MAX8732A/MAX8733A/MAX8734A 19-3711 Rev 0 5/05 High-Efficiency, Quad-Output, Main Power- Supply Controllers for Notebook Computers General Description Features No Current-Sense Resistor Needed (MAX8734A) The MAX8732A/MAX8733A/MAX8734A dual step-down, switch-mode power-supply (SMPS) controllers generate Accurate Current Sense with Current-Sense logic-supply voltages in battery-powered systems. The Resistor (MAX8732A/MAX8733A) MAX8732A/MAX8733A/MAX8734A include two pulse- 1.5% Output Voltage Accuracy width modulation (PWM) controllers, adjustable from 2V to 3.3V and 5V 100mA Bootstrapped Linear 5.5V or fixed at 5V and 3.3V. These devices feature two Regulators linear regulators providing 5V and 3.3V always-on out- puts. Each linear regulator provides up to 100mA output Internal Soft-Start and Soft-Stop Output Discharge current with automatic linear-regulator bootstrapping to the main SMPS outputs. The MAX8732A/MAX8733A/ Quick-PWM with 100ns Load Step Response MAX8734A include on-board power-up sequencing, a 3.3V and 5V Fixed or Adjustable Outputs power-good (PGOOD) output, digital soft-start, and inter- (Dual Mode) nal soft-stop output discharge that prevents negative volt- 4.5V to 24V Input Voltage Range ages on shutdown. Additionally, the outputs are high Enhanced Ultrasonic Pulse-Skipping Mode impedance when V falls below its UVLO set point while CC (25kHz min) the outputs are enabled. Power-Good (PGOOD) Signal Maxims proprietary Quick-PWM quick-response, con- stant on-time PWM control scheme operates without Overvoltage Protection Enable/Disable sense resistors and provides 100ns response to load tran- Ordering Information sients while maintaining a relatively constant switching fre- quency. The unique ultrasonic pulse-skipping mode 5V/3.3V maintains the switching frequency above 25kHz, which PIN- SWITCHING PART TEMP RANGE eliminates noise in audio applications. Other features PACKA GE FREQUENCY include pulse skipping, which maximizes efficiency in (kHz) light-load applications, and fixed-frequency PWM mode, MAX8732AEEI+ -40C to +85C 28 QSOP 200/300 which reduces RF interference in sensitive applications. MAX8732AEEI -40C to +85C 28 QSOP 200/300 The MAX8732A features a 200kHz/5V and 300kHz/3.3V MAX8733AEEI+ -40C to +85C 28 QSOP 400/500 SMPS for highest efficiency, while the MAX8733A fea- MAX8733AEEI -40C to +85C 28 QSOP 400/500 tures a 400kHz/5V and 500kHz/3.3V SMPS for thin and light applications. The MAX8734A provides a pin- Ordering Information continued at end of data sheet. selectable switching frequency, allowing either 200kHz/ +Denotes lead-free package. 300kHz or 400kHz/500kHz operation of the 5V/3.3V Pin Configurations SMPSs, respectively. The MAX8732A/MAX8733A/ MAX8734A are available in 28-pin QSOP packages and TOP VIEW operate over the extended temperature range N.C. 1 28 BST3 (-40C to +85C). PGOOD 2 27 LX3 The MAX8732A/MAX8733A/MAX8734A are pin-for-pin ON3 3 26 DH3 upgrades to the MAX1777/MAX1977/MAX1999. ON5 4 25 LDO3 The MAX1999 evaluation kit (EV kit) can be used to ILIM3 5 24 DL3 MAX8734A evaluate the MAX8732A/MAX8733A/MAX8734A. SHDN 6 23 GND FB3 7 22 OUT3 Applications REF 8 21 OUT5 Notebook and Subnotebook Computers FB5 9 20 V+ PDAs and Mobile Communication Devices PRO 10 19 DL5 ILIM5 11 18 LDO5 3- and 4-Cell Li+ Battery-Powered Devices SKIP 12 17 VCC TON 13 16 DH5 Quick-PWM and Dual Mode are trademarks of Maxim BST5 14 15 LX5 Integrated Products, Inc. QSOP Pin Configurations continued at end of data sheet. 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.High-Efficiency, Quad-Output, Main Power- Supply Controllers for Notebook Computers ABSOLUTE MAXIMUM RATINGS V+, SHDN to GND..................................................-0.3V to +25V LDO3, LDO5, REF Short Circuit to GND ....................Momentary LDO3 Current (internal regulator) Continuous................+100mA BST to GND ..........................................................-0.3V to +30V LDO3 Current (switched over to OUT3) Continuous......+200mA LX to BST ..............................................................-6V to +0.3V CS to GND (MAX8732A/MAX8733A only).................-2V to +6V LDO5 Current (internal regulator) Continuous................+100mA LDO5 Current (switched over to OUT5) Continuous......+200mA V , LDO5, LDO3, OUT3, OUT5, ON3, ON5, REF, CC FB3, FB5, SKIP, PRO, PGOOD to GND ...............-0.3V to +6V Continuous Power Dissipation (T = +70C) A 28-Pin QSOP (derate 10.8mW/C above +70C).........860mW DH3 to LX3 ..............................................-0.3V to (V + 0.3V) BST3 Operating Temperature Range ...........................-40C to +85C DH5 to LX5 ..............................................-0.3V to (V + 0.3V) BST5 ILIM3, ILIM5 to GND...................................-0.3V to (V + 0.3V) Junction Temperature......................................................+150C CC Storage Temperature Range .............................-65C to +150C DL3, DL5 to GND....................................-0.3V to (V + 0.3V) LDO5 TON to GND (MAX8734A only) ................................-0.3V to +6V Lead Temperature (soldering, 10s) .................................+300C 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 (Circuit of Figure 1 and Figure 2, no load on LDO5, LDO3, OUT3, OUT5, and REF, V+ = 12V, ON3 = ON5 = V , V = 5V, CC SHDN T = 0C to +85C, unless otherwise noted. Typical values are at T = +25C.) A A PARAMETER CONDITIONS MIN TYP MAX UNITS MAIN SMPS CONTROLLERS LDO5 in regulation 6 24 V+ Input Voltage Range V V+ = LDO5, V < 4.43V 4.5 5.5 OUT5 3.3V Output Voltage in V+ = 6V to 24V, FB3 = GND, V = 5V 3.285 3.330 3.375 V SKIP Fixed Mode V+ = 6V to 24V, FB5 = GND, V = 5V, SKIP MAX8732A/MAX8734A (TON = V ) CC 5V Output Voltage in Fixed Mode 4.975 5.050 5.125 V V+ = 7V to 24V, FB5 = GND, V = 5V, SKIP MAX8733A/MAX8734A (TON = GND) Output Voltage in V+ = 6V to 24V, either SMPS 1.975 2.00 2.025 V Adjustable Mode Output Voltage Adjust Range Either SMPS 2.0 5.5 V FB3, FB5 Adjustable-Mode Dual-Mode comparator 0.1 0.2 V Threshold Voltage Either SMPS, V = 5V, 0 to 5A -0.1 SKIP DC Load Regulation Either SMPS, SKIP = GND, 0 to 5A -1.5 % Either SMPS, V = 2V, 0 to 5A -1.7 SKIP Line Regulation Either SMPS, 6V < V+ < 24V 0.005 %/V Current-Limit Threshold ILIM = V , GND - CS (MAX8732A/MAX8733A), CC 93 100 107 mV (Positive, Default) GND - LX (MAX8734A) V = 0.5V 40 50 60 ILIM GND - CS Current-Limit Threshold (MAX8732A/MAX8733A), V = 1V 93 100 107 mV ILIM (Positive, Adjustable) GND - LX (MAX8734A) V = 2V 185 200 215 ILIM SKIP = GND, ILIM = V , GND - CS CC Zero-Current Threshold 3mV (MAX8732A/MAX8733A), GND - LX (MAX8734A) Current-Limit Threshold SKIP = ILIM = V , GND - CS CC -120 mV (Negative, Default) (MAX8732A/MAX8733A), GND - LX (MAX8734A) Soft-Start Ramp Time Zero to full limit 1.7 ms 2 MAX8732A/MAX8733A/MAX8734A