BL9352A

V1.1 BL9352A 45V, 1.6MHz, 600mA Step-Down Converter FEATURES GENERAL DESCRIPTION    The BL9352A is a wide input range, highefficiency, and high frequency DC-to-DC stepdown switching regulator, capable of delivering up to 0.6A of output current. With a fixed switching frequency of 1.6MHz, this current mode PWM controlled converter allows the use of small external components, such as ceramic input and output caps, as well as small inductors. Including cold crank and double battery jumpstarts, the minimum input voltage may be as low as 4.5V and the maximum up to 45V, with even higher transient voltages. With these high input voltages, linear regulators cannot be used for high supply currents without overheating the regulator. Instead, high efficiency switching regulators such as BL9352A must be used to minimize thermal dissipation. BL9352A is available SOT23-6 Packages.            APPLICATIONS    PIN OUT www.belling.com.cn Wide Input Operating Range from 4.5V to 45V 420mΩ internal NMOS Up to 95% Efficiency at 16V in 12V out L=47uH with 300mA loading Internal compensation Capable of Delivering 600mA continuous output current Fixed 1.6MHz PWM operation Internal soft start Output voltage adjustable down to 0.795V Cycle-by-cycle current limit Current Mode control Short-circuit protection Logic Control Shutdown EN can be short to VIN Thermal shutdown and UVLO Available in SOT23-6 Package 1 Smart/Industrial/Power Meters Industrial Applications Automotive Applications BL9352A PINOUT DESCRIPTION Pin # Name Description Bootstrap pin for top Switch. In Typ. application, a 0.1uF or larger capacitor should be 1 BST connected between this pin and the LX pin to supply current to the top Switch gate and top Switch driver. 2 GND 3 FB 4 EN Analog Ground Output feedback pin. In Typ. application, FB senses the output voltage and is regulated by the control loop to 800mV. Connect a resistive divider at FB. Drive EN pin high to turn on the regulator and low to turn off the regulator. Input voltage pin, In Typ. application, VIN supplies power to the IC. Connect a 4.5V to 5 VIN 45V supply to VIN and bypass VIN to GND with a suitably large capacitor to eliminate noise on the input to the IC. 6 LX LX is the Switching node that supplies power to the output Connect the output LC filter from LX to the output load. TYPICAL APPLICATION 100nF Vout 4.7uH~47uH 12V/0~600mA BST VIN 12.3V ~ 45V VIN LX 33pF 10uF +0.1uF FB EN 127K 10uF+0.1uF +470uF 9.09K GND 100nF 4.7uH~47uH BST VIN 5.3V ~ 45V VIN Vout 5V/0~600mA LX 33pF 10uF +0.1uF FB EN 127K 23.7K GND www.belling.com.cn 2 10uF+0.1uF +470uF BL9352A 100nF Vout 4.7uH~47uH 3.3V/0~600mA BST VIN 4.5V ~ 45V VIN LX 33pF FB EN 10uF +0.1uF 127K 40.2K GND 10uF+0.1uF +470uF BLOCK DIAGRAM EN BST IN + UVLO & Thermal shutdown REG &REF Current Sense - + EA + COMP network Σ - FB PWM Logic DRIVER OSC Slope Comp GND ABSOLUTE MAXIMUM RATING Parameter Input Voltage Range Max Operating Junction Temperature(Tj) LX, EN Voltage BST Voltage FB Voltage LX to ground curren Operating Temperature(To) SOT23-6 Package Thermal Resistance (jc) Storage Temperature(Ts) ESD Rating Value -0.3V-50V 150C –0.3V to VIN+0.3V –0.3V to LX+6V –0.3V to 6V Internally limited -40C –85C 110C / W -55C - 150C 2000V Note: Exceed these limits to damage to the device. Exposure to absolute maximum rating conditions may affect device reliability. www.belling.com.cn 3 LX BL9352A ELECTRICAL CHARACTERISTICS (VIN = VEN = 16V, unless otherwise specified. Typical values are at TA = 25C .) SYMBOL VIN Vin(UVLO) PARAMETER Input Voltage Range Input UVLO Vin(UVLO)hys Input UVLO Hysteresis IQ Input Supply Current Isd VFB VFB_LOAD VFB_line Input Shutdown Current IFB Ven_OFF Ven_OFF En hys IEN Load regulation Line regulation Feedback voltage input current En high level En low level En Hysteresis Enable input current Test conditions MIN 4.5 2.3 Vfb=5V no loading Ven