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Product Attributes

Introduction

ALD810023/ALD910023 are members of the ALD8100xx (quad-channel) and ALD9100xx (dual-channel) Supercapacitor Auto Balance MOSFET (SAB™ MOSFET) family. SAB MOSFETs are fabricated using production-proven EPAD® technology and are designed to address voltage and leakage current balancing of series-connected supercapacitors. Supercapacitors, also known as ultracapacitors or supercaps, can achieve leakage current balancing in series connections by placing one or more devices across each supercapacitor cell, preventing overvoltage conditions. Each SAB MOSFET has a precisely defined gate threshold voltage in Vt mode, which is 2.30V when the gate-drain-source terminals (VGS = VDS) are connected together at a drain-source current of IDS(ON) = 1μA. In this mode, the input voltage VIN = VGS = VDS. Different VIN levels produce output current IOUT = IDS(ON) characteristics, forming an effective variable resistance whose value varies exponentially with VIN. When connected across each series-connected supercapacitor, this balances the voltage and current of each supercapacitor cell within its rated limits. The voltage-dependent on-resistance characteristic of the ALD810023/ALD910023 effectively controls overvoltage rise across supercapacitors when connected in parallel with them. In a series-connected supercapacitor stack, when the voltage across one supercapacitor rises, the voltages across the others fall, with the supercapacitor having the highest leakage current exhibiting the lowest voltage. The SAB MOSFETs connected across these supercapacitors present complementary opposing current levels, introducing virtually no additional leakage current beyond that generated by the supercapacitors themselves.

Features

• Simple and cost-effective to use
• Factory-precision trimmed
• Automatic regulation and balancing of leakage current
• Effective charge balancing for supercapacitors
• Single IC package balances up to 4 supercaps
• Balances 2-cell, 3-cell, and 4-cell series-connected supercaps
• Scalable to larger supercapacitor banks and arrays
• Minimal additional leakage current
• Zero leakage current at 0.3V below rated voltage
• Balances series and/or parallel connected supercaps
• Leakage current is an exponential function of cell voltage
• Active current range from < 0.3 nA to > 1000 μA
• Always active with fast response time
• Minimizes leakage current and power consumption

Applications

• Series supercapacitor cell leakage current balancing
• Energy harvesting
• Long-term backup battery with supercapacitor output
• Zero-power voltage divider at selected voltage
• Matched current mirrors and current sources
• Zero-power mode maximum voltage limiter
• Scaled supercapacitor banks and arrays