e TM ADVANCED EPAD LINEAR DEVICES, INC. SABMBOVP/SABMBOVP2XX TM PRECISION DUAL SAB OVER VOLTAGE PROTECTION PCB GENERAL DESCRIPTION FEATURES & BENEFITS ALD s SABMBOVP2XX family of Over Voltage Protection Printed Extremely low output currents at input voltages below the Circuit Boards (PCB) are innovative circuits designed to provide threshold voltage precision Over Voltage Protection (OVP) in stacked supercapacitor Precision threshold voltage set point voltage balancing and other voltage clamping applications. The Extreme change of output current in response to small SABMBOVP2XX circuit can be viewed as a precision voltage clamp changes in input voltage, i.e. dI/dV = ~3mA/1mV circuit that offers a superior zener-diode type of functionality and High maximum clamp output current of 100 mA or greater performs to superior specification and characteristics in creating a Over Voltage Protection for any size of supercapacitor stacks strong, precision voltage clamp. Typically, the clamp current in series or in parallel changes from a few nA to over 100mA (about 1,000,000 times) at Ultra-low power for energy harvesting and battery-powered the clamp voltage within a 100mV transition. applications Fully automatic OVP - no trimming adjustments, no additional circuits and no software The SABMBOVP2XX PCB is populated with an ALD9100XX Supercapacitor Auto Balancing (SAB) MOSFET IC chip that Broad selection of threshold voltages for wide variety of OVP specifies the circuit threshold or clamping voltage. SAB MOSFETs applications are ALD exclusive EPAD MOSFETs designed to address voltage Corrects imbalances in both capacitance value and DC leakage current balancing of multiple supercapacitor cells connected in series. SAB MOSFETs and the SABMBOVP2XX boards are designed to be compact, economical and effective in balancing any size supercapacitors with little or no additional power dissipation. MECHANICAL DRAWING The SABMBOVP is a blank PCB designed to be used with the entire ALD9100XX family of SAB MOSFETs for system designers and application developers. The SABMBOVP contains two OVP SABMBOVP circuits, each functioning as a precision voltage clamp with J1 extremely high current gain characteristics. Inside each of two V+ SABMBOVP circuits on the PCB, the internal voltages of the circuit U1 are shifted so that the balancing output current from the SAB J2 VA MOSFET is amplified to produce nominally 1mA of balancing (clamp) output current at V equal to the rated SAB MOSFET IN RP4 threshold voltage. RP2 Q2 Q1 The SABMBOVP boards two circuits function as a pair of push- pull matched OVP circuits to balance supercapacitors connected in series. Each OVP circuit can also be used individually with any J9 electronic circuitry requiring precision over-voltage clamps. The two OP2 OVP circuits offer a very energy efficient solution that can be applied 1600 mil J3 to other low-loss energy harvesting and long-life battery operated applications. They can also be connected in cascade mode, VB resulting in a single OVP circuit with twice the clamp voltage. ORDERING INFORMATION J8 ON2 Part Number Description J6 J7 Blank Universal PCB ready for one OP1 SABMBOVP J4 ALD9100XX Dual SAB MOSFET IC ON1 VC SABMBOVP2XX SABMBOVP Board with one installed J5 ALD9100XXSALI Example: V- SABMBOVP225 SABMBOVP Board with one installed ALD910025SALI Note: SABMBOVP2XX is optional with specific 600 mil ALD9100XXSALI units installed. XX = 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30. * Magnified, not to scale See page 6 for full listing of part numbers. 2021 Advanced Linear Devices, Inc., Vers. 1.1 www.aldinc.com 1 of 6 E N A D E L B RP3 RX2 RX1 RX3 RP1 RX4PRECISION OVP VOLTAGE CLAMPING EXAMPLE SABMBOVP2XX is higher at the threshold voltage due to an active current amplifier on board, it is still far below any other means of The SABMBOVP PCB is typically populated with one ALD SAB correcting for capacitance imbalances. At input voltages of about MOSFET IC chip selected to establish the threshold or clamping 0.1V below the threshold voltage, the average additional power voltage of the circuit. The ALD910025 chip, for example, provides dissipation due to use of SABMBOVP2XX boards is zero, which a threshold voltage of 2.50V, which allows the OVP circuit to behave makes this method of supercapacitor balancing very energy efficient. similar to a pair of super precision zener diodes stacked in series, It is especially suited for low loss energy harvesting and long life each clamping the output at 2.5V. The following scenario illustrates battery operated applications. the relative magnitude of input voltage vs. output current change: The SABMBOVP2XX circuit features a sharp and high gain current The SABMBOVP PCB balances a pair of series-connected amplifier, which produces greater than 1,000,000 times output supercapacitor cells by featuring two near identical over-voltage current increase with small increments of less than 100 mV input clamp circuits, one for parallel connection to each cell. Each board voltage change. has two output channels with each having a nominal threshold setting of 2.5V. At 2.5V input voltage (V ), the nominal output Supercapacitors, also known as ultracapacitors, when connected IN current (I ) is typically 1.0mA. At V voltages less than 2.5V, two cells in series can be balanced with a single SABMBOVP2XX OUT IN I decreases rapidly. Hence, at V = ~2.40V I is equal to PCB. Supercapacitors, when connected more than two cells in OUT IN OUT = 2.30V, I drops to 0.01A. At any V less 0.07A, and at V series, can be balanced with more than one SABMBOVP2XX board IN OUT IN than 2.40V, there is essentially no SABMBOVP power dissipation (each with ALD9100XX packages installed). or any energy draw from the supercapacitors. The ALD9100XX SAB MOSFET family offers the user a selection At V above the 2.5V threshold level, I increases sharply and of different threshold voltages for various supercapacitor nominal IN OUT steeply, to near vertical. It features high gain dI/dV at small operating voltage values and desired leakage balancing incremental voltages of V greater than 2.5V. At V of 2.53V, for characteristics. Each SAB MOSFET generally requires connecting IN IN instance, the output current (I ) is typically about 100mA, its V+ pin to the most positive voltage and its V- and IC pins to the OUT at V at 2.4V. This high current 1,400,000 times higher than I most negative voltage within the package. Note that each Drain OUT IN level (avalanche effect) change tends to limit the V to rise very pin has an internal reverse biased diode to its Source pin, and IN slowly and clamps the V to 2.53V. The standard SABMBOVP225 each Gate pin has an internal reverse biased diode to V-. All other IN board is designed to limit I to approximately 100mA at V pins must have voltages within V+ and V- voltage limits within the OUT IN voltages above 2.53V. If the user needs to increase this clamp same packaged unit. current, then an external resistor can be parallel connected across each of R and R . An external 24 1W resistor connected across Standard ESD protection facilities and handling procedures for static P1 P3 each R /R resistor would increase the max. clamp output current sensitive devices must also be used while installing the ALD9100XX P1 P3 to 200mA. units. Once installed, the connection configuration will protect the ALD9100XX units from ESD damage. When connected to a For a pair of 2.7V rated supercapacitors connected in series, the supercapacitor stack, the ALD9100XX is further protected from SABMBOVP225 functions to limit each supercapacitor to about virtually any ESD damage due to the large capacitance of the 2.53V maximum V voltage. Accordingly, when two supercapacitor supercapacitors, which sinks any ESD charge and thereby reduces IN cells are connected to the SABMBOVP225 PCB and are not any of the terminal voltages to minimal harmless values. balanced in either their capacitance values and/or leakage currents, the cell with the higher voltage tends to be limited in V rise by the IN corresponding SABMBOVP225 circuit with up to 100mA bypass SABMBOVP2XX PRINTED CIRCUIT BOARDS current. A 5.00V power supply connected across two supercapacitor cells in series would limit one cell to a maximum of 2.53V leaving Additional features include: the other cell at 2.47V (5.00V - 2.53V). If a cell voltage initially exceeds 2.53V, it rapidly discharges and its cell voltage is clamped 1) ALD9100XX Dual SAB MOSFET with other required at 2.53V while the other cell voltage reamains at 2.47V. components installed and tested. 2) Optional reverse biased external clamping power diodes In this example, supercapacitors should be normally set and (schottky rectifiers) can be installed by user. operated at 2.40V for optimal operation without energy loss. If the 3) Multiple SABMBOVP2XX PCBs can be cascaded to form desired normal operating voltage is 2.5V instead, then perhaps a a series chain, paralleling a series-connected chain of SABMBOVP226 should be selected instead. supercapacitors. 4) Compact size of 0.6 in by 1.6 in with mounting holes. 5) Rated for RoHS compatible/industrial temperature range PLUG-AND-PLAY BALANCING SOLUTION of -40C to +85C. The SABMBOVP2XX is a simple, out-of-the-box plug-and-play PCB The SABMBOVP Printed Circuit Board is available as a blank PCB solution for development, prototyping, demonstration and board, made with RoHS compliant FR4 material, ready for mounting evaluation, or production deployment. It is suited for balancing a single ALD9100XX 8-lead SOIC unit. SABMBOVP2XX PCB are supercapacitor stacks ranging from two in series to hundreds in SABMBOVP with an ALD9100XX chip and other components series, and for supercapacitor capacitance values ranging from 0.1F factory-installed and tested. ALD9100XX are supplied with a 2- to 3000F and beyond. Although the current dissipation of the digit suffix, which denotes the specific ALD9100XX component SABMBOVP/SABMBOVP2XX Advanced Linear Devices, Inc. 2 of 6