Single-cell Li-Ion charger with USB input and integrated protection
It accepts a USB input up to 10.2 V and delivers a programmable constant charge current with a maximum of 500 mA. The charger integrates over-temperature, over-voltage, reverse-current, and short-circuit fault protection, eliminating the need for external supervisory components.
500 mA charge current — what it means for charge time
The 500 mA maximum charge current sets the ceiling for how fast a single Li-Ion cell can be charged. For a typical 1000 mAh cell, this gives a 2-hour charge time from empty, assuming the input supply can sustain the current. The charge current is constant and programmable via an external resistor, so the designer can set a lower rate for smaller cells or thermal budget constraints. This current level suits handheld devices, wearables, and IoT nodes where the battery is under 2000 mAh.
Temperature range: -5°C to 125°C — watch the cold end
The operating junction temperature range spans -5°C to 125°C. The -5°C lower limit is unusual for a charger IC — most industrial parts start at -40°C. This means the BQ24232HARGTR is not rated for charging below -5°C, which is a Li-ion safety constraint (charging below 0°C can damage the cell). For designs that must charge in freezing environments, a different charger with a -40°C lower limit or a battery heater strategy is needed. The 125°C upper limit covers hot enclosures and high ambient conditions typical of portable gear.
Fault protection set — no external supervisor needed
The BQ24232HARGTR integrates over-temperature, over-voltage, reverse-current, and short-circuit protection. Over-voltage protection guards against input spikes above the battery voltage; reverse-current blocking prevents battery discharge back into the input when the supply is removed. Short-circuit protection on the output limits fault current. This protection set covers the main failure modes for a single-cell Li-ion charger, so the BOM does not need a separate battery protector or ideal-diode OR-ing controller.
Package and footprint: 16-VQFN (3x3 mm)
The device comes in a 16-VFQFN exposed-pad package, supplier device package 16-VQFN (3x3 mm). The small 3x3 mm footprint saves board area in space-constrained designs like earbuds, smartwatches, or USB dongles.
The base product number is BQ24232, and the HARGTR suffix denotes the specific package and reel configuration.