A8672 Fixed Frequency High Current Synchronous Buck Regulator With Fault Warnings and Power OK Discontinued Product This device is no longer in production. The device should not be purchased for new design applications. Samples are no longer available. Date of status change: September 1, 2016 Recommended Substitutions: no direct replacement For existing customer transition, and for new customers or new appli- cations, contact Allegro Sales. NOTE: For detailed information on purchasing options, contact your local Allegro field applications engineer or sales representative. Allegro MicroSystems, LLC reserves the right to make, from time to time, revisions to the anticipated product life cycle plan for a product to accommodate changes in production capabilities, alternative product availabilities, or market demand. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, LLC assumes no respon- sibility for its use nor for any infringements of patents or other rights of third parties which may result from its use.A8672 Fixed Frequency High Current Synchronous Buck Regulator With Fault Warnings and Power OK Description Features and Benefits The A8672 is a synchronous buck converter capable of High efficiency integrated FETs optimized for lower duty delivering up to 8 A. The A8672 utilizes valley current mode cycle voltage conversion: 27 m high side, 12 m low side control, allowing very short on-times to be achieved. This makes Power input voltage range: 3 to 16 V it ideal for applications that require very low output voltages Control input voltage range: 4.5 to 16V relative to the input voltage, combined with high switching Adjustable output voltage, down to 0.6 V frequencies. Valley current mode control inherently provides 5 V LDO Regulator improved transient response over traditional switcher schemes, Extremely short minimum controllable on-time through the use of a voltage feedforward loop and frequency example: allows 12 V conversion to 0.6 V at >1 MHz modulation during large signal load changes. Reference accuracy of 1% throughout temperature range F A U L T and Power OK pins for operating and The A8672 includes a comprehensive set of diagnostic flags, protection modes allowing the host platform to react to a myriad of different Low power mode (LPM) or fixed continuous conduction conditions. A fault output indicates when either the temp- mode (FCCM) operation erature is becoming unusually high, or a single point failure Programmable soft-start / hiccup shutdown period has occurred for example, the switching node (LX) shorted to Ultra-fast transient response ground, or the timing resistor going open-circuit. A Power OK (POK) output is also provided after a fixed delay, to indicate Applications when the output voltage is within regulation. The selectable Servers Network and telecom pulse-by-pulse current limit avoids the requirement to oversize Point of load supplies Storage the inductor to cope with large fault currents. Package: 28-contact QFN with exposed The device package (EG) is a 28-contact, 4 mm 5 mm, thermal pad (suffix EG) 0.75 mm nominal overall height QFN with exposed thermal pad. The package is lead (Pb) free, with 100% matte tin leadframe plating. Approximate size Typical Application Diagram C5 V L1 IN 47 nF VOUT 1 H 12 V 1.2 V BOOT VIN LX C1 C2 C3 C4 R1 C6 C7 22 F 22 F 22 F 22 F 90.9k 100 F 100 F A8672 TON R6 VDD 10 k VREG BIAS FB C8 MODE C9 V 2.2 F pull-up ILIM R7 470 nF EN R4 PAD 10 k R2 R3 249 k 20 k 20 k COMP FAULT FAULT C12 R5 POK 22 pF POK 56 k SS AGN D PGND C10 C11 10 nF 680 pF V = 12 V, V = 1.2 V, and f = 500 kHz IN OUT SW A8672-DS, Rev. 3 July 5, 2018 MCO-0000466