Analog Devices Inc./Maxim Integrated MAX793TESE+T

Overview

MAX793TESE+T from Maxim Integrated is a 3.0V/3.3V microprocessor supervisory circuit with fixed reset threshold (3.00V–3.15V), backup-battery switchover, active-low open-drain RESET output, and integrated watchdog timer (1.6s timeout). It monitors VCC supply integrity, asserts reset below threshold, gates CE signals with ≤7ns propagation delay, and supports battery-freshness seal for lithium backup. Used in embedded controllers requiring reliable power-up/down sequencing and brownout protection.

For engineers reviewing the MAX793TESE+T datasheet, MAX793TESE+T pinout, MAX793TESE+T application, or MAX793TESE+T equivalent, key selection criteria include guaranteed reset assertion down to VCC = 1V, battery voltage exceeding VCC (up to 3.6V), low-line early-warning output (LOWLINE), on-board CE gating, and BATT OK status monitoring - all in a 16-pin narrow SO package.

Technical Context

The MAX793TESE+T implements a precision voltage comparator with 10mV typical hysteresis for stable reset assertion/deassertion, coupled with a dedicated VCC-to-VBATT switchover circuit that activates when VCC falls below VSW (2.55V–2.68V, depending on variant). Its watchdog timer continuously monitors WDI transitions and forces WDO low after 1.6s of inactivity.

It integrates a manual reset input (MR) with internal 70µA pullup and 200ms timeout, an uncommitted power-fail comparator (PFI/PFO), and chip-enable gating logic that disables CE IN during reset while preserving write-cycle completion via 10µs hold time on CE OUT.

Key Specifications

Pinout & Package

MAX793TESE+T is housed in a 16-pin narrow SO (SOIC-16) package with 1.27mm pitch, JEDEC MS-012AC compliant, RoHS-compliant and lead-free (+T suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX793TESA+, MAX793TESE+ offers RoHS compliance and surface-mount compatibility; compared with MAX795TESE+, it adds watchdog, early-warning, and memory protection features essential for robust embedded control.

Availability

MAX793TESE+T is available at Aetrix Electronics and suitable for battery-powered embedded controllers, intelligent industrial controllers, critical µP power monitoring systems, and portable instrumentation requiring stable component supply and long-term lifecycle support.

Supply support for MAX793TESE+T 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 MAX793 series belongs to Maxim's microprocessor supervisory product line, engineered specifically for reliable power monitoring and system-level fault recovery in 3.0V/3.3V embedded systems.

FAQ

What is the exact reset threshold voltage range for MAX793TESE+T?

The MAX793TESE+T has a fixed reset threshold of 3.00V to 3.15V (VCC falling), optimized for 3.3V ±5% supplies. This ensures reset is asserted before the supply drops below 3.0V - the minimum required for stable µP operation. The threshold is factory-trimmed and includes 10mV hysteresis to prevent oscillation during slow supply ramps. MAX793TESE+T does not support adjustable reset thresholds like the MAX794.

Does MAX793TESE+T support backup battery voltages higher than VCC?

Yes, MAX793TESE+T supports VBATT up to 3.6V - exceeding its nominal 3.0V/3.3V VCC range. Its internal p-channel MOSFET switch automatically connects OUT to BATT when VCC falls below the battery switch threshold (VSW ≈ 2.55V–2.68V), enabling seamless switchover without external components. This design allows use of standard 3.6V lithium batteries in 3.3V systems, a key feature confirmed in the MAX793TESE+T datasheet absolute maximum ratings and electrical characteristics tables.

How does the battery freshness seal function in MAX793TESE+T?

The battery freshness seal in MAX793TESE+T isolates the BATT pin from internal circuitry until first power-up, preventing battery drain during storage. To enable it: apply VBATT, ground PFO, bring VCC above VRST, wait for reset timeout (200ms), then cycle VCC. Once enabled, the seal remains active until VCC rises above VRST again. Leakage is <1nA at +25°C - verified in MAX793TESE+T typical operating characteristics (TOC14). This feature is exclusive to MAX793/MAX794, not present in MAX795.

Can MAX793TESE+T drive CMOS RAM directly, and what is its output current capability?

Yes, MAX793TESE+T drives CMOS RAM directly via the OUT pin, which sources up to 75mA in normal mode (VCC > VSW) and 250µA in battery-backup mode (VCC = 0V). Output voltage is VCC − 0.12V (min) in normal mode and VBATT − 0.1V (min) in backup mode. The internal p-channel switch exhibits <160Ω on-resistance at +25°C (TOC1), ensuring stable RAM VDD under load. For >75mA, use BATT ON to drive an external PMOS transistor.

What is the purpose and behavior of the LOWLINE output on MAX793TESE+T?

The LOWLINE output on MAX793TESE+T provides early power-fail warning by asserting low when VCC falls to VLR = VRST − 30mV (≈2.97V for T-grade), giving the µP ~30mV margin before reset. It is an open-drain output intended for NMI interrupt generation. LOWLINE remains low until VCC rises above VRST + 15mV hysteresis. Unlike RESET, it does not time out - it stays active as long as VCC is below the warning threshold. This enables firmware-controlled data save operations prior to full reset.