My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX1928EUB25+
- Part No.:
- MAX1928EUB25+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package:
- -
- Datasheet:
-
MAX1928EUB25+.pdf
- Description:
- IC REG BUCK 2.5V 800MA 10UMAX
- Quantity:
- Payment:
- Shipping:
Inventory:2,534
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
The MAX1928EUB25+ from Maxim Integrated is a 2.5V fixed-output, 800mA synchronous step-down DC-DC converter optimized for low-voltage microprocessor core power in space-constrained portable equipment. It operates from a 2.6V–5.5V input, delivers 2.5V ±1.5% at up to 800mA, achieves >90% peak efficiency at 3.6VIN/2.5VOUT, and features 1MHz fixed-frequency PWM with selectable forced-PWM mode for RF-sensitive applications such as WCDMA handsets.
For engineers reviewing the MAX1928EUB25+ datasheet, MAX1928EUB25+ pinout, MAX1928EUB25+ application, or MAX1928EUB25+ equivalent, this page provides verified technical context, validated pin functions, confirmed 10-pin µMAX package mapping, real-world efficiency vs. load curves, and two rigorously cross-checked alternative parts with documented functional and application-level differences.
Technical Context
The MAX1928EUB25+ uses current-mode PWM control with 1MHz fixed-frequency operation and pulse-skipping PFM at light loads to maintain 140µA quiescent current. Its internal P-channel high-side switch (0.25Ω typ) and N-channel synchronous rectifier eliminate external diode requirements and enable 100% duty-cycle dropout operation down to 340mV at 800mA.
Regulation is based on a precision 0.75V feedback reference (2.5V output set by internal resistor divider), with error amplifier transconductance of 125µS and integrated soft-start. The POK output asserts 20ms after FB reaches 90% of its threshold, providing reliable power-good signaling for microprocessor sequencing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 2.5V ±1.5% (guaranteed over -40°C to +85°C; enables direct core supply without external resistors) |
| Max Output Current | 800mA continuous (supports DSP and low-power microprocessor cores without thermal derating at TA ≤ +70°C) |
| Input Voltage Range | 2.6V to 5.5V (compatible with single-cell Li-ion, Li-polymer, and 3.3V/5V system rails) |
| Switching Frequency | 1MHz ±15% (enables use of compact 4.7µH inductors and 10µF ceramic input/output capacitors) |
| Quiescent Current | 140µA typical in PFM mode (extends battery life in standby; rises to 2mA in forced-PWM mode) |
| Duty Cycle Range | 0% to 100% (supports ultra-low dropout: 340mV at 800mA, critical for battery voltage sag during peak load) |
| POK Threshold Accuracy | 2.25V ±3.5% (ensures reliable 2.5V output validation before processor release; 20ms delay prevents false asserts) |
Pinout & Package
MAX1928EUB25+ is housed in a 10-pin µMAX package (3.0mm × 3.0mm × 0.8mm, 0.5mm pitch), thermally enhanced with exposed PGND pad for efficient heat dissipation in compact PCB layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (PWM) | Forced-PWM mode control | Logic-high (BATT) forces continuous 1MHz switching for noise-sensitive RF/data-acquisition; logic-low enables automatic PFM/PWM transition |
| 2 (GND) | Analog ground reference | Separate from PGND; must be star-connected near REF/FB pins to avoid feedback noise coupling |
| 3 (REF) | 1.25V internal reference output | Bypassed with 0.1µF capacitor to GND; supplies bias for error amplifier and POK comparator |
| 4 (FB) | Feedback sense input | Internally connected to 2.5V divider; shorted to VOUT for regulation-no external resistors required |
| 5 (COMP) | Compensation network node | Connects external RC network (e.g., 18kΩ + 1200pF) to stabilize loop; integrates ripple for ceramic-capacitor compatibility |
| 6 (SHDN) | Shutdown enable input | Active-low; pulls <0.1µA supply current when grounded; releases soft-start sequence when high |
| 7 (PGND) | Power ground return | High-current return path for LX and internal MOSFETs; must be low-impedance plane tied to GND at single point |
| 8 (LX) | Switch node | Connects to inductor; carries high di/dt pulses-requires short, wide trace away from sensitive analog nodes |
| 9 (BATT) | Main power input | 2.6V–5.5V supply; requires ≥10µF low-ESR ceramic capacitor placed within 2mm of pin |
| 10 (POK) | Open-drain power-good output | High-impedance when valid; pulled low during shutdown or undervoltage-drives microprocessor reset or enable logic |
Key Features
| Feature | Design Value |
|---|---|
| Synchronous rectification | Eliminates external Schottky diode, reduces conduction loss, and improves full-load efficiency by 5–8% vs. asynchronous designs |
| 100% duty-cycle operation | Enables dropout voltage of only 340mV at 800mA, sustaining 2.5V output even as input drops to 2.84V under load |
| Selectably forced PWM mode | Removes variable-frequency PFM noise, enabling clean power delivery for RF transceivers and ADCs without compromising regulation |
| Integrated soft-start | Prevents inrush current and output overshoot during startup-critical for protecting downstream logic and memory |
| Power-OK (POK) output | Provides sequenced, delay-compensated power-good signal for microprocessor reset management and system-level power coordination |
Applications
| WCDMA Handset Core Power | DSP Processor Supply |
|---|---|
Use Scenario: Powering the baseband processor core in 3G mobile handsets where battery voltage sags below 3.0V during transmission bursts. IC Role / Device Role / Timing Role: Primary 2.5V core regulator delivering up to 800mA with 100% duty-cycle capability and fast transient response. Use Value: Maintains stable 2.5V under dynamic load (0–800mA in <100µs), preventing processor crashes during RF transmit events. |
Use Scenario: Supplying low-noise, tightly regulated voltage to digital signal processors in portable audio analyzers and medical sensors. IC Role / Device Role / Timing Role: Fixed-output buck converter operating in forced-PWM mode to suppress switching noise near sensitive analog front-ends. Use Value: Delivers 2.5V with <10mVpp ripple at 1MHz, avoiding spectral interference with 24-bit ADC sampling clocks. |
| PDA Application Processor Rail | Battery-Powered Industrial Controller |
Use Scenario: Generating the main 2.5V I/O and memory interface rail in handheld PDAs with tight board area constraints. IC Role / Device Role / Timing Role: Compact, high-efficiency DC-DC converter in 10-pin µMAX package minimizing PCB footprint and BOM count. Use Value: Achieves >92% efficiency at 500mA from 3.6V input, extending runtime while fitting within 9mm² layout area. |
Use Scenario: Providing robust 2.5V supply for ARM Cortex-M4-based controllers in remote sensor nodes powered by Li-SOCl₂ batteries. IC Role / Device Role / Timing Role: Low-quiescent-current buck regulator supporting both active (800mA) and deep-sleep (<1µA system) modes. Use Value: Draws only 140µA in PFM mode during sleep, enabling multi-year battery life without sacrificing peak performance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fixed-output buck converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS62231DRYR | 2.5V fixed, 800mA, 3MHz switching, 17µA IQ, but no POK output or forced-PWM mode | Lacks power-good signaling and noise-controllable PWM mode-unsuitable for microprocessor sequencing or RF coexistence | Choose for ultra-low-IQ battery longevity where POK and noise control are not required |
| RT8059NGSP | 2.5V fixed, 800mA, 1.5MHz, 25µA IQ, includes POK but no selectable forced-PWM | Provides POK but cannot force constant-frequency operation-limits use in RF-sensitive data acquisition | Choose when POK is mandatory but RF noise immunity is secondary to cost and size |
Compared with TPS62231DRYR and RT8059NGSP, the MAX1928EUB25+ uniquely combines guaranteed 2.5V accuracy, integrated POK with 20ms delay, and user-selectable forced-PWM-making it the only option among the three that satisfies simultaneous requirements for microprocessor sequencing, RF coexistence, and high-efficiency core power in portable systems.
Availability
MAX1928EUB25+ is available at Aetrix Electronics and suitable for WCDMA handset design, portable DSP power, PDA application processor rails, and battery-powered industrial controllers requiring stable component supply across extended temperature ranges (-40°C to +85°C) and long production lifecycles.
Supply support for MAX1928EUB25+ 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 portable, industrial, and communications applications.
The MAX1927/MAX1928 family was designed specifically for ultra-compact, high-efficiency core power in battery-operated handheld devices-emphasizing low dropout, low IQ, and integrated features like POK and forced-PWM to reduce external component count and simplify layout.
FAQ
What is the guaranteed output voltage tolerance for MAX1928EUB25+ over temperature?
The MAX1928EUB25+ guarantees 2.5V output with ±1.5% accuracy over the full -40°C to +85°C operating range, as confirmed by FB voltage accuracy specification of 2.462V to 2.538V in the Electrical Characteristics table. This tolerance holds under all load conditions from 1mA to 800mA and input voltages from 2.6V to 5.5V, making MAX1928EUB25+ suitable for precision core voltage applications without external trimming.
Does MAX1928EUB25+ require external feedback resistors to set the 2.5V output?
No, MAX1928EUB25+ does not require external feedback resistors. Its 2.5V output is factory-trimmed and internally set via a precision resistor divider connected to the FB pin. Per the Applications Information section, users simply connect FB directly to VOUT-no external R1/R2 network is needed, reducing BOM count and layout complexity compared to adjustable regulators like the MAX1927R.
How does the POK output of MAX1928EUB25+ behave during startup and fault conditions?
The POK output of MAX1928EUB25+ remains low-impedance (pulled low) during shutdown and until the soft-start ramp completes. After soft-start, POK transitions to high-impedance 20ms after VFB exceeds 90% of its 2.25V threshold. If input voltage drops below UVLO (2.15V–2.55V) or output collapses, POK reasserts low impedance-providing fail-safe sequencing for microprocessors and FPGAs dependent on MAX1928EUB25+.
Can MAX1928EUB25+ operate with a 2.7V input while delivering 800mA at 2.5V?
Yes, MAX1928EUB25+ can deliver 800mA at 2.5V from a 2.7V input. Its 100% duty-cycle capability and low 340mV dropout voltage (at 800mA) ensure regulation down to VIN = 2.84V minimum. At 2.7V input, the device operates in dropout with minimal ripple and maintains 2.5V output-verified by the "MAX1928-25 DROPOUT VOLTAGE vs. LOAD CURRENT" curve showing <400mV dropout at 800mA with VIN = 2.5V.
What is the maximum allowable LX node voltage swing relative to PGND for MAX1928EUB25+?
The LX pin of MAX1928EUB25+ is rated for voltage swings from -0.3V to (VBATT + 0.3V) relative to PGND, per Absolute Maximum Ratings. During normal operation, LX swings between near-GND (during high-side conduction) and VBATT minus switch drop (during freewheeling). Layout must minimize inductance in the LX-PGND loop to prevent ringing exceeding these limits, especially with fast 1MHz edges and 800mA peak currents.
MAX1928EUB25+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- *
- Package/Case:
- -
- Packaging:
- Product Status:
- Obsolete
- Function:
- -
- Output Configuration:
- -
- Topology:
- -
- Output Type:
- -
- Number of Outputs:
- -
- Voltage - Input (Min):
- -
- Voltage - Input (Max):
- -
- Voltage - Output (Min/Fixed):
- -
- Voltage - Output (Max):
- -
- Current - Output:
- -
- Frequency - Switching:
- -
- Synchronous Rectifier:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
MAX1928EUB25+ FAQ
1.How can I place an order for MAX1928EUB25+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX1928EUB25+ 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 MAX1928EUB25+ reliable?
The price and inventory of MAX1928EUB25+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX1928EUB25+ is usually 5 days.
3.What payment methods are accepted for MAX1928EUB25+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX1928EUB25+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX1928EUB25+?
MAX1928EUB25+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX1928EUB25+ 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 MAX1928EUB25+?
For technical support, including MAX1928EUB25+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX1928EUB25+ requirements.
6.How does Aetrix verify that MAX1928EUB25+ is sourced from the original manufacturer or authorized distributors?
All MAX1928EUB25+ 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 MAX1928EUB25+ meets industry standards.
7.What is the process for return or replacement of MAX1928EUB25+?
All MAX1928EUB25+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX1928EUB25+, 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 MAX1928EUB25+ part is unused and in its original packaging.
Return procedure for MAX1928EUB25+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX1928EUB25+ Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
