AT1799

AT1799 2A Step-Down Voltage Regulator Feature Description ‧ 4.75V to 16V Supply Voltage Operating AT1799 is a voltage-mode PWM step-down DC-DC converter capable of driving up to 2A Range. over id range with ex ‧ 380KHz ±15% Fixed Switching Frequency. lloads and a wd erienput supply haracteristics. cellent ine loa gulation c High ‧ Voltage-Mode PWM Step-Down Regulator. efficiency is obtained through the use of a low ‧ Built-in Power MOSFET, Rds(on)≒100mΩ. Rds(on) P-channel power switch. ‧ 2A Output Current, Up to 91.9% Efficiency It uses a fixed switching frequency up to 380KHz ‧ 1.215V±1.5% Internal Reference thus allowing smaller sized components. The ‧ Shutdown Current less than 20uA. output ltage l s u pro via an ‧ Thermal-Shutdown and Built-in Soft-Start. externalvoresistiveevel iltagser-divigrammable built-in vo e der. The ‧ Cycle-by-Cycle Current-Limit Protection. soft-start can reduce inrush current on the input ‧ Short Circuitry Protection. source at turn on. ‧ Under-Voltage Lockout Protection. ‧ Output Voltage Adjustable From 1.215V to The device also has built-in cycle-by-cycle current-limit, thermal shutdown, under-voltage 16V. lockout and an ON/OFF logic-control that can ‧ SOP-8 Package. power down the regulator to a shutdown mode. In shutdown mode the regulator draws less than 20uA of supply current. When a short circuit is detected Application on the output , the device immediately change ‧ Distributed Power Systems switching frequency to 42 KHz and duty cycle is ‧ Battery Charger. limited to 5% to protect IC from damage. ‧ Palmtop Computers, PDAs. ‧ DSL Modems AT1799 is available in SOP-8 package. Block Diagram Aimtron reserves the right without notice to change this circuitry and specifications. 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw 8/23/2006 REV:1.1 Email: service@aimtron.com.tw 1 AT1799 2A Step-Down Voltage Regulator Pin Configuration Ordering Information Part number AT1799S AT1799S_GRE : Date Code *For more marking information, contact out sales representative directly Package SOP-8 SOP-8,Green Marking Date Code ,Date Code with one bottom line Pin Descriptions Pin N0. 1 2 3 4 Symbol IN EN COMP FB GND SW I/O P I O I P O Description Power Input. IN supplies power to the IC and Step-down converter switch. IN must be bypassed with a low-ESR capacitor. Enable input. EN is a digital input that turns the regulator on/off. Drive EN high to turn on the regulator, drive it low to turn it off. Error Amplifier Output. A series RC network connected to this pin compensates AT1799. Feedback Input. Connect a resistive divider from switching output to FB to ground. Ground. Power Switching Output. 5,6 7,8 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw 8/23/2006 REV:1.1 Email: service@aimtron.com.tw 2 AT1799 2A Step-Down Voltage Regulator Absolute Maximum Ratings *1 Parameter IN , EN voltage SW voltage FB, COMP voltage Quiescent current Thermal Resistance (Junction to ambient θJA)*2 Junction Temperature (Tj) Lead Temperature (Soldering 10 sec) Storage Temperature HBM ESD Susceptibility*3 MM Rated Value -0.3 to 16 -1 to IN+1 -0.3 to 6 5 105 150 260 -65~150 2 200 unit V V V mA ℃/W ℃ ℃ ℃ KV V 1. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. 2. Measured on approximately 1” square of 1 oz. copper FR4 board. 3. Device are ESD sensitive. Handling precaution recommended. The Human Body model is a 100pF capacitor discharged through a 1.5KΩ resistor into each pin. Recommended Operation Conditions Parameter Power supply voltage Operating temperature Symbol Min. IN Top 4.75 -20 Values Typ. 12 +25 Max. 16 +85 Unit V ℃ 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw 8/23/2006 REV:1.1 Email: service@aimtron.com.tw 3 AT1799 2A Step-Down Voltage Regulator Electrical Characteristics (IN=12V, EN=5V, Ta=+25℃, unless otherwise noted) Parameter Input operating voltage Input under-voltage lockout threshold UVLO hysteresis Quiescent Current Shutdown Current Oscillator Frequency Short-Circuit Frequency Feedback Regulation voltage FB Input Bias Current Current limit Maximum Duty Cycle Minimum Duty Cycle SW Switch On-Resistance SW Leakage Current Load Regulation Line Regulation Error Amplifier Voltage Gain Error Amplifier Trans-conductance Soft-Start Time EN Threshold Voltage EN Pull Up Current Thermal Shutdown Symbol IN VUVLO Test Condition IN Rising Min. 4.75 3.8 - Typ. 12 4.2 500 3.5 20 380 42 Max. Units 16 4.6 50 440 V V mV mA uA KHz KHz V nA A % % mΩ µA % %/V dB Iin ISHDN fSW VFB IFB DMAIN DMIIN RSW-DS(ON) ISW VFB=1.5V EN =GND Ta=+25℃ FB=0V Ta=+25℃ VFB=1.215V FB=1.0V FB=1.5V ISW=2A IN=13.5V,VSW=GND , EN=0V 0 A