Analog Devices Inc./Maxim Integrated DS1210N+

Overview

DS1210N+ from Maxim Integrated is a nonvolatile controller IC that converts standard CMOS RAM into battery-backed nonvolatile memory by monitoring VCCI, switching to dual-battery backup on power-fail, and unconditionally write-protecting RAM via CEO inhibition. Key specs: 4.5–4.74V VCC trip point (TOL=GND), <100nA battery current, -40°C to +85°C industrial temp range, 8-pin PDIP package.

For engineers reviewing the DS1210N+ datasheet, DS1210N+ pinout, DS1210N+ application, or DS1210N+ equivalent, this page delivers verified functional role, precise power-fail thresholds, battery redundancy behavior, CEO timing constraints, and industrial-grade thermal performance for SRAM backup system design.

Technical Context

The DS1210N+ implements five tightly integrated functions: (1) bidirectional VCCI/VBAT power switching with <0.3V forward drop; (2) precision comparator-based power-fail detection at two selectable thresholds (4.5–4.74V or 4.25–4.49V); (3) CE-to-CEO write-protection logic with 20ns max propagation delay and cycle-completion hold; (4) battery voltage self-test at power-up using 2.0V threshold; and (5) automatic redundant battery selection via internal isolation switch.

It operates exclusively in CMOS SRAM backup systems where data integrity during brownout or main power loss is critical. The device forces CEO low and VCCO to VOL in freshness seal mode until VCCI exceeds VCCTP and then falls below VBAT, ensuring batteries remain unengaged until first valid write.

Key Specifications

Pinout & Package

DS1210N+ is housed in an 8-pin plastic dual in-line package (PDIP) with 300-mil width, designed for through-hole PCB assembly and thermal dissipation up to 110°C/W (θJA).

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS1210N+, DS1216H+ offers plug-and-play NV SRAM but forfeits configurable trip points and battery redundancy, while MAX6900 adds RTC capability at the cost of losing direct hardware-level write protection and CEO timing control.

Availability

DS1210N+ is available at Aetrix Electronics and suitable for industrial data loggers, medical device memory backup, telecom base station clock memory, and energy meter real-time clock storage requiring stable component supply and long-term lifecycle assurance.

Supply support for DS1210N+ 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 DS1210N+ belongs to Maxim's nonvolatile memory controller product line, engineered specifically to provide hardware-enforced, low-leakage battery backup for CMOS SRAM in mission-critical systems.

FAQ

What is the primary function of the DS1210N+ in a memory system?

The DS1210N+ serves as a hardware-based nonvolatile controller that converts standard CMOS RAM into battery-backed memory. It monitors VCCI for out-of-tolerance conditions, switches power to VBAT1 or VBAT2 upon power-fail, and asserts CEO to inhibit writes-ensuring data integrity without software intervention. Its core value lies in deterministic, sub-20ns write-protection timing and <100nA battery drain, making DS1210N+ ideal for long-life industrial SRAM backup.

How does the TOL pin affect the DS1210N+ power-fail detection threshold?

The TOL pin configures the DS1210N+ VCC trip point: grounding TOL sets detection between 4.50V and 4.74V; connecting TOL to VCCO shifts it to 4.25V–4.49V. This dual-threshold capability allows system designers to align DS1210N+ response with specific power supply tolerances-critical for avoiding false triggers in noisy industrial rails or accommodating tighter brownout margins in telecom gear.

Can the DS1210N+ operate with only one battery, and how should VBAT2 be handled?

Yes, DS1210N+ fully supports single-battery operation. When only VBAT1 is used, VBAT2 must be grounded per datasheet Note 3. Leaving VBAT2 floating risks undefined behavior, while grounding it disables redundancy but preserves full DS1210N+ functionality-including battery self-test, CEO write protection, and freshness seal mode. This configuration maintains DS1210N+'s <100nA IBAT and industrial temperature rating.

What happens during DS1210N+ power-up if battery voltage is below 2.0V?

If either VBAT1 or VBAT2 measures <2.0V at DS1210N+ power-up, the device inhibits the second memory cycle to flag low battery condition. System firmware can detect this by performing a read-verify-write-read sequence on any SRAM location: failure to retain written data confirms battery depletion. This built-in test eliminates need for external voltage monitors and ensures DS1210N+ proactively prevents data corruption before backup activation.

Does the DS1210N+ require external components to function as a complete nonvolatile RAM solution?

Yes-DS1210N+ is a controller, not a complete module. A functional nonvolatile RAM system requires DS1210N+ plus external CMOS SRAM, at least one battery (VBAT1), optional second battery (VBAT2), and decoupling capacitors on VCCI and VCCO. No external comparators, MOSFETs, or timing resistors are needed, as DS1210N+ integrates all power-switching, detection, and protection logic-making DS1210N+ a minimal-component, high-reliability solution.