The one-cell battery operation is very attractive since it allows for the design of smaller and more lightweight products at lower cost. In multiple-cell operation of rechargeable batteries often one cell can be destroyed by a deep discharge. With one battery cell and depending on the application, one inductor only as external component, a very small circuit can be realized with the PR4401/4402 – both SOT23 packaged. The driven LED current is almost independent from the supply voltage, which guarantees a constant brightness even with a discharging battery.
PR4401 and PR4402 samples are available upon request