MIC28510 75V/4A Hyper Speed Control Synchronous DC/DC Buck Regulator SuperSwitcher II General Description Features Hyper Speed Control architecture enables: The Micrel MIC28510 is an adjustablefrequency, synchronous buck regulator featuring unique adaptive on High Delta V operation (V = 75V and V = 0.8V) IN OUT time control architecture. The MIC28510 operates over an Small output capacitance input supply range of 4.5V to 75V and provides a regulated 4.5V to 75V voltage input output of up to 4A of output current. The output voltage is 4A output current capability, up to 95% efficiency adjustable down to 0.8V with a guaranteed accuracy of 1%. Adjustable output voltage form 0.8V to 24V Micrels Hyper Speed Control architecture allows for ultra 1% FB accuracy fast transient response while reducing the output capacitance Any Capacitor stable: and also makes (High V ) / (Low V ) operation possible. IN OUT This adaptive t ripple control architecture combines the Zero-ESR to highESR output capacitors ON advantages of fixedfrequency operation and fast transient 100kHz to 500kHz switching frequency response in a single device. Internal compensation The MIC28510 offers a full suite of protection features to Foldback currentlimit and hiccup mode short-circuit ensure protection of the IC during fault conditions. These protection include undervoltage lockout to ensure proper operation Thermal shutdown under powersag conditions, internal softstart to reduce Supports safe startup into a prebiased load inrush current, foldback current limit, hiccup mode short- circuit protection, and thermal shutdown. 40C to +125C junction temperature range 28-pin 5mm 6mm MLF package All support documentation can be found on Micrels web site at: www.micrel.com. Applications Distributed power systems Communications/networking infrastructure Industrial power Solar energy Typical Application Efficiency (V = 48V) IN vs. Output Current 100 90 5.0V 80 3.3V 2.5V 70 1.8V 60 1.5V 1.2V 50 1.0V 0.8V 40 f = 250kHz SW 30 20 10 01 2 3 45 6 OUTPUT CURRENT (A) Hyper Speed Control, SuperSwitcher II and Any Capacitor are trademarks of Micrel, Inc. MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc. Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. MIC28510 Ordering Information Part Number Junction Temperature Range Package Lead Finish MIC28510YJL 40C to 125C 28-pin 5mm 6mm MLF Pb-Free Pin Configuration 28-Pin 5mm 6mm MLF (JL) Pin Description Pin Number Pin Name Pin Function 1, 3 NC No Connect. Power Ground. PGND is the ground path for the MIC28510 buck converter power stage. The 2, 5, 6, PGND pin connects to the sources of low-side N-Channel internal MOSFETs, the negative PGND 7, 8, 21 terminals of input capacitors, and the negative terminals of output capacitors. The loop for the power ground should be as small as possible and separate from the signal ground (SGND) loop. 4, 9, 10, Switch Node (Output). Internal connection for the high-side MOSFET source and low-side SW 11, 12 MOSFET drain. High-Side Internal N-Channel MOSFET Drain Connection (Input).The PVIN operating voltage 13, 14, 15, 16, PVIN range is from 4.5V to 75V. Input capacitors between the PVIN pins and the power ground (PGND) 17, 18, 19 are required and keep the connection short. Boost (Output). Bootstrapped voltage to the high-side N-channel internal MOSFET driver. A 20 BST Schottky diode is connected between the VDD pin and the BST pin. A boost capacitor of 0.1F is connected between the BST pin and the SW pin. Current Sense (Input). High current output driver return. The CS pin connects directly to the switch node. Due to the high-speed switching on this pin, the CS pin should be routed away from 22 CS sensitive nodes. CS pin also senses the current by monitoring the voltage across the low-side internal MOSFET during OFF-time. 2 March 2012 M9999-030912-A