XR76108 and XR76112 8A and 12A Synchronous Step Down COT Regulator FEATURES 8A and 12A Capable Step Down General Description Regulators 4.5V to 5.5V Low VIN Operation The XR76108 and XR76112 are synchronous step-down 4.5V to 22V Wide Single Input regulators combining the controller, drivers, bootstrap Voltage diode and MOSFETs in a single package for point-of-load 0.6V Adjustable Output Voltage supplies. The XR76108 has a load current rating of 8A and the XR76112 has a load current rating of 12A. A wide 4.5V Controller, drivers, bootstrap diode and MOSFETs integrated in one package to 22V input voltage range allows for single supply operation from industry standard 5V, 12V and 19.6V rails. Proprietary Constant On-Time Control No Loop Compensation Required With a proprietary emulated current mode Constant On- Ceramic Output Cap. Stable operation Time (COT) control scheme, the XR76108 and XR76112 Programmable 200ns-2s On-Time provide extremely fast line and load transient response Constant 200kHz-800kHz Freq. using ceramic output capacitors. They require no loop Selectable CCM or CCM/DCM compensation, simplifying circuit implementation and Operation reducing overall component count. The control loop also Precision Enable and Power-Good Flag provides 0.25% load and 0.1% line regulation and maintains constant operating frequency. A selectable Programmable Soft-start power saving mode, allows the user to operate in 5x5mm 30-pin QFN Package discontinuous mode (DCM) at light current loads thereby significantly increasing the converter efficiency. APPLICATIONS A host of protection features, including over-current, Distributed Power Architecture over-temperature, short-circuit and UVLO, help achieve safe operation under abnormal operating conditions. Point-of-Load Converters The XR76108/12 are available in a RoHS-compliant, Power Supply Modules green/halogen-free space-saving QFN 5x5mm package. FPGA, DSP, and Processor Supplies Base Stations, Switches/Routers, and Servers Typical Application 1.220 VIN 1.215 VIN PVIN C 1.210 BST Enable/Mode EN/MODE BST VOUT L1 Power Good 1.205 PGOOD SW CIN 1.200 R3 VCC XR76108 R LIM XR76112 C FF R1 1.195 SS ILIM COUT 1.190 TON FB C C R VCC SS ON R2 AGND PGND 1.185 1.180 5 10 15 20 V (V) IN Figure 1: XR76108/12 Application Diagram Figure 2: XR76112 Line Regulation www.exar.com Rev. 2B V (V) OUT XR76108 and XR76112 Absolute Maximum Ratings Operating Ratings PVIN .............................................................. 3V to 22V These are stress ratings only and functional VIN ............................................................. 4.5V to 22V operation of the device at these ratings or any V ............................................................ 4.5V to 5.5V CC other above those indicated in the operation (2) SW, ILIM ................................................... -1V to 22V sections of the specifications below is not PGOOD, VCC, TON, SS, EN ............................ -0.3V to 5.5V implied. Stresses beyond those listed under (3) Switching Frequency ........................... 200kHz-800kHz Absolute Maximum Ratings may cause Junction Temperature Range (T ) .............. -40C to 125C J permanent damage to the device. Exposure to XR76108 Package Power Dissipation max at 25C ..... 3.8W any Absolute Maximum Rating condition for XR76112 Package Power Dissipation max at 25C ..... 4.1W extended periods may affect device reliability XR76108 JEDEC51 Package Thermal Resistance ........ 26C/W JA and lifetime. XR76112 JEDEC51 Package Thermal Resistance JA ........ 24C/W PV , V .................................................... -0.3V to 25V IN IN Note 1: No external voltage applied V .......................................................... -0.3V to 6.0V CC (1) Note 2: SW pins DC range is -1V, transient is -5V for less BST ....................................................... -0.3V to 31V than 50ns BST-SW ...................................................... -0.3V to 6V Note 3: Recommended (1,2) SW, I .................................................. -1V to 25V LIM All other pins ..................................... -0.3V to VCC+0.3V Storage Temperature .............................. -65C to 150C Junction Temperature .......................................... 150C Power Dissipation ................................ Internally Limited Lead Temperature (Soldering, 10 sec) ................... 300C ESD Rating (HBM Human Body Model) ................... 2kV ESD Rating (CDM Charged Device Model) ............. 1.5kV (1) Ordering Information Part Number Operating Temperature Range Lead-Free Package Packing Method XR76108EL-F Bulk Tape & Reel XR76108ELMTR-F Tape & Reel XR76108ELTR-F 5x5mm (2) -40CT +125C Yes J QFN XR76112EL-F Bulk XR76112ELMTR-F Tape & Reel XR76112ELTR-F Tape & Reel XR76108 Evaluation Board XR76108EVB XR76112 Evaluation Board XR76112EVB NOTES: 1. Refer to www.exar.com/XR76108, www.exar.com/XR76112 for most up-to-date Ordering Information. 2. Visit www.exar.com for additional information on Environmental Rating. Electrical Characteristics Specifications are for Operating Junction Temperature of TJ = 25C only limits applying over the full Operating Junction Temperature range are denoted by a . Typical values represent the most likely parametric norm at T = 25C, and are provided for reference purposes only. Unless otherwise J indicated, V =12V IN Parameter Min. Typ. Max. Units Conditions Power Supply Characteristics 12 22 V regulating or in dropout 4.5 CC V VIN, Input Voltage Range 4.5 5.0 5.5 VCC tied to VIN IVIN, VIN supply current 0.7 1.3 mA Not switching, VIN=12V, VFB=0.7V I , V Quiescent current 0.7 1.3 mA Not switching, V =V =5V, V =0.7V VCC CC CC IN FB 2/17 www.exar.com Rev. 2B