B2526 ETC1 | Alldatasheet

Document overview

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  • PDF pages: 7

Technical content

Features

  • 3.0V to 5.5V Input
  • 110µµµµA Typical on-State Supply Current
  • 1µµµµA Typical off-State Supply Current
  • 500mA Minimum Continuous Load Current
  • 1.25A Maximum Current Limit
  • 2.4V Typical Under Voltage Lockout (UVLO)
  • Open-Drain Fault Flag Pin
  • Thermal Shutdown
  • Available with Active-High or Active-Low Enable

Applications

  • USB Host and self-Powered Hubs
  • USB Power Management
  • Battery-Charger Circuits
  • Hot Plug-In Power Supplies
  • Bus-Powered Hubs Bay LinearBay LinearBay LinearBay Linear Inspire the Linear PowerInspire the Linear PowerInspire the Linear PowerInspire the Linear Power Top View BAY B2526 FLAG (B) EN (B) VOUT (A) GND VINFLAG (A) EN (A) SO-8 VOUT (B) Logic Charge Pump Logic Charge Pump

8 Out (A)

5 Out (B)

6 GND

EN (A) 1 FLG (A) 2 FLB (B) 3 EN (B) 4

Bay Linear, Inc 2418Armstrong St., Livermore CA USA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com B2526 ABSOLUTE MAXIMUM RATINGS OPERATING RATING Output Current……………………Internally Limited Storage Temperature………………-65 °C to +150°C Lead Temperature (Soldering 5 sec.)………….260 °C Thermal Resistance ELECTRICAL CHARACTERISTICS at VIN = 5V, Ta=25°C, unless otherwise specified. (Note 1) Parameters Conditions Typ Min Max Units Supply Current (Note1) Switch Off, OUT = Open (Note1) Switch On, OUT = Open 0.75 110 5 160 µA Enable Input Threshold Low to High Transition High to Low Transition, (Note1) 2.1 1.9 0.8 2.4 V Enable Input Current V EN = 0V to 5.5V ± 0.01 -1 1 µA Enable Input Capacitance 1 pF Switch Resistance V IN = 5V IOUT = 500mA, Each Switch VIN = 3.3V IOUT = 500mA, Each Switch 100 140 140 180 mΩ Output Turn-On Delay RL = 10Ω 0.5 ms Output Turn-On Rise Time RL = 10Ω 1 ms Output Turn-Off Delay RL = 10Ω 1 20 µs Output Turn-Off Fall Time RL = 10Ω 1 20 µs Output Leakage Current Each output (output disabled) 10 µA Continuous Load Current Each output 0.5 A Short Circuit Current Limit Each output (enable into load), V OUT = 4.0V 0.5 0.75 1.25 A Current Limit Threshold Ramped Load applied to enable output, VOUT ≤ 4.0V 1.6 2.2 A Over temperature Shutdown Threshold TJ Increasing TJ Decreasing 135 125 °C Error Flag Output Resistance V IN = 5.0V, IL = 10mA VIN = 3.3V, IL = 10mA 10 15 Ω Error Flag Off Current V FLAG = 5V 0.01 1 µA UVLO Threshold V IN = Increasing VIN = Decreasing 2.5 2.3 V General Note: Devices are ESD protected, however, handling precautions recommended. TEST CIRCUIT (Only 1 Output Shown) Functional Characteristics Test Circuit EN (A) FLG (A) Out (A) IN GND Out (B) FLG (B) EN (B) 10K 0.1µµµµF B2526 ILOAD (for Current Limit Response) RL CL + IOUT Ferrite Bead

Bay Linear, Inc 2418Armstrong St., Livermore CA USA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com B2526 DETAILED DESCRIPITION Power Switch The power switch is an N-Channel MOSFET with a maximum on-state resistance of 140m Ω (VIN = 5V). the power switch supplies a minimum of 500mA per switch. Enable The Logic enable disables the power switch and the bias for the charge pump, driver and other circuitry to reduce the supply cu rrent to less than 5µA when a logic high is present on the EN pin for B2526-2 or a logic low is present on EN for B2526-1. The enable input is compatible with both TTL and CMOS logic levels. Driver The driver controls the gate voltage of the power switch. To Limit large current surges the driver incorporates circuitry that controls the rise and fall times of the output voltage. Charge Pump An internal charge pump supplies power to the driver circuit and provides the necessary voltages to pull the gate of the MOSFET above the source. Fault Flag FLG (A)/(B) FLG is a N-Channel, open drain MOSFET output. The fault flag is active (low) for one or more of the following conditions: under - voltage (while 2V < VIN < 2.7V), current limit or thermal shutdown. The flag output MOSFET is capable of sinking a 10mA load to typically 100mV above ground. Multiple FLG pins may be “wired NORed” to a common pull-up resistor. Thermal Shutdown An internal thermal sense circuit shuts off the power switch when the junction temperature rises to approximately 150 °C. Hysteresis is built into the thermal sense circuit. Current Sense A sense FET monitors the current supplied to the load. When an overload or short circuit is encountered, the current sense circ uitry sends a control signal to the driver. The driver in turn reduces the gate voltage and sends the power FET into its saturation r egion, which switches the output into a constant current mode. The 2526 current-limit profile exhibits a small foldback effect of approximately 500mA. Once this current-limit threshold is exceeded the device enters constant current mode. The constant curren t is specified as the short circuit current limit in the “Electrical Characteristics" table. It is important to note that the 2526 will deliver load current up to the current-limit Threshold which is typically 1.6A (2.2Amax)." Under-Voltage Lockout (UVLO) UVLO prevents the output MOSFET form turning on until VIN exceeds 2.5V. In the under-voltage state, the FLG will be low. After the switch turns on, if the voltage drops below approximately 2.3V, UVLO shuts off the output MOSFET and signals fault flag. Under-voltage detection functions only when at least one switch is enabled. PIN DESCRIPTION Pin No. Pin Name Pin Function 1 & 4 EN (A)/(B) Enable (Input): Logic-compatible enables input. High input > 2.1V typical. Low input < 1.9V typical (B2526-1 active high, B2526 -2 active low). 2 & 3 FLAG (A)/(B) Fault Flag (Output): Active-low, open-drain output. Indicates over current, UVLO and thermal shutdown. 6 GND Ground: Supply return. 7 V IN Supply Input: Output MOSFET drain. Also supplies IC’s internal circuitry. Connect to positive supply. 8 & 5 V OUT (A)/(B) Switch Output: Output MOSFET source. Typically connect to switched side of load.

Bay Linear, Inc 2418Armstrong St., Livermore CA USA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com B2526

Bay Linear, Inc 2418Armstrong St., Livermore CA USA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com B2526 Two-Port Self Powered Hub (Using B2526 & B4300) B2526 B4300

Bay Linear, Inc 2418Armstrong St., Livermore CA USA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com B2526 BLOCK DIAGRAM TYPICAL APPLICATION

2 Port USB Self-Powered Hub

EN (A) FLG (A) Out (A) IN GND Out (B) FLG (B) EN (B) B2526-2 Over-Current ON/OFF 3.3V USB Controller USB Port VBUS GND USB Port VBUS GND 47µ47µ47µ47µF ++++ 47µ47µ47µ47µF ++++ 100K VCC 5V 100K10K 10K 0.1µµµµF0.1µµµµF Data (Two Pair to USB Controller)

Bay Linear, Inc 2418Armstrong St., Livermore CA USA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com Advance Information- These data sheets contain descriptions of products that are in development. The specifications are based on the engineering ca lculations, computer simulations and/ or initial prototype evaluation. Preliminary Information- These data sheets contain minimum and maximum specifications that are based on the initial device characterizations. These lim its are subject to change upon the completion of the full characterization over the specified temperature and supply voltage ranges. The application circuit examples are only to explain the representative applications of the devices and are not intended to gua rantee any circuit design or permit any industrial property right to other rights to execute. Bay Linear takes no responsibility for any problems related to any indust rial property right resulting from the use of the contents shown in the data book. Typical parameters can and do vary in different applications. Customer’s technical experts must validate all operating parameters including “ Typical” for each customer application. LIFE SUPPORT AND NUCLEAR POLICY Bay Linear products are not authorized for and should not be used within life support systems which are intended for surgical i mplants into the body to support or sustain life, in aircraft, space equipment, submarine, or nuclear facility applications without the specific written consent of Bay Linear President.