High-Voltage, Dual-Output Step-Down Charge Pump

Linear Technology’s new LTC3256 is a high-voltage, low-noise, dual-output power supply that  takes a single positive input and generates 5- and 3.3-V step-down supplies with high efficiency and no inductors. Featuring a 5.5-to-38-V input voltage range, the LTC3256 includes independently enabled dual outputs: a 5-V, 100-mA supply and a 250-mA, 3.3-V low-dropout (LDO) regulator for a total of 350 mA available output current. This combination of regulators offers much lower power dissipation than a dual-LDO solution. The device is well-suite for a variety of applications,  including automotive ECU/CAN transceiver supplies and general-purpose 12-to-5-V and 3.3-V conversion.Linear LT3256


The LTC3256’s features and  specs:

  • Input voltage range of  5.5 to 38 V
  • Independently enabled 5- and 3.3-V fixed outputs
  • 5-V Output: 100 mA max
  • 3.3V LDO Output: 250 mA Max
  • Multi-mode step-down charge pump (2:1, 1:1) with automatic mode switching
  • Low quiescent current
  • 20 μA with both outputs regulating (no load)
  • Less than 0.5 μA in Shutdown
  • Engineered for ISO26262 diagnostic coverage in systems
  • 1.1-V Reference output for system diagnostics
  • Power-on reset and watchdog controller with adjustable timing
  • Overcurrent fault protection on each output
  • Overtemperature protection
  • 150°C Max operating junction temperature
  • Thermally enhanced 16-lead MSOP package

Source: Linear Technology

New High-Linearity I/Q Demodulator

Linear Technology recently introduced the LTC5586, which is a new high-linearity I/Q demodulator with more than 1-GHz, –1-dB flatness bandwidth supporting next-generation 5G wireless infrastructure equipment. It’s intended for applications ranging from DPD receivers for base stations to software-defined radios (SDR).Linear LTC5586

The LTC5586’s features and specs:

  • 5 mm × 5 mm plastic QFN package
  • Ultra-wide bandwidth DC to 1 GHz
  • 300 MHz to 6 GHz operating frequency range
  • Image rejection (adjusted) 70 dBc at 3.5 GHz
  • OIP3 at 3.5 GHz, +35 dBm
  • OIP2 at 3.5 GHz (Adjusted), +70 dBm
  • Maximum power gain at 1.9 GHz, 7.7 dB
  • SPI Serial Bus Tunable Performance: Image Rejection (I & Q Amplitude & Phase Balance); IIP2 & IIP3 Performance; HD2 & HD3 Performance; DC Offset Null; LO Frequency Match; RF Front-End Attenuator and RF Switch Control; and IF Gain Control

The LTC5586 starts at $7.79 each in 1,000-piece quantities.

Source: Linear Technology

New FMEA-Compliant µModule Regulator

Linear Technology recently introduced the LTM8003 step-down DC/DC µModule regulator. With a 40-V input voltage rating and 3.5 A of continuous output current, the LTM8003’s pinout is failure mode effects analysis (FMEA) compliant, so the output voltage remains at or below the regulation voltage in the event of a short-circuit to GND, a short-circuit to a nearby pin, or if a pin is left floating.  Linear 8003

The LTM8003 operates in four operation: Burst Mode, pulse skip mode, pulse skip mode with spread spectrum, and external synch mode. The quiescent current in Burst Mode operation is 25 µA (max), which makes the LTM8003 a good option for battery-operated systems.

The LTM8003’s specs and features:

  • Wide Input Voltage Range: 3.4 to 40 V
  • Wide Output Voltage Range: 0.97 to 18 V
  • 3.5 A Continuous Output Current (6 A Peak)
  • FMEA-compliant pinout
  • 150°C maximum operating temperature (H-Grade)
  • Selectable switching frequency: 200 kHz to 3 MHz
  • External synchronization
  • Low quiescent current = 25 µA
  • Programmable soft-start
  • 6.25 mm × 9 mm × 3.32 mm BGA package

The LTM8003 starts at 1,000-piece pricing starts at $11.30 each in 1,000-piece quantities.

Source: Linear Technology

1.5-A Synchronous Step-Down DC/DC Converter Delivers 93% Efficiency

Linear Technology’s new LT8608 is a 1.5-A, 42-V input synchronous step-down switching regulator that delivers 93% efficiency while switching at 2 MHz. It is well suited for avoiding critical noise-sensitive frequency bands (e.g., AM radio) while using a compact footprint. Burst Mode operation keeps quiescent current under 2.5 µA in no-load standby conditions. Its 3-to-42-V input voltage range makes it ideal for automotive applications that must regulate through cold-crank and stop-start scenarios with minimum input voltages as low as 3 V and load dump transients in excess of 40 V. Its internal 2-A switches can deliver up to 1.5 A of continuous output current.Linear 8608

The LT8608 maintains a minimum dropout voltage of only 200 mV (at 500 mA) under all conditions. Spread-spectrum frequency modulation and special design techniques offer low EMI operation. In addition, a fast minimum on-time of only 45 ns enables 2-MHz constant frequency switching from a 16-V input to a 1.5-V output. The LT8608’s 10-lead thermally enhanced MSOP package and high switching frequency keeps external inductors and capacitors small for a thermally efficient footprint.

The LT8608’s features and specifications include:

  • Wide input voltage range: 3 to 42 V
  • Ultralow Quiescent Current Burst Mode operation:
    • Less 2.5-µA IQ Regulating 12 VIN to 3.3 VOUT
    • Output Ripple less than 10 mVPP
  • High Efficiency 2-MHz Synchronous Operation:
    • 93% Efficiency at 0.5 A, 5 VOUT from 12 VIN
  • 1.5-A Maximum Continuous Output Current
  • Fast Minimum Switch-On Time: 45 ns
  • Adjustable and Synchronizable: 200 kHz to 2.2 MHz
  • Spread-Spectrum Frequency Modulation for Low EMI
  • Allows Use of Small Inductors
  • Low Dropout
  • Peak Current Mode Operation
  • Accurate 1-V Enable Pin Threshold
  • Internal Compensation
  • Output Soft-Start and Tracking
  • Small 10-Lead MSOP Package

Source: Linear Technology

Rugged RS-485 Transceivers for PROFIBUS-DP Networks

Linear Technology recently introduced the LTC2876 and LTC2877, which are high-voltage-tolerant RS-485 transceivers targeted for PROFIBUS-DP (decentralized periphery) networks. Whether transmitting,  receiving, in standby or powered off, the LTC2876 and LTC2877 tolerate ±60 V on their bus pins, eliminating common damage due to transmission line faults.Linear 2877
LTC2876 and LTC2877 features and specs:

  • Protected from overvoltage line faults to ±60 V
  • ±52-kV ESD Interface Pins, ±15 kV on all other pins
  • Extended common mode range: ±25 V
  • 1.65-to-5.5-V Logic supply pin for flexible digital interfacing (LTC2877)
  • 5-V Supply can operate down to 3 V for low-power, low-swing applications
  • Wide operating temperature range: –40°C to 125°C
  • Available in small DFN and MSOP packages

Source: Linear Technology 

Synchronous Step-Down Regulator with Ultralow DCR Current Sensing

Linear Technology Corp. recently introduced the LTC7130, which is a constant frequency peak current mode synchronous step-down DC/DC converter with temperature-compensated ultralow DCR current sensing and clock synchronization. According to Linear Technology, the LTC7130 “offers the ability to directly parallel multiple ICs for higher current capability” and “also enhances the signal-to-noise ratio of the current sense signal, enabling the use of a very low DC resistance power inductor to maximize efficiency in high current applications.”Linear LTC7130

The LTC7130’s features and specifications:

  • A wide VIN Range of 4.5 to 20 V
  • High efficiency (up to 95%)
  • Proprietary current mode architecture
  • High current parallel operation
  • Ultralow DCR current sensing with temperature compensation
  • Programmable output current limit
  • High-speed differential remote sense amplifier
  • ±0.5% Output voltage regulation accuracy
  • Output short-circuit protection with soft recovery
  • Programmable and synchronizable fixed frequency from 250 to 770 kHz
  • EXTVCC for reduced power dissipation
  • Fault Indicator for output UV/OV conditions

The LTC7130 is available in a thermally enhanced 6.25 mm × 7.5 mm × 2.22 mm BGA package (RoHS lead-free and leaded SnPb (63/37) finishes). The E-and I-grades are guaranteed in the 40°C to 125°C operating junction temperature range. The 1,000-piece price starts at $7.95 each for the E grade.

Source: Linear Technology

60-V, 7-A Step-Down µModule Regulator

Linear Technology’s LTM8064 is a step-down DC/DC µModule (power module) regulator with a 6-to-58-V (60 VMAX) input voltage range and adjustable load current control with ±10% accuracy at 7 A. You can use it as a point-of-load step-down regulator operating from 24, 36, and 48 V voltage rails in test equipment, high-end computers, test equipment, avionics, and more. It also operates as a constant current source to precisely regulate and control (adjust) the load current up to 7 A when sourcing and 9.1 A when sinking. Among the  applications requiring precision load current control are Peltier devices for cooling/heating and  battery and supercapacitor chargers.Linear 8064

The LTM8064 includes DC/DC controller, MOSFETs, inductor, and supporting components. Two resistors, bulk input capacitors, and output capacitors are needed to complete the design. Housed in a 16 mm × 11.9 mm × 4.92 mm BGA package, the LTM8064 has an adjustable output voltage range of 1.2 to 36 V. The switching frequency is adjustable by one external resister from 100 kHz to 1 MHz or it can be synchronized to an external clock from 120 kHz to 1 MHz.

The LTM8064’s main features:

  • Operates from –40°C to 125°C
  • Wide input voltage range: 6 to 58 V
  • 1.2-to-36-V Output voltage
  • Constant-voltage, constant-current (CVCC)
  • Two-Quadrant: Sources and Sinks Output Current
  • Parallelable for increased output current, even from different voltage sources
  • Adjustable output current up to 7 A when sourcing or 9.1 A when sinking
  • Selectable switching frequency: 100 kHz to 1 MHz
  • Programmable soft-start
  • Tiny 16 mm × 11.9 mm × 4.92 mm surface-mount BGA package

Pricing starts at $16.50 each in 1,000-unit quantities.

Source: Linear Technology

Precision Set & Readback PMBus-Compatible µModule Regulator

Linear Technology recently announced the LTM4675 dual 9-A or single 18-A, µModule (micromodule) step-down DC/DC regulator with PMBus serial digital interface. It comes in a 11.9 mm × 16 mm × 3.51 mm BGA package. The I²C-based interface enables you to manage a system’s power condition and consumption. Calibrated and guaranteed from –40°C to 125°C, output DC voltage accuracy is ±0.5% over line and load regulation, and load current readback accuracy is ±2.5% maximum.Linear 4675

The LTM4675—which features EEPROM, power MOSFETs, inductors and supporting components—dual analog control loops and precision mixed-signal circuitry. It is drop-in pin-compatible with the larger package (16 mm × 16 mm BGA) higher power dual 13A LTM4676A, eliminating layout changes so that system designers can easily switch between the devices during the prototype phase. This eliminates redesign of power circuits if power requirements change during board prototyping. The LTM4675 has applications in optical transport systems, datacom and telecom switches and routers, industrial test equipment, robotics, RAID and enterprise systems where energy costs, cooling and maintenance are critical and must be continuously and precisely measured.

The LTM4675 operates from a 4.5-to-17-V input supply and steps down VIN to two outputs ranging from 0.5 to 5.5 V. Two channels can current share to provide up to 18 A (i.e., 9 A + 9 A as one output). Power-up turn-on time is 70 ms. To evaluate the performance of the LTM4675, the free LTpowerPlay GUI-based development system is available for download, and a USB-to-PMBus converter and demo kit are available. With ±0.5% maximum DC output error over temperature, ±2.5% current readback accuracy, integrated 16-bit delta-sigma ADC and EEPROM, the LTM4675 combines best-in-class analog switching regulator performance with precision mixed-signal data acquisition. At start-up, output voltages, switching frequency and channel phase angle assignments can be set by pin-strapping resistors.

The LTM4675 internal operating temperature range is from –40°C to 125°C.  It costs $24 in 1,000-piece units.

Source: Linear Technology

Dual Synchronous Step-Down DC/DC Converter Delivers 95% Efficiency

Linear Technology recently announced the LT8616, a 42-V input capable, high-efficiency dual synchronous monolithic step-down switching regulator. Its dual channel design delivers independent 2.5- and 1.5-A continuous current to outputs as low as 0.8 V. A dual channel synchronous rectification topology delivers up to 95% efficiency while Burst Mode operation keeps quiescent current under 6.5 µA (both channels enabled) in no-load standby conditions, making it ideal for always-on systems. Switching frequency can be programmed from 200 kHz to 3 MHz and is synchronizable throughout this range.LT8616 Linear

The LT8616’s 35-ns minimum on-time enables 16 VIN to 1.8 VOUT step-down conversions, while switching at 2 MHz helps you avoid critical noise-sensitive frequency bands, such as AM radio while having a very compact solution footprint. Its 3.4- to 42-V input voltage range makes it ideal for automotive applications which must regulate through cold-crank and stop-start scenarios with minimum input voltages as low as 3.4 V and load dump transients in excess of 40 V. Each channel of the LT8616 maintains a minimum dropout voltage of only 400 mV (at 1 A) under all conditions, enabling it to excel in scenarios such as automotive cold-crank. The LT8616’s 28-lead thermally enhanced TSSOP package and high switching frequency keeps external inductors and capacitors small, providing a compact, thermally efficient footprint.

The LT8616 utilizes dual internal top and bottom high efficiency power switches with the necessary boost diodes, oscillator, control and logic circuitry integrated into a single die. Each channel switches 180° out-of-phase to reduce output ripple. Each channel has a separate input for added design flexibility. Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping output ripple below 15 mVPP. Unique design techniques and a new high speed process enable high efficiency over a wide input voltage range, and the LT8616’s current-mode topology provides fast transient response and excellent loop stability. Other features include internal compensation, power good flags, output soft-start/tracking and thermal protection.

The LT8616 is available in a thermally enhanced 28-lead TSSOP package. Three temperature grades are available, with operation from –40°C to 125°C (junction) for the extended (E) and industrial (I) grades and a high temperature (H) grade of –40°C to 150°C. The 1,000-piece price starts at $4.15.


  • 3.4 to 42 V Input voltage range
  • 5- and 1.5-A Buck regulators with separate inputs
  • Fast minimum switch on-time: 35 ns
  • Ultralow quiescent current burst mode operation
  • 180° Out-of-phase switching
  • Adjustable and synchronizable: 200 kHz to 3 MHz
  • Accurate 1-V Enable pin thresholds
  • Internal compensation
  • Output soft-start and tracking
  • TSSOP Package:
  • Thermally enhanced 28-lead TSSOP package


Compact 20A Hot Swap Controller Integrates MOSFET & Current Sensing

Linear Technology Corp. recently announced the LTC4234, a 20A Hot Swap controller with integrated MOSFET and current sensing, which provides a small footprint hot-plug solution for high-density circuit boards. The LTC4234 ensures safe board insertion and removal from live 2.9-to-15-V backplanes by controlling an internal N-channel power MOSFET to gently power up bulk capacitors and avoid sparks, connector damage and system glitches. By integrating the two most critical and largest Hot Swap components-power MOSFET and sense resistor, the LTC4234 reduces design time and saves board area. The internal, production-tested MOSFET’s safe operating area (SOA) is specified to ensure a rugged hot-plug solution, especially for space-constrained boards and cards in servers, network routers and switches, solid-state drives, and industrial systems.Linear LTC4234

Upon insertion, the LTC4234 waits for connector contact bounce to finish before soft-starting the output. A ground-referenced signal proportional to the load current is provided for monitoring with an external analog-to-digital converter (ADC). The current limit can be reduced from its 22.5A default with a single resistor, affording quick adjustment for dynamic load changes and various applications. For higher current applications, two LTC4234s are easily paralleled for a 40A solution. During overcurrent conditions, the controller limits MOSFET power dissipation by folding back its current limit for an adjustable timeout period. Undervoltage and overvoltage thresholds protect downstream loads against voltages outside a valid window, preventing circuit malfunction and damage.

The LTC4234’s features:

  • Enables safe board insertion
  • Integrated 4-mΩ MOSFET with sense resistor
  • Guaranteed safe operating area
  • Wide operating voltage range of 2.9 to 15 V
  • Current limit for overcurrent fault protection
  • Current and temperature monitor, power good & fault outputs
  • –40°C to 125°C Operating temperature range
  • 38-Pin 5 mm × 9 mm QFN Ppackage

The LTC4234 starts at $4.95 each in 1,000-piece quantities. Device samples and evaluation circuit boards are available online or from your local Linear Technology sales office.

Source: Linear Technology



60-V LED Driver with Internal 4-A Switch & PWM Generator

Linear Technology’s LT3952 is a current mode step-up DC/DC converter with an internal 60-V, 4-A DMOS power switch. It is specifically designed to drive high power LEDs in multiple configurations. It combines input and output current regulation loops with output voltage regulation to operate as a flexible current/voltage source.  The LT3952’s 3-to-42-V input voltage range makes it ideal for a wide variety of applications, including automotive, industrial, and architectural lighting.Linear 3952

The LT3952 can drive up to 16 350-mA white LEDs from a nominal 12-V input, delivering in excess of 15 W. It incorporates a high side current sense, enabling its use in boost mode, buck mode, buck-boost mode or SEPIC topologies. Internal spread spectrum frequency modulation minimizes EMI concerns. The LT3952 delivers efficiencies of over 94% in the boost topology, eliminating the need for external heat sinking, and internal LED short-circuit protection enables added reliability required in most applications. A frequency adjust pin permits the user to program the switching frequency between 200 kHz and 3 MHz, optimizing efficiency while minimizing external component size and cost. The LT3952 delivers over 90% efficiency while switching at 2 MHz in a tiny solution footprint. The LT3952 provides a very compact high power LED driver solution in a thermally enhanced TSSOP-28E package.

The LT3952 has a gate driver for a PMOS LED disconnect switch, delivering dimming ratios of up to 4,000:1 using an external PWM signal. For less demanding dimming requirements, the CTRL pin can be used to offer a 10:1 analog dimming range and an internal PWM generator can be used for 5:1 dimming. The LT3952’s fixed frequency, current-mode architecture offers stable operation over a wide range of supply and output voltages. Output short-circuit protection and open LED protection enhance system reliability. Other features include frequency synchronization, spread spectrum frequency modulation, programmable VIN undervoltage and overvoltage protection, and an input current limit and monitor.

The LT3952EFE is available in a thermally enhanced 28-lead TSSOP package. Three temperature grades are available, with operation from –40°C to 125°C (junction) for the extended, and industrial grades, and a high temperature grade of –40°C to 150°C. Pricing starts at $3.95 each in 1,000-piece quantities and all versions are available from stock. For more information, visit www.linear.com/product/LT3952

Source: Linear Technology

3.3-V/5-V 4-Mbps CAN Transceiver

Linear Technology Corporation introduces the LTC2875, an exceptionally rugged, high-voltage-tolerant controller area network (CAN) transceiver to greatly reduce field failures without the need of costly external protection devices. In practical CAN systems, installation cross-wiring faults, ground voltage faults or lightning induced surge voltages can cause overvoltage conditions that exceed absolute maximum ratings of typical transceivers. The LTC2875 features ±60-V overvoltage fault and ±25-kV HBM ESD protection on the data transmission lines, protecting bus pins during operation and shutdown. Whether a circuit is transmitting, receiving or powered off, the LTC2875 tolerates any voltage within ±60 V without damage, increasing the robustness of typical CAN networks.Linear LTC2875

CAN bus systems are becoming increasingly popular in industrial controls, instrumentation networks and automotive electronics. The CAN bus has a well defined protocol stack, with support for standalone controllers, FPGAs and ASICs, making implementation easier over alternative interfaces, such as RS-485. The LTC2875 provides the flexibility to be powered from a 3.3-V or 5-V rail, which is very useful in industrial applications where a 5V rail may not be present. In addition to the high fault and ESD protection, the device features a low electromagnetic emission (EME) driver with a transmit data (TXD) dominant timer to prevent faulty controllers from clamping the bus, as well as a high electromagnetic immunity (EMI) receiver with an extended ±36-V common mode range to enable operation in electrically noisy environments and in the presence of ground loops. The LTC2875 features a high speed data rate of 4 Mbps with an adjustable slew rate for data rates as low as 1 kbps. A shutdown mode brings all of the LTC2875’s outputs to high impedance and reduces power consumption to 1 µA.

The LTC2875 is offered in commercial, industrial, automotive and military (–55°C to 125°C) temperature grades and is available in 3 mm × 3 mm DFN-8 and SO-8 packages, with industry-standard pinouts.

Pricing starts at $1.72 each in 1,000-piece quantities.

Source: Linear Technology

20-A Step-Down µModule Regulator Optimized for Low VIN to Low VOUT Conversion

Linear Technology Corp. recently introduced the LTM4639, which is 20-A DC/DC step-down µModule (micromodule) regulator. According to Linear, the regulator can convert “2.5 to 7 V main-power system rails to point-of-load voltages as low as 0.6 V.”

Linear Technology LTM4639

Linear Technology LTM4639

The LTM4639—which includes an inductor, DC/DC controller, MOSFETs, and compensation circuitry—is housed in a 4.92-mm BGA package with a 15 mm × 15 mm footprint. For 3.3-V input to 1.5-V output conversion at 20-A load, efficiency is 88%, power loss is 3.9 W, and junction temperature rise above ambient temperature is 37°C. The micromodule regulator provides a precise output voltage regulation. Up to four devices can be paralleled for up to 80-A output while operating out-of-phase to reduce the number of input and output capacitors.

The LTM4639’s input supply range is 2.375 to 7 V. For operation from 3.3 V and lower, a 5-V, low-power auxiliary supply is needed to bias internal circuitry. Output voltage ranges from 0.6 to 5.5 V with protection functions for overcurrent and overvoltage conditions.

The LTM4639 is rated for operation from –40°C to 125°C. The 1,000-piece price is $19.45 each.

Source: Linear Technology

Linear Ultrathin 1.8-mm, 3A µModule Regulator

Linear Technology Corp. recently announced the LTM4623 3A µModule (micromodule) step-down regulator in an ultrathin 1.8-mm profile LGA package with only a 6.25 mm × 6.25 mm footprint. With solder paste, the package height is less than 2 mm, meeting the height restrictions of many PCIe, Advanced Mezzanine Cards (AMC) for AdvancedTCA carrier cards in embedded computing systems. The small size and low height allow the LTM4623 to be mounted on the backside of the PCB, freeing space on the topside for components such as memory and FPGAs.linearLTM4623

The LTM4623 operates from 4-to-20-V input supplies and precisely regulates an output voltage from 0.6 to 5.5 V with 1.5% maximum total DC output voltage error. Application examples include ultra-dense data storage, gateway controllers, and 40-to-100-Gbps network equipment.

The LTM4623 solution fits in a 0.5 cm2 dual-sided PCB or less than 1 cm2 on a single-sided PCB. The circuit only requires one input capacitor and one output capacitor, a resistor to set VOUT, and a small capacitor for VOUT tracking and soft-start. With an auxiliary 5-V bias, the LTM4623 operates from input supplies as low as 2.375V. The operating efficiency for converting 12 VIN to 1.5 VOUT and 3.3 VOUT at 3A is 80% and 88%, respectively. Power loss for 12 VIN to 1.5 VOUT is 1.1 W, resulting in only a 24°C rise in junction temperature. The LTM4623 is rated for operation from –40°C to 125°C.

One thousand-piece pricing starts at $6.05 each.

Source: Linear Technology

Linear Battery Charger with Multi-Chemistry Operation

Linear Technology Corp. recently introduced the LTC4079, which is a 60-V, constant-current/constant-voltage, 250-mA multi-chemistry battery charger. According to Linear, its “low quiescent current linear topology offers a simple inductorless design and accepts a wide 2.7 V to 60 V input voltage range.”LinearLTC4079


The LTC4079’s features, characteristics, and capabilities include:

  • A resistor-programmable 1.2- to 60-V battery charge voltage range with ±0.5% charge voltage accuracy
  • Adjustable charge current from 10 to 250 mA with an external resistor
  • A low-profile (0.75 mm) 10-pin 3 mm x 3 mm DFN package with backside metal pad for excellent thermal performance.
  • Guaranteed foperation from –40°C to 125°C in both E-and I-grades.
  • One thousand-piece pricing starts at $2.35 each for the E-grade.

Source: Linear Technology