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Analog Devices Inc./Maxim Integrated MAX1733EUK
- Part No.:
- MAX1733EUK
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package:
- SC-74A, SOT-753
- Datasheet:
-
MAX1733EUK.pdf
- Description:
- IC REG BUCK ADJ 250MA SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:5,499
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Product details
Overview
MAX1733EUK from Maxim Integrated is an adjustable-output, synchronous step-down DC-DC converter delivering up to 250mA at 1.25V–2.0V from a 2.7V–5.5V input. It features 40µA quiescent current, 1.2MHz max switching frequency, and internal synchronous rectification for >90% efficiency-designed for space-constrained battery-powered logic supplies in portable electronics.
For engineers reviewing the MAX1733EUK datasheet, MAX1733EUK pinout, MAX1733EUK application, or MAX1733EUK equivalent, key selection criteria include its adjustable feedback architecture (1.25V FB threshold), SOT23-5 package constraints, shutdown current of 0.01µA, and compatibility with ceramic output capacitors via LX-sensed feedback configurations.
Technical Context
The MAX1733EUK employs a proprietary current-limited control scheme with fixed minimum on/off times (0.25–0.55µs) to maintain regulation across load currents from light to 250mA. Its high-side and low-side MOSFETs feature on-resistances of ≤1.1Ω and ≤1.6Ω respectively at 5.5V input, enabling efficient operation without external diodes.
Internal digital soft-start ramps the current limit in 25% steps to limit inrush, while UVLO (1.55V–1.65V falling threshold, 200mV hysteresis) ensures reliable startup above 2.0V. The device operates over –40°C to +85°C and integrates a 1.25V ±1.5% precision bandgap reference for feedback stability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage Range | 1.25V to 2.0V (adjustable via external resistor divider on FB pin) |
| Input Voltage Range | 2.7V to 5.5V - supports single-cell Li+ (2.7–4.2V) and 3.3V/5V rails |
| Max Output Current | 250mA - guaranteed continuous delivery with thermal derating in SOT23-5 |
| Quiescent Current | 40µA - enables >1000-hour standby in coin-cell or Li+ applications |
| Shutdown Current | 0.01µA - reduces system leakage during deep sleep modes |
| Switching Frequency | Up to 1.2MHz - permits use of 10µH inductors and compact 2.2µF/22µF ceramic/tantalum caps |
| FB Threshold Voltage | 1.25V ±1.5% - sets output accuracy baseline; used with R1/R2 divider for VOUT = 1.25 × (1 + R1/R2) |
Pinout & Package
MAX1733EUK is housed in a RoHS-compliant (lead-free option available) 5-pin SOT23-5 package (drawing 21-0057F, variant U5-1), with 0.9mm body height and standard 0.95mm pitch. Thermal pad is not present; power dissipation limited to 571mW at +70°C ambient.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 IN | Power Input | 2.7V–5.5V supply rail; requires local 2.2µF ceramic bypass to GND |
| 2 GND | Ground Reference | Common return for power, feedback, and control; must be star-connected near IN/CIN |
| 3 SHDN | Active-Low Enable | Pull to GND for 0.01µA shutdown; connect to IN for normal operation |
| 4 FB | Feedback Input | Connects to voltage divider; regulates output by holding FB at 1.25V nominal |
| 5 LX | Switch Node | Drives external 10µH inductor; source of switching waveform and ceramic-COUT feedback path |
Key Features
| Feature | Design Value |
|---|---|
| Synchronous Rectification | Eliminates external Schottky diode, improving efficiency >90% and reducing BOM count |
| Digital Soft-Start | Limits inrush current by ramping current limit in 25% increments-reduces input capacitor stress |
| Adjustable Output Architecture | Supports precise 1.25V–2.0V outputs using two external resistors; enables flexible core/logic rail generation |
| Ceramic Output Capacitor Support | LX-sensed feedback configuration (Fig. 3) enables stable 2.2µF ceramic COUT with <10mVp-p ripple |
| UVLO with Hysteresis | 1.55V–1.65V threshold with 200mV hysteresis prevents oscillation during brownout recovery |
Applications
| Cellular Handset Core Supply | PDAs and Palmtop Logic Rails |
|---|---|
|
Use Scenario: Powering ARM7/ARM9 core voltage (1.3V–1.8V) from single Li+ cell in GSM/CDMA handsets. IC Role / Device Role / Timing Role: Primary step-down regulator providing tightly regulated, low-noise core supply with fast transient response to CPU burst loads. Use Value: 40µA quiescent current extends talk time; 1.2MHz switching allows miniature 10µH inductor and avoids AM radio band interference. |
Use Scenario: Generating 1.5V I/O or 1.8V memory supply in handheld PDAs powered by alkaline or Li+ batteries. IC Role / Device Role / Timing Role: High-efficiency buck converter replacing linear regulators to minimize thermal rise in sealed plastic enclosures. Use Value: Synchronous topology achieves >90% efficiency at 100mA, reducing heat dissipation by >60% versus LDO alternatives. |
| Battery-Powered Medical Sensors | Industrial Handheld Terminals |
|
Use Scenario: Supplying 1.25V analog front-end and 1.8V microcontroller in disposable glucose meters or pulse oximeters. IC Role / Device Role / Timing Role: Low-quiescent-current DC-DC converter enabling multi-year shelf life and extended field operation on coin cells. Use Value: 0.01µA shutdown current preserves battery charge during long idle periods; ±1.5% initial accuracy ensures sensor ADC reference stability. |
Use Scenario: Providing 1.8V FPGA I/O or 2.0V CPLD core voltage in ruggedized warehouse scanners operating from 3.3V or 5V battery packs. IC Role / Device Role / Timing Role: Compact, robust buck regulator supporting wide input range (2.7V–5.5V) and surviving cold-cranking transients. Use Value: UVLO hysteresis (200mV) prevents erratic restart during battery voltage sag; SOT23-5 footprint simplifies layout in dense PCBs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down DC-DC converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS62231DRYR | Fixed 1.8V output; 2.05V–6.0V input; 300mA rating; 2.25MHz switching | Not adjustable; higher frequency demands tighter layout but enables smaller LC values | Select when fixed 1.8V output suffices and board space allows 2.25MHz filtering |
| RT8059GJ6 | Adjustable 0.6V–5.0V; 2.5V–5.5V input; 600mA rating; 1.5MHz switching; integrated compensation | Higher current capability and wider VOUT range, but larger 6-pin WDFN package | Choose for higher load headroom or lower output voltages (<1.25V); requires re-layout due to different pinout |
Compared with MAX1733EUK, the TPS62231DRYR offers higher switching frequency and current but lacks adjustability, while the RT8059GJ6 provides broader output flexibility and higher drive strength at the cost of larger footprint and different thermal profile-neither is pin-compatible, requiring schematic and layout revision.
Availability
MAX1733EUK is available at Aetrix Electronics and suitable for cellular handset core supplies, PDA logic rails, battery-powered medical sensors, industrial handheld terminals, and portable instrumentation requiring stable component supply with long lifecycle visibility.
Supply support for MAX1733EUK 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, and consumer applications.
The MAX1733EUK belongs to Maxim's low-voltage DC-DC converter product line, engineered specifically for ultra-compact, high-efficiency power conversion in battery-operated portable devices where size, quiescent current, and reliability are critical.
FAQ
What output voltage range does the MAX1733EUK support?
The MAX1733EUK supports an adjustable output voltage range of 1.25V to 2.0V, set by an external resistor divider connected to the FB pin. Its internal 1.25V ±1.5% feedback reference ensures accurate regulation across temperature and load, making MAX1733EUK ideal for generating custom logic or core supply rails in portable systems.
How does the MAX1733EUK achieve high efficiency without an external Schottky diode?
The MAX1733EUK integrates synchronous rectification using internal high-side and low-side MOSFETs, eliminating the forward voltage drop and associated losses of an external Schottky diode. This architecture enables >90% efficiency across 10mA–250mA loads, directly contributing to longer battery life in MAX1733EUK-based designs.
Can the MAX1733EUK operate with ceramic output capacitors?
Yes-the MAX1733EUK supports ceramic output capacitors using the LX-sensed feedback configuration shown in Figure 3 of the datasheet. This method compensates for phase lag, enabling stable regulation with just 2.2µF X7R ceramic COUT and achieving <10mVp-p ripple-significantly reducing size and cost versus tantalum alternatives in MAX1733EUK applications.
What is the shutdown current specification for the MAX1733EUK?
The MAX1733EUK draws only 0.01µA in shutdown mode when the SHDN pin is pulled low. This ultra-low leakage preserves battery charge during extended idle periods, making MAX1733EUK especially suitable for always-on sensor nodes and medical devices requiring multi-year shelf life before first use.
Does the MAX1733EUK include built-in protection features?
Yes-the MAX1733EUK incorporates undervoltage lockout (UVLO) with 1.55V–1.65V thresholds and 200mV hysteresis, cycle-by-cycle current limiting (300–565mA high-side, 200–430mA low-side), and thermal shutdown. These protections ensure robust operation under input brownouts, short circuits, and overload conditions-key for reliable MAX1733EUK deployment in unattended equipment.
MAX1733EUK Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- Packaging:
- Bulk
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2.7V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 1.25V
- Voltage - Output (Max):
- 2V
- Current - Output:
- 250mA
- Frequency - Switching:
- Up to 1.2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
MAX1733EUK FAQ
1.How can I place an order for MAX1733EUK through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX1733EUK 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 MAX1733EUK reliable?
The price and inventory of MAX1733EUK are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX1733EUK is usually 5 days.
3.What payment methods are accepted for MAX1733EUK?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX1733EUK transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX1733EUK?
MAX1733EUK orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX1733EUK 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 MAX1733EUK?
For technical support, including MAX1733EUK datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX1733EUK requirements.
6.How does Aetrix verify that MAX1733EUK is sourced from the original manufacturer or authorized distributors?
All MAX1733EUK 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 MAX1733EUK meets industry standards.
7.What is the process for return or replacement of MAX1733EUK?
All MAX1733EUK units undergo pre-shipment inspection (PSI). If there is an issue with MAX1733EUK, 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 MAX1733EUK part is unused and in its original packaging.
Return procedure for MAX1733EUK:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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