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Analog Devices Inc./Maxim Integrated MAX8640ZEXT18+T
- Part No.:
- MAX8640ZEXT18+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package:
- 6-TSSOP, SC-88, SOT-363
- Datasheet:
-
MAX8640ZEXT18+T.pdf
- Description:
- IC REG BUCK 1.8V 500MA SC70-6
- Quantity:
- Payment:
- Shipping:
Inventory:2,739
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Product details
Overview
MAX8640ZEXT18+T from Maxim Integrated is a 500mA, 4MHz synchronous step-down DC-DC converter in a 6-pin SC70 package, delivering a factory-preset 1.8V output with ±1% initial accuracy and 28µA quiescent current. It supports input voltages from 2.7V to 5.5V and enables ultra-compact power delivery for space-constrained portable electronics using only a 1µH inductor and 2.2µF output capacitor.
For engineers reviewing the MAX8640ZEXT18+T datasheet, MAX8640ZEXT18+T pinout, MAX8640ZEXT18+T application, or MAX8640ZEXT18+T equivalent, key selection criteria include guaranteed 500mA load capability, ultrasonic pulse-skipping down to 1mA, voltage-positioning load regulation, and compatibility with low-ESR ceramic capacitors in handheld battery-powered systems.
Technical Context
The MAX8640ZEXT18+T employs a proprietary hysteretic PWM control scheme optimized for high efficiency and fast transient response at up to 4MHz switching frequency. Its internal synchronous rectification eliminates external Schottky diodes, while voltage-positioning feedback-derived from the LX node-removes phase lag from the output capacitor, enabling stable loop operation with tiny ceramic output capacitors.
This architecture delivers low output ripple across all loads, maintains ultrasonic skip-mode operation down to 1mA, and achieves fast line- and load-transient response due to direct LX-sensed regulation. The device integrates fast soft-start to suppress inrush current and features thermal shutdown with 20°C hysteresis for robust operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Factory-preset 1.8V (±1% initial accuracy) - eliminates external feedback resistors and simplifies BOM. |
| Switching Frequency | Up to 4MHz - enables use of 1µH inductor and 2.2µF output capacitor for minimal board area. |
| Max Output Current | 500mA guaranteed - supports core/I/O rails for microprocessors, DSPs, and baseband ICs. |
| Quiescent Current | 28µA typical - extends battery life in always-on or low-duty-cycle portable applications. |
| Input Voltage Range | 2.7V to 5.5V - compatible with single-cell Li+ (3.0–4.2V), alkaline (3.0–4.5V), and regulated 3.3V/5V supplies. |
| Load Regulation | Voltage-positioning type - output droop equals inductor DCR × load current, reducing transient overshoot by ~50% vs. conventional buck. |
| Shutdown Current | 0.01µA typical - ensures near-zero power draw when disabled, critical for system-level power gating. |
Pinout & Package
MAX8640ZEXT18+T is housed in a lead-free, RoHS-compliant 6-pin SC70 package (2.0mm × 2.1mm), optimized for high-density PCB layouts in portable devices.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (LX) | Inductor switch node | Connects to internal p-channel and n-channel MOSFET drains; high-impedance during shutdown; requires short, low-inductance trace to minimize EMI. |
| 2, 5 (GND) | Ground reference | Dual ground pins must be connected together directly under the IC and tied to input/output capacitor grounds to ensure stable regulation and low noise. |
| 3 (OUT) | Output sense input | Internally connected to feedback network; bypass with ceramic capacitor placed adjacent to pin 3 and pin 2 to stabilize regulation loop. |
| 4 (SHDN) | Active-low enable input | Logic-low ≥10µs after VIN exceeds UVLO (2.6V) resets internal logic; enables precise system-level power sequencing. |
| 6 (IN) | Power input | Accepts 2.7V–5.5V; requires local ceramic bypass capacitor placed close to pin 6 and pin 5 to suppress switching noise and supply transients. |
Key Features
| Feature | Design Value |
|---|---|
| 4MHz switching frequency | Enables smallest possible passive components: 1µH inductor + 2.2µF ceramic output capacitor reduces solution size by >40% vs. 2MHz alternatives. |
| Voltage-positioning load regulation | Output droop tracks inductor DCR × ILOAD, halving peak-to-peak voltage excursions during load transients versus standard buck converters. |
| Ultrasonic pulse-skipping mode | Maintains switching above 20kHz down to 1mA load, eliminating audible noise while sustaining 28µA quiescent current. |
| Internal synchronous rectification | Replaces external Schottky diode, improving full-load efficiency by ~8–12% and eliminating diode forward-voltage drop and thermal derating concerns. |
| Fast soft-start | Prevents input inrush current during startup, reducing stress on Li+ batteries and upstream regulators without requiring external timing components. |
Applications
| Microprocessor Core Power | I/O Power Supply |
|---|---|
|
Use Scenario: Powers ARM Cortex-M or RISC-V MCU cores in wearables and IoT edge nodes operating from single-cell Li+. IC Role / Device Role / Timing Role: Primary 1.8V core regulator delivering up to 500mA with tight voltage tolerance and fast load transient recovery. Use Value: Factory-preset 1.8V eliminates feedback resistor layout errors; 4MHz operation allows <1.5mm² total solution size including passives. |
Use Scenario: Supplies 1.8V I/O banks for FPGAs, PMICs, or sensor hubs in compact handheld devices. IC Role / Device Role / Timing Role: Secondary regulated rail with independent enable control via SHDN pin for dynamic power domain management. Use Value: 28µA quiescent current minimizes standby power; voltage-positioning regulation prevents I/O timing violations during burst data transfers. |
| Smartphone Baseband Power | Portable Medical Sensor Module |
|
Use Scenario: Provides clean 1.8V supply to LTE/5G modem baseband processors during RF transmission bursts. IC Role / Device Role / Timing Role: High-PWM-frequency buck converter delivering low-noise, low-ripple power with sub-200ns load-step response. Use Value: Ultrasonic skip mode avoids interference with RF bands; fast transient response (<10µs settling) maintains signal integrity during TX/RX transitions. |
Use Scenario: Powers analog front-end and low-power MCU in FDA-cleared glucose monitors or pulse oximeters. IC Role / Device Role / Timing Role: Primary DC-DC regulator ensuring stable 1.8V under varying battery voltage (3.0–4.2V) and intermittent sensor activation. Use Value: Shutdown current of 0.01µA extends shelf life and operational runtime; SC70 footprint fits within 8mm × 8mm PCB constraints. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS62231DRYR | 2.25V–5.5V input; 1.8V fixed output; 3MHz switching; 350mA rated; 6-pin WSON (2.0 × 2.0mm) | Lower max output current (350mA vs. 500mA); no voltage-positioning regulation; higher quiescent current (12µA vs. 28µA) | Choose for cost-sensitive designs where 350mA suffices and smaller WSON footprint is preferred over SC70. |
| RT8059GJ6 | 2.5V–5.5V input; 1.8V fixed output; 2MHz switching; 500mA rated; 6-pin SOT-563 (1.6 × 1.6mm) | Slower switching limits inductor size reduction (requires ≥2.2µH); lacks ultrasonic skip mode; no LX-sensed feedback | Choose when board space is tighter than performance requirements, accepting larger inductors and higher light-load ripple. |
Compared with TPS62231DRYR and RT8059GJ6, MAX8640ZEXT18+T uniquely combines 500mA capability, 4MHz operation, voltage-positioning regulation, and ultrasonic skip mode in a proven SC70 package-making it optimal for high-performance, space-constrained battery-powered systems demanding both efficiency and transient fidelity.
Availability
MAX8640ZEXT18+T is available at Aetrix Electronics and suitable for microprocessor core power, I/O power, and smartphone baseband supply applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for MAX8640ZEXT18+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
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, automotive, and consumer applications.
The MAX8640Y/MAX8640Z product line was designed specifically for ultra-compact, high-efficiency DC-DC conversion in battery-powered handheld devices-emphasizing minimal external components, low quiescent current, and robust transient behavior.
FAQ
What is the output voltage of the MAX8640ZEXT18+T?
The MAX8640ZEXT18+T features a factory-preset output voltage of 1.8V with ±1% initial accuracy at 25°C and ±2% over the full -40°C to +85°C operating range. This fixed output eliminates the need for external feedback resistors and ensures consistent regulation without calibration.
Does the MAX8640ZEXT18+T require an external Schottky diode?
No, the MAX8640ZEXT18+T does not require an external Schottky diode because it integrates synchronous rectification using internal n-channel and p-channel MOSFETs. This design improves efficiency by up to 12% at full load and removes diode-related thermal and layout constraints.
What is the minimum recommended input voltage for reliable operation of the MAX8640ZEXT18+T?
The MAX8640ZEXT18+T has an undervoltage lockout (UVLO) threshold of 2.6V (typical) with 100mV hysteresis. Reliable operation begins when VIN rises above 2.70V, and the device operates continuously across 2.7V to 5.5V-making it compatible with single-cell Li+ and alkaline battery sources.
Can the MAX8640ZEXT18+T be used with a 2.2µH inductor instead of the recommended 1µH?
While the MAX8640ZEXT18+T is optimized for 1µH inductors to leverage its 4MHz switching frequency, a 2.2µH inductor may be used with verification. Doing so lowers peak inductor current and may improve heavy-load efficiency but reduces switching frequency and increases solution size-potentially negating the key advantage of the MAX8640ZEXT18+T.
How does the MAX8640ZEXT18+T achieve low output ripple at light loads?
The MAX8640ZEXT18+T maintains low output ripple at light loads through ultrasonic pulse-skipping mode, which keeps switching frequencies above 20kHz even down to 1mA load. Combined with voltage-positioning feedback and ceramic output capacitors, this ensures stable regulation and minimal AC content across the full load range.
MAX8640ZEXT18+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 6-TSSOP, SC-88, SOT-363
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2.7V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 1.8V
- Voltage - Output (Max):
- -
- Current - Output:
- 500mA
- Frequency - Switching:
- 4MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SC-70-6
MAX8640ZEXT18+T FAQ
1.How can I place an order for MAX8640ZEXT18+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX8640ZEXT18+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 MAX8640ZEXT18+T reliable?
The price and inventory of MAX8640ZEXT18+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX8640ZEXT18+T is usually 5 days.
3.What payment methods are accepted for MAX8640ZEXT18+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX8640ZEXT18+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX8640ZEXT18+T?
MAX8640ZEXT18+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX8640ZEXT18+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 MAX8640ZEXT18+T?
For technical support, including MAX8640ZEXT18+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX8640ZEXT18+T requirements.
6.How does Aetrix verify that MAX8640ZEXT18+T is sourced from the original manufacturer or authorized distributors?
All MAX8640ZEXT18+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 MAX8640ZEXT18+T meets industry standards.
7.What is the process for return or replacement of MAX8640ZEXT18+T?
All MAX8640ZEXT18+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX8640ZEXT18+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 MAX8640ZEXT18+T part is unused and in its original packaging.
Return procedure for MAX8640ZEXT18+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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