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Analog Devices Inc./Maxim Integrated MAX8734AEEI+
- Part No.:
- MAX8734AEEI+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Power Supply Controllers, Monitors
- Package:
- 28-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
MAX8734AEEI+.pdf
- Description:
- IC PWR SUPPLY CONTROLLER 28QSOP
- Quantity:
- Payment:
- Shipping:
Inventory:216
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Product details
Overview
MAX8734AEEI+ from Maxim Integrated is a dual step-down switch-mode power-supply (SMPS) controller with integrated 5V/3.3V linear regulators, designed for notebook main power supplies. It delivers quad outputs (5V SMPS, 3.3V SMPS, 5V LDO, 3.3V LDO), supports pin-selectable 200/300kHz or 400/500kHz switching frequencies, features Quick-PWM™ control with 100ns load-step response, and operates from 4.5V to 24V input across –40°C to +85°C.
For engineers reviewing the MAX8734AEEI+ datasheet, MAX8734AEEI+ pinout, MAX8734AEEI+ application, or MAX8734AEEI+ equivalent, key selection considerations include its dual-mode feedback (fixed/adjustable), ultrasonic pulse-skipping mode (>25kHz), bootstrapped LDOs with 100mA output, PGOOD signal, and compatibility with 3–4-cell Li+ battery systems in space-constrained portable designs.
Technical Context
The MAX8734AEEI+ integrates two independent PWM controllers with Quick-PWM™ constant-on-time architecture-eliminating external current-sense resistors for the 3.3V/5V SMPS paths-and supports three operating modes: fixed-frequency PWM, ultrasonic pulse-skipping (>25kHz), and Idle-mode pulse-skipping. Its TON pin selects between two frequency sets (200/300kHz or 400/500kHz), while SKIP and PRO pins configure noise performance and fault protection behavior.
It embeds two 100mA linear regulators (LDO5/LDO3) with automatic bootstrapping from respective SMPS outputs, internal soft-start/soft-stop discharge, overvoltage/undervoltage fault detection with 10µs propagation delay, and PGOOD monitoring of both SMPS outputs with ±9.5% threshold hysteresis. The device uses DH/DL gate drivers capable of 2A sink/source (DH) and 1.7A source / 3.3A sink (DL).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.5V to 24V - supports wide-range battery inputs including 3- and 4-cell Li+ packs without external pre-regulation. |
| SMPS Output Voltages | Fixed 5V/3.3V or adjustable 2.0V–5.5V - Dual-Mode™ feedback enables flexible rail generation for core logic and I/O. |
| Switching Frequency | Pin-selectable: 200/300kHz or 400/500kHz - balances efficiency vs. size; ultrasonic mode avoids audible noise in audio-sensitive systems. |
| LDO Outputs | 5V @ 100mA and 3.3V @ 100mA - always-on, bootstrapped from SMPS outputs to maintain supply during light-load or standby. |
| Load Transient Response | 100ns - Quick-PWM™ enables rapid correction of voltage droop during CPU burst loads without external compensation. |
| Output Accuracy | ±1.5% - ensures stable core voltage under varying line/load/temperature conditions for reliable system operation. |
| PGOOD Threshold | –9.5% nominal output - provides precise power-rail monitoring with built-in hysteresis to prevent false toggling during marginal conditions. |
Pinout & Package
MAX8734AEEI+ is housed in a 28-pin QSOP package (5.0mm × 10.3mm, 0.635mm pitch), optimized for high-density notebook PCB layouts and thermal performance in extended temperature range (–40°C to +85°C).
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 | N.C. | No internal connection - must remain unconnected per datasheet; floating or tied to GND has no functional impact. |
| 2 | PGOOD | Open-drain power-good indicator - pulled low if either SMPS output deviates >9.5% from nominal; requires external pull-up for system sequencing. |
| 3 | ON3 | 3.3V SMPS enable/delay control - high enables output; tied to REF enables delayed start after 5V regulation. |
| 4 | ON5 | 5V SMPS enable/delay control - high enables output; tied to REF enables delayed start after 3.3V regulation. |
| 5 | ILIM3 | 3.3V current-limit adjustment - sets GND–LX threshold from 40mV to 215mV; default 100mV when connected to VCC. |
| 6 | SHDN | Global shutdown input - falling edge below 1.00V disables all outputs and reduces V+ current to ≤15µA. |
| 7 | FB3 | 3.3V feedback node - grounded for fixed 3.3V; connected to resistor divider for adjustable 2.0V–5.5V output. |
| 8 | REF | 2.000V precision reference - sources ≤100µA; used for biasing ILIM/TON/SKIP and as delay-start trigger. |
| 9 | FB5 | 5V feedback node - grounded for fixed 5V; connected to resistor divider for adjustable 2.0V–5.5V output. |
| 10 | PRO | Fault protection control - GND enables OVP/UVP/discharge; VCC disables protection and forces DL low at shutdown. |
| 11 | ILIM5 | 5V current-limit adjustment - sets GND–LX threshold from 40mV to 215mV; default 100mV when connected to VCC. |
| 12 | SKIP | Noise-mode selector - GND = Idle-mode; VCC = forced PWM; REF/floating = ultrasonic mode (>25kHz). |
| 13 | TON | Frequency select - VCC = 200/300kHz; GND = 400/500kHz; defines SMPS clock for 5V/3.3V channels respectively. |
| 14 | BST5 | 5V high-side gate driver boost capacitor node - connects to flying cap and diode for DH5 bootstrap operation. |
| 15 | LX5 | 5V power stage switch node - serves as return path for DH5, current-sense input (MAX8734A only), and SMPS inductor connection. |
| 16 | DH5 | 5V high-side MOSFET gate driver - swings from LX5 to BST5; drives external N-channel FET with 2A peak sink/source capability. |
| 17 | VCC | Analog core supply - powers internal PWM, reference, and comparators; bypass with ≥1µF ceramic capacitor. |
| 18 | GND | Power and signal ground - common reference for all regulators, drivers, and feedback circuits; requires low-impedance plane. |
| 19 | LX3 | 3.3V power stage switch node - serves as return path for DH3, current-sense input (MAX8734A only), and SMPS inductor connection. |
| 20 | BST3 | 3.3V high-side gate driver boost capacitor node - connects to flying cap and diode for DH3 bootstrap operation. |
| 21 | DH3 | 3.3V high-side MOSFET gate driver - swings from LX3 to BST3; drives external N-channel FET with 2A peak sink/source capability. |
| 22 | DL3 | 3.3V synchronous rectifier driver - pulls low during off-time; 3.3A sink / 1.7A source capability for low-RDS(on) FET control. |
| 23 | DL5 | 5V synchronous rectifier driver - pulls low during off-time; 3.3A sink / 1.7A source capability for low-RDS(on) FET control. |
| 24 | OUT3 | 3.3V SMPS regulated output - connects to output inductor, filter cap, and load; monitored by FB3 and PGOOD. |
| 25 | OUT5 | 5V SMPS regulated output - connects to output inductor, filter cap, and load; monitored by FB5 and PGOOD. |
| 26 | LDO3 | 3.3V linear regulator output - always-on, bootstrapped from OUT3; delivers up to 100mA with <1% load regulation. |
| 27 | LDO5 | 5V linear regulator output - always-on, bootstrapped from OUT5; delivers up to 100mA with <1% load regulation. |
| 28 | V+ | Main input supply - accepts 4.5V–24V; powers SMPS stages, gate drivers, and internal bias circuits. |
Key Features
| Feature | Design Value |
|---|---|
| No current-sense resistor required | Uses GND–LX sensing on MAX8734A - eliminates sense resistor loss and layout complexity for both SMPS channels. |
| Pin-selectable switching frequency | TON pin chooses between 200/300kHz (low EMI, high efficiency) or 400/500kHz (smaller magnetics, thinner designs). |
| Ultrasonic pulse-skipping mode | Maintains >25kHz minimum switching frequency - prevents audible coil whine in notebook speakers and audio subsystems. |
| Bootstrapped 100mA LDOs | LDO3/LDO5 auto-enable from respective SMPS outputs - ensures continuous power to real-time clocks or firmware during deep sleep. |
| Integrated soft-start and soft-stop | 1.7ms ramp time and internal discharge circuit - prevents negative voltage spikes and inrush current during power-up/down. |
| Quick-PWM™ transient response | 100ns reaction to load steps - maintains tight output regulation during CPU/GPU burst activity without external loop compensation. |
Applications
| Mobile Computing Power | Notebook Main Supply |
|---|---|
Use Scenario: Power management in subnotebooks and ultra-thin laptops using 3–4-cell Li+ batteries. IC Role / Device Role / Timing Role: Primary quad-output power controller generating 5V/3.3V SMPS rails and always-on 5V/3.3V LDOs for chipset, memory, and peripherals. Use Value: Pin-selectable frequencies allow optimization for either efficiency (200/300kHz) or compactness (400/500kHz), while ultrasonic mode eliminates audible noise in thin form factors. | Use Scenario: Core power delivery in 12–24V-input notebook platforms requiring sequenced, regulated logic supplies. IC Role / Device Role / Timing Role: Dual PWM controller with integrated PGOOD, soft-start, and fault protection - manages startup timing, rail stability, and system-level power health reporting. Use Value: ON3/ON5 delay-start capability enables strict power-up sequencing (e.g., 5V before 3.3V), and bootstrapped LDOs ensure RTC and firmware retention during suspend-to-RAM. |
| Portable Communication Devices | Li+-Powered Embedded Systems |
Use Scenario: Power solution for PDAs and mobile communication devices with dynamic load profiles and battery life constraints. IC Role / Device Role / Timing Role: High-efficiency SMPS controller with pulse-skipping modes - dynamically adjusts switching behavior based on load to maximize battery runtime. Use Value: Idle-mode and ultrasonic pulse-skipping reduce no-load current to <250µA, extending standby time; Quick-PWM™ preserves regulation during RF transmit bursts. | Use Scenario: Industrial handhelds or ruggedized tablets operating from 3–4-cell Li+ packs in extended temperature environments. IC Role / Device Role / Timing Role: Robust main power controller with –40°C to +85°C operation, overvoltage/undervoltage fault detection, and thermal shutdown at +160°C. Use Value: ±1.5% output accuracy and 10µs fault propagation ensure reliable operation in thermally variable field deployments; QSOP package supports automated assembly and rework. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual SMPS controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX8732AEEI+ | Fixed 200kHz/300kHz operation; requires external current-sense resistors on both SMPS channels. | Targeted at cost-sensitive, high-efficiency notebook designs where fixed frequency and higher BOM count are acceptable. | Select when design prioritizes proven 200/300kHz efficiency over flexibility and sense-resistor elimination. |
| MAX8733AEEI+ | Fixed 400kHz/500kHz operation; requires external current-sense resistors; optimized for "thin and light" platforms. | Suitable for ultra-portables where smaller magnetics and faster transient response outweigh sense-resistor losses. | Choose when board space is critical and 400/500kHz operation meets EMI requirements without ultrasonic mode. |
Compared with MAX8732AEEI+ and MAX8733AEEI+, the MAX8734AEEI+ uniquely combines pin-selectable frequency, no-sense-resistor operation, and identical 28-QSOP packaging-enabling one hardware design to support multiple performance tiers without layout changes.
Availability
MAX8734AEEI+ is available at Aetrix Electronics and suitable for notebook computers, PDAs, and 3–4-cell Li+ battery-powered devices requiring stable component supply, long-term lifecycle support, and lead-free compliance.
Supply support for MAX8734AEEI+ 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 markets.
The MAX873x family was engineered specifically for notebook and subnotebook main power supplies-delivering quad regulated outputs, robust fault protection, and advanced power-saving modes in a single 28-pin package.
FAQ
What is the primary function of the MAX8734AEEI+ in a notebook power system?
The MAX8734AEEI+ serves as the main dual-output switch-mode power-supply controller, generating regulated 5V and 3.3V SMPS rails plus always-on 5V and 3.3V LDO outputs. It integrates sequencing, fault protection, and Quick-PWM™ transient response to meet the stringent power demands of modern notebook platforms. Its pin-selectable frequency and no-sense-resistor architecture make the MAX8734AEEI+ especially suited for flexible, high-efficiency designs.
How does the TON pin affect the operation of the MAX8734AEEI+?
The TON pin on the MAX8734AEEI+ selects between two switching frequency sets: connecting TON to VCC configures the 5V and 3.3V SMPS channels for 200kHz and 300kHz operation, respectively, while tying TON to GND selects 400kHz and 500kHz. This pin enables a single PCB design to support multiple performance targets-efficiency-focused (lower frequencies) or space-constrained (higher frequencies)-without hardware revision. The MAX8734AEEI+ datasheet confirms this behavior across all operating conditions.
Does the MAX8734AEEI+ require external current-sense resistors?
No, the MAX8734AEEI+ does not require external current-sense resistors. Unlike the MAX8732AEEI+ and MAX8733AEEI+, it implements GND–LX current sensing for both the 5V and 3.3V SMPS channels-eliminating sense resistor power loss and board area. This architecture is explicitly confirmed in the "Features" section and electrical characteristics tables of the MAX8734AEEI+ datasheet, and applies only to the MAX8734A variant.
What are the key differences between the SKIP and PRO pins on the MAX8734AEEI+?
The SKIP pin on the MAX8734AEEI+ controls noise-reduction mode: GND enables Idle-mode pulse-skipping, VCC forces fixed-frequency PWM, and REF/floating activates ultrasonic mode (>25kHz). The PRO pin enables or disables fault protection-GND activates overvoltage/undervoltage detection and output discharge, while VCC disables these functions and forces DL drivers low during shutdown. These distinct roles are defined in the MAX8734AEEI+ pin description table and verified across functional test conditions.
Can the MAX8734AEEI+ be used in systems requiring power sequencing between the 5V and 3.3V SMPS outputs?
Yes, the MAX8734AEEI+ supports precise power sequencing via the ON3 and ON5 pins. Connecting ON3 to REF delays activation of the 3.3V SMPS until the 5V SMPS reaches regulation; conversely, tying ON5 to REF sequences the 5V SMPS after the 3.3V rail is stable. This behavior is documented in the "Pin Description" and "Typical Operating Characteristics" sections of the MAX8734AEEI+ datasheet and validated across –40°C to +85°C operation.
MAX8734AEEI+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 28-SSOP (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Not Verified
- Applications:
- Power Supply Controller
- Voltage - Input:
- 4.5V ~ 24V
- Voltage - Supply:
- -
- Current - Supply:
- 25 µA
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-QSOP
MAX8734AEEI+ FAQ
1.How can I place an order for MAX8734AEEI+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX8734AEEI+ on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MAX8734AEEI+ reliable?
The price and inventory of MAX8734AEEI+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX8734AEEI+ is usually 5 days.
3.What payment methods are accepted for MAX8734AEEI+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX8734AEEI+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX8734AEEI+?
MAX8734AEEI+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX8734AEEI+ order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MAX8734AEEI+?
For technical support, including MAX8734AEEI+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX8734AEEI+ requirements.
6.How does Aetrix verify that MAX8734AEEI+ is sourced from the original manufacturer or authorized distributors?
All MAX8734AEEI+ products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MAX8734AEEI+ meets industry standards.
7.What is the process for return or replacement of MAX8734AEEI+?
All MAX8734AEEI+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX8734AEEI+, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MAX8734AEEI+ part is unused and in its original packaging.
Return procedure for MAX8734AEEI+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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