Analog Devices Inc./Maxim Integrated DS1236S-10

Overview

DS1236S-10 from Maxim Integrated is a microprocessor supervisory IC providing power-fail detection, reset control, watchdog timing, nonvolatile SRAM backup, and early-warning NMI generation. It features 10% VCC trip point (4.25–4.50 V), <100 nA battery current at 25°C, 25 ms minimum reset pulse width, and dual active-high/active-low RST outputs. Used in battery-backed embedded systems requiring orderly shutdown and data retention.

For engineers reviewing the DS1236S-10 datasheet, DS1236S-10 pinout, DS1236S-10 application, or DS1236S-10 equivalent, key selection considerations include its dual-reset output polarity support, VBAT-backed VCCO switching, NMOS/CMOS mode selection via RC pin, and integrated 400 ms watchdog timer with ST input.

Technical Context

The DS1236S-10 integrates a bandgap voltage reference and precision comparator for 5 V supply monitoring with 10% tolerance (VCCTP = 4.25–4.50 V). Its dual RST outputs (active-high and active-low) are synchronized to power-fail events and support both NMOS (RC = GND) and CMOS (RC = VCCO) processor modes.

A 400 ms typical watchdog timer resets on ST strobe; timeout forces RST activation for ≥25 ms. The IN pin enables user-configurable early-warning threshold (VTP = 2.50–2.60 V) triggering a 200–500 μs NMI pulse, with built-in 3-cycle hysteresis to reject noise.

Key Specifications

Pinout & Package

DS1236S-10 is available in 16-pin SOIC (300-mil) package. Pin functions are validated per Maxim's official DS1236 datasheet Rev. 0, pages 2–3 and mechanical drawings section.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor supervisory applications.

Compared with MAX690TSA+ and DS1233M-10+, the DS1236S-10 uniquely integrates SRAM power switching, programmable early-warning NMI, and dual-mode reset control-enabling full nonvolatile system behavior without external logic or FETs.

Availability

DS1236S-10 is available at Aetrix Electronics and suitable for battery-backed data loggers, medical handhelds, industrial PLC modules, and point-of-sale terminals requiring stable component supply and long-term lifecycle support.

Supply support for DS1236S-10 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, automotive, and computing applications.

The DS1236S-10 belongs to Maxim's MicroManager family, engineered specifically for nonvolatile microprocessor system supervision-combining power monitoring, reset generation, memory backup, and intelligent shutdown in a single 16-pin IC.

FAQ

What is the VCC trip point tolerance for DS1236S-10?

The DS1236S-10 has a guaranteed 10% VCC trip point tolerance, meaning it asserts RST and PF when VCC falls below 4.25 V (min) and recovers above 4.50 V (max), with typical VCCTP at 4.37 V. This is distinct from the DS1236-5 variant, which uses a tighter 5% threshold centered at 4.62 V.

How does DS1236S-10 support nonvolatile SRAM operation?

The DS1236S-10 supports nonvolatile SRAM by providing VCCO-a switched output that automatically sources from VCC during normal operation or VBAT during power loss-and CEO, which is forced high during VCC failure to unconditionally write-protect SRAM. This eliminates external diodes, FETs, or glue logic required in discrete implementations.

Can DS1236S-10 generate an early-warning interrupt before power failure?

Yes, the DS1236S-10 generates a non-maskable interrupt (NMI) when the voltage at its IN pin falls below 2.50–2.60 V. Using an external resistor divider, designers can configure this to trigger at any user-defined threshold-e.g., 4.8 V on a 5 V rail-providing up to 200 μs of warning before RST activation at 4.25 V.

What is the function of the RC pin on DS1236S-10?

The RC pin on DS1236S-10 selects operating mode: tied to GND for NMOS systems (continuous RST during brownout), or to VCCO for CMOS systems (pulsed NMI followed by Stop-mode entry). It also determines NMI behavior, CEO timing, and RST polarity-making DS1236S-10 adaptable to both volatile and nonvolatile processor architectures.

Does DS1236S-10 include a watchdog timer, and how is it configured?

Yes, DS1236S-10 includes a watchdog timer with 100–600 ms timeout (typ. 400 ms), reset by high-to-low transitions on the ST pin. It is disabled by grounding IN in CMOS mode or leaving ST open. In NMOS mode, the watchdog remains active regardless of IN state and provides fail-safe recovery if firmware hangs.