Energy Storage & Power Conversion

The LTC6813-1 is a multicell battery stack monitor that measures up to 18 series connected battery cells with a total measurement error of less than 2.2mV. The cell measurement range of 0V to 5V makes the LTC6813-1 suitable for most battery chemistries. All 18 cells can be measured in 290µs, and lower data acquisition rates can be selected for high noise reduction.

Multiple LTC6813-1 devices can be connected in series, permitting simultaneous cell monitoring of long, high voltage battery strings. Each LTC6813-1 has an isoSPI interface for high speed, RF immune, long distance communications. Multiple devices are connected in a daisy chain with one host processor connection for all devices. This daisy chain can be operated bidirectionally, ensuring communication integrity, even in the event of a fault along the communication path.

The LTC6813-1 can be powered directly from the battery stack or from an isolated supply. The LTC6813-1 includes passive balancing for each cell, with individual PWM duty cycle control for each cell. Other features include an onboard 5V regulator, nine general purpose I/O lines and a sleep mode, where current consumption is reduced to 6µA.

Applications

• Electric and Hybrid Electric Vehicles
• Backup Battery Systems
• Grid Energy Storage
• High Power Portable Equipment

The LTC6810 is a multicell battery stack monitor. The LTC6810 measures up to 6 series-connected battery cells with a total measurement error of less than 1.8mV. The cell measurement range of 0V to 5V makes the LTC6810 suitable for most battery chemistries. All 6 cells can be measured in 290μs, and lower data acquisition rates can be selected for high noise reduction.

Multiple LTC6810-1 devices can be connected in series, permitting simultaneous cell monitoring of long, high voltage battery strings. Each LTC6810 has an isoSPI interface for high speed, RF-immune, long distance communications. Using the LTC6810-1, multiple devices are connected in a daisy chain with one host processor connection for all devices. The LTC6810-1 supports bidirectional operation, allowing communication even with a broken wire. Using the LTC6810-2, multiple devices are connected in parallel to the host processor, with each device individually addressed.

The LTC6810 can be powered directly from the battery stack or from an isolated supply. The LTC6810 includes passive balancing for each cell, with PWM duty cycle control for each cell and the ability to perform redundant cell measurements. Other features include an onboard 5V regulator, 4 general purpose I/O lines and a sleep mode in which current consumption is reduced to 4μA.

Applications

• Electric and Hybrid Electric Vehicles
• Backup Battery Systems
• Grid Energy Storage
• High Power Portable Equipment

The ADuM4135 is a single-channel gate driver specifically optimized for driving insulated gate bipolar transistors (IGBTs). Analog Devices, Inc., iCoupler^® technology provides isolation between the input signal and the output gate drive.

The ADuM4135 includes a Miller clamp to provide robust IGBT turn-off with a single-rail supply when the gate voltage drops below 2 V. Operation with unipolar or bipolar secondary supplies is possible, with or without the Miller clamp operation.

The Analog Devices chip scale transformers also provide isolated communication of control information between the high voltage and low voltage domains of the chip. Information on the status of the chip can be read back from dedicated outputs. Control of resetting the device after a fault on the secondary is performed on the primary side of the device.

Integrated onto the ADuM4135 is a desaturation detection circuit that provides protection against high voltage shortcircuit IGBT operation. The desaturation protection contains noise reducing features such as a 300 ns masking time after a switching event to mask voltage spikes due to initial turn-on. An internal 500 µA current source allows low device count and the internal blanking switch allows the addition of an external current source if more noise immunity is needed.

The secondary UVLO is set to 11 V with common IGBT threshold levels taken into consideration.

Applications

• MOSFET/IGBT gate drivers
• PV inverters
• Motor drives
• Power supplies

The ADuM4136 is a single-channel gate driver specifically optimized for driving insulated gate bipolar transistors (IGBTs). Analog Devices, Inc., iCoupler^® technology provides isolation between the input signal and the output gate drive.

Operation with unipolar or bipolar secondary supplies is possible, allowing negative gate drive if needed.

The Analog Devices chip scale transformers also provide isolated communication of control information between the high voltage and low voltage domains of the chip. Information on the status of the chip can be read back from dedicated outputs. Control of resetting the device after a fault on the secondary side is performed on the primary side of the device.

Integrated onto the ADuM4136 is a desaturation detection circuit that provides protection against high voltage short-circuit IGBT operation. The desaturation protection contains noise reducing features such as a 312 ns (typical) masking time after a switching event to mask voltage spikes due to initial turn-on. An internal 537 μA (typical) current source allows low device count, and the internal blanking switch allows the addition of an external current source if more noise immunity is needed.

The secondary UVLO is set to 12 V with common IGBT threshold levels taken into consideration.

Applications

• MOSFET/IGBT gate drivers
• Photovoltaic (PV) inverters
• Motor drives
• Power supplies

The LT3999 is a monolithic, high voltage, high frequency DC/DC transformer driver providing isolated power in a small solution footprint.

The LT3999 has two 1A current limited power switches that switch out of phase. The duty cycle is programmable to adjust the output voltage. The switching frequency is programmed up to 1MHz and can be synchronized to an external clock for more accurate placement of switcher harmonics. The input operating range is programmed with the precision undervoltage and overvoltage lockouts. The supply current is reduced to less than 1μA during shutdown. A user-defined RC time constant provides an adjustable soft-start capability by limiting the inrush current at start-up.

The LT3999 is available in a 10-lead MSOP and 3mm × 3mm DFN package with exposed pad.

Applications

• Low Noise Isolated Supplies
• Medical Instrument and Safety
• Distributed Power
• Multiple Output Supplies
• Positive-to-Negative Supplies
• Noise Immunity in Data Acquisition, RS232 and RS485

The LT8302/LT8302-3 is a monolithic micropower isolated flyback converter. By sampling the isolated output voltage directly from the primary-side flyback waveform, the part requires no third winding or opto-isolator for regulation. The output voltage is programmed with two external resistors and a third optional temperature compensation resistor. Boundary mode operation provides a small magnetic solution with excellent load regulation. Low ripple Burst Mode operation maintains high efficiency at light load while minimizing the output voltage ripple. A 3.6A, 65V DMOS power switch is integrated along with all the high voltage circuitry and control logic into a thermally enhanced 8-lead SO package.

The LT8302/LT8302-3 operates from an input voltage range of 3V to 42V and delivers up to 18W of isolated output power. The high level of integration and the use of boundary and low ripple burst modes result in a simple to use, low component count, and high efficiency application solution for isolated power delivery.

Applications

• Isolated Automotive, Industrial, Medical Power Supplies
• Isolated Auxiliary/Housekeeping Power Supplies

Demonstration circuit 2350A is a multicell battery stack monitor featuring the LTC6812-1, a 15-cell monitor on the DC2350A-A, or the LTC6813-1, an 18-cell monitor on the DC2350A-B. Multiple boards can be linked through a 2-wire isolated serial interface (isoSPI) to monitor any number of cells in a stack. The demo circuit also features reversible isoSPI enabling a fully redundant communication path.

The DC2350 can communicate to a PC by connecting directly to a DC2026 Linduino^® One. The DC2026 must be loaded with the appropriate program (called a “sketch”) to control the battery stack monitor IC and receive data through a USB serial port. The DC2792/DC1941 can be connected to the DC2026 to provide a fully isolated isoSPI interface to the DC2350.

Demonstration circuit 2260A is an Addressable isoSPI Battery-Stack Monitor featuring the LTC6811-2. Multiple boards can be linked through a 2-wire isolated serial interface to monitor any number of cells on a stack.

The EVAL-ADuM3190EBZ supports the ADuM3190 isolated error amplifier based on Analog Devices, Inc. iCoupler^® technology. The ADuM3190 is ideal for linear feedback power supplies with primary side controllers enabling improvements in transient response, power density and stability as compared to commonly used optocoupler and shunt regulator solutions. Included in the ADuM3190 is a wide band operational amplifier which can be used to set up a variety of commonly used power supply loop compensation techniques. The ADuM3190 is fast enough to allow a feedback loop to react to fast transient conditions and over current conditions. Also included is a high accuracy 1.225V reference to compare with the supply output set point.

The EVAL-ADuM4136EBZ evaluation board supports the ADuM4136 single-channel gate driver, which is specifically optimized for driving insulated gate bipolar transistors (IGBTs). Analog Devices, Inc., iCoupler^® technology provides isolation between the input signal and the output gate driver.

The ADuM4136 provides operation with voltages of up to 35 V. With a dual-rail supply, the negative rail can go as low as −15 V, providing robust turn off of the IGBT.

The EVAL-ADuM4136EBZ evaluation board facilitates testing of the desaturation circuitry with pads available for standard desaturation detection. The evaluation board has layout locations for three different types of discrete switches, allowing for a wide range of device testing. Screw terminals provide easy access to supplying the secondary side with either a single or dual supply. 

For complete information about the ADuM4136, refer to the product data sheet that should be consulted in conjunction with user guide UG-1019 when using the evaluation board.

The DC2049A demonstrates how a power supply regulates two output voltage by using the LT3999 and low dropout (LDO) regulators.

The LT3999 is a monolithic push-pull DC/DC driver which features a wide input range and small external passive components.

The LT3999 has duty circle control for ΔV_IN compensation, which allows for a wide input voltage range and low LDO losses.

Demonstration circuit 2821A is a compact no-opto isolated flyback converter featuring the LT8302. The DC2821A outputs 12V, and maintains ±1% (typ) regulation with a load current from 5mA up to 1.4A and over an input voltage from 4V to 28V. The output current capability increases with the input voltage.

Transformer leakage inductance causes a voltage spike on the primary side after the power switch turns off. To limit this leakage inductance spike within the MOSFET voltage rating of 65V, an RC snubber and a TVS clamp are installed to damp the ringing and clamp the MOSFET drain voltage to a safe level.

The demo circuit can be easily modified for different applications using predesigned transformers.

The LT8302 data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with the quick start guide for DC2821A.

The circuit in Figure 1 is a completely isolated current sensor with an isolated power source. The circuit is highly robust and can be mounted close to the sense resistor for accurate measurements and minimum noise pickup. The output is a single 16 MHz bit stream from a sigma-delta modulator that is processed by a DSP using a sinc³digital filter.

The circuit is ideal for monitoring the ac current in solar photovoltaic (PV) converters where the peak ac voltage can be several hundred volts, and the current can vary between a few mA and 25 A.