XXRR7799220066 4400VV,, 66AA SSyynncchhrroonnoouuss SStteepp--DDoowwnn CCOOTT PPoowweerr MMoodduullee April 2016 Rev. 1A GENERAL DESCRIPTION EVALUATION BOARD MANUAL EVALUATION BOARD MANUAL The XR79206 is part of a family of 40V synchronous step-down power modules combining the controller, drivers, inductor, passive components and MOSFETs in a single package for point-of-load supplies. This module requires very few external components leading to ease of design and fast time to market. The XR79206 has load current rating of 6A. A wide 5V to 40V input voltage range allows for single supply operation from industry standard 24V 10%, 18V to 36V and rectified 18VAC and 24VAC rails. With a proprietary emulated current mode Constant On-Time (COT) control scheme, the XR79206 provides extremely fast line and load transient response using ceramic output capacitors. It requires no loop compensation, simplifying circuit implementation and reducing overall component count. The control loop also provides 0.2% load and 0.1% line regulation and maintains constant operating frequency. A FEATURES selectable power saving mode, allows the user to operate in Discontinuous Current Mode 6A step-down power module (DCM) at light current loads significantly o 5V to 40V wide single input increasing the converter efficiency. A host of voltage protection features, including overcurrent, o 0.6V adjustable output voltage over temperature, short-circuit and UVLO, help achieve safe operation under abnormal Controller, drivers, inductor, passive operating conditions. The XR79206 is available components and MOSFETs integrated in in a RoHS-compliant, green/halogen-free one package space-saving 10mm x 10mm x 4mm QFN Proprietary constant on-time control package. o No loop compensation required o Stable with ceramic output capacitors o Programmable 100ns to 1s on- time o Constant 400kHz to 800kHz frequency o Selectable CCM or DCM/CCM operation Precision enable and power-good flag Programmable soft-start 10mm x 10mm x 4mm QFN package Exar Corporation www.exar.com 48720 Kato Road, Fremont CA 94538, USA Tel. +1 510 668-7000 Fax. +1 510 668-7001 XXRR7799220066 4400VV,, 66AA SSyynncchhrroonnoouuss SStteepp--DDoowwnn CCOOTT PPoowweerr MMoodduullee April 2016 Rev. 1A D1 MMSZ4685 C A R14 10k R13 30.1k VIN 2-3=DCM/CCM 3 C29 0.22uF SW T3 2 Top VIN = 24V 1 Lin VIN+ RLIM uH (Short) J1 R3 35.7k 3.48k CSS VIN 1 2 1 1-2=CCM EN 47nF 2 EN RON C1 C2 C3 C4 C5 C6 C7 C8 C9 SS 22.1k 0.1uF VIN- CBST 10uF 10uF 10uF PGOOD 1 2 RPGOOD 10k VCC T4 U3A AGND 1 53 SS PGND 500kHz, 3.3V, 6A 2 52 PGood PGND T1 FB 3 AGND BST PVin PGND 51 FB PGND 4 75 79 77 73 50 Bottom Top AGND VOUT 5 49 VOUT+ AGND VOUT 6 48 VIN VOUT VOUT 7 47 1 VCC VOUT 8 46 2 PGND VOUT 9 78 45 LX VOUT 10 LX VOUT 44 C10 C11 C12 C13 C14 C15 C16 C17 C18 C19 C20 C21 C22 C23 C24 C25 C26 C27 LX VOUT 11 74 43 LX VOUT 12 42 0.1uF VOUT- RR CR LX VOUT 47uF 47uF 13 41 PGND VOUT 14 40 1 PGND VOUT 15 39 2 PGND VOUT 16 PGND 38 VOUT PGND 17 76 37 CAC PGND VOUT T2 79206 SW RFB1 CFF 9.09k 330pF VOUT C28 VIN U1B VCC CSNB 0.1uF 73 VCC PGND RFF 77 74 Vin VOUT 0.18k FB RVIN 0k R5VIN k RSNB VIN FB SW 78 76 LX PGND CIN CVCC 79 RFB2 BST3 75 0.1uF 4.7uF AGND 2k 79206 Fig. 1: XR79206 Evaluation Board Schematics PIN CONFIGURATION Fig. 2: XR79206 Pin Assignment Exar Corporation www.exar.com 48720 Kato Road, Fremont CA 94538, USA Tel. +1 510 668-7000 Fax. +1 510 668-7001 18 72 PGND TON 19 71 PGND ENMode 20 70 PGND AGND 21 69 PGND AGND 22 68 PGND ILIM 23 67 PGND BST2 24 66 LX BST1 25 65 LX PVin 26 64 LX PVin 27 63 LX PVin 28 62 LX PVin 29 61 LX PVin 30 60 LX PVin 31 59 VOUT PVin 32 58 VOUT PVin 33 57 VOUT NC 34 56 VOUT PGND 35 55 VOUT PGND 36 54 VOUT PGND