MAX1631EAI+T - Dual Buck PWM Controller 28-SSOP | Maxim
N.º de pieza: MAX1631EAI+T ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $7.45 | $7,45 |
| 10 | $6.82 | $68,20 |
| 100 | $5.79 | $579,00 |
| 500 | $5.1 | $2.550,00 |
| 1.000 | $4.55 | $4.550,00 |
MAX1631EAI+T Descripción general
What is a step-down DC-DC controller? A step-down (buck) controller is a switch-mode power supply IC that regulates an output voltage lower than the input by rapidly switching an external power MOSFET and storing energy in an external inductor. The MAX1631 family belongs to the hierarchy of voltage regulator -> switching regulator -> step-down controller -> PWM current-mode controller -> power management IC, and is widely used where high efficiency at varying battery voltages is required.
Key features include on-board power-up sequencing, power-good signaling with programmable delay, digital soft-start to limit inrush current, secondary winding control for auxiliary outputs, low-dropout (LDO) circuitry, and internal frequency-compensation networks. The MAX1631EAI+T supports dual adjustable outputs that can be preset to 3.3V and 5V, making it well-suited for powering system logic, memory, and I/O rails from a single battery or adapter source.
The architecture combines current-mode PWM control with an adaptive idle mode that skips switching cycles at light loads, sustaining high efficiency across the entire load range. Internal drivers can directly drive external N-channel MOSFETs without external gate drivers, simplifying the BOM. Housed in a 28-SSOP package (5.30 mm body width, 0.65 mm pitch), the part dissipates moderate thermal load at typical notebook power levels.
Typical applications include notebook computer main supplies (CPU core + I/O), battery-powered portable instruments, point-of-load regulators downstream of an AC adapter, and embedded systems requiring 3.3V/5V dual rails from a single 12V or 19V bus. The on-board power-good and sequencing features target multi-rail architectures where CPU, chipset, and peripheral rails must come up in a defined order.
When designing with this device, careful inductor selection and output capacitor ESR are critical for stability. The 28-SSOP package has a higher thermal resistance than QFN equivalents, so copper area on the PCB beneath the exposed pad (or wide traces on the SSOP leads) is recommended for sustained full-load operation at high VIN. A well-designed snubber across the external switching MOSFET reduces ringing and EMI.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, giving engineers a single source for selecting, sourcing, and validating the MAX1631EAI+T in new and legacy designs.
Alternativas directas para MAX1631EAI+T — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
MAX1631EAI+
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MAX1631AEAI+T
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MAX1631CAI+
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MAX1632EAI+
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MAX1634EAI+
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MAX1631EAI+T Valores máximos y características eléctricas
| Topología | Buck (Step-Down) |
| Función | Dual-Output PWM Step-Down DC-DC Controller |
| PWM Type | Current Mode, Hybrid |
| Número de salidas | 2 |
| Input Voltage Range (V+) | 4.2 V to 30 V |
| Tensión de salida | Adjustable; Selectable 3.3 V / 5 V fixed presets |
| Frecuencia de conmutación | 200 kHz to 300 kHz |
| Maximum Duty Cycle | 99% |
| Eficiencia | Up to 96% |
| Tipo de salida | Transistor Driver |
| Rectificador síncrono | Yes (drives external low-side N-MOSFET) |
| Salida Power Good | Yes, with programmable delay |
| Arranque suave | Digital, integrated |
| Rango de temperatura de funcionamiento | -40 C to +85 C (E grade) |
| Encapsulado / Carcasa | 28-SSOP (0.209", 5.30 mm width) |
| Tipo de montaje | Surface Mount |
| Estado RoHS | Compliant |
| Lead-Free | Yes |
| Packaging | Tape & Reel (TR) |
Configuración de pines de MAX1631EAI+T
| Pin 1 | ON1 — Output 1 enable control input |
| Pin 2 | ON2 — Output 2 enable control input |
| Pin 3 | REF — Internal 2.5V reference bypass |
| Pin 4 | SEQ — Sequencing threshold / timing |
| Pin 5 | SHDN — Shutdown control input (active low) |
| Pin 6 | PGOOD — Power-good open-drain output |
| Pin 7 | DLY — Power-good delay capacitor |
| Pin 8 | GND — Analog ground |
| Pin 9 | VCC — Internal 5V regulator output |
| Pin 10 | IN — Main supply input (4.2V to 30V) |
| Pin 11 | CSH1 — Current-sense high, output 1 |
| Pin 12 | CSL1 — Current-sense low, output 1 |
| Pin 13 | DH1 — High-side gate drive, output 1 |
| Pin 14 | DL1 — Low-side gate drive, output 1 |
| Pin 15 | BST1 — Boost capacitor, output 1 |
| Pin 16 | LX1 — Inductor switch node, output 1 |
| Pin 17 | FB1 — Feedback input, output 1 |
| Pin 18 | FB2 — Feedback input, output 2 |
| Pin 19 | LX2 — Inductor switch node, output 2 |
| Pin 20 | BST2 — Boost capacitor, output 2 |
| Pin 21 | DL2 — Low-side gate drive, output 2 |
| Pin 22 | DH2 — High-side gate drive, output 2 |
| Pin 23 | CSL2 — Current-sense low, output 2 |
| Pin 24 | CSH2 — Current-sense high, output 2 |
| Pin 25 | RT — Timing resistor for oscillator |
| Pin 26 | SYNC — External clock synchronization input |
| Pin 27 | SS — Soft-start capacitor |
| Pin 28 | PGND — Power ground |
Aplicaciones típicas
MAX1631EAI+T es adecuado para 6 aplicacións: Notebook Computer Main Supplies, Battery-Powered Portable Instruments, Industrial 24V Bus Point-of-Load Regulation, Networking Equipment Auxiliary Rails, Embedded System Dual-Rail Power, Automotive Infotainment Auxiliary Supplies.
Notebook Computer Main Supplies
The MAX1631EAI+T is purpose-built for notebook main supplies, where it generates 3.3V and 5V rails from a 6-cell to 8-cell Li-ion battery pack or 19V adapter. Its 4.2V to 30V input range covers the full battery-to-adapter transition, and up to 96% efficiency preserves battery run-time. The on-chip power-good and sequencing signals let designers enforce proper CPU/chipset rail-up order in dual-rail architectures.
Recomendado
Battery-Powered Portable Instruments
Handheld test instruments and field-portable data loggers benefit from the MAX1631EAI+T's 4.2V to 30V input range, which accepts 1S Li-ion to 4S Li-ion packs directly. The 99% maximum duty cycle enables low-dropout operation as batteries discharge, sustaining 3.3V regulation to below 4V input. Digital soft-start prevents inrush on hot-plug battery insertion, and 96% efficiency extends operational time between charges.
Recomendado
Industrial 24V Bus Point-of-Load Regulation
In industrial 24V bus systems, the MAX1631EAI+T generates isolated 3.3V and 5V rails for downstream MCUs, sensors, and analog front-ends. Its 30V input rating tolerates typical 24V industrial transients, while programmable 200 kHz to 300 kHz switching lets designers avoid sensitive frequencies. The 28-SSOP package handles the moderate thermal load of 5V/3A combined output with adequate PCB copper.
Recomendado
Networking Equipment Auxiliary Rails
Switches, routers, and small-cell base stations use the MAX1631EAI+T to generate 3.3V and 5V auxiliary rails from a 12V or 24V intermediate bus. Its power-good signal feeds the system supervisor to ensure proper sequencing during hot-swap events. The internal MOSFET drivers and small 28-SSOP footprint keep the BOM count low in space-constrained Layer-2/3 hardware where efficiency above 90% matters for thermal budget.
Recomendado
Embedded System Dual-Rail Power
Single-board computers and industrial embedded controllers commonly need 3.3V (logic) and 5V (legacy peripherals) from a single 12V supply, exactly what the MAX1631EAI+T provides. With two adjustable outputs and preset 3.3V/5V select pins, it eliminates the need for two separate buck regulators. Its integrated power-good and digital soft-start simplify the system power-up state machine.
Recomendado
Automotive Infotainment Auxiliary Supplies
Although not AEC-Q100 qualified, the MAX1631EAI+T's -40 C to +85 C operating range and 30V input tolerance make it usable in non-safety automotive infotainment subsystems. It generates 3.3V/5V rails from the 12V battery for head-unit audio DSPs and display controllers. Load-dump protection must be added externally since the part's 30V rating sits below 40V automotive transients.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para MAX1631EAI+T — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | MAX1631EAI+ | MAX1631AEAI+T | MAX1631CAI+ | MAX1632EAI+ | MAX1634EAI+ |
|---|---|---|---|---|---|---|
| Package | 28-SSOP | 28-SSOP (same) | 28-SSOP (same) | 28-SSOP (same) | 28-SSOP (same) | 28-SSOP (same) |
| Brand | Analog Devices (Maxim Integrated) | Analog Devices (Maxim Integrated) | Analog Devices (Maxim Integrated) | Analog Devices (Maxim Integrated) | Analog Devices (Maxim Integrated) | Analog Devices (Maxim Integrated) |
| Number of Outputs | 2 | 2 | 2 | 2 | 2 | 3 (triple-output) |
| Input Voltage Range | 4.2 V to 30 V | 4.2 V to 30 V | 4.2 V to 30 V | 4.2 V to 30 V | 4.2 V to 30 V | 4.2 V to 30 V |
| Switching Frequency | 200 kHz to 300 kHz | 200 kHz to 300 kHz | 200 kHz to 300 kHz | 200 kHz to 300 kHz | 200 kHz to 300 kHz | 200 kHz to 300 kHz |
| Output Voltage Presets | 3.3 V / 5 V selectable | 3.3 V / 5 V selectable | 3.3 V / 5 V selectable | 3.3 V / 5 V selectable | Higher current variant | Triple adjustable |
| Max Duty Cycle | 99% | 99% | 99% | 99% | 99% | 99% |
| Packaging | Tape & Reel (TR) | Tube | Tape & Reel (TR) | Tube | Tube | Tube |
Diferenciadores clave
- Single-IC dual 3.3V/5V output with integrated power-good and sequencing (frente a MAX1632EAI+)
- Preset dual-rail output simplifies notebook 3.3V + 5V generation (frente a MAX1634EAI+)
- Wide 4.2V-30V input range with 99% duty cycle for LDO mode (frente a MAX1631AEAI+T)
Notas de diseño
Place the input bypass capacitor (typically 0.1 uF ceramic + 22 uF electrolytic) within 5 mm of the IN pin, with the ceramic closest to the IC. Keep the high-side MOSFET source, current-sense resistor, and low-side return path as tight as possible to minimize ringing on the LX node. The 28-SSOP thermal pad is not exposed; use copper pours on top and bottom layers stitched with thermal vias under the LX traces to dissipate heat.
Route the feedback traces (FB1, FB2) away from the LX switching nodes and gate-drive signals to avoid noise injection. Use a Kelvin-sense connection for current-sense resistors (CSH/CSL). Keep the loop area of the BST capacitor and the high-side MOSFET gate as small as possible to limit ringing; the datasheet typical application circuit shows the BST capacitor placed directly across BST and LX pins.
Do not operate the MAX1631EAI+T below the 4.2V minimum input or above 30V; both conditions can damage the internal MOSFET drivers. Use a timing resistor (RT) between 33 kohm and 200 kohm; values outside this range risk oscillator instability. Verify inductor saturation current at peak load (IL_PEAK = IOUT + (VOUT*(V_IN-VOUT))/(2*f_sw*L*V_IN)) plus 30% margin. According to the datasheet, output capacitor ESR below 50 mohm is required for stability with default compensation.
Información de cumplimiento
RoHS compliance confirmed per Maxim product page and lead-free tape-and-reel packaging. REACH, halogen-free, and conflict-mineral status not in the verified data - flagged as 'unknown' rather than assumed.
