CN3085

CN3085 is a charge management IC for NiMH batteries, supporting single to three-cell NiMH battery charging. The device integrates a power transistor internally, eliminating the need for external current sensing resistors and blocking diodes. CN3085 requires minimal external components, making it ideal for portable products. A thermal regulation circuit keeps the die temperature within a safe range when the device power dissipation is high or the ambient temperature is elevated. A high-precision voltage comparator is integrated on-chip to accurately set the constant-current charge termination voltage. The CN3085 charge current is set by a single external resistor. When the input voltage is removed, CN3085 automatically enters a low-power sleep mode, reducing battery current consumption to less than 3µA. Additional features include input undervoltage lockout, trickle charging at low battery voltage, automatic recharge, constant-current charging, maintenance charging (timer-based), battery temperature monitoring, and status indication. CN3085 is available in a thermally enhanced 8-pin small outline package (SOP8/PP). CN3085 is a linear charger IC for NiMH battery charge management. CN3085 requires no external blocking diodes or current sensing resistors and needs only minimal external components, making it well suited for portable products. The charge current is set by an external resistor, with a maximum charge current of up to 1A. The internal power management circuit of CN3085 automatically reduces the charge current when the junction temperature exceeds 135°C. This feature allows users to maximize the device's power handling capability without concern about overheating damaging the IC or external components. As a result, designers can target typical-case conditions rather than worst-case scenarios when setting the charge current, since CN3085 will automatically reduce the charge current under worst-case conditions. When the input voltage is removed or falls below the battery voltage, CN3085 enters a low-power sleep mode with battery current consumption less than 3µA, thereby extending standby time.

Applications

• Digital cameras
• Electronic dictionaries
• Portable devices
• NiMH battery charging applications

Key features

• Integrated power transistor
• 1% voltage accuracy
• Trickle charging at low battery voltage
• User-programmable charge current up to 1A
• Constant-current/constant-temperature charging to maximize charge current while preventing overcharging
• Automatic low-power sleep mode on power supply dropout
• Status output drives LED or interfaces with MCU
• Maintenance (timed) charging
• Automatic recharge
• Battery temperature monitoring
• SOP8/PP package
• Lead-free, RoHS compliant, halogen-free