Features and Benefits
- Provide time delays between enabling of regulators
- Can be cascaded with regulators for multiple supply sequencing
- Output stages
High voltage (up to 22 V) open-drain output (ADM1085/ADM1087)
Push-pull output (ADM1086/ADM1088)
- Power supply monitoring from 0.6 V
- Capacitor adjustable time delays
- High voltage (up to 22 V) enable input
- Low power consumption (15 µA)
- Specified over –40°C to +125°C temperature range
- 6-lead SC70 package
Product DetailsThe 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 ADM0185 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.
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (1)
The ADM1087 evaluation board (EVAL-ADM1087EBZ) is a fully featured board for evaluating ADM1087 sequencers.
The board is designed to power up with a 9 V input supply that can be turned on and off using a dedicated switch (Switch S1, ON/OFF).
Complete specifications for the ADM1087 can be found in the ADM1087 data sheet, available at www.analog.com, and should be consulted in conjunction with this user guide when using the evaluation board.
Solutions Bulletins & Brochures (1)
Technical Articles (1)
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.