The AD688 is a high precision ±10 V tracking reference. Low tracking error, low initial error and low temperature drift give the AD688 reference absolute ±10 V accuracy performance previously unavailable in monolithic form. The AD688 uses a proprietary ion-implanted buried Zener diode, and laser-wafer-drift- trimming of high stability thin-film resistors to provide outstanding performance at low cost.The AD688 includes the basic reference cell and three additional amplifiers. The amplifiers are laser-trimmed for low offset and low drift and maintain the accuracy of the reference. The amplifiers are configured to allow Kelvin connections to the load and/or boosters for driving long lines or high current loads, delivering the full accuracy of the AD688 where it is required in the application circuit.The low initial error allows the AD688 to be used as a system reference in precision measurement applications requiring 12-bit absolute accuracy. In such systems, the AD688 can provide a known voltage for system calibration and the cost of periodic recalibration can therefore be eliminated. Furthermore, the mechanical instability of a trimming potentiometer and the potential for improper calibration can be eliminated by using the AD688 and calibration software.The AD688 is available in three versions. The AD688AQ and BQ grades are packaged in 16-pin cerdip (0.3') packages and are specified for operation from -40°C to +85°C. The AD688SQ grade is specified for operation from -55°C to +125°C.PRODUCT HIGHLIGHTS Precision Tracking. The AD688 offers precision tracking ±10 V Kelvin output connections with no external components. Tracking error is less than 1.5 mV and fine-trim is available for applications requiring exact symmetry between the +10 V and −10 V outputs.  Accuracy. The AD688 offers 12-bit absolute accuracy without any user adjustments. Optional fine-trim connections are provided for applications requiring higher precision. The fine-trimming does not alter the operating conditions of the Zener or the buffer amplifiers and thus does not increase the temperature drift.  Low output noise. Output noise of the AD688 is low— typically 6 μVp-p. A pin is provided for broadband noise filtering using an external capacitor.

The REF01 / REF02 / REF03 series of precision voltage references provide a stable 10.0 V, 5.0 V, or 2.5 V output with minimal change in response to variations in supply voltage, ambient temperature or load conditions. The devices are available in 8-lead SOIC, PDIP, CERDIP, and TO-99 packages, as well as 20-terminal LCC packages (883 only), furthering the usability of the devices in both standard and high stress applications.With an external buffer and a simple resistor network, the TEMP terminal can be used for temperature sensing and approximation. A TRIM terminal is also provided on the device for fine adjustment of the output voltage.The small footprint, wide supply range, and application versatility make the REF0x series of references ideal for general-purpose and space-constrained applications.Newer designs should use the ADR01 / ADR02 / ADR03 / ADR06 series of references, which offer higher accuracy and temperature stability over a wider operating temperature range, while maintaining full pin-for-pin compatibility with the REF01 / REF02 / REF03 series. This data sheet applies to commercial-grade products only. Contact sales or visit analog.com for military-grade (883) data sheets.APPLICATIONS Precision data systems High resolution converters Industrial process control systems Precision instruments Military and aerospace applications

The AD536A is a complete monolithic integrated circuit that performs true rms-to-dc conversion. It offers performance comparable or superior to that of hybrid or modular units costing much more. The AD536A directly computes the true rms value of any complex input waveform containing ac and dc components. A crest factor compensation scheme allows measurements with 1% error at crest factors up to 7. The wide bandwidth of the device extends the measurement capability to 300 kHz with less than 3 dB errors for signal levels greater than 100 mV.An important feature of the AD536A, not previously available in rms converters, is an auxiliary dB output pin. The logarithm of the rms output signal is brought out to a separate pin to allow the dB conversion, with a useful dynamic range of 60 dB. Using an externally supplied reference current, the 0 dB level can be conveniently set to correspond to any input level from 0.1 V to 2 V rms.The AD536A is laser trimmed to minimize input and output offset voltage, to optimize positive and negative waveform symmetry (dc reversal error), and to provide full-scale accuracy at 7 V rms. As a result, no external trims are required to achieve the rated unit accuracy.The input and output pins are fully protected. The input circuitry can take overload voltages well beyond the supply levels. Loss of supply voltage with the input connected to external circuitry does not cause the device to fail. The output is short-circuit protected.The AD536A is available in two accuracy grades (J and K) for commercial temperature range (0°C to 70°C) applications, and one grade (S) rated for the −55°C to +125°C extended range. The AD536AK offers a maximum total error of ±2 mV ± 0.2% of reading, while the AD536AJ and AD536AS have maximum errors of ±5 mV ± 0.5% of reading. All three versions are available in a hermetically sealed 14-lead DIP or a 10-pin TO-100 metal header package. The AD536AS is also available in a 20-terminal leadless hermetically sealed ceramic chip carrier.The AD536A computes the true root-mean-square level of a complex ac (or ac plus dc) input signal and provides an equivalent dc output level. The true rms value of a waveform is a more useful quantity than the average rectified value because it relates directly to the power of the signal. The rms value of a statistical signal also relates to its standard deviation.An external capacitor is required to perform measurements to the fully specified accuracy. The value of this capacitor determines the low frequency ac accuracy, ripple amplitude, and settling time.The AD536A operates equally well from split supplies or a single supply with total supply levels from 5 V to 36 V. With 1 mA quiescent supply current, the device is well suited for a wide variety of remote controllers and battery-powered instruments.

The AD536A is a complete monolithic integrated circuit that performs true rms-to-dc conversion. It offers performance comparable or superior to that of hybrid or modular units costing much more. The AD536A directly computes the true rms value of any complex input waveform containing ac and dc components. A crest factor compensation scheme allows measurements with 1% error at crest factors up to 7. The wide bandwidth of the device extends the measurement capability to 300 kHz with less than 3 dB errors for signal levels greater than 100 mV.An important feature of the AD536A, not previously available in rms converters, is an auxiliary dB output pin. The logarithm of the rms output signal is brought out to a separate pin to allow the dB conversion, with a useful dynamic range of 60 dB. Using an externally supplied reference current, the 0 dB level can be conveniently set to correspond to any input level from 0.1 V to 2 V rms.The AD536A is laser trimmed to minimize input and output offset voltage, to optimize positive and negative waveform symmetry (dc reversal error), and to provide full-scale accuracy at 7 V rms. As a result, no external trims are required to achieve the rated unit accuracy.The input and output pins are fully protected. The input circuitry can take overload voltages well beyond the supply levels. Loss of supply voltage with the input connected to external circuitry does not cause the device to fail. The output is short-circuit protected.The AD536A is available in two accuracy grades (J and K) for commercial temperature range (0°C to 70°C) applications, and one grade (S) rated for the −55°C to +125°C extended range. The AD536AK offers a maximum total error of ±2 mV ± 0.2% of reading, while the AD536AJ and AD536AS have maximum errors of ±5 mV ± 0.5% of reading. All three versions are available in a hermetically sealed 14-lead DIP or a 10-pin TO-100 metal header package. The AD536AS is also available in a 20-terminal leadless hermetically sealed ceramic chip carrier.The AD536A computes the true root-mean-square level of a complex ac (or ac plus dc) input signal and provides an equivalent dc output level. The true rms value of a waveform is a more useful quantity than the average rectified value because it relates directly to the power of the signal. The rms value of a statistical signal also relates to its standard deviation.An external capacitor is required to perform measurements to the fully specified accuracy. The value of this capacitor determines the low frequency ac accuracy, ripple amplitude, and settling time.The AD536A operates equally well from split supplies or a single supply with total supply levels from 5 V to 36 V. With 1 mA quiescent supply current, the device is well suited for a wide variety of remote controllers and battery-powered instruments.

The ADM1085-ADM1088 are Simple Sequencing™ circuits which provide a time delay between the enabling of voltage regulators at power-up in multiple supply systems. When the output voltage of the first regulator reaches a preset threshold, a time delay is initiated before an enable signal allows subsequent regulators to power-up. Any number of these devices can be cascaded with regulators to allow sequencing of multiple power supplies.Threshold levels can be set with a pair of external resistors in a voltage divider configuration. By choosing appropriate resistor values, the threshold can be adjusted to monitor voltages as low as 0.6V. The ADM1086 and ADM1088 have push-pull output stages, with active-high (ENOUT) and active-low (ENOUT) logic outputs, respectively. Similarly, the ADM1085 has an active-high (ENOUT) logic output and the ADM1087 has an active-low (ENOUT) output. Both the ADM1085 and ADM1087 have open-drain output stages which can be pulled up to voltage levels as high as 22V through an external resistor. This level shifting property of the ADM1085 and ADM1087 ensures compatibility with enable input logic levels of different regulators and converters.All four models have a dedicated enable input pin which allows the output signal to the regulator to be controlled externally. This is an active-high input (ENIN) for the ADM1085 and ADM1086, and an active-low input (ENIN) for the ADM1087 and ADM1088. The Simple Sequencers™ are specified over the extended –40°C to +125°C temperature range, and with low current consumption of 15µA (typ) and 6-lead SC70 packaging, they are suitable for low power portable applications.

The ADM690-ADM695 family of supervisory circuits offers complete single chip solutions for power supply monitoring and battery control functions in microprocessor systems. These functions include µP reset, backup battery switchover, watchdog timer, CMOS RAM write protection, and power failure warning. The complete family provides a variety of configurations to satisfy most microprocessor system requirements.The ADM690, ADM692 and ADM694 are available in 8-pin DIP packages and provide: Power-on reset output during power-up, power-down and brownout conditions. The RESET output remains operational with VCC as low as 1 V. Battery backup switching for CMOS RAM, CMOS microprocessor or other low power logic. A reset pulse if the optional watchdog timer has not been toggled within a specified time. A 1.3 V threshold detector for power fail warning, low battery detection, or to monitor a power Supply other than +5 V.The ADM691, ADM693 and ADM695 are available in 16-pin DIP and small outline packages and provide three additional functions. Write protection of CMOS RAM or EEPROM. Adjustable reset and watchdog timeout periods. Separate watchdog timeout, backup battery switchover, and low VCC status outputs.The ADM690-ADM695 family is fabricated using an advanced epitaxial CMOS process combining low power consumption (5 mW), extremely fast Chip Enable gating (5 ns) and high reliability. RESET assertion is guaranteed with VCC as low as 1 V. In addition, the power switching circuitry is designed for minimal voltage drop thereby permitting increased output current drive of up to 100 mA without the need for an external pass transistor.

The ADM690-ADM695 family of supervisory circuits offers complete single chip solutions for power supply monitoring and battery control functions in microprocessor systems. These functions include µP reset, backup battery switchover, watchdog timer, CMOS RAM write protection, and power failure warning. The complete family provides a variety of configurations to satisfy most microprocessor system requirements.The ADM690, ADM692 and ADM694 are available in 8-pin DIP packages and provide: Power-on reset output during power-up, power-down and brownout conditions. The RESET output remains operational with VCC as low as 1 V. Battery backup switching for CMOS RAM, CMOS microprocessor or other low power logic. A reset pulse if the optional watchdog timer has not been toggled within a specified time. A 1.3 V threshold detector for power fail warning, low battery detection, or to monitor a power supply other than +5 V.The ADM691, ADM693 and ADM695 are available in 16-pin DIP and small outline packages and provide three additional functions. Write protection of CMOS RAM or EEPROM. Adjustable reset and watchdog timeout periods. Separate watchdog timeout, backup battery switchover, and low VCC status outputs.The ADM690-ADM695 family is fabricated using an advanced epitaxial CMOS process combining low power consumption (5 mW), extremely fast Chip Enable gating (5 ns) and high reliability. RESET assertion is guaranteed with VCC as low as 1 V. In addition, the power switching circuitry is designed for minimal voltage drop thereby permitting increased output current drive of up to 100 mA without the need for an external pass transistor.

The ADM709 contains a power supply monitor which generates a system reset during power-up, power-down and brownout conditions. When VCC falls below the reset threshold, RESET goes low and holds the µP in reset. On power-up the RESET output is held low for 140 ms after VCC rises above the threshold. The RESET output remains operational with VCC as low as 1 V.Three supply-voltage threshold levels are available suitable for +5 V, +3.3 V and for +3 V supply monitoring. The actual reset voltage threshold is found in the data sheet.The ADM709 is available in 8-pin DIP and SOIC packages.APPLICATIONS Microprocessor Systems Computers Controllers Intelligent Instruments Critical mP Monitoring Automotive Systems Critical mP Power Monitoring 

The ADM691A/ADM693A/ADM800L/ADM800M family of supervisory circuits offers complete single chip solutions for power supply monitoring and battery control functions in microprocessor systems. These functions include mP reset, backup-battery switchover, watchdog timer, CMOS RAM write protection, and power-failure warning. The family of products provides an upgrade for the MAX691A/93A/800M family of products.All parts are available in 16-pin DIP and SO packages. The ADM691A is also available in a space-saving TSSOP package. The following functionality is provided: Power-on reset output during power-up, power-down and brownout conditions. The circuitry remains operational with VCC as low as 1 V. Battery backup switching for CMOS RAM, CMOS micro-processor or other low power logic. A reset pulse if the optional watchdog timer has not been toggled within a specified time. A 1.25 V threshold detector for power fail warning, low battery detection, or to monitor a power supply other than +5 V.

The ADM803 supervisory circuit monitors the power supply voltage in microprocessor systems. It provides a reset output during power-up, power-down and brownout conditions. On power-up, an internal timer holds reset asserted for 240ms. This holds the microprocessor in a reset state until conditions have stabilized. The reset output remains operational with VCC as low as 1V. The ADM803 provides an active-low reset signal RESET, and has an open-drain output stage which requires an external pull-up resistor.Seven reset threshold options are available. The reset comparator features built-in glitch immunity, making it immune to fast transients on VCC.The ADM803 is available in 3-lead SC70 and consumes only 17µA, making it suitable for low power portable equipment.APPLICATIONS Microprocessor Systems Computers Controllers Intelligent Instruments Automotive Systems