MAX8704 19-3420 Rev 0 9/04 High-Current, Low-Voltage Linear Regulator with Power-Limited, External MOSFET General Description Features The MAX8704 high-current linear regulator uses an Low-Cost, High-Current Linear Regulator external n-channel MOSFET to generate low-voltage External MOSFET Protection supplies for notebook computers. This linear regulator MOSFET Power Limit delivers an output voltage as low as 0.5V from an input voltage as low as 1.0V. Normally, this low input require- 50mV (typ) Current Limit ment would make the design of such a regulator very dif- Thermal Limit ficult. In this application, the 5V bias supply that is 1.0V to 5.5V Input Supply Voltage always available in the system powers the MAX8704 dri- 1.2V or 1.5V Preset, or Adjustable Output Voltage ver and control circuitry. The MAX8704 includes a fixed current limit and an Power-Good (PGOOD) Open-Drain Output with adjustable power limit to protect the external MOSFET 3ms Startup Delay from overheating. Additionally, the MAX8704 includes Programmable Soft-Start an internal thermal limit to prevent damage to the con- troller and provide remote thermal protection for the Shutdown with Output Discharge external MOSFET. The MAX8704 features an adjustable soft-start function and generates a delayed power-good (PGOOD) signal that signals when the linear regulator is in regulation. The MAX8704 is available in a 10-pin MAX package. Applications Ordering Information V and V CPU Supplies MCH CCP PART TEMP RANGE PIN-PACKAGE Notebook Computers MAX8704EUB -40C to +85C 10 MAX Desktop Computers Servers VID Power Supplies Low-Voltage Bias Supplies Pin Configuration TOP VIEW V 1 10 DRV IN V 2 9 GND CC MAX8704 PGOOD 3 8 CSP PLIM 4 7 CSN SS/EN 5 6 FB MAX MAX is a registered trademark of Maxim Integrated Products, Inc. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLEHigh-Current, Low-Voltage Linear Regulator with Power-Limited, External MOSFET ABSOLUTE MAXIMUM RATINGS V , V to GND.......................................................-0.3V to +6V Operating Temperature Range ...........................-40C to +85C CC IN CSP, CSN, DRV to GND...........................................-0.3V to +6V Junction Temperature......................................................+150C FB, PLIM, SS/EN, PGOOD to GND.............-0.3V to (V + 0.3V) Storage Temperature Range .............................-65C to +150C CC Continuous Power Dissipation (T = +70C) Lead Temperature (soldering, 10s) .................................+300C A 10-Pin MAX (derated 5.6mW/C above +70C).........444mW 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. ELECTRICAL CHARACTERISTICS (V = 2.5V, V = 5.0V, PLIM = FB = GND, CSP = CSN, SS/EN floating, T = 0C to +85C, unless otherwise noted. Typical values IN CC A are at T = +25C.) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS V 1.0 5.5 IN Input Voltage Range V V 4.5 5.5 CC FB = V 1.462 1.50 1.538 Preset Output Voltage CC V V OUT (Fixed) FB = GND 1.170 1.20 1.230 Feedback Voltage Accuracy V FB = CSN 490 500 510 mV FB (Adjustable) Load-Regulation Error V - V = 45mV -2.5 -2 % CSP CSN Line-Regulation Error V = 1V to 5.5V 0.01 % IN FB Input Bias Current I V = 0.6V -1 +1 A FB FB CSN Input Bias Current I V = 1.6V 50 100 A CSN CSN V - V - CC CC Output high 1.0 0.7 DRV Output Voltage Swing V V DRV Output low 0.7 1.0 DRV Slew Rate C = 40nF 0.2 V/s DRV FB forced above the regulation point, Quiescent Supply Current (V)I 1.5 3 mA CC CC V = 1.6V CSN FB forced above the regulation point, Quiescent Supply Current (V)I 510 A IN IN V = 1.6V CSN Shutdown Supply Current (V ) SS/EN = GND 35 70 A CC Shutdown Supply Current (V ) SS/EN = GND 5 10 A IN FAULT DETECTION Thermal-Shutdown Threshold T Rising edge, 20C hysteresis +140 C SHDN V Undervoltage-Lockout CC Rising edge, 15mV hysteresis 4.2 4.45 V Threshold Current-Limit Threshold V PLIM = GND 45 50 57 mV CSLIMIT Power-Limit Threshold V Rising edge 0.96 1.0 1.04 V PWRLIMIT V - V = 30mV, V = 0.5V, CSP CSN CSN 2 Power-Limit Conversion Gain K 155 200 233 A/V PLIM V = 3.5V IN Power-Limit Conversion Gain V - V = 25mV to 45mV, V = 0.5V, CSP CSN CSN 12 % Variation V = 2V to 4.5V IN 2 MAX8704