Linear Regulator with Current and Temperature Monitor Outputs

Linear Technology Corp

Linear Technology Corp

The LT3081 is a rugged 1.5-A wide input voltage range linear regulator with key usability, monitoring, and protection features. The device has an extended safe operating area (SOA) compared to existing regulators, making it well suited for high input-to-output voltage and high output current applications where older regulators limit the output.

The LT3081 uses a current source reference for single-resistor output voltage settings and output adjustability down to ”0.” A single resistor can be used to set the output current limit. This regulator architecture, combined with low-millivolt regulation, enables multiple ICs to be easily paralleled for heat spreading and higher output current. The current from the device’s current monitor can be summed with the set current for line-drop compensation, where the LT3081’s output increases with current to compensate for line drops.

The LT3081 achieves line and load regulation below 2 mV independent of output voltage and features a 1.2-to-40-V input voltage range. The device is well suited for applications requiring multiple rails. The output voltage is programmable with a single resistor from 0 to 38.5 V with a 1.2-V dropout. The on-chip trimmed 50-µA current reference is ±1% accurate. The regulation, transient response, and output noise (30 µVRMS) are independent of output voltage due to the device’s voltage follower architecture.

Two resistors are used to configure the LT3081 as a two-terminal current source. Input or output capacitors for stability are optional in either linear regulator or current-source operation mode. The LT3081 provides several monitoring and protection functions. A single resistor is used to program the current limit, which is accurate to ±10%. Monitor outputs provide a current output proportional to temperature (1 µA/°C) and output current (200 µA/A), enabling easy ground-based measurement. The current monitor can compensate for cable drops. The LT3081’s internal protection circuitry includes reverse-input protection, reverse-current protection, internal current limiting, and thermal shutdown.

A variety of grades/temperature ranges are offered including: the E and  I grades (–40°C to 125°C), the H grade (–40°C to 150°C), and the high-reliability MP grade (–55°C to 50°C). Pricing for the E-grade starts at $2.60 each in 1,000-piece quantities.

Linear Technology Corp.

Dual-Display Digital Multimeter

The DM3058E digital multimeter (DMM) is designed with 5.5-digit resolution and dual display. The DMM can enable system integration and is suitable for high-precision, multifunction, and automatic measurement applications.

The DM3058E is capable of measuring up to 123 readings per second. It can quickly save or recall up to 10 preset configurations, including built-in cold terminal compensation for thermocouples.

The DMM provides a convenient and flexible platform with an easy-to-use design and a built-in help system for information acquisition. In addition, it supports 10 different measurement types including DC voltage (200 mV to approximately 1,000 V), AC voltage (200 mV to approximately 750 V), DC current (200 µA to approximately
10 A), AC current (20 mA to approximately 10 A), frequency measurement (20 Hz to approximately 1 MHz), 2-Wire and 4-Wire resistance (200 O to approximately 100 MO), and diode, continuity, and capacitance.

The DM3058 is ideal for research and development labs and educational applications, as well as low-end detection, maintenance, and quality tests where automation combined with capability and value are needed.

The DM3058E digital multimeter costs $449.

Rigol Technologies, Inc.

Two-Channel CW Laser Diode Driver with an MCU Interface

The iC-HT laser diode driver enables microcontroller-based activation of laser diodes in Continuous Wave mode. With this device, laser diodes can be driven by the optical output power (using APC), the laser diode current (using ACC), or a full controller-based power control unit.

The maximum laser diode current per channel is 750 mA. Both channels can be switched in parallel for high laser diode currents of up to 1.5 A. A current limit can also be configured for each channel.

Internal operating points and voltages can be output through ADCs. The integrated temperature sensor enables the system temperature to be monitored and can also be used to analyze control circuit feedback. Logarithmic DACs enable optimum power regulation across a large dynamic range. Therefore, a variety of laser diodes can be used.

The relevant configuration is stored in two equivalent memory areas. Internal current limits, a supply-voltage monitor, channel-specific interrupt-switching inputs, and a watchdog safeguard the laser diodes’ operation through iC-HT.

The device can be also operated by pin configuration in place of the SPI or I2C interface, where external resistors define the APC performance targets. An external supply voltage can be controlled through current output device configuration overlay (DCO) to reduce the system power dissipation (e.g., in battery-operated devices or systems).

The iC-HT operates on 2.8 to 8 V and can drive both blue and green laser diodes. The diode driver has a –40°C-to-125°C operating temperature range and is housed in a 5-mm × 5-mm, 28-pin QFN package.

The iC-HT costs $13.20 in 1,000-unit quantities.

iC-Haus GmbH

Low-Power, High-Efficiency Boost Regulator

The TS3300 is an ultra-low-power, load-independent, high-efficiency boost regulator. It operates from supply voltages as low as 0.6 up to 4.5 V and can deliver at least 75 mA of continuous output current.

The TS3300 can be powered from a variety of power sources including single- or multiple-cell alkaline or single Li-chemistry batteries. The boost regulator’s output voltage range can be user-specified from 1.8 to 5.25 V to simultaneously power a range of low-power analog circuits, microcontrollers, and low-energy Bluetooth radios. The TS3300 produces a 3-V output from a 1.2-V input source. Its efficiency performance is constant over a 100:1 span in output current. To power low-energy radios, the TS3300’s internal, low-dropout linear regulator can deliver up to 100 mA output current while reducing boost-converter-generated output voltage ripple.

Drawing only 3.5 µA no-load supply current, the TS3300 is ideal for “always on” and other battery-powered or portable applications where an extended battery run-time is required. The TS3300 operates from low power sources (e.g., photovoltaic cells to three alkaline cells) and is ideally suited for handheld/portable applications (e.g., wireless remote sensors, RFID tags, wireless microphones, solar cell post-regulator/chargers, post-regulators for energy harvesting, blood glucose meters, and personal health-monitoring devices).

The TS3300 is fully specified over the –40°C-to-85°C temperature range and is available in a low-profile, thermally-enhanced 16-pin 3mm × 3mm TQFN package with an exposed backside paddle. The TS3300 costs $0.85 in 1,000-unit quantities.

Touchstone Semiconductor

Accurate Measurement Power Analyzer

The PA4000 power analyzer provides accurate power measurements. It offers one to four input modules, built-in test modes, and standard PC interfaces.

The analyzer features innovative Spiral Shunt technology that enables you to lock onto complex signals. The Spiral Shunt design ensures stable, linear response over a range of input current levels, ambient temperatures, crest factors, and other variables. The spiral construction minimizes stray inductance (for optimum high-frequency performance) and provides high overload capability and improved thermal stability.

The PA4000’s additional features include 0.04% basic voltage and current accuracy, dual internal current shunts for optimal resolution, frequency detection algorithms for noisy waveform tracking, application-specific test modes to simplify setup. The analyzer  easily exports data to a USB flash drive or PC software. Harmonic analysis and communications ports are included as standard features.

Contact Tektronix for pricing.

Tektronix, Inc.