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 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 ADM696 / ADM697 supervisory circuits offer 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 ADM696 / ADM697 are available in 16-pin DIP and small outline packages and provide the following functions: Power-On Reset output during power-up, power-down and brownout conditions. The RESET voltage threshold is adjustable using an external voltage divider. The RESET output remains operational with VCC as low as 1 V. A Reset pulse if the optional watchdog timer has not been toggled within specified time. Separate watchdog time-out and low line status outputs. Adjustable reset and watchdog timeout periods. A 1.3 V threshold detector for power fail warning, low battery detection, or to monitor a power supply other than VCC. Battery backup switching for CMOS RAM, CMOS micro-processor or other low power logic (ADM696). Write protection of CMOS RAM or EEPROM (ADM697).The ADM696 / ADM697 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 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

The ADR130 is the first family of tiny, micropower, low voltage, high precision voltage references in the industry. Featuring0.35% initial accuracy and 25 ppm/°C of temperature drift inthe tiny TSOT-23 package, the ADR130 voltage reference only requires 80 μA for typical operation. The ADR130 design includes a proprietary temperature drift curvature correction technique that minimizes the nonlinearities in the output voltage vs. temperature characteristics.Available in the industrial temperature range of −40°C to+125°C, the ADR130 is housed in a tiny TSOT-23 package.For 0.5 V output, tie SET (Pin 5) to VOUT (Pin 4). For 1.0 V output, tie SET (Pin 5) to GND (Pin 2). All Members of the ADR130 Model VOUT Accuracy Tempco 1K Price ADR130A 0.5/1.0V ±3.5mV 50ppm/°C $0.97 ADR130B 0.5/1.0V ±1.75mV 25ppm/°C $1.60 APPLICATIONS Battery-powered instrumentation Portable medical equipment Communication infrastructure equipment

The ADR430/ADR431/ADR433/ADR434/ADR435 series is a family of XFET® voltage references featuring low noise, high accuracy, and low temperature drift performance. Using Analog Devices, Inc., temperature drift curvature correction and extra implanted junction FET (XFET) technology, voltage change vs. temperature nonlinearity in the ADR430/ADR431/ADR433/ADR434/ ADR435 is minimized.The XFET references operate at lower current (800 μA) and lower supply voltage headroom (2 V) than buried Zener references. Buried Zener references require more than 5 V of headroom for operation. The ADR430/ADR431/ADR433/ADR434/ADR435 XFET references are low noise solutions for 5 V systems.The ADR430/ADR431/ADR433/ADR434/ADR435 family has the capability to source up to 30 mA of output current and sink up to −20 mA. It also comes with a trim terminal to adjust the output voltage over a ±0.5% range without compromising performance.The ADR430/ADR431/ADR433/ADR434/ADR435 are available in 8-lead MSOP and 8-lead narrow SOIC packages. All versions are specified over the extended industrial temperature range of −40°C to +125°C.Applications Precision data acquisition systems High resolution data converters Medical instruments Industrial process control systems Optical control circuits Precision instruments

The LTC3526/LTC3526B are synchronous, fixed frequency step-up DC/DC converters with output disconnect. Synchronous rectification enables high efficiency in the low profile 2mm × 2mm DFN package. Battery life in single AA/AAA powered products is extended further with an 850mV start-up voltage and operation down to 500mV once started.A switching frequency of 1MHz minimizes solution footprint by allowing the use of tiny, low profile inductors and ceramic capacitors. The current mode PWM design is internally compensated, reducing external parts count. The LTC3526 features automatic Burst Mode operation at light load conditions, while the LTC3526B features continuous switching at light loads. Anti-ringing control circuitry also reduces EMI concerns by damping the inductor in discontinuous mode. Additional features include a low shutdown current of under 1μA and thermal shutdown.The LTC3526/LTC3526B are housed in a 2mm × 2mm × 0.75mm DFN package.For new designs, we recommend the LTC3526L/LTC3526LB.   Startup Voltage Frequency Burst Mode Notes LTC3526 1V 1MHz Yes Not Recommended For New Designs LTC3526B 1V 1MHz No Not Recommended For New Designs LTC3526-2 1V 2MHz Yes Not Recommended For New Designs LTC3526B-2 1V 2MHz No Not Recommended For New Designs LTC3526L 0.85V 1MHz Yes   LTC3526LB 0.85V 1MHz No   LTC3526L-2 0.85V 2MHz Yes   LTC3526LB-2 0.85V 2MHz No   APPLICATIONS Medical Instruments Flash-Based MP3 Players Noise Canceling Headphones Wireless Mice Bluetooth Headsets

The LT3740 is a synchronous step-down switching regulator controller that drives N-channel power MOSFET stages. The controller uses valley current mode architecture to achieve very low duty cycles with excellent transient response without requiring a sense resistor.The LT3740 includes an internal step-up converter to provide a bias 7.8V higher than the input voltage for the drive. This enables the part to work from an input voltage as low as 2.2V.The XREF pin is an external reference input that allows the user to override the internal 0.8V feedback reference with any lower value, allowing full control of the output voltage during operation, output voltage tracking or soft-start.The LT3740 has three current limit levels that can be chosen by connecting the RANGE pin to ground, open, and input respectively.Applications Notebook and Palmtop Computers, PDA Portable Instruments Distributed Power Systems

The ADM1060 is a programmable supervisory/sequencing device that offers a single chip solution for multiple power supply fault detection and sequencing in communications systems.In central offices, servers, and other infrastructure systems, a common backplane dc supply is reduced to multiple board supplies using dc-to-dc converters. These multiple supplies are used to power different sections of the board, such as 3.3 V logic circuits, 5 V logic circuits, DSP core, and DSP I/O circuits. There is usually a requirement that certain sections power up before others; for example, a DSP core may need to power up before the DSP I/O, or vice versa, to avoid damage, miscommunication, or latch-up. The ADM1060 facilitates this, providing supply fault detection and sequencing/combinatorial logic for up to seven independent supplies. The seven supply fault detectors consist of one high voltage detector (up to +14.4 V), two bipolar voltage detectors (up to +6 V or down to −6 V), and four positive low voltage detectors (up to +6 V). All of the detectors can be programmed to detect undervoltage, overvoltage, or out-ofwindow (undervoltage or overvoltage) conditions. The inputs to these supply fault detectors are via the VH (high voltage) pin, VBn (positive or negative) pins, and VPn (positive only) pins. Either the VH supply or one of the VPn supplies is used to power the ADM1060 (whichever is highest). This ensures that in the event of a supply failure, the ADM1060 is kept alive for as long as possible, thus enabling a reliable fault flag to be asserted and the system to be powered down in an ordered fashion.Other inputs to the ADM1060 include a watchdog detector (WDI) and four general-purpose inputs (GPIn). The watchdog detector can be used to monitor a processor clock. If the clock does not toggle (transition from low to high or from high to low) within a programmable timeout period (up to 18 sec.), a fail flag will assert. The four general-purpose inputs can be configured as logic buffers or to detect positive/negative edges and to generate a logic pulse or level from those edges. Thus, the user can input control signals from other parts of the system (e.g., RESET or POWER_GOOD) to gate the sequencing of the supplies supervised by the ADM1060.The ADM1060 features nine programmable driver outputs (PDOs). All nine outputs can be configured to be logic outputs, which can provide multiple functions for the end user such as RESET generation, POWER_GOOD status, enabling of LDOs, and watchdog timeout assertion. PDOs 1 to 4 have the added feature of being able to provide an internally charge-pumped high voltage for use as the gate drive of an external N-channel FET that could be placed in the path of one of the supplies being supervised.APPLICATIONS Central office systems Servers Infrastructure network boards High density, multivoltage system cards

The ADM1186-1 and ADM1186-2 are integrated, four-channel, voltage monitoring and sequencing devices. A 2.7 V to 5.5 V power supply is required on the VCC pin for power.Four precision comparators monitor four voltage rails, with all comparators sharing a 0.6 V reference and a worst-case accuracy of 0.8%. Resistor networks that are external to the VIN1, VIN2, VIN3, and VIN4 pins set the Under Voltage (UV) trip points for the monitored supply rails.The ADM1186-1 and ADM1186-2 have four open drain enable outputs, OUTx, that are used to enable power supplies. An open drain power good output, PWRGD, is provided that indicatesthe four VINx inputs are above their UV thresholds.A state machine monitors the state of the UP and DOWN pins on the ADM1186-1 or the UP/overbar: DOWN pin on the ADM1186-2 to control the supply sequencing direction. In the ‘Wait Start’state, a rising edge transition on the UP or UP/DOWN pin triggers a power-up sequence. A falling edge transition on the DOWN or UP/DOWN pin in the ‘Power Up Done’ statetriggers a power down sequence.During a power up sequence, the state machine enables each power supply in turn. The supply output voltage is monitored to determine if it rises above the UV threshold level within a userdefined duration called the blanking time. If a supply rises above the UV threshold then the next enable output in the sequence is turned on. In addition to the blanking time a user may also define sequencing time delays between each enable output turning on. When all four enable outputs are on, and the four VINx pins are above their UV trip points the power up sequence is complete. The ADM1186-1 provides an open drain pin, SEQ_DONE, that is asserted high to provide an indication that an up sequence is complete. The SEQ_DONE pins is allows multiple cascadedADM1186-1 devices to be perform controlled power up and down sequences. During a power down sequence the enable outputs turn off inreverse order. The sequence time delays between successive supplies the same as during the power up sequence, and no blanking time is used during a power down sequence. At the end of a down sequence the SEQ_DONE pin is brought low. During sequencing and when powered up, the state machine continuously monitors for any fault conditions. Faults include a UV condition on any of the inputs, or an unexpected controlinput. Any fault that occurs causes the state machine to enter a fault handler. This immediately turns off all enable outputs, and ensures that the device is ready to start a new up sequence. The ADM1186-1 has a bi-directional open drain pin, FAULT, that facilitates fault handling when using multiple devices. An ADM1186-1 experiencing a fault condition drives the FAULT pin low, causing other connected ADM1186-1devices to enter their own fault handling state.The ADM1186-1 is available in a 20-lead QSOP package andthe ADM1186-2 is available in a 16-lead QSOP package.