BQ24086 , BQ24088 , BQ24085 are all BQ2408x series are highly integrated Li-Ion batteries, ideal for low dropout designs of single-cell LiLi-Pol linear chargers for space-constrained applications Space-constrained Ion or Li in portable applications -Pol package. The BQ2408x series provides a current and constant voltage. Charge termination ±0.5% voltage regulation accuracy based on minimum current. One internally adjusts the time phase dynamically during thermal regulation. The BQ2408x automatically restarts charging if the battery voltage falls below an internal threshold, using a safety timer for precharge regulation; indicating charge removed, fault and power good outputs. Several versions of this device family implement low-power terminal AC adapters.

Function

Integrated power FETs and current sensors provide multiple protection features and functional options.

Reverse leakage protection prevents the battery in a small package and the battery is charged three times.

Thermal regulation maximizes charge rate Programmable charge timer provides backup.

Charge termination with minimum current and termination of charge protection dynamically adjust timing during thermal regulation.

Status output setting for LED or system interface sleep mode when external input power is on.

Short circuit and thermal protection make it easy to design the bq2408x in cradle chargers or in end equipment while using low cost or high automatic sleep modes for low power consumption.

Small 3×3 mm MLP package device information (1).

Optional Battery Insertion and Battery Missing Part Number Package Dimensions (NOM).

Input overvoltage protection (1) for all available packages.

Typical Application Circuit Diagram

Pin Configuration and Function

BQ24086 and BQ24088 DRC package 10-pin VSON top view

BQ24085 DRC Package 10-Pin VSON Top View

BQ24087 DRC Pack 10-Pin VSON Top View

Detailed description:

Overview: The charging current is programmable using an external component (RISET resistor). The charging process begins with an external input supply connected to the system, the charger is enabled by CE = LO, the battery voltage is below the recharge threshold, V(BAT) 112 °C), as shown in the figure below.

Using the TJ (REG) charging profile

Modifies the activation of the charge cycle integrated thermal control loop if operating conditions cause the IC junction temperature to exceed TJ(REG). The internal connection activates the thermal control loop temperature monitoring voltage below the fixed, temperature stable internal voltage. The temperature monitoring voltage at the junction is inversely proportional to the IC junction temperature. Thermal cycling overrides other charger control loops and reduces charging current until the IC junction temperature returns to TJ(REG), effectively regulating the IC junction temperature.

Thermal Regulation Circuit Diagram

The effective modified charge cycle of the thermal loop is shown in the figure below.

Charge Profile, Thermal Cycling Activated

Functional block diagram