XR76203 / XR76205 / XR76208 40V 3A/5A/8A Synchronous Step Down COT Regulators General Description FEATURES The XR76203, XR76205 and XR76208 are synchronous step-down Controller, drivers, bootstrap diode and regulators combining the controller, drivers, bootstrap diode and MOSFETs integrated in one package MOSFETs in a single package for point-of-load supplies. The XR76203, 3A, 5A and 8A step down regulators XR76205, and XR76208 have load current ratings of 3A, 5A and 8A Wide 5V to 40V input voltage range respectively. A wide 5V to 40V input voltage range allows for single 0.6V adjustable output voltage supply operation from industry standard 24V 10%, 18V - 36V, and Proprietary Constant On-Time control rectified 18VAC and 24VAC rails. No loop compensation required With a proprietary emulated current mode Constant On-Time (COT) Stable ceramic output capacitor operation control scheme, the XR76203, XR76205, and XR76208 provide Programmable 200ns to 2s on-time extremely fast line and load transient response using ceramic output Constant 100kHz to 800kHz frequency capacitors. They require no loop compensation, simplifying circuit imple- Selectable CCM or CCM / DCM mentation and reducing overall component count. The control loop also CCM / DCM for high efficiency at light-load provides 0.07% load and 0.15% line regulation and maintains constant CCM for constant frequency at light-load operating frequency. A selectable power saving mode allows the user to Programmable hiccup current limit with thermal operate in discontinuous conduction mode (DCM) at light current loads, compensation thereby significantly increasing the converter efficiency. Precision enable and Power Good flag Programmable soft-start A host of protection features, including over-current, over-temperature, short-circuit and UVLO, helps achieve safe operation under abnormal 30-pin 5x5mm QFN package operating conditions. APPLICATIONS The XR76203, XR76205, and XR76208 are all available in a RoHS- Distributed power architecture compliant, green / halogen-free, space-saving QFN 5x5mm package. Point-of-Load converters Power supply modules FPGA, DSP, and processor supplies Base stations, switches / routers, and servers Ordering Information back page Typical Application Line Regulation 3.340 V IN VIN PVIN 3.330 C BST Enable/Mode EN/MODE BST 3.320 V OUT L1 Power Good 3.310 PGOOD SW C IN XR76 20 8 3.300 VCC R XR76 20 5 R LIM C FF 3.290 R1 XR76 20 3 SS ILIM C OUT 3.280 TON FB 3.270 C C R VCC SS ON R2 AGND PGND 3.260 5 10152025 303540 V (V) IN 1 / 22 Rev 1D V (V) OUTXR76203 / XR76205 / XR76208 Absolute Maximum Ratings Operating Conditions PV ...............................................................................5V to 40V Stresses beyond the limits listed below may cause IN permanent damage to the device. Exposure to any V .................................................................................5V to 40V IN Absolute Maximum Rating condition for extended periods (1) may affect device reliability and lifetime. SW, ILIM.....................................................................-1V to 40V PV , V ...................................................................-0.3V to 43V IN IN PGOOD, V , T , SS, EN, FB...............................-0.3V to 5.5V CC ON V ...........................................................................-0.3V to 6.0V (3) CC Switching frequency......................................100kHz to 800kHz (1) BST..........................................................................-0.3V to 48V Junction temperature range.................................-40C to +125C BST-SW.......................................................................-0.3V to 6V XR76203 JEDEC51 Package Thermal Resistance, .....28C/W JA (1, 2) SW, ILIM..................................................................-1V to 43V XR76205 JEDEC51 Package Thermal Resistance, .....26C/W JA ALL other pins.................................................-0.3V to VCC+0.3V XR76208 JEDEC51 Package Thermal Resistance, .....25C/W JA Storage temperature...........................................-65C to +150C XR76203 Package Power Dissipation at 25C......................3.6W Junction temperature..........................................................150C XR76205 Package Power Dissipation at 25C......................3.8W Power dissipation...............................................Internally Limited XR76208 Package Power Dissipation at 25C......................4.0W Lead temperature (Soldering, 10 sec)................................300C ESD rating (HBM - Human Body Model)...............................2kV Note 1: No external voltage applied. Note 2: SW pins minimum DC range is -1V, transient is -5V for less than 50ns. Note 3: Recommended frequency. Electrical Characteristics Unless otherwise noted: T = 25C, V = 24V, BST = V , SW = AGND = PGND = 0V, C = 4.7F. Limits applying over J IN CC VCC the full operating temperature range are denoted by a Symbol Parameter Conditions Min Typ Max Units Power Supply Characteristics V VCC regulating 5.5 40 Input voltage range V IN I VIN input supply current Not switching, V = 24V, V = 0.7V 0.7 2 mA VIN IN FB I VIN input supply current (XR76203) f = 300kHz, R = 215k, VFB = 0.58V 12 mA VIN ON I VIN input supply current (XR76205) f = 300kHz, R = 215k, VFB = 0.58V 15 mA VIN ON I VIN input supply current (XR76208) f = 300kHz, R = 215k, VFB = 0.58V 19 mA VIN ON I Shutdown current Enable = 0V, V = 12V 1 A OFF IN Enable and Under-Voltage Lock-Out UVLO V EN pin rising threshold 1.8 1.9 2.0 V IH EN 1 V EN pin hysteresis 70 mV EN H 1 V EN pin rising threshold for DCM/CCM 2.8 3.0 3.1 V IH EN 2 operation V EN pin hysteresis 100 mV EN H 2 2 / 22 Rev 1D