BL2554CB5TR

BL2554 Adjustable USB Load Current Switch DESCRIPTION FEATURES The BL2554 is Adjustable USB Load Current Switch Current Limited designed for high-side load switching applications. The internal currentlimiting circuit protects the input supply against large output short circuit current which may cause the supply to fall out of regulation.           The current limit threshold is programmed with an external resistor from ISET Pin to ground. The quiescent supply current is typically 150μA, making the device ideal for portable batteryoperated equipment. In shutdown mode, the supply current decreases to less than 0.1μA. Additional features include thermal shutdown and constant current output characteristics if current exceed its current limit. The BL2554 is available in SOT23-5 and SOT23-6 packages. TYPICAL APPLICATION 2.5 to 5.5V input voltage range Controlled turn-on 0.15-1.3A adjustable current limit +/-6% current limit accuracy 0.25ohm on resistance Fast current limit response time Logic Control Shutdown (IQ4000V Note: Exceed these limits to damage to the device. Exposure to absolute maximum rating conditions may affect device reliability. RECOMMENDED WORK CONDITIONS Parameter Value Input Voltage Range Operating Junction Temperature(Tj) Max. 5.5V -20C –125C ELECTRICAL CHARACTERISTICS (Vin=5V, TA=25C) Symbol Parameter Vin Input Voltage Range Iq Quiescent Current Conditions Min Typ 2.6 Active, Vfb=0.65, No Switching 150 Shutdown Switch Rdson Iout=500mA Ilimit Adjustable current limit R_Iset=53K ohm R_Iset=25K ohm R_Iset=20K ohm 250 0.5 1.0 1.3 Vout=5V, Vin=0V 0.1 Vh_on Reverse Voltage Leakage Current ON Input High Voltage Vl_on ON Input Low Voltage Tsd Unit V 300 uA 1 Rdson Irevlk Max 5.5 A 5 1.5 uA V 0.4 Thermal shutdown Temp. uA mohm 155 V o C SETTING THE CURRENT LIMIT THRESHOLD RILIM ( KΩ) Typical Current Limit (mA) RILIM ( KΩ) Typical Current Limit (mA) 200 180 151 100 82 68 138 152 179 266 324 389 51 43 30 20 520 612 873 1295 www.belling.com.cn 2 V1.6 BL2554 PIN DESCRIPTION NAME PIN # SOT23-6 6 2 Vout GND PIN # SOT23-5 1 2 Iset 3 5 On Vin nFAULT 4 5 - 3 1 4 DESCRIPTION Switch Output, the output of power switch Ground Current limit setting pin. Connecting a resistor (R_Iset) from this pin to ground will adjust the current limit Control input, enable pin, active high Supply input voltage Fault flagging pin. Connect a pull up resistor to IN, when in fault conditions, this pin is asserted low ELECTRICAL PERFORMANCE Tested under TA=25C, unless otherwise specified Turn on delay and rise time Turn off delay and fall time Device enabled into short circuit www.belling.com.cn Full load to short circuit transient response 3 V1.6 BL2554 Short circuit to full load recovery response No load to short circuit transient response Short circuit to no load recovery response No load to 1transient response 1to no load transient response Switch current Vs. dropout voltage www.belling.com.cn 4 V1.6 BL2554 BLOCK DIAGRAM DETAILED DESCRIPTION Operation The BL2554 is a current limited switch that protects systems and loads which can be damaged or disrupted by the application of high currents. The core of each device is a 0.10Ω P-channel MOSFET and a controller capable of functioning over a wide input operating range of 2.6-5.5V. The controller protects against system malfunctions through current limiting, undervoltage lockout and thermal shutdown. The current limit is adjustable from 0.15A to 1.3A through the selection of an external resistor. On/Off control The ON pin controls the state of the switch. When ON is high, the switch is in the on state. Activating ON continuously holds the switch in the on state so long as there is no fault. An undervoltage on VIN or a junction temperature in excess of 155°C overrides the ON control to turn off the switch. The BL2554 does not turn off in response to an over current condition but instead remains operating in a constant current mode so long as ON is active and the thermal shutdown or undervoltage lockout have not activated. The ON pin www.belling.com.cn 5 control voltage and VIN pin have independent and recommended operating ranges. The ON pin voltage can be driven by a voltage level higher than the input voltage. Current limiting The current limit ensures that the current through the switch doesn't exceed a maximum value while not limiting at less than a minimum value. The current at which the parts will limit is adjustable through the selection of an external resistor connected to ISET. Information for selecting the resistor is found in the Application Info section. The BL2554 has no current limit blanking period so it will remain in a constant current state until the ON pin is deactivated or the thermal shutdown turns-off the switch. Thermal Shutdown The thermal shutdown protects the die from internally or externally generated excessive temperatures. During an over-temperature condition the switch is turned-off. The switch automatically turns-on again if temperature of the die drops below the threshold temperature. V1.6 BL2554 PACKAGE OUTLINE Package SOT23-5 Devices per reel 3000 Unit mm Devices per reel 3000 Unit mm Package specification: Package SOT23-6 Package specification: www.belling.com.cn 6 V1.6