LINEAR Manuals

The LTC1625 is a synchronous step-down switching regulator controller that drives external N-Channel power MOSFETs using few external components. Current mode control with MOSFET VDS sensing eliminates the need for a sense resistor and improves efficiency. The frequency of a nominal 150kHz internal oscillator can be synchronized to an external clock over a 1.5:1 frequency range. Burst Mode operation at low load currents reduces switching losses and low dropout operation extends operating time in battery-powered systems. A forced continuous mode control pin can assist secondary winding regulation by disabling Burst Mode operation when the main output is lightly loaded. Fault protection is provided by foldback current limiting and an output overvoltage comparator. The LTC1625 is available in 16-Lead Narrow SSOP and SO Packages.

The LTC ®1407/LTC1407A are 12-bit/14-bit, 3Msps ADCs with two 1.5Msps simultaneously sampled differential inputs

The LTC1293/4/6 is a family of data acquisition systems which contain a serial I/O successive approximation A/D converter. It uses LTCMOS TM switched capacitor technology to perform either 12-bit unipolar, or 11-bit plus sign bipolar A/D conversions. The input multiplexer can be configured for either single ended or differential inputs (or combinations thereof). An on-chip sample and hold is included for all single ended input channels. When the LTC1293/4/6 is idle it can be powered down in applications where low power consumption is desired. The LTC1296 includes a System Shutdown Output pin which can be used to power down external circuitry, such as signal conditioning circuitry prior to the input mux. The serial I/O is designed to communicate without external hardware to most MPU serial ports and all MPU parallel I/O ports allowing up to eight channels of data to be transmitted over as few as three wires.

The LTC1407-1/LTC1407A-1 are 12-bit/14-bit, 3Msps ADCs with shutdown feature.

The LTC4309 is a hot-swappable 2-wire bus buffer that allows I/O card insertion into a live backplane without corruption of the data and clock buses. It provides bidirectional buffering, keeping the backplane and card capacitances isolated. Low offset and high VOL tolerance allow cascading of multiple devices on the clock and data buses. If SDAOUT or SCLOUT are low for 30ms, FAULT will pull low indicating a stuck bus low condition. If DISCEN is tied high, the LTC4309 will automatically break the bus connection and generate up to 16 clock pulses and a stop bit in an attempt to free the bus. A connection will resume if the stuck bus is cleared. If DISCEN is connected to GND, the buses will remain connected with no clock or stop bit generation. ACC input enables rise-time accelerators for high capacitively loaded buses. During insertion, the SDA and SCL lines are precharged to 1V to minimize bus disturbances. When driven high, the ENABLE input allows the LTC4309 to connect after a stop bit or bus idle. Driving ENABLE low breaks the connection between SDAIN and SDAOUT, SCLIN and SCLOUT. READY is an open drain output which indicates that the backplane and card sides are connected.

The LTC4307 is a low offset hot swappable 2-wire bus buffer that allows I/O card insertion into a live backplane without corruption of the data and clock busses. It provides bidirectional buffering, keeping the backplane and card capacitances isolated. The LTC4307 has low offset and high VOL tolerance, allowing multiple devices to be cascaded on the clock and data busses. If SDAOUT or SCLOUT are low for 30ms, the LTC4307 will automatically break the bus connection and generate clock pulses to attempt to free the bus. The connection will resume if the stuck bus is cleared. During insertion, the SDA and SCL lines are pre-charged to 1V to minimize bus disturbances. The ENABLE input allows the LTC4307 to connect after a stop bit or bus idle. Driving ENABLE low breaks the connection between SDAIN and SDAOUT, SCLIN and SCLOUT. The READY output indicates that the backplane and card sides are connected.

LTC1285/LTC1288 3V micropower sampling 12-bit A/D converters in SO-8 packages

LTC1196/LTC1198 are 600ns, 8-bit A/D converters with sampling rates up to 1MHz. They are offered in 8-pin SO packages and operate on 3V to 6V supplies. Power dissipation is only 10mW with a 3V supply or 50mW with a 5V supply. The LTC1198 automatically powers down to a typical supply current of 1nA whenever it is not performing conversions. These 8-bit switched-capacitor successive approximation ADCs include sample-and-holds. The LTC1196 has a differential analog input; the LTC1198 offers a software selectable 2-channel MUX. The 3-wire serial I/O, SO-8 packages, 3V operation and extremely high sample rate-to-power ratio make these ADCs an ideal choice for compact, high speed systems. These ADCs can be used in ratiometric applications or with external references. The high impedance analog inputs and the ability to operate with reduced spans below 1V full scale (LTC1196) allow direct connection to signal sources in many applications, eliminating the need for gain stages. These ADCs have low power consumption (10 mW), low noise (40 μV RMS) and high accuracy (±1/2LSB), making them suitable for a wide variety of applications, including data acquisition, motor control, instrumentation and power measurement.

The LTC1403/LTC1403A are 12-bit/14-bit, 2.8Msps serial ADCs with features such as low power dissipation and single supply operation.

The LT5534 is a 50MHz to 3GHz RF power detector with a dynamic range of 60dB. It features exceptional accuracy over temperature and power supply, fast transient response, and can be used for RF power detection, optical receiver gain control, etc.

The LTC1090 is a data acquisition component which contains a serial I/O successive approximation A/D converter. It uses LTCMOS switched capacitor technology to perform either 10-bit unipolar, or 9-bit plus sign bipolar A/D conversions. It has 4 differential/8 single ended input channels that can be configured for either single ended or differential inputs. It also includes an on-chip sample and hold circuit. The serial I/O is compatible with industry standard full duplex serial interfaces. The output data can be programmed for a length of 8, 10, 12 or 16 bits, allowing easy interface to shift registers and a variety of processors. The LTC1090A is specified with total unadjusted error less than ±0.5LSB.

The LTC2248 / LTC2247 / LTC2246 are 14-bit 65Msps / 40Msps / 25Msps low power 3V A/D converters designed for digitizing high frequency, wide dynamic range signals. They are perfect for demanding imaging and communications applications.

The LTC1921 monitors two independent -48V supplies, including their fuses, and drives up to three optoisolators to indicate status, in accordance with standard backplane specifications. It features dual supply overvoltage and undervoltage detection circuits, and can ignore fast supply transients to eliminate false detection. The LTC1921 operates from -10V to -80V with a typical power dissipation of less than 10mW. It is available in an 8-pin MSOP package.

The LTC1798 series of micropower bandgap references combine high accuracy, low drift, very low supply current and small package size. The combination of ultralow quiescent current and low dropout voltage of only 200mV (max) makes them ideal for battery-powered equipment. The output voltage is set by an external resistor divider for the adjustable LTC1798. This series of references uses curvature compensation to obtain low temperature coefficient and trimmed thin-film resistors to achieve high output accuracy. These references can source up to 10mA and sink up to 2mA, making them ideal for precision regulator applications. They are stable without an output bypass capacitor, but are also stable with capacitance up to 1µF. This feature is important in critical applications where PC board space is a premium and fast settling is demanded. The LTC1798 series references provided power dissipa- tion advantages over shunt references. In addition to supply current, shunt references must also idle the entire load current to operate. The LTC1798 series is available in the SO-8 package.