I. Overall Description

The JZ3125 is a complete constant current/constant voltage linear charger IC, powering a single battery or a 2-battery supercapacitor from 2.7V to 6V. The device includes an on-chip power MOSFET, eliminating the need for external sensing resistors and blocking diodes. Thermal feedback regulates the charging current to limit the mold temperature under high power operation or high ambient temperatures. The voltage regulation is set by a resistor divider externally. The charging current can be set externally with a resistor.

The internal source-balanced circuit maintains equal voltage for each super capacitor. When the input power is removed, the JZ3125 automatically enters a low-power sleep mode, reducing the super capacitor current to below 3uA.

Additional features include chip enable, undervoltage lockout, and supercapacitor power good indicator.

JZ3125 is a thermally enhanced 8-pin SOP package.

Section 2: Application

Electric Meter

SuperCap backup circuit

PC Card, USB modem

Portable device

III. Features

Operating Voltage Range: 2.7V to 6V

Die-mounted MOSFET

No external blocking diode or current detecting resistor required.

Constant pressure is set by an external resistor.

Charging current is set by an external resistor.

Continuous charging current up to 1.5A

Automatic battery balancing to prevent overvoltage during supercapacitor charging

Constant current/constant voltage operation with thermal regulation, maximizing charging rate without overheating risk.

*Automatic low-power sleep mode activated when input power voltage is removed

Super Capacitor Power Normal Indicator

Microchip startup

eSOP8 Software Package

Lead-free, RoHS-free, Halogen-free