Analog Devices Inc./Maxim Integrated MAX8514EEI

Overview

MAX8514EEI from Maxim Integrated is a wide-input (4.5V–28V), triple-output power-supply controller integrating a voltage-mode PWM step-down DC-DC controller (VOUT1: 1.25V–5.5V), a positive LDO controller (VOUT2: 0.8V–5.5V), and a negative LDO controller (VOUT3N: –1V to –18V), all with integrated power-on reset (140ms delay), input power-fail monitoring, and output sequencing-designed for xDSL modems and set-top boxes.

For engineers reviewing the MAX8514EEI datasheet, MAX8514EEI pinout, MAX8514EEI application, or MAX8514EEI equivalent, this device supports high-frequency operation (up to 1.4MHz), external clock synchronization, lossless foldback current limiting, adjustable soft-start, and negative-output LDO control using an external NPN transistor-critical for compact, noise-sensitive broadband power systems.

Technical Context

The MAX8514EEI implements a voltage-mode PWM architecture with a 25MHz error amplifier bandwidth and internal 1.25V reference, enabling precise regulation of its primary buck output. Its dual LDO controllers operate independently: OUT2 uses an NMOS/NPN driver (DRV2) referenced to 0.8V FB2, while OUT3N employs an NPN-based negative regulator driven by DRV3N and controlled via FB3N (0V-referenced, ±10mV regulation threshold).

Sequencing is managed via the SEQ pin (GND = staggered, VL = tracking), and fault protection includes programmable current limit (via ILIM/CSP/CSN), thermal shutdown (+170°C), and input undervoltage lockout (VL UVLO at 3.6V–4.2V). The FREQ pin sets switching frequency from 300kHz to 1.4MHz using a single resistor, with SYNC/EN supporting external clock synchronization within ±30% tolerance.

Key Specifications

Pinout & Package

MAX8514EEI is housed in a 28-pin QSOP package (5.3mm × 10.2mm, 0.65mm pitch) with exposed pad for thermal enhancement. Pin functions are electrically validated per Maxim's MAX8514 functional diagram and pin description table (Rev 1, April 2014).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar triple-output power controller applications.

Compared with MAX8513EEI and TPS54620RGYT, MAX8514EEI uniquely delivers integrated negative LDO control, power-fail signaling, and POR in one 28-pin QSOP-reducing total solution size by >40% and eliminating six external components versus discrete alternatives.

Availability

MAX8514EEI is available at Aetrix Electronics and suitable for xDSL modems, set-top boxes, and VoIP gateways requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature operation (–40°C to +85°C).

Supply support for MAX8514EEI 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 communications, computing, and industrial applications.

The MAX8513/MAX8514 product line was designed specifically for cost-sensitive, space-constrained broadband access equipment-integrating buck, dual-LDO, monitoring, and sequencing functions into a single IC to replace 5–7 discrete power components.

FAQ

What is the key functional difference between MAX8514EEI and MAX8513EEI?

The MAX8514EEI integrates a negative-output LDO controller (OUT3N) using DRV3N and FB3N to generate –1V to –18V rails with NPN pass transistors, whereas the MAX8513EEI provides a positive-output LDO controller (OUT3P) using DRV3P and FB3P for 0.8V–27V rails with PNP transistors. This makes MAX8514EEI the only choice for applications requiring a regulated negative supply without external charge pumps or inverters.

How does the MAX8514EEI achieve negative voltage regulation?

The MAX8514EEI achieves negative voltage regulation through its dedicated OUT3N channel: SUP3N supplies bias to DRV3N, which sources current into the base of an external NPN transistor configured as an emitter-follower; FB3N senses the emitter voltage and regulates it to 0V ±10mV, resulting in a stable negative output referenced to system ground. This topology avoids inductor-based inversion and supports fast transient response.

Can the MAX8514EEI be synchronized to an external clock, and what are the constraints?

Yes, the MAX8514EEI can be synchronized to an external clock applied to the SYNC/EN pin. The external frequency must fall within ±30% of the nominal switching frequency set by the FREQ resistor (e.g., if RFREQ sets 1.0MHz, sync range is 700kHz–1.3MHz). SYNC/EN must meet VIH ≥2.4V and VIL ≤0.8V, with pulse width ≥200ns, and operates only in enabled mode-not during shutdown.

What is the purpose of the SEQ pin on the MAX8514EEI, and how does it affect startup behavior?

The SEQ pin on the MAX8514EEI controls output voltage sequencing: tying SEQ to GND enables staggered startup (VOUT1 powers first, then VOUT2 and VOUT3N ramp sequentially to avoid output-capacitor charging glitches), while connecting SEQ to VL enables tracking mode (all outputs ramp proportionally together). This ensures reliable power-up of mixed-voltage ASICs and FPGAs without external sequencing ICs.

Does the MAX8514EEI include built-in protection features, and which ones are implemented?

Yes, the MAX8514EEI includes overcurrent protection (programmable foldback via ILIM/CSP/CSN), thermal shutdown (+170°C with 25°C hysteresis), input undervoltage lockout (VL UVLO at 3.6V–4.2V), and power-fail detection (PFI/PFO). It also features soft-start, current-limit blanking, and driver dead-time control (50ns) to prevent shoot-through-providing comprehensive fault coverage for unattended broadband equipment.