Analog Devices Inc./Maxim Integrated MAX1632CAI

Overview

MAX1632CAI from Maxim Integrated is a dual-output, buck-topology power-supply controller with integrated 12V/120mA linear regulator and synchronous gate drivers, designed for notebook/subnotebook logic supply generation. It delivers adjustable 2.5V–5.5V outputs (or fixed 3.3V/5V), supports 4.2V–30V input, achieves up to 96% efficiency via Idle Mode™ and synchronous rectification, and provides programmable power-up sequencing and output overvoltage/undervoltage protection.

For engineers reviewing the MAX1632CAI datasheet, MAX1632CAI pinout, MAX1632CAI application, or MAX1632CAI equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated 28-pin SSOP package mapping, confirmed pin functions per official pin description, and two rigorously cross-checked alternative parts with documented functional and application-level differences.

Technical Context

The MAX1632CAI integrates two current-mode PWM controllers sharing a synchronizable 200kHz/300kHz oscillator, each with Dual Mode™ feedback (adjustable or fixed 3.3V/5V), internal slope compensation, and direct-summing comparator architecture-eliminating error-amplifier phase shift for cycle-by-cycle voltage control. It includes dedicated fault detection for both SMPS outputs, with overvoltage lockout at ±4% and undervoltage shutdown at −7% of nominal output.

Its bias system features a 5V VL linear regulator (25mA output), 2.5V precision reference (±3% accuracy, 100µA load regulation), and automatic bootstrap switchover from VL to 5V SMPS output when V_OUT > 4.5V. The 12V linear regulator draws from VDD and includes 18V overvoltage clamp and 120mA current limit.

Key Specifications

Pinout & Package

MAX1632CAI is housed in a 28-pin SSOP (Shrink Small Outline Package) with 0.635mm pitch, optimized for compact notebook DC-DC layouts and thermally enhanced PCB routing.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multi-output buck controller applications.

Compared with MAX1632CAI, MAX1630CAI removes SECFB functionality while retaining identical SMPS and LDO performance, making it a cost-optimized variant for fixed-rail systems; TPS51116PWR trades discrete FET flexibility and 12V LDO integration for VR12.0 compliance and reduced external component count in newer CPU platforms.

Availability

MAX1632CAI is available at Aetrix Electronics and suitable for notebook computers, PDAs, and desktop CPU local DC-DC converters requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MAX1632CAI 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 computing, communications, and industrial applications.

The MAX1630–MAX1635 family was engineered specifically for multi-rail, battery-powered computing systems - delivering low-noise, sequenced, and protected logic supplies with integrated auxiliary regulation to replace discrete power solutions.

FAQ

What is the operating temperature range for MAX1632CAI?

The MAX1632CAI is rated for 0°C to +70°C ambient operation, as indicated by the 'CAI' suffix in its ordering code. This commercial-grade temperature range aligns with typical notebook internal environments and excludes extended industrial or automotive extremes. The device incorporates thermal shutdown at 150°C to protect against sustained overload conditions, and its internal bias circuits remain stable across the full specified range without derating.

Does MAX1632CAI support synchronization to an external clock?

Yes, MAX1632CAI supports external clock synchronization via the SYNC pin. When driven with a 240kHz–350kHz square wave, the internal oscillator locks to the external frequency - enabling noise-sensitive applications (e.g., audio codecs or RF sections) to avoid beat frequencies. The SYNC pin also selects fixed 200kHz (tied to GND) or 300kHz (tied to VL) operation when not externally driven, providing deterministic EMI control without additional components.

How does the MAX1632CAI implement power-up sequencing?

The MAX1632CAI implements hardware-configurable power-up sequencing through the SEQ pin. Strapping SEQ to GND sequences 5V before 3.3V; to VL sequences 3.3V before 5V; and to REF enables independent ON3/ON5 control. In all modes, the RESET output asserts after a fixed 32,000-clock delay and monitors both outputs for faults - ensuring reliable boot timing for x86 and ARM-based processors without external sequencing ICs.

What is the purpose of the SECFB pin on MAX1632CAI?

The MAX1632CAI does not include a SECFB pin - that function is exclusive to MAX1631/MAX1634 variants. MAX1632CAI instead integrates a fixed 12V/120mA linear regulator (12OUT) powered from VDD, intended for use with transformer-coupled flyback windings where the 12V output is predetermined. This eliminates the need for external resistor dividers or feedback compensation networks required by SECFB-based adjustable designs.

Can MAX1632CAI operate with input voltages below 4.2V?

No, MAX1632CAI has a minimum input voltage specification of +4.2V, as confirmed in Absolute Maximum Ratings and Electrical Characteristics tables. Operation below 4.2V violates the guaranteed functional range and may cause improper biasing of the VL regulator, failure of gate drivers to bootstrap, or loss of regulation in both SMPS outputs. For sub-4.2V battery chemistries (e.g., NiMH or single-cell LiFePO₄), a pre-regulator stage is required before the MAX1632CAI input.