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LM134 Dataheets PDF



Part Number LM134
Manufacturers National Semiconductor
Logo National Semiconductor
Description 3-Terminal Adjustable Current Sources
Datasheet LM134 DatasheetLM134 Datasheet (PDF)

LM134/LM234/LM334 3-Terminal Adjustable Current Sources March 2000 LM134/LM234/LM334 3-Terminal Adjustable Current Sources General Description The LM134/LM234/LM334 are 3-terminal adjustable current sources featuring 10,000:1 range in operating current, excellent current regulation and a wide dynamic voltage range of 1V to 40V. Current is established with one external resistor and no other parts are required. Initial current accuracy is ± 3%. The LM134/LM234/LM334 are true floating current sou.

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LM134/LM234/LM334 3-Terminal Adjustable Current Sources March 2000 LM134/LM234/LM334 3-Terminal Adjustable Current Sources General Description The LM134/LM234/LM334 are 3-terminal adjustable current sources featuring 10,000:1 range in operating current, excellent current regulation and a wide dynamic voltage range of 1V to 40V. Current is established with one external resistor and no other parts are required. Initial current accuracy is ± 3%. The LM134/LM234/LM334 are true floating current sources with no separate power supply connections. In addition, reverse applied voltages of up to 20V will draw only a few dozen microamperes of current, allowing the devices to act as both a rectifier and current source in AC applications. The sense voltage used to establish operating current in the LM134 is 64mV at 25˚C and is directly proportional to absolute temperature (˚K). The simplest one external resistor connection, then, generates a current with ≈+0.33%/˚C temperature dependence. Zero drift operation can be obtained by adding one extra resistor and a diode. Applications for the current sources include bias networks, surge protection, low power reference, ramp generation, LED driver, and temperature sensing. The LM234-3 and LM234-6 are specified as true temperature sensors with guaranteed initial accuracy of ± 3˚C and ± 6˚C, respectively. These devices are ideal in remote sense applications because series resistance in long wire runs does not affect accuracy. In addition, only 2 wires are required. The LM134 is guaranteed over a temperature range of −55˚C to +125˚C, the LM234 from −25˚C to +100˚C and the LM334 from 0˚C to +70˚C. These devices are available in TO-46 hermetic, TO-92 and SO-8 plastic packages. Features n n n n n n Operates from 1V to 40V 0.02%/V current regulation Programmable from 1µA to 10mA True 2-terminal operation Available as fully specified temperature sensor ± 3% initial accuracy Connection Diagrams SO-8 Surface Mount Package SO-8 Alternative Pinout Surface Mount Package TO-46 Metal Can Package DS005697-24 DS005697-12 DS005697-25 Order Number LM334M or LM334MX See NS Package Number M08A Order Number LM334SM or LM334SMX See NS Package Number M08A V− Pin is electrically connected to case. Bottom View Order Number LM134H, LM234H or LM334H See NS Package Number H03H TO-92 Plastic Package DS005697-10 Bottom View Order Number LM334Z, LM234Z-3 or LM234Z-6 See NS Package Number Z03A © 2000 National Semiconductor Corporation DS005697 www.national.com LM134/LM234/LM334 Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. V+ to V− Forward Voltage LM134/LM234/LM334 LM234-3/LM234-6 V+ to V− Reverse Voltage R Pin to V− Voltage Set Current Power Dissipation ESD Susceptibility (Note 6) Operating Temperature Range (Note 5) LM134 40V 30V 20V 5V 10 mA 400 mW 2000V −55˚C to +125˚C LM234/LM234-3/LM234-6 −25˚C to +100˚C LM334 0˚C to +70˚C Soldering Information TO-92 Package (10 sec.) 260˚C TO-46 Package (10 sec.) 300˚C SO Package Vapor Phase (60 sec.) 215˚C Infrared (15 sec.) 220˚C See AN-450 “Surface Mounting Methods and Their Effect on Product Reliability” (Appendix D) for other methods of soldering surface mount devices. Electrical Characteristics (Note 2) Parameter Set Current Error, V+ =2.5V, (Note 3) Ratio of Set Current to Bias Current Minimum Operating Voltage Conditions Min 10µA ≤ ISET ≤ 1mA 1mA < ISET ≤ 5mA 2µA ≤ ISET < 10µA 100µA ≤ ISET ≤ 1mA 1mA ≤ ISET ≤ 5mA 2 µA≤ISET≤100 µA 2µA ≤ ISET ≤ 100µA 100µA < ISET ≤ 1mA 1mA < ISET ≤ 5mA Average Change in Set Current with Input Voltage 2µA ≤ ISET ≤ 1mA 1.5 ≤ V+ ≤ 5V 5V ≤ V+ ≤ 40V 1mA < ISET ≤ 5mA 1.5V ≤ V ≤ 5V 5V ≤ V ≤ 40V Temperature Dependence of Set Current (Note 4) Effective Shunt Capacitance 15 15 pF Note 1: .“Absolute Maximum Ratings” indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is functional, but do not guarantee specific performance limits. Note 2: Unless otherwise specified, tests are performed at Tj = 25˚C with pulse testing so that junction temperature does not change during test Note 3: Set current is the current flowing into the V+ pin. For the Basic 2-Terminal Current Source circuit shown on the first page of this data sheet. ISET is determined by the following formula: ISET = 67.7 mV/RSET ( @ 25˚C). Set current error is expressed as a percent deviation from this amount. ISET increases at 0.336%/˚C @ Tj = 25˚C (227 µV/˚C). Note 4: ISET is directly proportional to absolute temperature (˚K). ISET at any temperature can be calculated from: ISET = Io (T/To) where Io is ISET measured at To (˚K). Note 5: For elevated temperature operation, TJ max is: LM134/LM234 Typ Max 3 5 8 14 18 14 18 0.8 0.9 1.0 0.02 0.01 0.03 0.02 0.96T T 1.04T 0.96T 0.05 0.03 23 23 14 Min LM334 Typ Max 6 8 12 18 14 18 0.8 0.9 1.0 0.02 0.01 0.0.


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