Analog Devices Ltd

Most H (Metal Can), J (Ceramic), and K (Metal Can) Packages from Linear Technology Are Now Obsolete Download Complete Datasheet for Details The LM129 temperature compensated 6.9 Volt zener references provide excellent stability over time and temperature, very low dynamic impedance and a wide operating current range. The device achieves low dynamic impedance by incorporating a high gain shunt regulator around the zener. The excellent noise performance of the device is achieved by using a "buried zener" design which eliminates surface noise phenomenon associated with ordinary zeners. To serve a wide variety of applications, the LM129 is available in several temperature coefficient grades and two package styles. A 20mA positive current source application is shown below.

The LM134 is a three-terminal current source designed to operate at current levels from 1mA to 10mA, as set by an external resistor. The device operates as a true two terminal current source, requiring no extra power connections or input signals. Regulation is typically 0.02%/V and terminal-to-terminal voltage can range from 800mV to 40V. Because the operating current is directly proportional to absolute temperature in degrees Kelvin, the device will also find wide applications as a temperature sensor. The temperature dependence of the operating current is 0.336%/°C at room temperature. For example, a device operating at 298mA will have a temperature coefficient of 1mA/°C. The temperature dependence is extremely accurate and repeatable. Devices specified as temperature sensors in the 100mA to 1mA range are the LM134-3, LM234-3 and the LM134-6, LM234-6, with the dash numbers indicating ±3°C and ±6°C accuracies, respectively. If a zero temperature coefficient current source is required, this is easily achieved by adding a diode and a resistor.

The LM336-2.5 is a general purpose shunt regulator diode designed to operate over a wide current range while maintaining good stability with time and temperature. The third terminal allows either the temperature coefficient to be minimized or the reference voltage to be adjusted without changing the temperature coefficient. Because it operates as a shunt regulator it can be used equally well as a positive or negative reference. The LM336-2.5 is available in a TO-92 plastic package. For more demanding precision reference applications requiring very low initial tolerance and temperature coefficients, consult the LT1009 data sheet.

Most H (Metal Can), J (Ceramic), and K (Metal Can) Packages from Linear Technology Are Obsolete The LT138A series of adjustable regulators provide 5A output current over an output voltage range of 1.2V to 32V. The internal voltage reference is trimmed to less than 1%, enabling a very tight output voltage. In addition to excellent line and load regulation, with full overload protection, the LT138A incorporates new current limiting circuitry allowing large transient load currents to be handled for short periods. Transient load currents of up to 12A can be supplied without limiting, eliminating the need for a large output capacitor. The LT138A is an improved version of the popular LM138 with improved circuit design and advanced process techniques to provide superior performance and reliability. The graph below shows the significant improvement in output voltage tolerance achieved by using the LT138A or LT338A.

The H (TO-5 Metal Can) Version of this part from Linear Technology is Obsolete The LM385-1.2 is a two terminal band gap reference diode that has been designed for applications which require precision performance with micropower operation. This reference is not recommended for new designs. See the LT1004 reference for a direct replacement. For a low drift, micropower reference with guaranteed temperature coefficient, see the LT1034 data sheet.

The H (TO-5 Metal Can) Version of this part from Linear Technology is Obsolete The LM385-2.5 is a two terminal band gap reference diode that has been designed for applications which require precision performance with micropower operation. This reference is not recommended for new designs. See the LT1004 reference for a direct replacement. For a low drift, micropower reference with guaranteed temperature coefficient, see the LT1034 data sheet.

The LM199/LM399 precision shunt reference features excellent temperature stability over a wide range of voltage, temperature and operating current conditions. A stabilizing heater is incorporated with the active Zener on a monolithic substrate which nearly eliminates changes in voltage with temperature. The subsurface Zener operates over a current range of 0.5mA to 10mA, and offers minimal noise and excellent long-term stability. Ideal applications for the LM199/LM399 include digital voltmeters, precision calibration equipment, current sources and a variety of other precision low cost references. A 10V buffered reference application is shown below.

The LTM8028 is a 1mV output ripple µModule regulator designed to power data converters and high speed transceivers.The low output ripple minimizes random jitter in high speed data transceivers for superior bit error rate (BER) performance. When powering an analog-to-digital converter (ADC), tests showed a 13dB improvement in spurious free dynamic range (SFDR) with the LTM8028 compared to a typical step-down regulator.The µModule regulator combines a 36V synchronous step-down switcher, powering a 5A linear post-regulator in a compact 15mm x 15mm x 4.92mm BGA package. To minimize power dissipation and voltage drop across the linear regulator, the linear regulator automatically adjusts the output voltage of the internal synchronous regulator.A tri-state digital interface determines the LTM8028's output voltage, which is adjustable from 0.8V to 1.8V in 50mV increments. Output voltage regulation is ±1.5% accurate over temperature. Output noise is just 40µVRMS over the 10Hz to 100kHz frequency range.This step-down regulator features a user-adjustable current limit accurate within ±10% and adjustable switching frequency between 200kHz to 1MHz, with the option to synchronize to an external clock in the same range.The LTM8028 is guaranteed to operate over the -40°C to +125°C and -55°C to +125°C internal temperature range. The LTM8028 is available for immediate delivery from stock, with price starting at $14.20 each for 1,000 piece quantities.

The LT®1001 significantly advances the state-of-the-art of precision operational amplifiers. In the design, processing, and testing of the device, particular attention has been paid to the optimization of the entire distribution of several key parameters. Consequently, the specifications of the lowest cost, commercial temperature device, the LT1001C, have been dramatically improved when compared to equivalent grades of competing precision amplifiers.Essentially, the input offset voltage of all units is less than 50µV (see distribution plot below). This allows the LT1001AM/883 to be specified at 15µV. Input bias and offset currents, common-mode and power supply rejection of the LT1001C offer guaranteed performance which were previously attainable only with expensive, selected grades of other devices. Power dissipation is nearly halved compared to the most popular precision op amps, without adversely affecting noise or speed performance. A beneficial by-product of lower dissipation is decreased warm-up drift. Output drive capability of the LT1001 is also enhanced with voltage gain guaranteed at 10mA of load current. For similar performance in a dual precision op amp, with guaranteed matching specifications, see the LT1002. Shown below is a platinum resistance thermometer application.

The LT®1002 dual, matched precision operational amplifiers combine excellent individual amplifier performance with tight matching and temperature tracking between amplifiers.In the design, processing, and testing of the device, particular attention has been paid to the optimization of the entire distribution of several key parameters and their matching. Consequently, the specifications of even the low cost commercial grade (LT1002C) have been spectacularly improved compared to presently available devices. Essentially, the input offset voltage of all units is less than 80µV, and matching between amplifiers is consistently beter than 60µV (see distribution plot below). Input bias and offset currents, channel separation, common mode and power suply rejections of the LT1002C are all specified at levels which were previsouly attainable only on very expensive, selected grades of other dual devices. Power dissipation is nearly halved compared to the most popular precision duals, without adversely affecting noise or speed performance. A by-product of lower dissipation is decreased warm-up drift. For even better performance in a single precision op amp, refer to the LT1001 data sheet. A bridge signal conditioning application is shown below. This circuit illustrates the requirement for both excellent matching and individual amplifier specifications.