Analog Devices Inc./Maxim Integrated MAX756CPA

Overview

MAX756CPA from Maxim Integrated is an 8-pin plastic DIP packaged CMOS step-up DC-DC converter optimized for low-input-voltage battery-powered systems. It accepts input as low as 0.7V, delivers pin-selectable 3.3V or 5V output (300mA at 3.3V / 200mA at 5V), achieves >87% efficiency at full load, and features integrated low-battery detection (LBI/LBO) and 60µA quiescent current - used in glucose meters and palmtop computers.

For engineers reviewing the MAX756CPA datasheet, MAX756CPA pinout, MAX756CPA application, or MAX756CPA equivalent, this page provides verified technical context, real-world design meaning of specifications, validated pin functions, confirmed alternative parts with functional trade-offs, and supply-chain support details specific to the MAX756CPA variant.

Technical Context

The MAX756CPA implements a constant-off-time pulse-frequency modulation (PFM) control scheme with no external oscillator, enabling ultra-low quiescent current (60µA) while maintaining high efficiency (>87% at 200mA). Its internal 1A/0.5Ω N-channel MOSFET switch operates up to 500kHz and supports bootstrapped operation powered from the OUT pin.

It integrates a precision 1.25V reference (±1.5% over temperature), active low-battery comparator with 1.25V threshold and 25mV hysteresis, and logic-controlled output selection via the 3/5 pin - all functional in shutdown mode where only 20µA is drawn while reference and LBI detector remain live.

Key Specifications

Pinout & Package

MAX756CPA uses an 8-pin plastic DIP package (0.300" wide, JEDEC MS-001), with GND (pin 7) requiring direct soldering to ground plane for optimal thermal and noise performance.

Key Features

Applications

Availability

MAX756CPA is available at Aetrix Electronics and suitable for glucose meters, palmtop computers, and portable data-collection terminals requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for MAX756CPA 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 is a U.S.-based semiconductor company specializing in analog and mixed-signal ICs for power management, sensing, and communication applications.

The MAX756 product line was designed specifically for ultra-low-voltage battery-powered systems - targeting medical, portable computing, and instrumentation markets where start-up voltage, quiescent current, and integration are critical.

FAQ

What is the minimum input voltage required for MAX756CPA to start up?

The MAX756CPA starts up from as low as 0.7V input voltage under light load conditions, enabling operation with nearly depleted single-cell alkaline or NiMH batteries. This value is confirmed in the Absolute Maximum Ratings and Typical Operating Characteristics plots, where startup voltage remains below 0.8V at 10mA load. The MAX756CPA maintains regulation down to 1.1V minimum operating voltage once started, making it ideal for energy-constrained portable medical devices.

How does the 3/5 pin select output voltage on MAX756CPA?

The 3/5 pin on MAX756CPA is a logic input that selects between two fixed output voltages: pulling it low (≤0.4V) configures the device for 5V output, while pulling it high (≥1.6V) selects 3.3V output. This selection is implemented internally via resistor networks - no external feedback components are required. The pin is CMOS-compatible, high-impedance, and must not be left floating; tie to GND or OUT for permanent configuration in production designs using MAX756CPA.

Does MAX756CPA include a built-in low-battery detection function?

Yes, MAX756CPA integrates a dedicated low-battery detection circuit with LBI (input) and LBO (open-drain output) pins. The internal comparator triggers when LBI falls below 1.25V ±25mV hysteresis, causing LBO to sink current. This function remains active even in shutdown mode (20µA), allowing continuous battery monitoring without waking the system. External resistor dividers set the detection threshold - for example, a 1MΩ/1MΩ divider on a 3V battery yields ~1.5V trip point, compatible with MAX756CPA's 1.25V reference.

What package type is used for MAX756CPA and what are its thermal limitations?

MAX756CPA uses an 8-pin plastic DIP package (JEDEC MS-001, 0.300" wide) rated for 0°C to +70°C operation. Its maximum continuous power dissipation at TA = +70°C is 727mW, derating linearly at 9.09mW/°C above that temperature. To achieve this rating, pin 7 (GND) must be soldered directly to a large copper ground plane - the datasheet explicitly requires low-impedance grounding to manage thermal resistance and prevent junction temperature exceedance beyond the 150°C limit.

Can MAX756CPA be used in place of MAX756CSA in a design?

MAX756CPA and MAX756CSA share identical electrical specifications and pinout but differ only in package: DIP vs. SO. They are functionally interchangeable if board layout accommodates the mechanical change - MAX756CPA's through-hole DIP requires different footprint and reflow profile than the surface-mount SO version. No circuit modification is needed, but thermal performance differs due to package thermal resistance (DIP = 138°C/W, SO = 213°C/W), so power handling must be re-evaluated for the target ambient and airflow conditions in the final MAX756CPA implementation.