Overview

The ISL9123B is a highly integrated buck-switching regulator capable of supplying output voltage down to 0.4V. The device features an extremely low quiescent current consumption of 950nA in regulation mode, 140nA in forced bypass mode (ISL9123/A), and 7nA in shutdown mode. It provides 86% efficiency at 10μA load (VIN = 3.6V, VOUT = 3.3V) and has peak efficiency greater than 97% (VIN = 3.6V, VOUT = 3.3V) for ISL9123/A. It supports input voltages from 1.8V to 5.5V.

The ISL9123/A device has automatic bypass functionality for situations in which the input voltage is close to or below the output voltage. In addition to the automatic bypass functionality, the forced bypass power-saving mode can be chosen if voltage regulation is not required. Forced bypass power saving mode is accessible using the I2C interface bus.

The device is capable of delivering up to 600mA of output current (VIN > 2.5V) and provides excellent efficiency because of its adaptive frequency hysteretic control architecture.

The device is designed for stand-alone applications and supports a default output voltage at Power-On Reset (POR). After POR, the output voltage can be adjusted in the range of 0.4V to 5.375V for (ISL9123/A) and to 1.180V (for ISL9123B) by using the I2C interface bus. Specific default output voltages are available upon request. The device requires only a single EIA 0603 size inductor and a minimum of two external capacitors. The power supply solution size is minimized by a 1.8mm x 1.0mm 8 Bump WLCSP and is also available in a 3.0mm x 2.0mm 8 Ld plastic DFN.

ISL9123 Functional Diagram
ISL9123 Functional Diagram
  • 950nA quiescent current
  • 86% efficiency at 10µA load (VIN = 3.6V, VOUT = 3.3V)
  • 97% peak efficiency (VIN = 3.6V, VOUT = 3.3V) (ISL9123/A)
  • Input voltage range: 1.8V to 5.5V
  • Output voltage range: 0.4V to 5.375V (ISL9123/A)
  • Output voltage range: 0.4V to 1.180V (ISL9123B)
  • Output current: up to 600mA (VIN > 2.5V)
  • Selectable forced and auto bypass power saving modes (ISL9123/A only)
  • PFM and PWM modes with seamless transition
  • I2C control and voltage adjustability
  • Hysteretic controller
  • Auxiliary switched output (ISL9123/A only)
  • Small 1.8mm x 1.0mm 8 Bump WLCSP, and 3.0mm x 2.0mm 8 Ld DFN packages

Applications

  • Smart watches and wristband devices
  • Wireless earphones
  • Internet of Things (IoT) devices
  • Water, gas, and oil meters
  • Portable medical devices
  • Hearing aid devices

Documentation

= Featured Documentation
Type Title Date
Datasheet
ISL9123, ISL9123A, ISL9123B Datasheet
PDF 1.57 MB
Brochure
Power Products Brochure
PDF 8.73 MB
Brochure
Industrial Power Management Brochure
PDF 5.49 MB 日本語
3 items

Design & Development

Boards & Kits

ISL9123xIIx-EVZ Evaluation Board

ISL9123xIIx-EVZ

Evaluation
Learn More

Ultra-Low IQ Buck Regulator Evaluation Board

The ISL9123xIIx-EVZ platform allows for quick evaluation of the high-performance features of the ISL9123, ISL9123A, and ISL9123B ultra-low IQ buck regulator in the...

Featured Documents:
ISL9123xIIx-EVZ Evaluation Board Manual

ECAD Models

Schematic symbols, PCB footprints, and 3D CAD models from SamacSys can be found by clicking on products in the Product Options table. If a symbol or model isn't available, it can be requested directly from the website.

Explore ECAD Models
Diagram of ECAD Models

Product Options

    Processing table
    PLP
    Pkg. Type
    Carrier Type
    Moisture Sensitivity Level (MSL)
    Price (USD) | 1ku
    Buy / Sample
    Part Number
    ISL9123BII7Z-T
    circleActive
    memory
    spa
    view_in_ar
    Samples Available
    		 2033 Dec WLCSP-BP Reel 1 Get Samples,
    ISL9123BII9Z-T
    circleActive
    memory
    spa
    view_in_ar
    Samples Available
    		 2033 Dec WLCSP-BP Reel 1 0.8787 Get Samples,
    Parametric Table tips

    Tips for Using This Parametric Table:

    • Hide Filters button in header: Collapse or expands filters
    • Column sort buttons in header: Sort Column alphabetically / numerically descending or ascending
    • Reset button in header: Reset all filters to the page default
    • Full Screen button in header: Expand the table to full screen view (user must close out of full screen before they can interact with rest of page)
    • Export button in header: Export the filtered results of the table to an Excel document
    • Filter parts search bar in header: Type to filter table results by part number
    • Hide column button in column headers: Select to hide columns in table
    • AND / OR toggle switches in header: Toggles the logic of this particular filter to be “AND” or “OR” logic for filtering results
    • Multiselect checkboxes at beginning of each row in table: Select these checkboxes to compare products against each other
    • Document icon next to product name in row: View the featured document for this product
    • Chip icon next to the right of the document icon in row: View the block diagram for this product
    • Cart icon to the right of the chip icon: Indicates that samples are available for this product