XXRR7799110033 2222VV,, 33AA SSyynncchhrroonnoouuss SStteepp--DDoowwnn CCOOTT PPoowweerr MMoodduullee April 2016 Rev. 1A EEVVAALLUUAATTIIOONN BBOOAARRDD MMAANNUUAALL GENERAL DESCRIPTION The XR79103 is part of a family of 22V 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 XR79103 has load current rating of 3A. A wide 4.5V to 22V input voltage range allows for single supply operation from industry standard 5V, 12V and 19.6V rails. With a proprietary emulated current mode Constant On-Time (COT) control scheme, the XR79103 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 0.2% line FEATURES regulation and maintains constant operating frequency. A selectable power saving mode, 3A step-down power module allows the user to operate in Discontinuous o 4.5V to 22V wide single input Current Mode (DCM) at light current loads, voltage significantly increasing the converter o 0.6V adjustable output voltage efficiency. A host of protection features, including overcurrent, over temperature, Controller, drivers, inductor, passive short-circuit and UVLO, helps achieve safe components and MOSFETs integrated in one package operation under abnormal operating conditions. The XR79103 is available in a Proprietary constant on-time control RoHS-compliant, green/halogen-free space- o No loop compensation required saving 6mm x 6mm x 4mm QFN package. o Stable with ceramic output capacitors o Programmable 100ns to 1s on- time o Constant 600kHz to 800kHz frequency o Selectable CCM or DCM/CCM operation Precision enable and power-good flag Programmable soft-start 6mm x 6mm 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 XXRR7799110033 2222VV,, 33AA SSyynncchhrroonnoouuss SStteepp--DDoowwnn CCOOTT PPoowweerr MMoodduullee April 2016 Rev. 1A D1 MMSZ4685-TP C A R1 10k R2 24.3k, 1% VIN 2-3=DCM/CCM SW 3 C11 0.22uF 2 1 RLIM 1-2=CCM R3 35.7k, 1% J1 CSS 0.8k EN 47nF VIN+ VIN = 4.5V - 22V RON VIN SS 7.15k CBST PGOOD C1 C2 C3 C4 C5 0.1uF 22uF VIN- RPGOOD 10k VCC U1A AGND 1 31 SS PVIN 2 PGood FB 3 BST PVin 30 FB PGND 45 29 PGND 4 AGND AGND 600kHz, 1.2V, 3A VOUT+ 43 44 5 28 VIN SW 6 46 27 VCC SW C7 C8 C9 C10 7 SW 26 C6 PGND SW 25 SW 47uF 47uF 0.1uF 8 RR 42k CR 2.2nF VOUT- SW SW 47 VOUT 24 VOUT 9 48 23 22nF PGND VOUT 10 22 CAC PGND VOUT XR79103 RBODE 0 RFB1 CFF 2k VOUT C12 VIN VCC CSNB 0.1uF VCC nF RFF 45 48 PVin VOUT FB RVIN R5VIN RSNB VIN FB SW 46 47 SW Ohm SW SW k 0 CIN CVCC 44 RFB2 BST2 43 0.1uF 4.7uF 2k AGND U1B XR79103 Fig. 1: XR79103 Evaluation Board Schematics PIN CONFIGURATION Fig. 2: XR79103 Pin Assignment Exar Corporation www.exar.com 48720 Kato Road, Fremont CA 94538, USA Tel. +1 510 668-7000 Fax. +1 510 668-7001 11 42 PGND TON 12 41 PGND ENMode 13 PGND 14 PGND 40 AGND 39 ILIM 15 38 SW BST1 16 37 VOUT PVin 17 36 VOUT PVin 18 35 VOUT PVin 19 34 VOUT PVin 20 33 VOUT PVin 21 32 VOUT PVin