Analog Devices

The ADM1278 is a hot swap controller that allows a circuit board to be removed from or inserted into a live backplane. It also features current, voltage, power, and temperature readback via an integrated 12-bit analog-to-digital converter (ADC), accessed using a PMBus™interface. The load current is measured using an internal current sense amplifier that measures the voltage across a sense resistor in the power path via the HS+ and HS− pins. A default current limit of 20 mV is set, but this limit can be adjusted, if required.The ADM1278 limits the current through the sense resistor by controlling the gate voltage of an external N-channel FET in the power path, via the GATE pin. The sense voltage, and therefore the load current, is maintained below the preset maximum. The ADM1278 protects the external FET by limiting the time that the FET remains on while the current is at its maximum value.This current-limit time is set by the choice of capacitor connected to the TIMER pin. In addition, a constant power foldback scheme is used to control the power dissipation in the MOSFET during power-up and fault conditions. The level of this power, along with the TIMER regulation time, can be set to ensure that the MOSFET remains within safe operating area (SOA) limits.In case of a short-circuit event, a fast internal overcurrent detector responds within 320 ns and signals the gate to shut down. A 1500 mA pull-down device ensures a fast FET response.The ADM1278 features overvoltage (OV) and undervoltage (UV) protection, programmed using external resistor dividers on the UV and OV pins. A PWRGD signal can be used to detect when the output supply is valid, using the PWGIN pin to accurately monitor the output.The ADM1278 is available in a 32-lead LFCSP with aRETRYpin that can be configured for automatic retry or latch-off when an overcurrent fault occurs.ApplicationsServersPower monitoring and control/power budgetingTelecommunication and data communication equipment

The ADM1281 is a hot-swap controller that allows a circuit board to be removed from or inserted into a live backplane. It also features current, voltage, power, and temperature readback through an integrated 12-bit analog-to-digital converter (ADC), accessed using a PMBus™ interface. The load current is measured using an internal current sense amplifier that measures the voltage across a sense resistor in the power path through the HS+ and HS− pins. A default current limit of 20 mV is set, but this limit can be adjusted, if required.The ADM1281 limits the current through the sense resistor by controlling the gate voltage of an external N-channel FET in the power path, through the GATE pin. The sense voltage, and therefore the load current, is maintained below the preset maximum. The ADM1281 protects the external FET by limiting the time that the FET remains on while the current is at its maximum value. This current-limit time is set by the choice of capacitor connected to the TIMER pin. In addition, a constant power foldback scheme is used to control the power dissipation in the MOSFET during power-up and fault conditions. The level of this power, along with the TIMER regulation time, can be set to ensure that the MOSFET remains within safe operating area (SOA) limits.In case of a short-circuit event, a fast internal overcurrent detector responds within 290 ns and signals the gate to shut down. A 2400 mA pull-down device ensures a fast FET response.The ADM1281 features overvoltage (OV) and undervoltage (UV) protection, programmed using external resistor dividers on the UV and OV pins. A PWRGD signal can be used to detect when the output supply is valid, using the PWGIN pin to accurately monitor the output.The ADM1281 is available in a 32-lead LFCSP with a RETRY pin that can be configured for automatic retry or latch-off when an overcurrent fault occurs.APPLICATIONSServersPower monitoring and control/power budgetingTelecommunication and data communication equipment

The ADM12914 is a quad voltage supervisory IC ideally suited for monitoring multiple rails in a wide range of applications. Each monitored rail has two dedicated input pins, VHx and VLx, which allows each rail to be monitored for both undervoltage (UV) and overvoltage (OV) conditions with high threshold accuracy of ±0.8%. Common active lowundervoltage(UV)and overvoltage(OV)pins are shared by each of the monitored voltage rails.The ADM12914 includes a 1 V buffered reference output, REF, that acts as an offset when monitoring a negative voltage. The three-state SEL pin determines the polarity of the third and fourth inputs, that is, it configures the device to monitor positive or negative supplies.The device incorporates an internal shunt regulator that enables the device to be used in higher voltage systems. This feature requires a resistor to be placed between the main supply rail and the VCCpin to limit the current flow into the VCCpin at a level no greater than 10 mA. The ADM12914 uses the internal shunt regulator to regulate VCCif the supply line exceeds the absolute maximum ratings.The ADM12914 is available in two models. The ADM12914-1 offers a latching overvoltage output that can be cleared by toggling theLATCHinput pin. The ADM12914-2 has a disable pin that can override and disable both theUVand theOVoutput signals.The ADM12914 is available in a 16-lead QSOP package. The device is specified over the extended temperature range of −40°C to +125°C.ApplicationsServer supply monitoringFPGA/DSP core and I/O voltage monitoringTelecommunications equipmentMedical equipment

The ADM1293 andADM1294are high accuracy integrated digital power monitors that offer digital current, voltage, and power monitoring using an on-chip, 12-bit analog-to-digital converter (ADC), communicated through a PMBus™ compliant I2C interface.These devices acquire the current by measuring the voltage difference across the external sense resistor. This voltage is amplified and digitized by an internal 12-bit ADC. The same ADC can also sample the primary input voltage and an auxiliary input voltage. The internal digital block can perform multiplication of the current and primary input voltage for power calculation. The ADM1293/ADM1294 also feature a power accumulator for energy metering. An industry-standard PMBus interface allows a master controller to read back these data from the device. The master controller can then combine this information with a known sense resistor value to calculate the current, voltage, power, and energy consumption over time on the monitored rail.In conditions such as overcurrent, overvoltage, undervoltage, and overpower, the ADM1293/ADM1294 devices can generate an interrupt signal to the microprocessor through the GPOx/ALERTx outputs. The threshold for these conditions is digitally programmed via PMBus.The ADM1293 is designed for high-side supply monitoring with a voltage monitoring range from 0 V to 20 V. The ADM1294 is designed for low-side supply monitoring. Its integrated shunt regulator allows it to be powered and to monitor supply in wide voltage ranges.The ADM1293/ADM1294 are available in 4 mm × 4 mm 16-lead LFCSP and 14-lead TSSOP packages with a specified operating ambient temperature range from −40°C to +105°C for the ADM1293 and an operating junction temperature range from −40°C to +105°C for the ADM1294.ApplicationsPower monitoring/power budgetingCentral office equipmentTelecommunications and data communications equipmentPCs/servers

The ADM13305 is a dual voltage supervisor designed to monitor two supplies and provide a reset signal to DSP and microprocessor-based systems.There are five models available, all of which feature a combination of internally pretrimmed undervoltage threshold options for monitoring 1.8 V, 2.5 V, 3.3 V, and 5 V supplies. There is also an adjustable input option with an undervoltage threshold voltage of 0.6 V.The ADM13305-18, ADM13305-25, and ADM13305-33 models have two internally fixed thresholds. The ADM13305-4 and ADM13305-5 offer one internally fixed threshold and one externally programmable threshold via a resistor string. See the Ordering Guide for a list of all available options.During power-up,RESETis asserted when the supply voltage exceeds 1.1 V. The device then monitors the SENSEv input pins and holds theRESEToutput low as long as either of the SENSEv inputs remains below the rising threshold voltage, VIT+.Once the supplies monitored at the SENSEv inputs rise above their associated thresholds, the reset signal remains low for the reset timeout period before deasserting. Subsequently, if a voltage monitored by the SENSEv pins falls below its associated falling threshold, VIT−,RESETthe output asserts. The ADM13305 features both an active high RESET and an active lowRESEToutput.As well as providing power-on reset signals, an on-chip watchdog timer can reset the microprocessor if it fails to strobe within the preset timeout period. A reset signal can also be asserted by an external push button through the manual reset input pin.The ADM13305 is available in an 8-lead, narrow body SOIC package. The device operates over the extended industrial temperature range of −40°C to +85°C.APPLICATIONSSupervising DSPs/microcontrollersIndustrial and portable equipmentWireless systemsNotebook/desktop computers

The ADM13307 is a triple voltage supervisor designed to monitor up to three voltage levels in DSP and microprocessor-based systems.There are five models available, all of which feature a combination of internally pretrimmed undervoltage threshold options for monitoring 1.8 V, 2.5 V, 3.3 V, and 5 V supplies. There are also two adjustable input options with undervoltage thresholds of either 0.6 V or 1.25 V.The ADM13307-18, ADM13307-25, and ADM13307-33 models have two internally fixed thresholds and one externally programmable threshold via a resistor string. The ADM13307-4 and ADM13307-5 offer one internally fixed threshold and two externally programmable thresholds. See the Data Sheet Ordering Guide for a list of all available options.During power-up,RESETis asserted when the supply voltage exceeds 1.1 V. The device then monitors the SENSEv input pins and holds theRESEToutput low as long as the SENSEv pins remain below the rising threshold voltage, VIT+.Once the supplies monitored at the SENSEv inputs rise above their associated thresholds, the reset signal remains low for the reset timeout period before deasserting. Subsequently, if a voltage monitored by the SENSEv pins falls below its associated falling input threshold voltage, VIT−, theRESEToutput asserts.The ADM13307 features both an active high RESET and an active lowRESEToutput.The manual reset input of the ADM13307 can be used to initiate a reset by means of an external push button or logic signal.The ADM13307 is available in an 8-lead narrow body SOIC package. The device operates over the extended industrial temperature range of −40°C to +85°C.APPLICATIONSSupervising DSPs/microcontrollersIndustrial and portable equipmentWireless systemsNotebook/desktop computers

TheADM3202/ADM3222/ ADM1385 are high speed, 2-channel RS232/V.28 interface devices which operate from a single +3.3 V power supply. Low power consumption and a shutdown facility (ADM3222 / ADM1385) makes them ideal for battery powered portable instruments.The ADM3202 / ADM3222 / ADM1385 conform to the EIA-232E and CCITT V.28 specifications and operate at data rates up to 230 kbps. Four external 0.1 µF charge pump capacitors are used for the voltage doubler/inverter permitting operation from a single +3.3 V supply.The ADM3222 / ADM1385 contain additional enable and shutdown circuitry. The EN input may be used to three-state the receiver outputs. The SD input is used to power down the charge pump and transmitter outputs reducing the quiescent current to less than 1 µA. The receivers remain enabled during shutdown unless disabled using EN.The ADM3202 is available in a 16-lead DIP, narrow and wide SO as well as a space saving TSSOP package. The ADM3222 is available in 18 lead DIP , SO and in 20 lead SSOP and TSSOP. The ADM1385 is available in a 20 lead SSOP package and is pin compatible with the LTC1385 CG.

The ADM1486 is a differential line transceiver suitable for high speed bidirectional data communication on multipoint bus transmission lines. It is designed for balanced data transmission, complies with EIA Standards RS-485 and RS-422 and is recommended for PROFIBUS applications. The part contains a differential line driver and a differential line receiver. Both the driver and the receiver may be enabled independently. When disabled or with power off, the driver outputs are tristated.