My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX8668ETET+T
- Part No.:
- MAX8668ETET+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Voltage Regulators - Linear + Switching
- Package:
- 16-WFQFN Exposed Pad
- Datasheet:
-
MAX8668ETET+T.pdf
- Description:
- IC REG QUAD BUCK/LNR SYNC 16TQFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,938
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MAX8668ETET+T from Maxim Integrated is a dual step-down DC-DC converter with dual low-noise LDO regulators, designed to power microprocessors and DSPs in portable electronics. It delivers 600mA at OUT1 and 1200mA at OUT2, supports adjustable output voltages from 0.6V to 3.3V, operates at 1.5MHz hysteretic-PWM, and achieves 100µA no-load supply current with all outputs enabled - enabling compact, high-efficiency power management in smartphones and digital cameras.
For engineers reviewing the MAX8668ETET+T datasheet, MAX8668ETET+T pinout, MAX8668ETET+T application, or MAX8668ETET+T equivalent, key selection criteria include its dual adjustable buck topology, individual enable inputs per regulator, 3mm × 3mm thin QFN package, and integrated voltage positioning for transient load stability without excessive output capacitance.
Technical Context
The MAX8668ETET+T implements two independent hysteretic-PWM step-down converters (OUT1/OUT2) with p-channel high-side switches and synchronous n-channel rectifiers, enabling fixed-frequency operation near 1.5MHz while minimizing external component count. Each buck stage features programmable feedback via FB1/FB2 pins, valley-current limiting (600mA/1200mA guaranteed), and voltage positioning through inductor DCR sensing.
Complementing the buck stages are two 300mA LDOs (OUT3/OUT4) with 1.7V minimum input, 250mV max dropout at full load, and ultra-low 20µA quiescent current. All four regulators feature individual EN inputs, thermal shutdown at +160°C, and UVLO thresholds of 2.5V (IN12) and 1.6V (IN34), supporting flexible sequencing in battery-powered systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Step-down output current | 600mA (OUT1), 1200mA (OUT2) - guaranteed delivery under worst-case thermal conditions, enabling direct powering of core logic rails. |
| Output voltage range | 0.6V to 3.3V (adjustable via FB1/FB2 resistive dividers) - supports modern low-voltage SoCs including ARM Cortex-A/M cores. |
| Switching frequency | 1.5MHz (typical) - allows use of tiny 2.2µH chip inductors (0805 size) and reduces EMI filtering burden. |
| No-load supply current | 100µA (typ, all regulators enabled) - extends battery life in standby modes of portable devices. |
| LDO dropout voltage | 250mV (max at 300mA) - enables operation from single-cell Li-ion (3.0V min) while maintaining regulation on 2.8V rails. |
| Package | 16-pin thin QFN, 3mm × 3mm - surface-mount footprint compatible with high-density mobile PCB layouts. |
| Operating temperature | –40°C to +85°C - qualified for industrial and consumer portable equipment environments. |
Pinout & Package
MAX8668ETET+T is housed in a 16-pin, 3mm × 3mm thin QFN package with exposed paddle (EP) that must be connected to GND, PGND1, and PGND2 for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (EN3) | Enable input for LDO OUT3 | Active-high control; drives regulator into low-quiescent shutdown when pulled low - enables precise power sequencing. |
| 2 (OUT3) | LDO output 3 | 300mA regulated output; requires 4.7µF ceramic bypass to GND - supplies noise-sensitive analog or I/O rails. |
| 3 (IN34) | Input supply for LDOs OUT3/OUT4 | 1.7V–5.5V input; must be ≤ VIN12 - shared input allows single LDO supply rail for multiple low-noise domains. |
| 4 (OUT4) | LDO output 4 | 300mA regulated output; independent of OUT3 - supports dual-sensor or dual-peripheral biasing. |
| 5 (EN4) | Enable input for LDO OUT4 | Independent enable; decouples OUT4 from system reset timing - critical for camera module or audio codec sequencing. |
| 6 (GND) | Analog ground reference | Common return for REF, FB1, FB2, and logic inputs - must be star-connected to minimize noise coupling. |
| 7 (REF) | Internal 0.6V reference output | Bypassed with 0.01µF ceramic capacitor - provides stable reference for external feedback networks and precision monitoring. |
| 8 (FB2) | Feedback input for step-down OUT2 | Connects to resistor divider between OUT2 and GND - sets output voltage and enables voltage positioning via LX2 node sensing. |
| 9 (PGND2) | Power ground for OUT2 buck stage | High-current return path for LX2 switching loop - must be isolated from AGND and tied directly to EP for EMI control. |
| 10 (LX2) | Switch node for OUT2 buck stage | Drives external 2.2µH inductor; contains fast-edge switching transients - requires tight layout with minimal loop area. |
| 11 (IN12) | Input supply for buck regulators OUT1/OUT2 | 2.6V–5.5V input; must be ≥ VIN34 - powers high-efficiency conversion for processor cores and memory interfaces. |
| 12 (LX1) | Switch node for OUT1 buck stage | Drives external 2.2µH inductor; synchronous rectification eliminates Schottky diode - improves light-load efficiency. |
| 13 (PGND1) | Power ground for OUT1 buck stage | Separate high-current return for LX1 loop - prevents cross-talk between buck stages and maintains regulation accuracy. |
| 14 (FB1) | Feedback input for step-down OUT1 | Connects to resistor divider between OUT1 and GND - enables independent voltage setting and transient optimization per rail. |
| 15 (EN1) | Enable input for buck OUT1 | Active-high; initiates soft-start with 25µs delay (tEN) - controls CPU core power-up sequence relative to peripherals. |
| 16 (EN2) | Enable input for buck OUT2 | Independent enable; supports staggered startup to limit inrush - essential for multi-rail SoC power management. |
| EP | Exposed thermal paddle | Must be soldered to solid GND plane - dissipates up to 1667mW at +70°C ambient and lowers junction temperature by >20°C. |
Key Features
| Feature | Design Value |
|---|---|
| Dual adjustable buck + dual LDO integration | Reduces BOM count by consolidating four independent power rails into one 3mm × 3mm IC - eliminates need for discrete regulators and associated passives. |
| Voltage positioning via FB/LX sensing | Compensates for inductor DCR-induced droop during load transients - cuts peak-to-peak output deviation by up to 50% and reduces required output capacitance by 30%. |
| 1.5MHz hysteretic-PWM architecture | Enables use of 2.2µH 0805 inductors and 2.2µF ceramic output caps - shrinks total solution size to < 25mm² per buck channel. |
| Individual EN inputs with soft-start | Supports arbitrary power-on sequencing (e.g., LDOs before bucks, or core before I/O) - eliminates external sequencers and simplifies firmware boot logic. |
| Ultra-low 20µA LDO quiescent current | Maintains regulation on always-on rails (e.g., RTC, sensor bias) while drawing less than 1µA total from coin cell - extends shelf life of portable medical devices. |
Applications
| Smartphone Application | Digital Camera Application |
|---|---|
|
Use Scenario: Powering application processor (ARM Cortex-A73/A53), DDR memory, and image signal processor (ISP) in a 5G smartphone. IC Role / Device Role / Timing Role: MAX8668ETET+T delivers 1.2V/600mA (core), 1.8V/1200mA (memory), and dual 2.8V/300mA LDOs (ISP analog, camera interface) with synchronized enable sequencing. Use Value: Voltage positioning minimizes VDD_CORE droop during burst capture, preventing CPU throttling; 100µA no-load current extends standby time beyond 72 hours. |
Use Scenario: Supplying CMOS image sensor, lens actuator driver, and video encoder in a compact 4K action camera. IC Role / Device Role / Timing Role: MAX8668ETET+T generates 1.1V/600mA (sensor digital), 2.8V/1200mA (sensor analog), and dual 3.3V/300mA LDOs (actuator bias, HDMI PHY). Use Value: Independent EN3/EN4 enables lens calibration before sensor activation; low-output-noise LDOs reduce image banding below 0.5 LSB RMS. |
| PDA / Palmtop Computer | Portable MP3/DVD Player |
|
Use Scenario: Powering OMAP-class applications processor, NAND flash, and touchscreen controller in a ruggedized handheld terminal. IC Role / Device Role / Timing Role: MAX8668ETET+T provides 1.0V/600mA (CPU), 1.8V/1200mA (DDR), and dual 3.3V/300mA LDOs (touch controller, SD card interface) with cold-temperature startup down to –40°C. Use Value: UVLO thresholds (2.5V IN12, 1.6V IN34) prevent brownout resets during battery sag; thermal shutdown protects against enclosure overheating in sealed enclosures. |
Use Scenario: Delivering clean, sequenced power to audio DAC, OLED display driver, and laser pickup motor in a pocket-sized DVD player. IC Role / Device Role / Timing Role: MAX8668ETET+T supplies 1.2V/600mA (DAC core), 3.3V/1200mA (OLED VDD), and dual 2.5V/300mA LDOs (audio bias, motor control logic). Use Value: Low 75µVRMS LDO noise ensures THD+N < –95dB in headphone output; 1.5MHz switching avoids audible beat frequencies in speaker amplifiers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-buck-plus-dual-LDO power management applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS65023RSBR | Fixed-output buck voltages (no FB adjustment); 3.3V/1.8V/1.2V preset; 600mA/600mA/600mA; 2.25MHz switching; no voltage positioning. | Suitable for simpler SoCs with unchanging rail requirements; lacks flexibility for custom voltage scaling or transient optimization. | Select TPS65023RSBR only when fixed 3.3V/1.8V/1.2V rails match system needs and board space permits larger 4mm × 4mm QFN. |
| RT8070ZSP | Dual adjustable buck (0.6V–5.5V) + single LDO (300mA); 2.5MHz switching; no individual LDO enables; 20V max input; no voltage positioning. | Targets higher-input systems (e.g., USB PD, 12V adapters); insufficient for dual-LDO-dependent applications like camera modules. | Choose RT8070ZSP only for cost-sensitive designs needing one LDO and higher VIN capability - not a functional replacement for MAX8668ETET+T's four-rail architecture. |
Compared with TPS65023RSBR and RT8070ZSP, the MAX8668ETET+T uniquely combines adjustable dual-buck outputs, dual independently enabled LDOs, voltage positioning, and 1.5MHz operation in a 3mm × 3mm footprint - making it the only option supporting dynamic rail tuning and strict noise/transient requirements in space-constrained portable devices.
Availability
MAX8668ETET+T is available at Aetrix Electronics and suitable for smartphone power management, digital camera subsystems, and portable media player designs requiring stable component supply, long-term lifecycle support, and traceable sourcing for production ramp.
Supply support for MAX8668ETET+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 semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for portable, industrial, and communications applications.
The MAX8668ETET+T belongs to Maxim's portable power management product line, engineered specifically to replace multi-chip discrete power solutions in battery-powered devices where size, efficiency, and sequencing flexibility are critical.
FAQ
What is the maximum input voltage for the MAX8668ETET+T step-down regulators?
The MAX8668ETET+T step-down regulators (OUT1 and OUT2) accept an input voltage range of 2.6V to 5.5V on the IN12 pin. This supply must be greater than or equal to the IN34 voltage. Exceeding 5.5V risks permanent damage, as absolute maximum rating for IN12 is +6.0V relative to GND. The MAX8668ETET+T includes undervoltage lockout that disables switching below 2.4V (typ) on IN12 to prevent unstable operation.
Can the MAX8668ETET+T generate different output voltages on OUT1 and OUT2 simultaneously?
Yes, the MAX8668ETET+T supports independent output voltage programming on OUT1 and OUT2 using separate resistor feedback networks connected to FB1 and FB2. Each output can be set anywhere from 0.6V to 3.3V. For example, OUT1 may be configured to 1.1V for a processor core while OUT2 is set to 2.8V for I/O - both operating concurrently with individual enable control. The MAX8668ETET+T datasheet provides exact resistor calculation formulas based on the 0.6V internal reference.
How does voltage positioning work on the MAX8668ETET+T, and why is it beneficial?
Voltage positioning on the MAX8668ETET+T uses the LX1/LX2 switch-node feedback to intentionally introduce controlled output droop proportional to load current - matching the expected IR drop across the inductor's DCR. This reduces peak-to-peak voltage deviation during rapid load transients by up to 50%, allowing smaller output capacitors and improving system stability. It is implemented via optional resistor R6 in the FB network and is unique to the MAX8668ETET+T among comparable dual-buck ICs.
What is the purpose of the REF pin on the MAX8668ETET+T, and how should it be used?
REF is the dedicated output of the MAX8668ETET+T's internal 0.600V ±1% precision reference. It must be bypassed with a 0.01µF ceramic capacitor to GND to ensure stability of the feedback loops for OUT1 and OUT2. While not intended as a general-purpose reference, REF provides a low-noise, temperature-stable node for external monitoring circuits or precision ADC references - and its accuracy directly affects the regulation tolerance of the adjustable buck outputs.
Does the MAX8668ETET+T support power sequencing, and how is it implemented?
Yes, the MAX8668ETET+T provides full power sequencing control via four independent enable inputs: EN1 and EN2 for the buck regulators, EN3 and EN4 for the LDOs. Each input has a defined enable time (tEN = 15µs for bucks, 35µs for LDOs) and a longer power-on time (tPWRON = 25µs for bucks, 45µs for LDOs) when exiting shutdown. This allows designers to implement custom startup orders - such as enabling LDOs before bucks, or sequencing core before I/O - without external hardware.
MAX8668ETET+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 16-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Topology:
- Step-Down (Buck) Synchronous (2), Linear (LDO) (2)
- Number of Outputs:
- 4
- Frequency - Switching:
- 1.5MHz
- Voltage/Current - Output 1:
- 0.6V ~ 3.3V, 600mA
- Voltage/Current - Output 2:
- 0.6V ~ 3.3V, 1.2A
- Voltage/Current - Output 3:
- 3.3V, 300mA
- w/LED Driver:
- No
- w/Supervisor:
- No
- w/Sequencer:
- No
- Voltage - Supply:
- 2.6V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-TQFN (3x3)
MAX8668ETET+T FAQ
1.How can I place an order for MAX8668ETET+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX8668ETET+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 MAX8668ETET+T reliable?
The price and inventory of MAX8668ETET+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX8668ETET+T is usually 5 days.
3.What payment methods are accepted for MAX8668ETET+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX8668ETET+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX8668ETET+T?
MAX8668ETET+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX8668ETET+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 MAX8668ETET+T?
For technical support, including MAX8668ETET+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX8668ETET+T requirements.
6.How does Aetrix verify that MAX8668ETET+T is sourced from the original manufacturer or authorized distributors?
All MAX8668ETET+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 MAX8668ETET+T meets industry standards.
7.What is the process for return or replacement of MAX8668ETET+T?
All MAX8668ETET+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX8668ETET+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 MAX8668ETET+T part is unused and in its original packaging.
Return procedure for MAX8668ETET+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX8668ETET+T Tags
-
TPS6521905RHBR
Texas Instruments
-
MIC3385YHL-TR
Microchip Technology
-
A4402ELPTR-T
Allegro MicroSystems
-
LM26480SQ-AA/NOPB
Texas Instruments
-
A4402KLPTR-T
Allegro MicroSystems
-
BD71847AMWV-E2
ROHM Semiconductor
-
ADP5040ACPZ-1-R7
Analog Devices Inc.
-
LT3048IDC#TRPBF
Analog Devices Inc.
-
ADP5037ACPZ-R7
Analog Devices Inc.
-
XRP7714ILB-F
MaxLinear, Inc.
-
LTC3260EDE#TRPBF
Analog Devices Inc.
-
LTC3260EMSE#PBF
Analog Devices Inc.
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…
