IEEE 802.3bt PD Controller Offers 99% Efficiency

Recently acquired by Linear Technology, Analog Devices has announced the LT4294 IEEE 802.3bt Powered Device (PD) interface controller. Intended for applications requiring up to 71 W of delivered power, this new Power over Ethernet (PoE) standard (IEEE 802.3bt) both increases the power budget and supports 10-Gb Ethernet (10GBASE-T). The LT4294’s features, benefits, and specs:

  • Available in 10-lead MSOP and 3 mm x 3 mm DFN Packages.
  • It maintains backward compatibility with older IEEE 802.3af and 802.3at PoE equipment.
  • It provides up to 99% of power available from the RJ-45 connector to the hot swap output.
  • Supports new features: additional PD classes (5, 6, 7, and 8), PD types (Type 3 and Type 4), and five-event classification.
  • It can be married to any high efficiency switching regulator.
  • It controls an external MOSFET to reduce overall PD heat dissipation and maximize power efficiency.
  • An external MOSFET architecture enables you to size the MOSFET to your application’s requirements.
  • It’s available in industrial and automotive grades, supporting operating temperature ranges from –40°C to 85°C and –40°C to 125°C, respectively.Linear LT4294

The LT4294 starts at $1.95 each in 1,000-piece quantities and is available in production quantities. The LT4294 complements the LT4295 802.3bt PD interface controller with integrated switcher, both of which provide an upgrade path from our existing PoE+/LTPoE++ PD controllers, including the LT4276 and LT4275.

Source: Linear Technology

100-V No-Opto Flyback Regulator

Linear Technology recently announced H-grade versions of the LT8304/-1 monolithic flyback regulators with guaranteed operation for junction temperatures as high as 150°C. By sampling the isolated output voltage directly from the primary-side flyback waveform, it requires no opto-coupler or third winding for regulation.Linear LT8304HThe LT8304H/-1’s features, specs, and benefits:

  • VIN Range from 3 to 100 V
  • Up to 24 W of output power
  • LT8304-1 Capable of output voltages up to 1 kV
  • Onboard 2-A, 150-V integrated DMOS power switch
  • Off-the-shelf power transformers
  • No opto-coupler or transformer third winding required for voltage feedback
  • 116-µA Quiescent current
  • Boundary mode operation
  • Accurate input enable & undervoltage lockout with hysteresis
  • Output diode temperature compensation
  • H Grades: –40°C to 150°C operating junction temperature

Source: Linear Technology

New Precision Rail-to-Rail Op-Amps

Linear Technology’s new LTC6258/59/60 and LTC6261/62/63 are part of a family of power-efficient op-amps ranging from 1.3 MHz GBW product at 20 µA supply current to 720 MHz GBW product at 3.3 mA supply current. The op-amps operate on 1.8-to-5.25-V supply, feature rail-to-rail inputs and outputs, and include versions with a Shutdown mode. Input offset voltage is 400 μV maximum. The devices are fully specified over the industrial (I, –40°C to 85°C) and extended (H, –40°C to 125°C) temperature ranges.Linear LTC6258

With supply current of only 20 μA per amplifier, the LTC6258/59/60 achieve 1.3 MHz gain bandwidth product and 240 V/ms slew rate. They include input EMI filters which provide 45 dB rejection at 1 GHz. They are stable for any gain and with any capacitive load.

The LTC6261/62/63 achieve 30 MHz GBW product and 7 V/μs slew rate, drawing just 240 μA per amplifier. Wideband voltage noise is just 13 nV/√Hz. They are stable for any gain and for capacitive loads up to 1 nF.

The single LTC6258 and LTC6261 are available in a space saving 2 mm × 2 mm DFN package, priced starting at $1.24 each in quantities of 1000 pieces. The dual LTC6259 and LTC6262 are available in the same size DFN package, as well as eight-lead SOT-23, MSOP-8, and MSOP-10 with Shutdown mode. The quad LTC6260 and LTC6263 are available in the MSOP-16 package.

LTC6258/59/60/61/62/63’s specs, features, and benefits:

  • Offset voltage: 400 μV maximum
  • Rail-to-rail input and output
  • Supply voltage range: 1.8 to 5.25 V
  • Operating temperature range: –40°C to 125°C
  • Single in 2 mm × 2 mm DFN packages
  • Dual in eight-lead MS8, MS10, TS0T-23, 2 mm × 2 mm DFN Packages
  • Quad in MS16 package

LTC6258/59/60’s specs, features, and benefits:

  • Gain bandwidth product: 1.3 MHz
  • Low quiescent current: 20 μA
  • C-load op-amp drives all capacitive loads
  • EMI rejection ratio: 45 dB at 1 GHz
  • Input bias current: 75 nA maximum
  • CMRR/PSRR: 95 dB/90 dB
  • Shutdown current: 7 μA maximum

LTC6261/62/63 specs, features, and benefits:

  • Gain bandwidth product: 30 MHz
  • Low quiescent current: 240 μA
  • Drives capacitive loads up to 1 nF
  • Input bias current: 100 nA maximum
  • CMRR/PSRR: 100 dB/95 dB
  • Shutdown current: 9 μA maximum

Source: Linear Technology

Highly Accurate 60-V I²C Battery Cell Monitor

Linear Technology Corp. recently introduced the LTC2944 multicell battery monitor, which makes direct measurements of 3.6-to-60-V battery stacks. No level shifting circuitry on the supply and measurement pins is required to interface with multicell voltages, so total current consumption is minimized and measurement accuracy is preserved. Well suited for multicell applications (e.g., electric vehicles, ebikes, and battery backup systems), the LTC2944 is a true high voltage battery monitor that measures charge, voltage, current and temperature to 1% accuracy, the essential parameters required to accurately assess battery state of charge (SoC).Linear Technology LTC2944

Battery current is measured by monitoring the voltage across an external, high-side sense resistor and integrating this information to infer charge. A bidirectional analog integrator accommodates either current polarity (battery charge or discharge). A programmable prescaler supports a wide range of battery capacities. Charge, voltage, current, and temperature information are communicated to the host system over an I²C/SMBus-compatible two-wire interface that is also used to configure the battery monitor. The host can program high and low thresholds for all measured parameters, which if tripped, signal an alert using either the SMBus alert protocol or by setting a register flag.

The LTC2944’s features, specs, and benefits:

  • Measures accumulated battery charge and discharge
  • 3.6-to-60-V Operating range for multicell applications
  • 14-Bit ADC Measures voltage, current, and temperature
  • 1% Charge, voltage, and current accuracy
  • ±50-mV Sense voltage range
  • High-side sense
  • I²C/SMBus Interface
  • Configurable alert output/charge complete input
  • Quiescent current less than 150 μA
  • Small eight-pin 3 mm × 3 mm DFN package

The LTC2944 is available in a small RoHS-compliant, eight-pin 3 mm × 3 mm DFN package. Pricing starts at $2.85 each in 1,000-piece quantities.

Source: Linear Technology

16-Bit, 1.5-Msps Per Channel Octal Simultaneous Sampling SAR ADC

Linear Technology Corp. recently introduced the LTC2320-16 16-bit, 1.5-Msps per channel, no-latency successive approximation register (SAR) ADC. Featuring eight simultaneously sampling channels supporting a rail-to-rail input common mode range, the LTC2320-16 offers a flexible analog front end that accepts fully differential, unipolar or bipolar analog input signals. It also accepts arbitrary input signals and maintains an 82-dB signal-to-noise ratio (SNR) and high common mode rejection ratio (CMRR) of 102 dB when sampling input signals up to the Nyquist frequency. Linear LTC2320-16


The LTC2320-16’s specs, features, and benefits:

  • Wide input bandwidth enables the digitization of input signals up to the Nyquist frequency of 750 kHz
  • 1.5 Msps per channel throughput rate
  • Eight simultaneous sampling channels
  • ±2 LSB INL (typ)
  • Guaranteed 16-bit, no missing codes
  • 8.192 VPP true differential inputs with rail-to-rail common mode
  • 82-dB SNR (typ) at fIN = 500 kHz
  • –90-dB THD (Typ) at fIN = 500kHz
  • Guaranteed operation to 125°C
  • Single 3.3- or 5-V supply
  • Low drift (20 ppm/°C max) 2.048- or 4.096-V internal reference
  • 1.8-to-2.5-V I/O voltages
  • CMOS or LVDS SPI-Compatible Serial I/O
  • Power dissipation 20 mW/Ch (typ, 5-V operation)
  • 52-pin 7 mm × 8 mm QFN package

The LTC2320-16 is available in commercial, industrial, and automotive (–40° to 125°C) temperature grades. Pricing begins at $16.50 each in 1,000-piece quantities. The DC2395A evaluation board for the LTC2320 SAR ADC family is available at

Source: Linear Technology

New 40-A µModule Regulator with 3-D Stacked-Inductor Packaging

Linear Technology recently introduced the LTM4636, which is a 40-A step-down µModule switching regulator with 3D construction for quicker heat dissipation and cooler operation in a small package. By stacking its inductor on top of a 16 mm × 16 mm BGA package, the LTM4636 benefits from the exposed inductor as a heat sink, permitting direct contact with airflow from any direction to cool the device.Linear LTM4636

The LTM4636 features, specs, and benefits:

  • Stacked inductor acts as heatsink; exposed inductor on top of package (3D construction)
  • Scalable: two to six devices in parallel delivers 80-to-240-A load current
  • Delivers 40 W (12 VIN, 1 VOUT, 40 A, 200 LFM) with only 40°C rise over ambient temperature.
  • Full-power 40 W is delivered up to 83°C ambient; half-power 20 W is supported at 110°C ambient.
  • Operates at 92%, 90% and 88% efficiency, delivering 15 A, 30 A, and 40 A, respectively, to a 1-V load (12 VIN). Designed to uniformly disperse heat from the bottom of the package to the PCB with 144 BGA solder balls, with banks of them assigned to GND, VIN, and VOUT where high current flows.
  • Operates from a 4.7 to 15 V input supply and regulates an output voltage from 0.6 to 3.3 V.
  • Total DC output voltage accuracy is ±3% from –40°C to 125°C.

The LTM4636 costs $38.85 in 1,000-piece quantities.

Source: Linear Technology

New USB Micromodule Transceiver Protects Against High Voltages

Linear Technology Corp. recently introduced the LTM2894 USB µModule (micromodule) reinforced isolator that guards against ground-to-ground voltage differentials and large common-mode transients. With a rugged interface and internal isolation, the LTM2894 is well suited for implementing USB in harsh environments where protection from high voltages is needed.LTM2894

The LTM2894’s features, specs, and benefits:

  • Isolated USB Transceiver: 7,500 VRMS for 1 minute
  • USB 2.0 Full sspeed and low speed compatible
  • Auto-configuration of USB bus speed
  • 4.4-to-36 V VBUS and VBUS2 opperating range
  • 3.3-V LDO Output supply signal references: VLO, VLO2
  • 50-kV/µs Common mode transient immunity
  • ±20-kV HBM ESD on USB interface pins
  • 1414 VPEAK Maximum continuous working voltage
  • 17.4-mm Creepage distance
  • 22 mm × 6.25 mm BGA Package

Source: Linear Technology

Ultra-Low Noise, Ultra-High PSRR Low-Dropout Voltage Linear Regulator

Linear Technology Corp. recently announced the LT3045 an ultra-low noise, ultra-high power supply ripple rejection (PSRR) low-dropout voltage linear regulator. It’s a higher output current version of its 200-mA LT3042 ultra-low noise LDO.LT3045 Linear

The LT3045’s features, benefits, and specs:

  • Ultra-low RMS Noise: 0.8 µVRMS (10 Hz to 100 kHz)
  • Ultra-low Spot Noise: 2 nV/√ Hz at 10 kHz
  • Ultra-high PSRR: Greater than 90 dB to 10 kHz; greater than 70 dB to 2.5 MHz
  • Output Current: 500 mA
  • Wide Input Voltage Range: 1.8 to 20 V
  • Single Capacitor Improves Noise and PSRR
  • 100-µA SET Pin Current: ±1% Initial Accuracy
  • Single Resistor Programs Output Voltage
  • High Bandwidth: 1 MHz
  • Programmable Current Limit
  • Low-Dropout Voltage: 260 mV
  • Output Voltage Range: 0 to 15 V
  • Power Good Flag with Programmable Threshold
  • Fast Start-Up Capability
  • Precision Enable/UVLO
  • Can Be Paralleled for Lower Noise and Higher Current
  • Internal Current Limit with Foldback
  • Minimum Output Capacitor: 10-μF Ceramic
  • Reverse-Battery and Reverse-Current Protection
  • 12-Lead MSOP and 10-Lead 3 mm × 3 mm DFN Packages

Source: Linear Technology

RMS Power Detector Offers High Accuracy Measurement

Linear Technology recently introduced the LTC5596, which is a high-frequency, wideband RMS power detector that provides accurate power measurement of RF and microwave signals independent of modulation and waveforms. It responds in an easy-to-use log-linear 29 mV/dB scale to signal levels from –37 to –2 dBm with accuracy better than ±1 dB error over the full operating temperature range and RF frequency range from 200 MHz to an unprecedented 30 GHz.Linear LTC5596

The LTC5596’s features and specs:

  • An extraordinarily wide bandwidth enables the detector to work seamlessly across multiple frequency bands using a common design with minimum calibration.
  • Operates from a single 3.3-V supply, drawing a nominal supply current of 30 mA.
  • Built-in improved ESD protection.
  • Two temperature grades: an I grade is designed for operation from –40° to 105°C case. A high-temperature H-grade has rated temperature from –40° to 125°C case.
  • Both temperature versions are available in a 2 mm × 2 mm plastic eight-lead DFN package.

The LTC5596 I-grade starts at $12.50 each in 1,000-piece quantities. The H-grade starts at $16.95 each. Both versions are available in production quantities.

Source: Linear Technology

40-VIN, 2.1-A Rail-to-Rail LDO+ Available in High-Temperature, 150°C H-Grade in TSSOP Package

Linear Technology Corp. recently unveiled a new higher temperature “H-grade” version of the LT3086 in the TSSOP package. The 40-V, 2.1-A low dropout linear regulator (LDO) includes current monitoring with externally settable current limit and temperature monitoring with external control of thermal limit temperature. It comprises a programmable power good status flag, cable drop compensation, and easy paralleling. The current reference provides regulation independent of output voltage.LTC3086 image


The LT3086’s features and specifications include:

  • –40°C to 150°C (H-Grade TSSOP Only) Operating Junction Temperature Range
  • 1.4 to 40 V Input Voltage Range
  • One Resistor Sets Output Voltage: 0.4 to 32 V
  • Output Current: 2.1 A
  • ±2% Tolerance Over Line, Load and Temperature
  • Output Current Monitor: IMON = IOUT/1000
  • Temperature Monitor with Programmable Thermal Limit
  • Programmable Current Limit
  • Programmable Cable Drop Compensation
  • Parallel Multiple Devices for Higher Current
  • Dropout Voltage: 330 mV
  • One Capacitor Soft-Starts Output and Decreases Noise
  • Low Output Noise: 40 μVRMS (10 Hz to 100 kHz)
  • Precision, Programmable External Current Limit
  • Power Good Flag with Programmable Threshold
  • Ceramic Output Capacitors: 10 μF Minimum
  • Quiescent Current in Shutdown: less than 1 μA
  • Reverse-Battery, Reverse-Current Protection
  • Available in 4 mm × 5 mm 16-Lead DFN, 16-Lead TSSOP, Seven-Lead DD-PAK and Seven-Lead TO-220 Packages

Source: Linear Technology

IEEE 802.3bt PD Controller

Linear Technology Corp. recently introduced the LT4295IEEE 802.3bt powered device (PD) interface controller for applications that require up to 71 W. The next Power over Ethernet (PoE) standard—IEEE 802.3bt—enables manufacturers to go beyond the 25.5 W allocated by the 2009 IEEE 802.3at standard. The new standard—PoE++ or 4PPoE—increases the power budget to enable new applications and features, while supporting 10GBASE-T and maintaining backward compatibility with older IEEE equipment. The LT4295 is IEEE 802.3bt (Draft 2.0) compliant and supports newly introduced features, including all additional PD classes (5, 6, 7, and 8), additional PD types (Type 3 and Type 4), and five-event classification.Linear-LT4295

The LT4295 is a single-signature 802.3bt PD controller that integrates an isolated switching regulator controller. It is capable of synchronous operation in both high-efficiency forward and no-opto flyback topologies with auxiliary power support. This simplifies front end PD designs by reducing component count and board space, which means the LT4295 can deliver power to PD loads using just one IC. Unlike traditional PD controllers, the LT4295 controls an external MOSFET to reduce overall PD heat dissipation and maximize power efficiency. You can size the MOSFET to your application’s requirements. Standard LT4295-based implementations routinely select 30-mΩ RDS(ON) MOSFETs.

The LT4295’s features and specs:

  • IEEE 802.3af/at/bt (Draft 2.0) Powered Device (PD) with Forward/Flyback Controller
  • External hot swap N-channel MOSFET for lowest power dissipation and highest system efficiency
  • Supports up to 71-W PDs
  • Five-event classification sensing
  • Superior surge protection (100-V absolute maximum)
  • Wide junction temperature range (–40° to 125°C)
  • 94% End-to-end efficiency with LT4321 ideal bridge
  • No-opto flyback operation
  • Auxiliary power support as low as 9 V
  • Available in 28-lead 4 mm × 5 mm QFN package

Source: Linear Technology

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