Buck-Boost Narrow VDC Battery Charger with SMBus Interface and USB OTG

Product Status: Mass Production


The ISL9237 is a buck-boost Narrow Output Voltage DC (NVDC) charger utilizing Intersil’s advanced R3™ Technology to provide high light-load efficiency, fast transient response and seamless DCM/CCM transitions for a variety of mobile and industrial applications.

In Charge mode, the ISL9237 takes input power from a wide range of DC power sources (conventional AC/DC charger adapters, USB PD ports, travel adapters, etc.) and safely charges battery packs with up to 3 cells in a series configuration.

ISL9237 supports On-the-Go (OTG) function for 2- and 3-cell battery applications. When OTG function is enabled, the ISL9237 operates in the reverse Buck mode to provide 5V at the USB port.

As a NVDC topology charger, it also regulates the system output to a narrow DC range for stable system bus voltage. The system power can be provided from the adapter, battery or a combination of both. The ISL9237 can operate with only a battery, only an adapter or both connected. For Intel IMVP8 compliant systems, the ISL9237 includes PSYS functionality, which provides an analog signal representing total platform power. The PSYS output will connect to a wide range of Intersil IMVP8 core regulators to provide an IMVP8 compliant power domain function.

The ISL9237 has serial communication via SMBus/I2 C that allows programming of many critical parameters to deliver a customized solution. These programming parameters include, but are not limited to: Adapter current limit, charger current limit, system voltage setting and trickle charging current limit.


  • Buck-boost NVDC charger for 1-, 2- or 3-cell Li-ion batteries
  • Input voltage range 3.2V to 23.4V (no dead zone)
  • System output voltage 2.4V to 13.824V
  • System power monitor PSYS output, IMVP-8 compliant
  • Up to 1MHz switching frequency
  • LDO output for charger VDD
  • Adapter current monitor (AMON)
  • Battery discharging current monitor (BMON)
  • PROCHOT# open-drain output, IMVP-8 compliant
  • Allows trickle charging of depleted battery
  • Optional ASGATE FET control
  • Ideal diode control in Turbo mode
  • Supports OTG function for 2- and 3-cell batteries
  • SMBus and auto-increment I2C compatible
  • Two-level adapter current limit available
  • Pb-free (RoHS compliant)
  • Package 4x4 32 Ld QFN


 Block Diagram


Basic Information
Production Status
Mass Production
Input Voltage Min (V)
Input Voltage Max (V)
Battery Charge Voltage (V)
2.4 to 13.824
Charging Voltage Accuracy Max (%)
Battery Charge Voltage Adjust (%)
8mV steps
Charge Current Limit Accuracy (%)
Trickle Charge Current Limit Accuracy (%)
64mA, 128mA, 256mA, or 512mA
Automatic Power Source Selection
DC Adapter Detection
R3 modulator
Switching Frequency Typ (kHz)
733 or 1000
Max Duty Cycle (%)
Audible Noise
Thermal Shutdown (°C)
150 °C
Battery Chemistry
Multi-Cell Li+/Polymer
Qualification Level
Input Voltage Range (V)
3.2 to 23.4
Can Sample
Temperature Range
-10 to +100

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