sollen
schwankt? Bei der Stromquelle kann ich das Bestätigen, was der Hersteller in seinen Datenblätter des LM334 aufführt. Egal ob Fön oder Kältespray der Strom bleibt konstant. Anders ist das bei der ersten OP-Stufe. Das stimmt was hier ein Forenmitglied geschrieben hat, ein OP07 wäre besser gewesen. Das grundsätzliche
terminated load (RL= 75 ), the reference current is: Figure 6. Current Reference Design Using an LM334 IREF = 4.44 mA. A suggested current reference design for the doubly terminated Current Source case, with RS-343A video levels and based on the LM334, a three-terminal adjustable current source, is
1% R6 1N5401 UB max. 35V 2 1% IC6 D1 R7 6 4 5 5 IN OUT 3 3 2 1% G 2 4 VC T 4 IC7 T K 2 7 S O S V+ LM334M A 1 8 +C7 +C10 1 3 K1 LT3080T R B @P - 10µF 2 10µF V- 2 M P C4 S S D 1 R R 1 0 100nF GND GND R 1 1 2 5 R8 +C9 0 V VCC OUT ADC_IOUT GND k 3 330 10µF 1 , + GND C5 R 6 N GND C12 G 1µF ADC_VOUT GND %
als Konstantstromquelle ELKO: Der Transistor-LED-und der FET-Konstantstromzweipol Liste von J-FETs LM334 betagter, aber guter IC, programmierbare Konstantstromquelle mit 1µA-10mA, 0,8-1V Spannungsabfall, kann per Transistor auf deutlich größere Ströme erweitert werden. Weblinks. ELKO: Transistor als Konstantstromquelle
R10, which con- Quiescentcurrentis≈10mAforaV of2.5V.Excitation verts it into a voltage again. The LM334 and 2N3904 are OUT will cause AC currents about this point of ~±4mA for a nottemperaturecompensatedsotheDCoutputcontains V OUT of~±1Vmax.Theopampisconfiguredforavoltage temperature information. 2-Wire Remote Geophone Preamp R9 20Ω LINEAR V + TECHNOLOGY R LM334Z 6mA V – R8 11Ω 3V Q1 12V R6 R2 2N3904 C R 4.99k+ R4 100k LT1431CZ C3 14k A R7 220µF R5 24.9k R1 243Ω VOUT 365Ω 2 – 7 C2 R10 2.5V ±1V GEOSPACE – 0.1µF 250Ω GS-20DX LT1677 6 RL= 630Ω GEOPHONE + 3 +
R10, which con- Quiescentcurrentis≈10mAforaV of2.5V.Excitation verts it into a voltage again. The LM334 and 2N3904 are OUT will cause AC currents about this point of ~±4mA for a nottemperaturecompensatedsotheDCoutputcontains V OUT of~±1Vmax.Theopampisconfiguredforavoltage temperature information. 2-Wire Remote Geophone Preamp R9 20Ω LINEAR V + TECHNOLOGY R LM334Z 6mA V – R8 11Ω 3V Q1 12V R6 R2 2N3904 C R 4.99k+ R4 100k LT1431CZ C3 14k A R7 220µF R5 24.9k R1 243Ω VOUT 365Ω 2 – 7 C2 R10 2.5V ±1V GEOSPACE – 0.1µF 250Ω GS-20DX LT1677 6 RL= 630Ω GEOPHONE + 3 +
TheactualjunctiontemperaturecanbemeasuredwhileinoperationbypullinglmAfromtheShutdownpinwiththehelpofanadjustable currentsource,liketheLM334.Thevoltageatthepinis650mVat25°C,decreasingby2mV/°C. 5. HOW TO DEAL WITH NEGATIVE TRANSIENTS ON THE V PIN S Of the problems caused by parasitics, one of the main issues for control ICs is a tendency
operation by pulling 1 mA from the shutdown pin with the help of an adjustable current source (like the LM334). The voltage at the pin is 650 mV at 25 °C, decreasing by 2 mV/°C. Changes in this voltage are a reasonable indication of the temperature of the die. www.irf.com AN-978 RevD 8 5. HOW TO DEAL WITH
operation by pulling 1 mA from the shutdown pin with the help of an adjustable current source (like the LM334). The voltage at the pin is 650 mV at 25 °C, decreasing by 2 mV/°C. Changes in this voltage are a reasonable indication of the temperature of the die. www.irf.com AN-978 RevD 8 5. HOW TO DEAL WITH
operation by pulling 1 mA from the shutdown pin with the help of an adjustable current source (like the LM334). The voltage at the pin is 650 mV at 25 °C, decreasing by 2 mV/°C. Changes in this voltage are a reasonable indication of the temperature of the die. www.irf.com AN-978 RevD 8 5. HOW TO DEAL WITH
operation by pulling 1 mA from the shutdown pin with the help of an adjustable current source (like the LM334). The voltage at the pin is 650 mV at 25 °C, decreasing by 2 mV/°C. Changes in this voltage are a reasonable indication of the temperature of the die. www.irf.com AN-978 RevD 8 5. HOW TO DEAL WITH
operation by pulling 1 mA from the shutdown pin with the help of an adjustable current source (like the LM334). The voltage at the pin is 650 mV at 25 °C, decreasing by 2 mV/°C. Changes in this voltage are a reasonable indication of the temperature of the die. www.irf.com AN-978 RevD 8 5. HOW TO DEAL WITH
operation by pulling 1 mA from the shutdown pin with the help of an adjustable current source (like the LM334). The voltage at the pin is 650 mV at 25 °C, decreasing by 2 mV/°C. Changes in this voltage are a reasonable indication of the temperature of the die. www.irf.com AN-978 RevD 8 5. HOW TO DEAL WITH
μA reference current, and operates from 1.2V to 40V drop; its internal compensation is configured LM334 to require no external bypass or compensation capacitors. It’s worth knowing about the LM334 (originated by Na- Based on the LT3092’s datasheet plot of output impedance, tionalSemiconductor), optimized
Voltage Reference Diodes, TO-92 LM285Z-ADJ Adjustable Micropower Voltage Reference Diodes, TO-92 LM334M 1μA to 10mA 3-Terminal Adjustable Current Source, SO-8 LM334SM 1μA to 10mA 3-Terminal Adjustable Current Source, SO-8 Alternate LM334Z 1μA to 10mA 3-Terminal Adjustable Current Source, TO-92 LM334Z
of the program is devoted to measuringthetemperature,sowe’llstartthere.Thetemperaturesensor is an LM334Z constant-current source. Current through the device variesattherateof0.1µAper1°Cchangeintemperature.Theprogram inthelistingpassescurrentfrompin2oftheStampthroughthesensor to a capacitor for a short
3.3V OR DAC VDD= 2.7V to 5.5V 1.5kΩ 1.5kΩ 1μF 9.2 mA 1% 1% 4.6 mA or IREF 4.6 mA 9.2 mA 4.6 mA V+ R LM334 2N2222 2N2222 V- 29Ω 69.8Ω 1kΩ 140Ω 1kΩ 1% 1% 1% 1% 1% 290Ω 1N457 1% DAC VSS DAC VSS DAC SS DAC VSS DAC V DAC V SS SS R G } To CRT/TV B 150Ω 150Ω 150Ω 1% 1% 1% DAC VSS DAC SS DAC VSS Figure 5-2: External
