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Analog Devices Inc./Maxim Integrated MAX1734EUK18+
- Part No.:
- MAX1734EUK18+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package:
- -
- Datasheet:
-
MAX1734EUK18+.pdf
- Description:
- IC REG BUCK 1.8V 250MA SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,344
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Product details
Overview
MAX1734EUK18+ from Maxim Integrated is a fixed-output 1.8V, 250mA synchronous step-down DC-DC converter in a 5-pin SOT23 package. It operates from 2.7V to 5.5V input, delivers >90% efficiency at 1.2MHz switching frequency, maintains ±3% output accuracy over load/temperature, and features 40µA quiescent current - ideal for powering core logic or I/O rails in battery-powered handheld devices.
For engineers reviewing the MAX1734EUK18+ datasheet, MAX1734EUK18+ pinout, MAX1734EUK18+ application, or MAX1734EUK18+ equivalent, key selection criteria include its factory-preset 1.8V output, internal synchronous rectification eliminating external diodes, logic-controlled shutdown (0.01µA), soft-start limiting inrush, and compatibility with low-ESR tantalum or ceramic output capacitors in space-constrained designs.
Technical Context
The MAX1734EUK18+ uses a proprietary current-limited control scheme with fixed 1.8V output regulation via internal resistor divider. Its high-side and low-side MOSFETs are integrated with on-resistances of ≤1.1Ω and ≤1.6Ω respectively, enabling efficient operation across 0–250mA load range without external compensation.
Startup occurs at ≥1.95V input with UVLO hysteresis (200mV), minimum on/off times are 0.25–0.55µs, and LX node supports fast transient response with <50mV output ripple under 20–200mA load steps - all enabled by internal digital soft-start and high-frequency operation up to 1.2MHz.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 1.8V ±3% over 0–250mA load and -40°C to +85°C - eliminates external feedback resistors and simplifies layout. |
| Input Voltage Range | 2.7V to 5.5V - supports single-cell Li+ (2.7–4.2V), alkaline, or regulated 3.3V/5V rails without pre-regulation. |
| Max Output Current | 250mA guaranteed - sufficient for powering microcontroller cores, RF transceivers, or sensor interfaces in portable systems. |
| Quiescent Current | 40µA typical - extends battery life in always-on or low-duty-cycle applications like PDAs and cordless handsets. |
| Switching Frequency | Up to 1.2MHz - enables use of compact 10µH inductors and 2.2µF ceramic input capacitors, reducing board area. |
| Shutdown Current | 0.01µA - ensures negligible battery drain during system sleep modes. |
| Efficiency | >90% at 250mA with VIN = 3.6V - exceeds linear regulator performance while avoiding thermal derating issues. |
Pinout & Package
Package: 5-pin SOT23-5 (JEDEC MO-178AA), 2.9mm × 1.6mm × 1.1mm body, gull-wing leads, RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 IN | Power Input | Accepts 2.7V–5.5V supply; requires local 2.2µF ceramic bypass to GND for stability and EMI suppression. |
| 2 GND | Ground Reference | Primary return path for power and control circuits; must connect to star ground point near input/output capacitors. |
| 3 SHDN | Active-Low Enable | Pull to GND for 0.01µA shutdown; tie to IN for continuous operation; logic-compatible with 0.4V/1.6V thresholds. |
| 4 OUT | Output Sense | Internal connection to fixed 1.8V voltage divider; no external components required - defines regulated output. |
| 5 LX | Switch Node | Drives external 10µH inductor; high dv/dt node requiring short, wide trace routing away from sensitive analog paths. |
Key Features
| Feature | Design Value |
|---|---|
| Synchronous Rectification | Integrated low-side MOSFET replaces Schottky diode - eliminates 0.3–0.4V forward drop, boosting efficiency and reducing thermal load. |
| Digital Soft-Start | Gradually ramps current limit in 25% steps - limits inrush current during cold start from Li+ cells or high-impedance sources. |
| High-Frequency Operation | 1.2MHz max switching - allows miniature passive components (10µH inductor, 2.2µF input cap) and reduces EMI fundamental frequency. |
| UVLO with Hysteresis | 1.55V turn-off / 1.95V turn-on (200mV hysteresis) - prevents oscillation during brown-out conditions and ensures clean power-up sequencing. |
| Low-Noise Regulation | ±3% output accuracy over full load/temperature range - meets tight tolerance requirements for DSP cores and precision analog peripherals. |
Applications
| Cellular Handset Power Rail | PDA Core Voltage Supply |
|---|---|
|
Use Scenario: Powers baseband processor core in GSM/PCS handset operating from single Li+ cell (2.7–4.2V). IC Role / Device Role / Timing Role: Primary step-down regulator delivering stable 1.8V at up to 250mA with fast load-transient response to handle burst-mode transmission. Use Value: Replaces inefficient LDOs, extending talk time by >30% while maintaining <50mV output ripple during 20–200mA load steps. |
Use Scenario: Supplies 1.8V to ARM-based application processor in palm-sized PDA with backlight and touchscreen interface. IC Role / Device Role / Timing Role: Main system rail regulator with logic-controlled shutdown to cut standby current below 10nA when device is idle. Use Value: Enables compact PCB layout using 10µH/22µF passive set and achieves >90% efficiency across 1–250mA dynamic load profile. |
| Cordless Telephone Baseband | Handheld Terminal I/O Interface |
|
Use Scenario: Generates 1.8V rail for DECT or 900MHz cordless phone digital baseband IC from 3.3V or 5V wall adapter. IC Role / Device Role / Timing Role: High-efficiency intermediate regulator converting higher input to low-voltage logic domain with minimal heat dissipation. Use Value: Eliminates need for heatsinking in sealed plastic enclosures and supports seamless transition between AC and battery backup modes. |
Use Scenario: Powers UART, SPI, and GPIO interfaces in ruggedized industrial handheld terminal with extended temperature operation. IC Role / Device Role / Timing Role: Robust DC-DC converter rated for -40°C to +85°C, providing stable 1.8V despite input voltage sag during motor or display activation. Use Value: Maintains ±3% regulation during 100mA load transients and withstands 5.5V input surges common in industrial power environments. |
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 |
|---|---|---|---|
| Texas Instruments TPS62231DRYR | 1.8V fixed, 300mA, 2.25–6.5V input, 3.6MHz switching, 17µA IQ - higher frequency but tighter input range and lower max current. | Requires smaller 2.2µH inductor but less tolerant of Li+ voltage sag below 2.25V; better suited for ultra-thin designs with strict size constraints. | Select when board space is critical and input stays above 2.25V; verify startup behavior at cold temperatures. |
| Analog Devices ADP2105AUJZ-1.8-R7 | 1.8V fixed, 600mA, 2.3–5.5V input, 3MHz switching, 25µA IQ - higher current capability and wider input range than MAX1734EUK18+. | Supports heavier loads (e.g., dual-core processors) and deeper input droop; includes power-good flag not present in MAX1734EUK18+. | Choose when future-proofing for higher current or needing PG signal for system sequencing; larger footprint (SOT23-6 vs SOT23-5). |
Compared with TPS62231DRYR and ADP2105AUJZ-1.8-R7, the MAX1734EUK18+ offers optimal balance of ultra-low quiescent current (40µA), proven 1.2MHz stability with standard 10µH inductors, and robust -40°C to +85°C operation - making it preferred for cost-sensitive, battery-life-critical handhelds where 250mA suffices.
Availability
MAX1734EUK18+ is available at Aetrix Electronics and suitable for cellular handsets, PDAs, and cordless telephones requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.
Supply support for MAX1734EUK18+ 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 U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and consumer applications.
The MAX1733/MAX1734 family was designed specifically for space-constrained, battery-powered portable electronics - delivering high-efficiency step-down conversion with minimal external components and ultra-low quiescent current.
FAQ
What is the output voltage tolerance of the MAX1734EUK18+ over temperature and load?
The MAX1734EUK18+ guarantees ±3% output voltage accuracy across the full -40°C to +85°C operating temperature range and 0–250mA load current. This specification is confirmed in the Electrical Characteristics table under "Output Voltage Accuracy (MAX1734)" with VIN = 2.7V to 5.5V and TA = -40°C to +85°C. The MAX1734EUK18+ achieves this using a factory-trimmed internal resistor divider, eliminating drift from external components.
Does the MAX1734EUK18+ require an external Schottky diode?
No, the MAX1734EUK18+ does not require an external Schottky diode because it integrates a synchronous rectifier - a low-side MOSFET that replaces the diode's function. As stated in the General Description, "Internal synchronous rectification greatly improves efficiency and eliminates the external Schottky diode required in conventional step-down converters." This reduces conduction losses and board component count.
What is the minimum input voltage required to start up the MAX1734EUK18+?
The MAX1734EUK18+ starts up when the input voltage rises to at least 1.95V (typical), per the "Startup Voltage" parameter in the Absolute Maximum Ratings and Electrical Characteristics sections. The device incorporates undervoltage lockout (UVLO) with hysteresis - it remains active above ~1.95V and shuts down when VIN falls below ~1.55V, ensuring reliable operation during Li+ battery discharge.
Can the MAX1734EUK18+ be used with ceramic output capacitors?
Yes, the MAX1734EUK18+ supports ceramic output capacitors, though the standard application circuit uses 22µF tantalum. Ceramic capacitors can be used with appropriate ESR considerations or by implementing the modified feedback configuration shown in Figure 3 of the datasheet - which references the LX node instead of OUT to stabilize the loop. This enables smaller 2.2µF–4.7µF X7R ceramics with <10mVp-p ripple.
What is the shutdown current of the MAX1734EUK18+ and how is it controlled?
The MAX1734EUK18+ draws only 0.01µA (10nA) in shutdown mode when the SHDN pin is pulled low to GND. This is specified as "Shutdown Supply Current" in the Electrical Characteristics tables. The SHDN pin is active-low with VIH ≥ 1.6V and VIL ≤ 0.4V, allowing direct interfacing with standard logic outputs or microcontroller GPIO pins to enable/disable the MAX1734EUK18+ dynamically.
MAX1734EUK18+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- *
- Package/Case:
- -
- Packaging:
- Product Status:
- Active
- 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:
- -
MAX1734EUK18+ FAQ
1.How can I place an order for MAX1734EUK18+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX1734EUK18+ 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 MAX1734EUK18+ reliable?
The price and inventory of MAX1734EUK18+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX1734EUK18+ is usually 5 days.
3.What payment methods are accepted for MAX1734EUK18+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX1734EUK18+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX1734EUK18+?
MAX1734EUK18+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX1734EUK18+ 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 MAX1734EUK18+?
For technical support, including MAX1734EUK18+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX1734EUK18+ requirements.
6.How does Aetrix verify that MAX1734EUK18+ is sourced from the original manufacturer or authorized distributors?
All MAX1734EUK18+ 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 MAX1734EUK18+ meets industry standards.
7.What is the process for return or replacement of MAX1734EUK18+?
All MAX1734EUK18+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX1734EUK18+, 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 MAX1734EUK18+ part is unused and in its original packaging.
Return procedure for MAX1734EUK18+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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