Analog Devices Inc./Maxim Integrated MAX709TCSA+

Overview

MAX709TCSA+ from Maxim Integrated is a precision power-supply monitor IC with active-low reset output, designed for +3V systems. It asserts RESET when VCC falls below 3.08V (±2% tolerance), holds reset for ≥140ms after VCC recovers, and operates down to 1V supply. Used in microprocessor-based embedded systems requiring reliable brownout detection and power-on reset timing.

For engineers reviewing the MAX709TCSA+ datasheet, MAX709TCSA+ pinout, MAX709TCSA+ application, or MAX709TCSA+ equivalent, key selection criteria include reset threshold accuracy (3.08V), guaranteed minimum 140ms reset timeout, immunity to short VCC transients (<40µs at 100mV overdrive), low quiescent current (35µA), and compatibility with 8-pin SO package layouts.

Technical Context

The MAX709TCSA+ integrates a precision voltage comparator, internal timing capacitor, and open-drain RESET driver - eliminating external components. Its reset threshold is laser-trimmed for ±2% accuracy across temperature, and the 140ms minimum timeout is internally generated without external RC networks.

It features dual-voltage operation support: functional down to VCC = 1.0V (RESET remains valid), and absolute maximum VCC = 6.0V. The device is immune to negative VCC transients ≤40µs when overdriven by 100mV below threshold, per characterization data at +25°C.

Key Specifications

Pinout & Package

MAX709TCSA+ is housed in an 8-pin SO (Small Outline) package, 3.9mm × 4.9mm body, 1.27mm pitch, lead-free compliant (indicated by '+' suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power-supply monitor applications.

Compared with MAX709TCSA+, MAX706TCSA+ adds supervisory features at the cost of increased complexity and price, while TPS3808G30DBVR trades package size and ultra-low IQ for reduced integration and absence of N.C. pins - making MAX709TCSA+ optimal for cost-sensitive, SO-based +3V reset-only applications.

Availability

MAX709TCSA+ is available at Aetrix Electronics and suitable for industrial control systems, medical sensor nodes, automotive body electronics, and point-of-sale terminals requiring stable component supply and long-term manufacturability.

Supply support for MAX709TCSA+ 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) is a U.S.-based semiconductor company specializing in analog, mixed-signal, and power-management ICs for industrial, communications, and computing markets.

The MAX709 belongs to Maxim's µP supervisory circuit product line, engineered specifically to replace discrete reset solutions in microprocessor-based systems with precise, low-cost, single-chip power monitoring.

FAQ

What is the exact reset threshold voltage for MAX709TCSA+?

The MAX709TCSA+ has a nominal reset threshold voltage of 3.08V, with a guaranteed tolerance of ±2% over the full operating temperature range (-40°C to +85°C). This value is laser-trimmed at wafer test and confirmed in the Electrical Characteristics table under "RESET Threshold, VTH" for suffix 'T'. The threshold remains stable across VCC variations and temperature drift, enabling robust brownout detection in +3V systems.

Does MAX709TCSA+ require external components to function?

No, the MAX709TCSA+ requires no external components to perform basic power-supply monitoring and reset generation. Its internal precision comparator, trimmed voltage reference, and timing circuit eliminate the need for external resistors, capacitors, or diodes. A pull-up resistor on the RESET pin is recommended but not strictly required for open-drain operation - this is a system-level interface choice, not a device dependency.

What is the minimum VCC voltage at which MAX709TCSA+ guarantees correct RESET output state?

The MAX709TCSA+ guarantees correct RESET output state down to VCC = 1.0V. Below this voltage, the RESET output transitions to a high-impedance (open-circuit) state rather than an undefined or floating condition. This behavior is explicitly specified in the General Description and Absolute Maximum Ratings sections, ensuring predictable µP reset behavior during deep brownout or controlled power-down sequences.

Is MAX709TCSA+ pin-compatible with other MAX709 variants like MAX709SCSA+?

Yes, all MAX709 variants - including MAX709TCSA+, MAX709SCSA+, and MAX709RCSA+ - share identical 8-pin SO package footprints and pinouts. The only differences are reset threshold voltage (determined by suffix 'T', 'S', or 'R') and temperature grade ('C' = 0°C to +70°C, 'E' = -40°C to +85°C). Since MAX709TCSA+ uses the 'C' grade and SO package, it is mechanically and electrically interchangeable with other 'C'-grade SO variants in the same family.

What is the maximum transient duration the MAX709TCSA+ can ignore without asserting RESET?

At +25°C, the MAX709TCSA+ ignores negative-going VCC transients up to 40µs in duration when the transient magnitude is 100mV below its 3.08V reset threshold - per Figure 1 in the Typical Operating Characteristics section. This immunity is process- and design-specific to the MAX709 family and applies equally to all suffixes, including 'T'. Transient rejection degrades slightly at temperature extremes but remains effective within datasheet-specified operating ranges.