Analog Devices Inc./Maxim Integrated MAX709SCPA

Overview

MAX709SCPA from Maxim Integrated is a precision power-supply monitor IC with active-low reset output, designed for +3V systems (2.93V nominal reset threshold), operating from 1.0V to 5.5V supply, delivering 140ms minimum power-on reset delay and guaranteed RESET state down to VCC = 1V. It eliminates external components in microprocessor supervisory circuits for embedded controllers and industrial logic systems.

For engineers reviewing the MAX709SCPA datasheet, MAX709SCPA pinout, MAX709SCPA application, or MAX709SCPA equivalent, this device serves as a low-cost, no-adjustment reset supervisor for 3V/3.3V microcontroller power rails where brownout immunity, transient rejection, and temperature-stable threshold are critical selection criteria.

Technical Context

The MAX709SCPA integrates a precision voltage comparator with hysteresis, internal timing capacitor, and open-drain RESET driver - all in an 8-pin µMAX package. Its reset threshold is factory-trimmed to 2.93V ±1.5%, with <±0.002%/°C normalized drift over –40°C to +85°C.

It operates across full VCC range (1.0V–5.5V) while maintaining valid RESET assertion during power-down transients as short as 4µs (for 100mV overdrive), and provides 35µA typical supply current at 3.6V - independent of RESET output state.

Key Specifications

Pinout & Package

MAX709SCPA is housed in an 8-pin µMAX package (3mm × 3mm, 0.5mm pitch), thermally enhanced with exposed paddle tied to GND. Pin 1 is top-left corner (dot-marked), pin numbering counterclockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX706RCPA and MAX809STR, the MAX709SCPA uniquely combines 2.93V precision threshold, 1.2mA RESET sink capability, robust transient immunity, and thermally optimized µMAX packaging - making it optimal for industrial 3V systems demanding reliability over minimal current draw.

Availability

MAX709SCPA is available at Aetrix Electronics and suitable for industrial automation, medical sensor nodes, and smart energy metering applications requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for MAX709SCPA 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 semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, automotive, and communications markets.

The MAX709SCPA belongs to Maxim's µP supervisory circuit family, engineered specifically for deterministic power-on/power-down reset generation in resource-constrained embedded systems with strict voltage-margin requirements.

FAQ

What is the exact reset threshold voltage of the MAX709SCPA?

The MAX709SCPA has a factory-trimmed nominal reset threshold of 2.93V, with a guaranteed tolerance of ±1.5% (2.85V to 3.00V) over the full –40°C to +85°C operating temperature range. This value is confirmed in the Electrical Characteristics table of the official MAX709 datasheet and applies specifically to the 'S' suffix variant. The MAX709SCPA maintains this threshold stability without external calibration.

Does the MAX709SCPA require external components to function?

No, the MAX709SCPA operates autonomously with no external resistors, capacitors, or trimming components required. Its internal precision voltage reference, comparator, and timing circuitry eliminate the need for external R/C networks. A 0.1µF ceramic bypass capacitor on VCC (pin 2) is recommended for noise immunity but is not strictly required for basic functionality - the MAX709SCPA will assert RESET correctly without it under clean supply conditions.

Can the MAX709SCPA drive a microcontroller reset pin directly?

Yes, the MAX709SCPA can drive most microcontroller reset pins directly via its open-drain RESET output (pin 7), provided an external pull-up resistor (typically 10kΩ to VCC) is used. It sinks up to 1.2mA at VCC ≥ reset threshold, which exceeds the input leakage and capacitance requirements of standard CMOS/TTL reset inputs. For bidirectional µP reset pins (e.g., Motorola 68HC11), a 4.7kΩ series resistor is recommended to prevent contention - as documented in the MAX709SCPA Applications Information section.

What is the minimum supply voltage at which MAX709SCPA guarantees correct RESET behavior?

The MAX709SCPA guarantees correct RESET output state down to VCC = 1.0V. Below this voltage, the RESET output becomes high-impedance (open-circuit) and no longer actively sinks current. This behavior is explicitly specified in the General Description and Absolute Maximum Ratings sections of the MAX709 datasheet and ensures predictable µP hold condition during deep brownout recovery - a key differentiator versus competitors that lose output validity below 1.5V.

Is the MAX709SCPA pin-compatible with other MAX709 variants like MAX709LCPA or MAX709MCPA?

No, the MAX709SCPA is not pin-compatible with MAX709LCPA or MAX709MCPA in terms of electrical function - though all share identical 8-pin µMAX physical packaging and pinout. The 'S', 'L', and 'M' suffixes denote different factory-set reset thresholds (2.93V, 4.65V, and 4.40V respectively), and substituting one for another will cause incorrect reset timing relative to the target supply rail. Mechanical pin alignment is identical, but functional compatibility requires matching the threshold to the system voltage.