onsemi MAX708RESA-TG

Overview

MAX708RESA-TG from onsemi is a precision microprocessor supervisory circuit that monitors power supply voltage, provides reset assertion during power-up/down and brownout conditions, and includes manual reset input and watchdog timer functionality. It operates over 4.75V to 5.5V supply range, delivers 200ms reset timeout, supports 1.6V threshold detection, and is used in embedded control systems requiring reliable power-on initialization and fault recovery.

For engineers reviewing the MAX708RESA-TG datasheet, pinout, applications, or equivalent options, key selection considerations include reset threshold accuracy (±1.5%), watchdog timeout stability (±10%), manual reset debounce behavior, and compatibility with 5V TTL/CMOS logic interfaces in industrial and telecom equipment.

Technical Context

The MAX708RESA-TG integrates a precision voltage reference, comparator-based reset generator, push-pull reset output, open-drain watchdog output (WDO), and manual reset input (MR). Its internal watchdog timer requires periodic strobing within 1.6 seconds to prevent WDO assertion.

Reset is asserted when V_CC drops below 4.63V (typical) and remains active for ≥200ms after V_CC rises above threshold. The device uses a bandgap reference and trimmed comparator to achieve ±1.5% threshold tolerance over temperature and supply variation.

Key Specifications

Pinout & Package

MAX708RESA-TG is housed in an 8-pin SOIC package (SO-8, 150 mil width) with standard JEDEC MS-012AC footprint and 1.27mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX708RESA-TG, MAX706TESA+ removes manual reset capability while retaining identical supervision timing, whereas TPS3808G18DBVR trades integrated watchdog functionality for threshold flexibility-making MAX708RESA-TG optimal for designs needing both MR and WDT in one 8-pin SOIC package.

Availability

MAX708RESA-TG is available at Aetrix Electronics and suitable for industrial control, telecom infrastructure, medical diagnostics, and point-of-sale terminal applications requiring stable component supply and long-term lifecycle assurance.

Supply support for MAX708RESA-TG 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

onsemi is a global semiconductor leader delivering energy-efficient silicon solutions for automotive, industrial, cloud, medical, and IoT applications.

The MAX708 family belongs to onsemi's precision voltage monitoring and reset IC product line, designed specifically for robust power-supply supervision in mission-critical embedded systems where deterministic reset behavior and watchdog reliability are mandatory.

FAQ

What is the reset timeout duration for MAX708RESA-TG?

The MAX708RESA-TG provides a guaranteed minimum reset pulse width of 200ms after V_CC rises above the reset threshold. This duration ensures sufficient time for power rail stabilization and microcontroller oscillator startup before releasing the processor from reset. The actual timeout is internally generated and does not require external components. MAX708RESA-TG maintains this specification across its full operating temperature range.

Does MAX708RESA-TG support manual reset functionality?

Yes, MAX708RESA-TG includes an active-low manual reset input (MR) pin that accepts pulses as short as 100ns to assert the RESET output. This allows hardware-initiated system resets independent of supply voltage conditions-for example, via front-panel buttons or remote control signals. The MR function is fully integrated and requires no external debounce circuitry beyond standard PCB layout practices. MAX708RESA-TG guarantees MR responsiveness across its entire −40°C to +85°C temperature range.

How does the watchdog timer in MAX708RESA-TG operate?

The MAX708RESA-TG watchdog timer requires a rising edge on the WDI pin at least once every 1.6 seconds (typical) to prevent assertion of the WDO output. If WDI is not strobed within this window, WDO goes low (open-drain) to signal a firmware hang. WDI is edge-sensitive and immune to noise-induced false triggers. MAX708RESA-TG implements this function entirely on-die with no external timing elements needed.

Can MAX708RESA-TG monitor a secondary voltage rail?

Yes, MAX708RESA-TG features dedicated PFI (Power-Fail Input) and PFO (Power-Fail Output) pins to monitor an auxiliary voltage rail. When PFI drops below 1.25V, PFO is pulled low to indicate undervoltage on that rail. This function operates independently of the main V_CC reset path, enabling dual-rail supervision-such as tracking a backup battery or isolated I/O supply-without interfering with primary system reset timing. MAX708RESA-TG maintains separate accuracy specs for both paths.

What package type is used for MAX708RESA-TG?

MAX708RESA-TG is packaged in an 8-pin SOIC (Small Outline Integrated Circuit) with 150-mil body width and 1.27mm lead pitch, compliant with JEDEC MS-012AC. This surface-mount package supports automated assembly and provides thermal and mechanical reliability for industrial applications. The "-TG" suffix denotes tape-and-reel packaging for high-volume production use. MAX708RESA-TG's pinout matches industry-standard supervisory IC footprints, simplifying layout reuse.