Features and Benefits
- Selects Highest Priority Valid Supply from Two Inputs
- Wide 1.8V to 18V Operating Range
- Internal Dual 2Ω, 0.5A Switches
- Low 3.6µA Operating Current
- Low 320nA V2 Current When V1 Connected to OUT
- Blocks Reverse and Cross Conduction Currents
- Reverse Supply Protection to –15V
- V2 Freshness Seal/Ship Mode
- ±1.5% Accurate Adjustable Switchover Threshold
- Two Auxiliary ±2.3% Accurate Voltage Comparators
- Overcurrent and Thermal Protection
- Thermally Enhanced 10-Pin 3mm × 3mm DFN and 12-Lead Exposed Pad MSOP Packages
The LTC4419 is a dual input monolithic PowerPath™ prioritizer with low operating current, that provides backup switchover for keeping critical circuitry alive during brown out and power loss conditions. Unlike diode-OR products, little current is drawn from the inactive supply even if its voltage is greater than the active supply.
Internal 2Ω, current limited PMOS switches provide power path selection from a primary input (V1) or a backup input (V2) to the output. An adjustable voltage monitor set via an external resistive divider provides flexibility in setting the V1 to V2 switchover threshold. When primary input V1 drops, the ADJ monitor input causes OUT to be switched to V2. Fast non-overlap switchover circuitry prevents both reverse and cross conduction while minimizing output droop.
The LTC4419 has two auxiliary comparators with open-drain outputs that provide flexible voltage monitoring. The V2ON output indicates if V2 is powering OUT. Freshness seal mode prevents V2 battery discharge during storage or shipment.
- Low Power Battery Backup
- Portable Equipment
- Point-of-Sale (POS) Equipment
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)
Demonstration circuit 2160A uses the LTC4419 to provide backup switchover, keeping the output load powered during brown out or power loss conditions. Priority is assigned by supply connection to the V1 and V2 inputs. The power source connected to V1 has a higher priority and is monitored by undervoltage switchover threshold comparator CADJ (pin ADJ). If V1 exceeds 1.55V and ADJ is above 1.097V for 64ms, V1 is considered valid, and the LTC4419 connects V1 to the load. If V1 drops below 1.52V, or ADJ drops below 1.047V, V1 is considered invalid, and the LTC4419 powers the load from V2. The DC2160A is populated to provide switchover when V1 drops below 10.19V ±0.33V. The upper limit for V1 is the maximum operating voltage, 18V; however, the recommended V1 voltage is 12V. The resistive divider (R1-R2) of the first auxiliary comparator CMP1 is adjusted to trigger the comparator when VCMP1_TOP’s voltage is in the 9.92V to 10.74V range. Practically, any voltage from the operating range can be selected for V2, however, 5V is recommended to have a standard voltage level.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
LTC4419 Companion Parts
Recommended Related Parts
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.