Analog Devices Inc./Maxim Integrated DS1314E

Overview

DS1314E from Maxim Integrated is a nonvolatile SRAM controller with integrated lithium battery monitoring and power-fail reset functionality. It converts standard CMOS SRAM into nonvolatile memory by automatically switching to battery backup when VCCI drops below 2.8V (TOL=GND) or 2.5V (TOL=VCCO), provides open-drain RST and BW outputs, and operates across -40°C to +85°C in a 20-pin TSSOP package.

For engineers reviewing the DS1314E datasheet, DS1314E pinout, DS1314E application, or DS1314E equivalent, this device is selected for systems requiring reliable SRAM data retention during power loss, predictive lithium battery replacement, and processor reset coordination - especially in industrial instrumentation, point-of-sale terminals, and embedded controllers with long-term unattended operation.

Technical Context

The DS1314E integrates three core functions: precision VCCI voltage monitoring with selectable trip points (2.8V/2.5V), bidirectional power-switching logic that routes VBAT to VCCO only when VCCI falls below VSW (2.6–2.8V), and periodic loaded-battery testing every 24 hours using a 1.2 MΩ internal resistor to detect end-of-life conditions before data loss occurs.

Its RST output delivers a 200 ms nominal power-on reset pulse and activates within 15 µs of VCCI falling below VCCTP; BW asserts low when VBAT drops below 2.5–2.7V under load and remains latched until battery replacement. All critical outputs (RST, BW, CEO) are open-drain with 4 mA sink capability and require external pull-ups.

Key Specifications

Pinout & Package

DS1314E is housed in a 20-pin Thin Shrink Small Outline Package (TSSOP) with 0.65 mm pitch, JEDEC MO-180 compliant, RoHS-compliant (U20+1 package code), and rated for reflow soldering at 260°C.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar nonvolatile SRAM controller applications.

Compared with DS1314E, DS1315E eliminates battery monitoring but embeds SRAM, while MAX6900 adds RTC functionality at the cost of higher quiescent current and larger footprint - making DS1314E optimal for pure SRAM supervision with predictive battery management.

Availability

DS1314E is available at Aetrix Electronics and suitable for industrial data loggers, point-of-sale terminals, medical diagnostic equipment, and telecom network edge devices requiring stable component supply, long-lifecycle support, and guaranteed RoHS compliance.

Supply support for DS1314E includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power management ICs for industrial, medical, and communications applications.

The DS1314E belongs to Maxim's nonvolatile memory interface product line, engineered specifically to extend SRAM data retention in mission-critical systems where battery-backed reliability and predictive maintenance are essential.

FAQ

What is the primary function of the DS1314E in an SRAM-based system?

The DS1314E serves as a nonvolatile SRAM controller that ensures data integrity during power loss by automatically switching SRAM power from VCCI to VBAT, inhibiting chip enable to prevent writes, and asserting RST to halt processor activity. Its design enables standard CMOS SRAM to behave like nonvolatile memory without requiring changes to memory architecture or software - a key capability confirmed in the DS1314E functional block diagram and memory backup section.

How does the DS1314E determine when to activate the Battery Warning (BW) output?

The DS1314E activates BW by performing a 1-second loaded-voltage test every 24 hours: it connects VBAT to a 1.2 MΩ internal resistor and compares the resulting voltage to a factory-programmed trip point (2.5–2.7V). If VBAT falls below this threshold under load, BW is latched low and remains active until the battery is physically replaced - a behavior explicitly defined in the Battery Voltage Monitoring section and confirmed by tBTCN and VBTP specifications.

Can the DS1314E be used with both 3.3V and 3.0V system supplies?

Yes - the DS1314E supports dual supply configurations via the TOL pin: connecting TOL to GND selects a 2.8–3.0V VCCI trip point for 3.3V systems, while connecting TOL to VCCO selects a 2.5–2.7V trip point for 3.0V systems. This configurability is documented in the Recommended Operating Conditions table and POWER MONITORING section, and applies directly to the DS1314E variant.

What is the purpose of Freshness Seal Mode in the DS1314E?

Freshness Seal Mode prevents battery discharge during manufacturing, shipping, and storage by withholding VCCO output until after the first VCCI power-up and subsequent power-fail event. This ensures zero standby current draw from the lithium cell prior to system activation - a feature explicitly described in the DS1314E datasheet's "FRESHNESS SEAL MODE" subsection and unique to the DS1314 family.

Does the DS1314E require external pull-up resistors on its open-drain outputs?

Yes - the DS1314E's RST, BW, and CEO outputs are open-drain and must be pulled up externally to function correctly. The datasheet specifies that both RST and BW can sink 4 mA, and recommends external pull-up resistors for proper logic-level translation and noise immunity - a requirement stated in Note 11 of the DC Electrical Characteristics table and reinforced in the Timing Diagrams section.