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Ultra-Low Quiescent Current, Low Noise 3.5W Buck-Boost Regulator

Optimized Power for Wearable Biometric Sensing and Internet of Things

Product Details

The MAX20343/MAX20344 is an ultra-low quiescent current, noninverting buck-boost converter with 1A current capability at 3.5V intended for applications that require long run times while also demanding bursts of high current. The device employs a unique control algorithm which seamlessly transitions between buck, buck-boost, and boost modes, minimizing discontinuities and subharmonics in the output voltage ripple. The low 1.9V input voltage for startup allows users to power the device from a variety of sources, and the near-zero minimum operating voltage gives the user the ability to extract as much as possible from their energy source. The MAX20343/MAX20344 has also been designed to keep inductance and output capacitance requirements as low as possible for space-constrained applications.

The MAX20343/MAX20344 is ideal for power in optical sensor applications as well as for powering radios in low power, wide area network (LPWAN) applications since in both cases noise must be minimal and efficiency must be high. For instance, the small light-load output voltage ripple allows a photoplethysmography (PPG) system to operate at low LED currents without interference. Additionally, seamless transitions between operating modes enables the use of dynamic voltage scaling (DVS) to minimize headroom on the LED and to save power in such systems. In applications where a low-power-density battery must be buffered by a super-capacitor to provide large LPWAN type bursts of current, the ultra-low operating voltage of the MAX20343/MAX20344 allows the user to extract as much energy as possible from the super capacitor. The low output inductance/capacitance requirement allows a small total solution size. For example in PPG systems, this provides the flexibility to place the MAX20343/MAX20344 on a remote optical module if overcrowding on the main PCB is an issue.

The MAX20343/MAX20344 is available with a highly configurable I2C serial interface or as a single-pin-enabled fixed-programming version. See Table 3 for specific device settings. MAX20343 operates over the -40°C to +85°C temperature range, is available in a 16-bump, 1.77mm x 2.01mm, 0.4mm pitch WLP package and a 12-pin, 2.50mm x 2.50mm, 0.5mm pitch FC2QFN package. MAX20344 operates over the -40° C to +125°C temperature range, and is available in a 12-pin, 2.50mm x 2.50mm, 0.5mm pitch FC2QFN package.

Key Features

  • Extend System Run Time
    • Ultra-Low, 3.5µA (typ) Quiescent Current
    • 250mW Ouptut Power with 500mV Input Voltage
    • Dynamic Voltage Scaling (DVS)
  • Low, Continuous Noise Profile
    • Eliminates Discontinuities Across Operating Voltage Range
    • Eliminates Post-Filtering LDO in Noise Sensitive Applications
  • Adaptable Load Transient Response
    • Adjustable Peak Current for Optimal Performance in Each Application
    • Fast Load Transient Response Minimizes Settling Time
    • Optional Feedback Integrator
      • Enable for up to 3.5W Output Power Capabilities
      • Disable for up to 1.75W Output Power and Faster Load Transient Settling Time
    • FAST Pin Pretriggers Load Response and Offers Improved Load Transient
  • Flexible Control Options
    • I2C Interface with Status Interrupts
    • EN and Status Pins, Single-Resistor VOUT Selection (RSEL)
    • See Table 3 for specific device defaults
  • Extended Operating Temperature from -40°C to +85°C (MAX20343), -40°C to +125°C (MAX20344)
  • Optimally Sized for Small Applications
    • 16-bump, 1.77mm x 2.01mm, 0.4mm Pitch WLP 12-pin, 2.50mm x 2.50mm, Side-Wettable, 0.5mm Pitch Flip-Chip QFN
    • Inductor/Capacitor Available in 0603/0402 Case Sizes

Applications/Uses

  • Biometric Optical Sensing Including PPG
  • Industrial Sensors
  • IoT
  • LPWAN (LTE/NB-IoT, LTE/Cat-M1)
Parametric specs for Step-Down/Up (Buck Boost) Regulator
VIN (V) (min) 0.4
VIN (V) (max) 5.5
VOUT1 (V) (min) 2.5
VOUT1 (V) (max) 5.5
IOUT1 (A) (max) 1
Switch Type Internal
Preset VOUT (V) 5
VOUT1 Tolerance (±%) 3
Output Adjust. Method Preset
Resistor
Synchronous Switching Yes
Power Good Signal Yes
ICC (mA) (max) 0.0035
# DC-DC Outputs 1
Alternate Topology Step-Down
Step-Up
Switching Frequency (kHz) 1000
2000
Design Tools EE-Sim
Package/Pins FC2QFN/12
WLP/16
Oper. Temp. (°C) -40 to +85
Budgetary
Price (See Notes)
$1.40 @1k
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Simplified Block Diagram

MAX20343: Typical Application Circuit MAX20343: Typical Application Circuit Zoom icon

Technical Docs

Design & Development

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Description

The MAX20343 evaluation kit (EV kit) is a fully assembled and tested circuit that evaluates the MAX20343 3.5W, buck-boost regulator. The MAX20343 is designed for low-noise, battery-powered applications that require long runtimes. The EV kit is compatible with both the I2C controlled and single-pin-enabled versions of the MAX20343.

Refer to the MAX20343 IC data sheet for detailed information regarding the operation and features of the device.

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Features

  • RoHS Compliant
  • Proven PCB Layout
  • Fully Assembled and Tested
  • USB Controllable for I2C Configured Devices

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Parameters

Parametric specs for Step-Down/Up (Buck Boost) Regulator
VIN (V) (min) 0.4
VIN (V) (max) 5.5
VOUT1 (V) (min) 2.5
VOUT1 (V) (max) 5.5
IOUT1 (A) (max) 1
Switch Type Internal
Preset VOUT (V) 5
VOUT1 Tolerance (±%) 3
Output Adjust. Method Preset
Resistor
Synchronous Switching Yes
Power Good Signal Yes
ICC (mA) (max) 0.0035
# DC-DC Outputs 1
Alternate Topology Step-Down
Step-Up
Switching Frequency (kHz) 1000
2000
Design Tools EE-Sim
Package/Pins FC2QFN/12
WLP/16
Oper. Temp. (°C) -40 to +85
Budgetary
Price (See Notes)
$1.40 @1k

Key Features

  • Extend System Run Time
    • Ultra-Low, 3.5µA (typ) Quiescent Current
    • 250mW Ouptut Power with 500mV Input Voltage
    • Dynamic Voltage Scaling (DVS)
  • Low, Continuous Noise Profile
    • Eliminates Discontinuities Across Operating Voltage Range
    • Eliminates Post-Filtering LDO in Noise Sensitive Applications
  • Adaptable Load Transient Response
    • Adjustable Peak Current for Optimal Performance in Each Application
    • Fast Load Transient Response Minimizes Settling Time
    • Optional Feedback Integrator
      • Enable for up to 3.5W Output Power Capabilities
      • Disable for up to 1.75W Output Power and Faster Load Transient Settling Time
    • FAST Pin Pretriggers Load Response and Offers Improved Load Transient
  • Flexible Control Options
    • I2C Interface with Status Interrupts
    • EN and Status Pins, Single-Resistor VOUT Selection (RSEL)
    • See Table 3 for specific device defaults
  • Extended Operating Temperature from -40°C to +85°C (MAX20343), -40°C to +125°C (MAX20344)
  • Optimally Sized for Small Applications
    • 16-bump, 1.77mm x 2.01mm, 0.4mm Pitch WLP 12-pin, 2.50mm x 2.50mm, Side-Wettable, 0.5mm Pitch Flip-Chip QFN
    • Inductor/Capacitor Available in 0603/0402 Case Sizes

Applications/Uses

  • Biometric Optical Sensing Including PPG
  • Industrial Sensors
  • IoT
  • LPWAN (LTE/NB-IoT, LTE/Cat-M1)

Description

The MAX20343/MAX20344 is an ultra-low quiescent current, noninverting buck-boost converter with 1A current capability at 3.5V intended for applications that require long run times while also demanding bursts of high current. The device employs a unique control algorithm which seamlessly transitions between buck, buck-boost, and boost modes, minimizing discontinuities and subharmonics in the output voltage ripple. The low 1.9V input voltage for startup allows users to power the device from a variety of sources, and the near-zero minimum operating voltage gives the user the ability to extract as much as possible from their energy source. The MAX20343/MAX20344 has also been designed to keep inductance and output capacitance requirements as low as possible for space-constrained applications.

The MAX20343/MAX20344 is ideal for power in optical sensor applications as well as for powering radios in low power, wide area network (LPWAN) applications since in both cases noise must be minimal and efficiency must be high. For instance, the small light-load output voltage ripple allows a photoplethysmography (PPG) system to operate at low LED currents without interference. Additionally, seamless transitions between operating modes enables the use of dynamic voltage scaling (DVS) to minimize headroom on the LED and to save power in such systems. In applications where a low-power-density battery must be buffered by a super-capacitor to provide large LPWAN type bursts of current, the ultra-low operating voltage of the MAX20343/MAX20344 allows the user to extract as much energy as possible from the super capacitor. The low output inductance/capacitance requirement allows a small total solution size. For example in PPG systems, this provides the flexibility to place the MAX20343/MAX20344 on a remote optical module if overcrowding on the main PCB is an issue.

The MAX20343/MAX20344 is available with a highly configurable I2C serial interface or as a single-pin-enabled fixed-programming version. See Table 3 for specific device settings. MAX20343 operates over the -40°C to +85°C temperature range, is available in a 16-bump, 1.77mm x 2.01mm, 0.4mm pitch WLP package and a 12-pin, 2.50mm x 2.50mm, 0.5mm pitch FC2QFN package. MAX20344 operates over the -40° C to +125°C temperature range, and is available in a 12-pin, 2.50mm x 2.50mm, 0.5mm pitch FC2QFN package.

Simplified Block Diagram

MAX20343: Typical Application Circuit MAX20343: Typical Application Circuit Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal.