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Analog Devices Inc./Maxim Integrated MAX8646ETG+
- Part No.:
- MAX8646ETG+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
MAX8646ETG+.pdf
- Description:
- IC REG BUCK ADJ 6A 24TQFN
- Quantity:
- Payment:
- Shipping:
Inventory:142
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Product details
Overview
MAX8646ETG+ from Maxim Integrated is a high-efficiency, voltage-mode synchronous step-down DC-DC regulator delivering up to 6A continuous output current with ±1% output voltage accuracy over load, line, and temperature. It operates from 2.35V to 3.6V input, supports adjustable switching frequency from 500kHz to 2MHz via external resistor, and integrates 23mΩ high-side and low-side nMOSFETs for POL applications in ASIC/CPU core power and DDR supplies.
For engineers reviewing the MAX8646ETG+ datasheet, MAX8646ETG+ pinout, MAX8646ETG+ application, or MAX8646ETG+ equivalent, key selection considerations include its 24-pin 4mm × 4mm thin QFN package, VID-selectable nine preset output voltages (0.6V–2.5V), safe-start into prebiased outputs, and type III compensation support for fast transient response in compact all-ceramic designs.
Technical Context
The MAX8646ETG+ employs voltage-mode control architecture with a >14MHz bandwidth error amplifier and fixed-frequency PWM operation. Its internal 23mΩ RDS(ON) MOSFETs enable high efficiency at heavy loads while minimizing critical parasitic inductances and simplifying PCB layout.
It features tri-state logic inputs (CTL1/CTL2) for nine factory-trimmed output voltages, an external reference input (REFIN), programmable soft-start via SS capacitor, and open-drain PWRGD with 90% regulation threshold. Thermal shutdown activates at +165°C with 20°C hysteresis, and hiccup-mode current limiting protects during sustained overloads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | Continuous 6A - supports high-power ASIC/CPU core rails without external MOSFETs or heatsinking. |
| Input Voltage Range | 2.35V to 3.6V - compatible with single-cell Li-ion, 3.3V system rails, and post-regulation from higher-voltage converters. |
| Output Voltage Accuracy | ±1% over load, line, and temperature - eliminates need for precision external resistors in feedback networks. |
| Switching Frequency | 500kHz to 2MHz (resistor-programmable) - enables small external inductors and all-ceramic capacitor designs. |
| MOSFET RDS(ON) | 23mΩ (high-side and low-side, typ.) - minimizes conduction loss and thermal stress at full 6A load. |
| Package | 24-pin, 4mm × 4mm thin QFN with exposed pad - provides low thermal resistance and space-efficient integration on dense PCBs. |
| Error Amplifier BW | >14MHz unity-gain bandwidth - enables high loop bandwidth (up to 20% of fSW) for fast transient response. |
| VID Outputs | Nine preset voltages (0.6V, 0.7V, 0.8V, 1.0V, 1.2V, 1.5V, 1.8V, 2.0V, 2.5V) - simplifies configuration without external resistors or DACs. |
Pinout & Package
The MAX8646ETG+ is housed in a lead-free, 24-pin, 4mm × 4mm thin QFN package with exposed thermal pad (EP). The package supports efficient heat dissipation when soldered to a large ground plane.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PREBIAS | Prebias discharge control | Leaving unconnected prevents output capacitor discharge during soft-start; grounding enables discharge for safe startup into prebiased rails. |
| VDD | Bias supply input | Internal LDO input; must be connected to IN via 10Ω resistor and bypassed with 1µF ceramic capacitor to GND. |
| CTL1 / CTL2 | VID voltage select inputs | Tri-state logic inputs (VDD/unconnected/GND) selecting one of nine preset output voltages; must be set before EN assertion. |
| REFIN | Reference voltage input | Accepts internal 0.6V reference (when tied to SS) or external reference; enables tracking and DDR compliance. |
| SS | Soft-start timing node | 8µA current source charges external capacitor to control ramp rate and limit inrush current at startup. |
| FB | Feedback sense input | Regulates output to 0.6V reference; used with external divider for custom voltages or with VID pins for preset values. |
| OUT | Output voltage sense | Direct connection to output rail for remote sensing; left floating when using external resistor divider. |
| FREQ | Frequency programming | Resistor-to-GND sets switching frequency from 500kHz to 2MHz; determines size of inductor and output capacitors. |
| PWRGD | Power-good status output | Open-drain signal pulled low if FB falls below 90% of VREFIN for ≥48 clock cycles; indicates valid regulation. |
| BST | Bootstrap supply | Connects 0.1µF capacitor to LX to generate gate drive voltage for high-side MOSFET; critical for proper high-side turn-on. |
| LX | Switch node | Internally connected pins (14–16) driving external inductor; high-impedance during shutdown. |
| PGND | Power ground return | Four dedicated pins (17–20) for low-impedance return path of high-current switching loop; must connect to solid PGND plane. |
| IN | Main power input | Three pins (21–23) accepting 2.35V–3.6V; requires 22µF ceramic decoupling to PGND close to package. |
| EN | Enable control | Logic input enabling/disabling regulation; <12µA shutdown current; hysteresis ensures noise immunity. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 23mΩ MOSFETs | Eliminates external power switches and reduces BOM count, layout complexity, and footprint vs. controller-only solutions. |
| Safe-start into prebiased output | Prevents reverse current flow and output collapse when powering up into an already charged rail - essential for DDR and hot-swap systems. |
| Type III compensation support | Enables stable high-bandwidth loop design with ceramic output caps, achieving fast transient response and minimal output capacitance. |
| VID-selectable output voltages | Nine factory-trimmed outputs (0.6V–2.5V) with ±1% accuracy remove need for 0.1% feedback resistors and simplify board-level configuration. |
| Hiccup-mode overcurrent protection | Shuts down and auto-restarts during sustained overload or short-circuit, preventing thermal runaway and enabling self-recovery. |
| Thermal shutdown with hysteresis | Triggers at +165°C and re-enables only after die cools by 20°C - avoids oscillation near thermal limit and ensures robust reliability. |
Applications
| ASIC/CPU Core Power | DDR Memory Supply |
|---|---|
Use Scenario: Delivering tightly regulated 1.2V or 1.5V core voltage to high-performance processors under dynamic load conditions. IC Role / Device Role / Timing Role: Primary point-of-load regulator providing fast transient response and ±1% accuracy across temperature and load steps. Use Value: Enables first-pass silicon bring-up by maintaining voltage within processor spec limits during 0–6A load transients, reducing need for bulk output capacitance. | Use Scenario: Generating matched 1.8V or 2.5V supply for DDR2/DDR3 memory subsystems requiring sink/source capability and tracking. IC Role / Device Role / Timing Role: Synchronous buck regulator with REFIN input and prebias support, configured for DDR voltage-tracking compliance. Use Value: Supports DDR sink/source current requirements and safe startup into precharged memory rails without damaging termination networks. |
| Base Station RF Power | RAID Controller Supply |
Use Scenario: Providing clean, low-noise 3.3V or 2.5V bias to RF front-end ICs and analog signal chains in telecom infrastructure. IC Role / Device Role / Timing Role: High-efficiency post-regulator stepping down from intermediate bus to sensitive RF supply rails. Use Value: Achieves >90% efficiency at 6A with ceramic output caps, minimizing thermal load and EMI in densely packed base station modules. | Use Scenario: Powering multi-core RAID controllers and SAS/SATA PHYs requiring stable 1.2V, 1.8V, or 3.3V rails with fast fault recovery. IC Role / Device Role / Timing Role: Robust POL regulator with hiccup-mode OCP and thermal shutdown for mission-critical storage subsystems. Use Value: Ensures continuous operation during transient overloads (e.g., burst I/O) and graceful recovery from short circuits without system reset. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS54620RGYT | 6A synchronous buck with 4.5–17V input range; lower switching frequency range (300kHz–2MHz); no VID pins; uses current-mode control. | Designed for higher-input industrial/telecom rails; lacks preset voltage selection and prebias-safe startup. | Choose when input exceeds 3.6V or current-mode control is preferred; requires external feedback resistors and additional soft-start circuitry. |
| RTQ2132BGQW | 6A buck with 2.7–6V input; integrated FETs; 500kHz–2.2MHz frequency; ±1% accuracy; no VID pins but supports I²C programmability. | Offers digital interface for dynamic voltage scaling; lacks tri-state VID simplicity and prebias-specific safety features. | Prefer when firmware-controlled voltage adjustment is needed; not drop-in for VID-based legacy designs or DDR prebias use cases. |
Compared with TPS54620RGYT and RTQ2132BGQW, the MAX8646ETG+ uniquely combines VID-selectable outputs, guaranteed prebias-safe startup, and voltage-mode control optimized for ceramic-capacitor, high-frequency POL designs - making it optimal for space-constrained, low-input-voltage ASIC and memory power applications.
Availability
MAX8646ETG+ is available at Aetrix Electronics and suitable for ASIC core power, DDR memory supplies, base station RF bias, and RAID controller power applications requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.
Supply support for MAX8646ETG+ 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 industrial, communications, computing, and consumer applications.
The MAX8646ETG+ belongs to Maxim's high-current, high-frequency POL regulator product line, designed specifically for space-constrained, low-input-voltage point-of-load applications demanding ±1% accuracy, fast transient response, and simplified layout with integrated power switches.
FAQ
What is the maximum output current supported by the MAX8646ETG+?
The MAX8646ETG+ delivers up to 6A continuous output current under specified thermal conditions (TA ≤ +85°C, proper PCB layout with exposed pad thermal connection). This rating is validated across the full input range (2.35V–3.6V) and output voltage range (0.6V–0.9×VIN), with derating required above ambient temperatures where junction temperature exceeds +150°C.
Does the MAX8646ETG+ support startup into a prebiased output rail?
Yes, the MAX8646ETG+ supports safe startup into a prebiased output via its PREBIAS pin. When left unconnected, the device prevents reverse current flow from the output capacitor during soft-start, avoiding potential damage to downstream components. This feature is explicitly verified in the datasheet and is critical for DDR and hot-swap applications.
How is the switching frequency set on the MAX8646ETG+?
The switching frequency of the MAX8646ETG+ is set by an external resistor (RFREQ) connected from the FREQ pin to GND. The frequency ranges from 500kHz to 2MHz and is calculated using RFREQ = (49.9kΩ × µs) / (0.95 − 0.05 × fS), where fS is in Hz. A 50kΩ resistor yields ~1MHz, and 23.2kΩ yields ~2MHz - both values are production-validated.
What are the nine VID-selectable output voltages of the MAX8646ETG+?
The MAX8646ETG+ offers nine factory-trimmed output voltages selectable via CTL1 and CTL2 logic states: 0.6V, 0.7V, 0.8V, 1.0V, 1.2V, 1.5V, 1.8V, 2.0V, and 2.5V. Each is guaranteed to ±1% over load, line, and temperature. The mapping is defined in Table 1 of the datasheet and requires static configuration prior to enabling EN.
What package type and thermal characteristics does the MAX8646ETG+ use?
The MAX8646ETG+ uses a lead-free, 24-pin, 4mm × 4mm thin QFN package with exposed thermal pad (T2444-4). Its thermal resistance θJA is 45°C/W (typ.) on a 2-layer board with 1in² copper, and θJC is 4.5°C/W. The exposed pad must be soldered to a solid ground plane to achieve rated 6A performance and avoid thermal shutdown.
MAX8646ETG+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 24-WFQFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2.35V
- Voltage - Input (Max):
- 3.6V
- Voltage - Output (Min/Fixed):
- 0.6V
- Voltage - Output (Max):
- 3.24V
- Current - Output:
- 6A
- Frequency - Switching:
- 500kHz ~ 2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-TQFN (4x4)
MAX8646ETG+ FAQ
1.How can I place an order for MAX8646ETG+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX8646ETG+ 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 MAX8646ETG+ reliable?
The price and inventory of MAX8646ETG+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX8646ETG+ is usually 5 days.
3.What payment methods are accepted for MAX8646ETG+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX8646ETG+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX8646ETG+?
MAX8646ETG+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX8646ETG+ 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 MAX8646ETG+?
For technical support, including MAX8646ETG+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX8646ETG+ requirements.
6.How does Aetrix verify that MAX8646ETG+ is sourced from the original manufacturer or authorized distributors?
All MAX8646ETG+ 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 MAX8646ETG+ meets industry standards.
7.What is the process for return or replacement of MAX8646ETG+?
All MAX8646ETG+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX8646ETG+, 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 MAX8646ETG+ part is unused and in its original packaging.
Return procedure for MAX8646ETG+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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