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Allegro MicroSystems A4403GEUTR-T
- Part No.:
- A4403GEUTR-T
- Manufacturer:
- Allegro MicroSystems
- Package:
- 16-WQFN Exposed Pad
- Datasheet:
-
A4403GEUTR-T.pdf
- Description:
- IC REG BUCK ADJ 3A 16QFN
- Quantity:
- Payment:
- Shipping:
Inventory:18,073
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Product details
Overview
A4403GEUTR-T from Allegro MicroSystems is a valley current-mode controlled synchronous buck converter IC designed for high-input-voltage, low-output-voltage DC/DC conversion in space-constrained industrial and telecom power supplies. It delivers 3 A continuous output current, supports 9–46 V input range, achieves switching frequencies up to 2 MHz via user-configurable on-time resistor, and integrates internal high-side and low-side MOSFET drivers with thermal protection.
For engineers reviewing the A4403GEUTR-T datasheet, A4403GEUTR-T pinout, A4403GEUTR-T application, or A4403GEUTR-T equivalent, key selection considerations include its 50 ns minimum on-time capability for high step-down ratios, valley-current limiting without slope compensation, integrated soft-start and top-off charge pump for light-load PFM operation, and QFN-16 (4 mm × 4 mm) thermally enhanced package with exposed pad.
Technical Context
The A4403GEUTR-T implements valley current-mode control with constant on-time modulation-on-time is set by external resistor at TON pin and inversely scaled with VIN to maintain stable switching frequency across line variations. Its feed-forward architecture ensures fast line transient response and eliminates need for slope compensation.
Internal diagnostics include cycle-by-cycle valley current limiting (3.6 A typical), VIN undervoltage lockout (6.4–7.5 V threshold with 0.7–1.1 V hysteresis), overtemperature shutdown (165°C trip), and FB overvoltage protection (0.88 V threshold). The device operates in forced CCM or automatic PFM mode below ~1 mA load, enabled by integrated top-off charge pump and optimized gate drive.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 9–46 V - supports wide-range industrial and automotive battery-fed inputs without pre-regulation |
| Output Current | 3 A continuous - sufficient for powering FPGAs, DSPs, or multi-rail subsystems from single stage |
| Switching Frequency | 0.45–2 MHz - enables use of sub-10 µH inductors and <22 µF ceramic output capacitors |
| Feedback Reference Voltage | 0.8 V ±1% - precise regulation target enabling accurate output setting with standard resistor networks |
| Minimum On-Time | 50 ns - allows >10:1 step-down (e.g., 42 V → 3.3 V at 1 MHz) without pulse-skipping instability |
| Quiescent Current | <100 µA in shutdown - critical for always-on systems with battery backup or energy harvesting |
| Thermal Resistance θJA | 36 °C/W - validated on JEDEC 4-layer PCB; requires exposed pad soldered to ground plane for full rating |
Pinout & Package
The A4403GEUTR-T is housed in a 16-contact, 4 mm × 4 mm × 0.75 mm QFN package with exposed thermal pad (suffix EU), lead-free and 100% matte tin plating. The exposed pad must be connected to PCB ground plane via multiple thermal vias for optimal thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Primary input supply rail | Accepts 9–46 V; powers internal regulators and high-side driver; requires local 10 µF X7R ceramic decoupling |
| LX | Switch node | Connects to inductor and recirculation diode cathode; high dv/dt node requiring tight layout and minimal trace length |
| BOOT | Bootstrap supply for high-side driver | Requires 22 nF ceramic capacitor between BOOT and LX; enables NMOS high-side switch operation |
| FB | Output voltage feedback input | Monitors resistive divider; regulates output to 0.8 V reference; bias current <100 nA minimizes divider error |
| ISEN | Valley current sense input | Measures voltage across external 50 mΩ sense resistor; triggers cycle termination when valley current reaches limit |
| TON | On-time configuration terminal | Current-sourced pin; sets on-time (and thus fSW) via resistor to VIN; tolerance ±15% |
| SS | Soft-start timing capacitor connection | Charged by 10 µA internal current source; soft-start duration = 0.8 × CSS / 10 µA |
| DIS | Enable/disable logic input | Active-low enable; open-circuit disables device; internal pull-up ensures safe default-off state |
| GND / SGND / PAD | Ground references | GND = power ground; SGND = isolated current-sense ground (must tie to GND near ISEN); PAD = thermal pad tied to PCB ground plane |
Key Features
| Feature | Design Value |
|---|---|
| Valley current-mode control | Eliminates slope compensation requirement and maintains stable current limit across full 9–46 V input range |
| User-configurable switching frequency | Set from 450 kHz to 2 MHz via single external resistor on TON pin-no external clock needed |
| Integrated top-off charge pump | Ensures gate drive integrity during light-load PFM operation, preventing dropout or regulation loss below 1 mA |
| Comprehensive fault protection | Includes cycle-by-cycle overcurrent, input UVLO with hysteresis, overtemperature shutdown (165°C), and FB overvoltage lockout |
| Thermally enhanced QFN-16 | θJP = 2 °C/W to exposed pad enables >2 W dissipation on standard 4-layer board with proper thermal design |
Applications
| Printers & Scanners | Cable/DSL Modems |
|---|---|
|
Use Scenario: Powering FPGA-based imaging engines and motor drivers in compact office peripherals. IC Role / Device Role / Timing Role: Primary 3.3 V/5 V buck regulator delivering 3 A peak current with fast transient response to handle burst-mode scanning loads. Use Value: 50 ns minimum on-time enables direct 24 V or 48 V input conversion-eliminating pre-regulator stage and reducing BOM count by 30%. |
Use Scenario: Generating stable 12 V and 5 V rails for DOCSIS-compliant cable modems operating from 48 V PoE or AC/DC adapters. IC Role / Device Role / Timing Role: High-efficiency main DC/DC converter supporting dynamic load steps up to 2 A/µs during packet transmission bursts. Use Value: Valley current limiting ensures consistent 3.6 A current limit across 9–46 V input-preventing false trips during brownout conditions. |
| Industrial Control Systems | High-Power LED Drivers |
|
Use Scenario: Providing isolated 5 V and 3.3 V supplies for PLC I/O modules and fieldbus transceivers in harsh factory environments. IC Role / Device Role / Timing Role: Robust primary regulator with -40°C to +105°C ambient operation, UVLO hysteresis, and thermal shutdown. Use Value: Integrated diagnostics (VIN UVLO, TJTSD, FB OVP) reduce need for external supervision ICs-cutting system-level component count and validation effort. |
Use Scenario: Constant-current LED string driver for architectural lighting where dimming requires precise low-voltage regulation. IC Role / Device Role / Timing Role: Buck controller configured in constant-current mode using ISEN feedback; regulates LED current via external sense resistor. Use Value: 0.8 V reference and <100 nA FB bias current enable high-accuracy current setting with minimal resistor-divider error-even at 0.1% tolerance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MPQ4313-AEC1 from Monolithic Power Systems | Automotive-grade AEC-Q100 qualified; 3.5 A rating; fixed 2.2 MHz fSW; no TON pin-frequency not user-adjustable | Better suited for automotive infotainment where qualification and EMI robustness are mandatory; lacks programmable on-time flexibility | Select MPQ4313-AEC1 only if AEC-Q100 compliance and higher current margin are required-and frequency tuning is unnecessary. |
| TPS54332 from Texas Instruments | Current-mode control (not valley); 3.5 A; 100 kHz–2.5 MHz adjustable via RT; higher quiescent current (120 µA vs. <100 µA) | More mature ecosystem with WEBENCH support; less suitable for ultra-high step-down due to 130 ns min on-time | Choose TPS54332 when design reuse, TI reference designs, or compatibility with existing 12 V input architectures is prioritized over minimum on-time performance. |
Compared with MPQ4313-AEC1 and TPS54332, the A4403GEUTR-T uniquely combines sub-50 ns on-time capability, valley-current architecture eliminating slope compensation, and integrated top-off charge pump-making it optimal for high-ratio, high-frequency, low-quiescent industrial DC/DC where layout simplicity and transient fidelity are critical.
Availability
A4403GEUTR-T is available at Aetrix Electronics and suitable for industrial control systems, telecom infrastructure equipment, and high-power LED lighting requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.
Supply support for A4403GEUTR-T 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
Allegro MicroSystems is a U.S.-based semiconductor company specializing in high-performance power ICs, magnetic sensors, and precision motion control solutions for automotive, industrial, and consumer markets.
The A4403GEUTR-T belongs to Allegro's valley current-mode buck converter product line, engineered specifically for high-input-voltage, high-frequency, low-output-voltage applications where minimal external components and superior transient response are essential.
FAQ
What is the minimum recommended output capacitance for stable operation of the A4403GEUTR-T?
The A4403GEUTR-T requires a minimum output capacitance of 10 µF ceramic (X5R/X7R) to ensure control loop stability. The device is optimized for 20 µF total output capacitance-split across two 10 µF devices-to minimize ESL effects and maintain 90 kHz bandwidth with 45° phase margin at full load. Using less than 10 µF risks loop instability and poor transient response; exceeding 1000 µF degrades bandwidth and increases overshoot risk during load steps.
How does the A4403GEUTR-T achieve high step-down ratios without pulse-skipping?
The A4403GEUTR-T achieves high step-down ratios-such as 42 V to 3.3 V-by leveraging its 50 ns minimum on-time capability and valley current-mode control. Unlike traditional current-mode controllers requiring slope compensation, the A4403GEUTR-T maintains stable operation down to very short on-times because valley sensing inherently rejects noise and avoids subharmonic oscillation. This allows reliable 1 MHz+ operation even at extreme duty cycles (<10%), eliminating pulse-skipping and associated output ripple.
Can the A4403GEUTR-T operate with an input voltage below 9 V?
No-the A4403GEUTR-T has a specified minimum input voltage of 9 V per its Recommended Operating Conditions and absolute maximum ratings. Below 9 V, the internal housekeeping regulators and gate drivers cannot sustain proper operation, and VIN undervoltage lockout (UVLO) activates at 6.4–7.5 V with hysteresis. Attempting operation below 9 V may result in erratic switching, failure to start, or unregulated output. For lower-input applications, consider the A4402 or other members of Allegro's buck family rated for 3–36 V.
What is the purpose of the SGND pin on the A4403GEUTR-T, and how should it be connected?
The SGND pin on the A4403GEUTR-T provides a dedicated, low-noise ground reference for the current-sense amplifier to reject common-mode noise from the power ground path. It must be connected directly to the GND net *at the ISEN pin location*-not at the main power ground star point-to avoid injecting switching noise into the sense path. While SGND and GND are internally connected, separating their PCB traces until the ISEN filter improves current-limit accuracy and prevents false triggering under high dv/dt conditions.
Does the A4403GEUTR-T require an external recirculation diode, and what type is recommended?
Yes-the A4403GEUTR-T requires an external Schottky diode (D1) connected from LX to VOUT to provide recirculation current path during the off-time. A low-forward-voltage, low-inductance Schottky diode rated for ≥3 A average current and ≥46 V reverse voltage is recommended-such as the Vishay VSK340 or ON Semiconductor MBR340. The diode must be placed adjacent to the LX and VOUT pins with minimal trace length to reduce ringing and EMI; mounting on the PCB backside further isolates thermal coupling from the A4403GEUTR-T die.
A4403GEUTR-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Series:
- -
- Package/Case:
- 16-WQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 9V
- Voltage - Input (Max):
- 46V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 46V
- Current - Output:
- 3A
- Frequency - Switching:
- 450kHz ~ 2MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 105°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-QFN (4x4)
A4403GEUTR-T FAQ
1.How can I place an order for A4403GEUTR-T through Aetrix?
Please submit a Request for Quotation (RFQ) for A4403GEUTR-T 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 A4403GEUTR-T reliable?
The price and inventory of A4403GEUTR-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A4403GEUTR-T is usually 5 days.
3.What payment methods are accepted for A4403GEUTR-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A4403GEUTR-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A4403GEUTR-T?
A4403GEUTR-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A4403GEUTR-T 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 A4403GEUTR-T?
For technical support, including A4403GEUTR-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A4403GEUTR-T requirements.
6.How does Aetrix verify that A4403GEUTR-T is sourced from the original manufacturer or authorized distributors?
All A4403GEUTR-T 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 A4403GEUTR-T meets industry standards.
7.What is the process for return or replacement of A4403GEUTR-T?
All A4403GEUTR-T units undergo pre-shipment inspection (PSI). If there is an issue with A4403GEUTR-T, 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 A4403GEUTR-T part is unused and in its original packaging.
Return procedure for A4403GEUTR-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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