My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX1721EUT
- Part No.:
- MAX1721EUT
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package:
- SOT-23-6
- Datasheet:
-
MAX1721EUT.pdf
- Description:
- IC REG CHARGE PUMP INV SOT23-6
- Quantity:
- Payment:
- Shipping:
Inventory:2,700
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
The MAX1721EUT from Maxim Integrated is a monolithic CMOS switched-capacitor voltage inverter with logic-controlled shutdown, designed to generate a regulated negative output (–VIN) from a +1.5V to +5.5V input supply. It operates at 125kHz, delivers up to 25mA continuous output current, achieves 99.9% voltage conversion efficiency, and uses only two 1µF external capacitors - ideal for space-constrained analog biasing in portable instrumentation and LCD power rails.
For engineers reviewing the MAX1721EUT datasheet, MAX1721EUT pinout, MAX1721EUT application, or MAX1721EUT equivalent, this device is selected for ultra-small footprint negative supply generation where low quiescent current (50µA), fast wake-up (<80µs), and active ground pull-down during shutdown are critical design requirements.
Technical Context
The MAX1721EUT implements a four-switch charge-pump topology with integrated power MOSFETs and oscillator control circuitry. Its output voltage follows VOUT ≈ –VIN with droop determined by IOUT × RO (RO = 23Ω typ at VIN = +5V), and it features noninverting shutdown logic (SHDN high = normal operation).
Unlike regulated converters, it provides unregulated inversion with output impedance dominated by internal switch resistance and capacitor ESR. Startup requires input supply capability of ≥90mA peak transient current to ensure reliable turn-on under load.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | +1.5V to +5.5V - supports single-cell Li-ion, alkaline, and 3.3V/5V logic rails without level-shifting. |
| Oscillator Frequency | 125kHz - enables use of small 1µF ceramic flying/output capacitors and reduces EMI vs. lower-frequency alternatives. |
| Output Current | 25mA continuous - sufficient for op-amp biasing, GaAs PA gate drive, and small LCD segment drivers. |
| Voltage Conversion Efficiency | 99.9% - minimizes thermal rise and extends battery life in low-power portable systems. |
| Quiescent Current | 50µA - ensures minimal standby drain in always-on subsystems. |
| Shutdown Supply Current | 1nA - enables multi-year shelf life in battery-backed applications. |
| Wake-Up Time | <80µs - supports rapid power cycling in duty-cycled sensor nodes and display backlight control. |
Pinout & Package
Package: 6-pin SOT23-6, surface-mount, -40°C to +85°C operating temperature range.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| C1+ | Positive terminal of flying capacitor | Connects to top plate of C1; switching node that alternately charges to VIN and discharges to generate inverted output. |
| C1- | Negative terminal of flying capacitor | Connects to bottom plate of C1; referenced to GND during charge phase and to OUT during discharge phase. |
| IN | Positive input supply | Accepts +1.5V to +5.5V; powers internal oscillator and switches; must support ≥90mA peak startup surge. |
| SHDN | Noninverting shutdown control | Logic high = normal operation; logic low = shutdown (OUT actively pulled to GND via 4Ω). |
| OUT | Inverting charge-pump output | Delivers unregulated –VIN output; voltage droops linearly with load (VOUT = –(VIN – IOUT × 23Ω)). |
| GND | Ground reference | Common return for IN, C1-, SHDN, and OUT sink path; requires low-impedance layout to minimize noise and droop. |
Key Features
| Feature | Design Value |
|---|---|
| Logic-controlled shutdown | 1nA shutdown current with active GND pull-down on OUT - eliminates need for external discharge resistors in hold-off states. |
| Ultra-small footprint | 6-pin SOT23-6 package - saves >50% board area vs. 8-pin SOIC inverters and enables placement near noise-sensitive analog ICs. |
| High-efficiency inversion | 99.9% conversion efficiency at light loads - reduces thermal stress and allows operation in sealed enclosures without heatsinking. |
| Minimal external components | Only two 1µF ceramic capacitors required - eliminates electrolytics, simplifies BOM, and improves long-term reliability. |
| Fast dynamic response | <80µs wake-up time - supports microsecond-scale power gating in real-time signal chains and precision ADC reference supplies. |
Applications
| Local Negative Supply from a Positive Supply | Small LCD Panels |
|---|---|
Use Scenario: Generating –5V from a +5V microcontroller rail to power dual-supply op-amps in portable data loggers. IC Role / Device Role / Timing Role: Unregulated voltage inverter providing clean, low-noise negative bias without LDO post-regulation. Use Value: Eliminates discrete inductor-based solutions, reducing EMI and enabling PCB area savings while maintaining ±0.1% gain accuracy in instrumentation amplifiers. | Use Scenario: Supplying –3.3V bias to STN LCD segment drivers in handheld medical devices. IC Role / Device Role / Timing Role: Compact charge-pump inverter delivering stable negative gate voltage for low-threshold LCD backplane switching. Use Value: Enables full-contrast display operation from single 3.3V Li-ion cell with <10mVp-p ripple at 5mA load, meeting ISO 13485 display readability requirements. |
| GaAs PA Bias Supply | Battery-Operated Equipment |
Use Scenario: Providing –2.5V gate bias to GaAs FET power amplifiers in UHF RFID readers. IC Role / Device Role / Timing Role: Low-quiescent-current inverter supporting pulsed RF transmission with fast turn-on to minimize dead time between receive/transmit cycles. Use Value: Achieves 25mA peak gate drive with 50µA standby draw, extending battery life to >12 months in intermittent-use field scanners. | Use Scenario: Creating –1.5V supply from +1.5V alkaline cell for low-voltage comparator hysteresis networks in smoke detectors. IC Role / Device Role / Timing Role: Ultra-low-input-voltage inverter enabling negative reference generation directly from primary cell without boost stage. Use Value: Supports operation down to 1.25V input, ensuring functional margin across full battery discharge curve while consuming <1µA average over 10-year service life. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar switched-capacitor voltage inverter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX1720EUT | 12kHz oscillator frequency; requires 10µF capacitors; 90µA quiescent current; inverted shutdown polarity. | Better suited for ultra-low-ripple applications where larger capacitors are acceptable and slower response is tolerable. | Select MAX1720EUT when EMI sensitivity outweighs size constraints and startup speed is noncritical. |
| MAX860ESA+ | Regulated –2×VIN output; µMAX-8 package; 50mA output; requires external inductor and diode. | Provides stable regulated negative voltage for precision analog circuits where load regulation <1% is mandatory. | Choose MAX860ESA+ only when output regulation, not just inversion, is required - not a drop-in replacement. |
Compared with MAX1720EUT, the MAX1721EUT offers 10× higher switching frequency for smaller capacitors and faster transient response but trades off slightly higher quiescent current; versus MAX860ESA+, it sacrifices regulation and higher output current for zero-inductor simplicity and minimal footprint.
Availability
MAX1721EUT is available at Aetrix Electronics and suitable for battery-powered instrumentation, portable medical displays, GaAs RF biasing, and low-voltage analog subsystems requiring stable component supply across extended production lifecycles.
Supply support for MAX1721EUT 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) designs precision analog, mixed-signal, and power management ICs for industrial, automotive, and communications applications.
The MAX1719/MAX1720/MAX1721 product line targets ultra-compact, low-quiescent-current DC-DC voltage inversion in space- and power-constrained portable electronics.
FAQ
What is the shutdown behavior of the MAX1721EUT?
The MAX1721EUT features noninverting logic-controlled shutdown: driving SHDN high enables normal operation, while driving SHDN low places the device in shutdown mode. During shutdown, the charge-pump switching halts, supply current drops to 1nA, and the OUT pin is actively pulled to GND through a 4Ω internal resistor - eliminating need for external discharge paths. This behavior is confirmed in the Electrical Characteristics table and Pin Description section of the MAX1721EUT datasheet.
Can the MAX1721EUT generate regulated output voltage?
No, the MAX1721EUT is an unregulated switched-capacitor voltage inverter. Its output voltage follows VOUT ≈ –VIN with droop proportional to load current (VDROOP– = IOUT × RO, where RO = 23Ω typ). It does not include feedback or regulation circuitry. For regulated –2×VIN output, refer to the MAX868; for regulated –VIN, consider LDO-based solutions downstream of the MAX1721EUT.
What capacitor values are required for the MAX1721EUT?
The MAX1721EUT requires two 1µF ceramic capacitors: C1 (flying capacitor) between C1+ and C1–, and C2 (output reservoir capacitor) between OUT and GND. A third 1µF bypass capacitor (C3) between IN and GND is recommended. These values are specified in the Typical Operating Circuit and Applications Information sections, and enable optimal 125kHz operation with minimal output resistance and ripple.
What is the maximum continuous output current of the MAX1721EUT?
The MAX1721EUT delivers up to 25mA continuous output current at room temperature with VIN = +5V and proper capacitor selection (1µF ceramics). This value is guaranteed across the full –40°C to +85°C operating range per the Absolute Maximum Ratings and Electrical Characteristics tables. Peak short-circuit current is rated at 100mA, but sustained operation above 25mA will cause excessive droop and thermal stress.
How does the MAX1721EUT differ from the MAX1719EUT?
The MAX1721EUT and MAX1719EUT share identical pinout, package, and core specifications (125kHz frequency, 25mA output, 1µF capacitors), but differ in shutdown logic polarity: MAX1719EUT uses inverting shutdown (SHDN high = shutdown), whereas MAX1721EUT uses noninverting shutdown (SHDN low = shutdown). This distinction is explicitly documented in the Pin Description and Shutdown Mode sections of the datasheet.
MAX1721EUT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- SOT-23-6
- Packaging:
- Bulk
- Product Status:
- Active
- Function:
- Ratiometric
- Output Configuration:
- Positive or Negative
- Topology:
- Charge Pump
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 1.5V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- -Vin, 2Vin
- Voltage - Output (Max):
- -
- Current - Output:
- 25mA
- Frequency - Switching:
- 125kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-6
MAX1721EUT FAQ
1.How can I place an order for MAX1721EUT through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX1721EUT 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 MAX1721EUT reliable?
The price and inventory of MAX1721EUT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX1721EUT is usually 5 days.
3.What payment methods are accepted for MAX1721EUT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX1721EUT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX1721EUT?
MAX1721EUT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX1721EUT 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 MAX1721EUT?
For technical support, including MAX1721EUT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX1721EUT requirements.
6.How does Aetrix verify that MAX1721EUT is sourced from the original manufacturer or authorized distributors?
All MAX1721EUT 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 MAX1721EUT meets industry standards.
7.What is the process for return or replacement of MAX1721EUT?
All MAX1721EUT units undergo pre-shipment inspection (PSI). If there is an issue with MAX1721EUT, 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 MAX1721EUT part is unused and in its original packaging.
Return procedure for MAX1721EUT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX1721EUT 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…
