MAX6877/MAX6878/MAX6879 19-3771 Rev 1 10/05 Dual-/Triple-Voltage, Power-Supply Trackers/Sequencers/Supervisors General Description Features Pin-Selectable Tracking or Sequencing Control The MAX6877/MAX6878/MAX6879 multivoltage power for Up to Three Supply Voltages trackers/sequencers/supervisors monitor up to three system voltages and provide proper power-up and Capacitor-Adjustable Power-Up/Down Tracking Slew Rate power-down control for systems requiring voltage track- ing or sequencing. These devices ensure controlled Capacitor-Adjustable Power-Up Sequencing Delay voltage tracking within a specified range or sequencing Internal Charge Pumps to Enhance External in the proper order as system power supplies are n-Channel FETs enabled. The MAX6877/MAX6878/MAX6879 generate Capacitor-Adjustable Timeout Period Power-Good all required voltages and timing to control up to three Output (MAX6877/MAX6878) external n-channel pass FETs for the OUT1/OUT2/ Adjustable Undervoltage Lockout or OUT3 supply voltages (see the Selector Guide for dif- Logic-Enable Input ferent features of each device). Internal 100 Pulldown for Each Output to The MAX6877/MAX6878/MAX6879 feature adjustable Discharge Capacitive Load Quickly undervoltage thresholds for each input supply. When all 0.5V to 5.5V Nominal IN /OUT Range the voltages are above these adjustable thresholds, the 2.7V to 5.5V Operating Voltage Range devices turn on the external n-channel MOSFETs to Immune to Short Voltage Transients either sequence or track the voltages to the system. During voltage-tracking mode, the voltage at the GATE Small 4mm x 4mm 24-Pin or 16-Pin Thin QFN of each MOSFET is increased to slowly bring up all Packages supplies at a controlled slew rate. The MAX6877/ MAX6878/MAX6879 feature an autoretry or latch-off Ordering Information mode with capacitor-adjusted timing. These devices also provide a controlled power-down PIN- PKG PART TEMP RANGE (tracking mode) when the system shuts off in an orderly PACKAGE CODE manner. When an unexpected fault occurs, the outputs MAX6877ETG+ -40C to +85C 24 Thin QFN T2444-4 are all pulled down simultaneously with an internal Ordering Information continued at end of data sheet. 100 pulldown to help discharge capactive loads at +Denotes lead-free package. the MOSFETs source. The MAX6877/MAX6878/ MAX6879 feature independent internal charge pumps to fully enhance the external FETs for low-voltage drop Pin Configurations at highpass current. The MAX6877 and MAX6878 also feature a power-good output with a selectable timeout period that can be used for system reset. TOP VIEW The MAX6877/MAX6878/MAX6879 are available in small 4mm x 4mm 24-pin and 16-pin thin QFN pack- 18 17 16 15 14 13 ages and are fully specified over the -40C to +85C GATE2 19 12 TRK/SEQ extended operating temperature range. OUT1 11 LTCH/RTR 20 Applications 10 TIMEOUT GATE1 21 MAX6877 Multivoltage Systems IN3 22 9 SLEW EP* Networking Systems IN2 23 8 DELAY + Telecom GND IN1 24 7 Storage Equipment 12 3 45 6 Servers/Workstations 4mm x 4mm THIN QFN *EXPOSED PADDLE CONNECTED TO GND. Pin Configurations continued at end of data sheet. Selector Guide appears 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. EVALUATION KIT AVAILABLE V OUT2 CC GATE3 ABP SET3 OUT3 SET2 FAULT SET1 PG/RST EN/UV MARGINDual-/Triple-Voltage, Power-Supply Trackers/Sequencers/Supervisors ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND, unless otherwise noted.) IN1, IN2, IN3, V ....................................................-0.3V to +6V Input/Output Current (all pins except CC ABP OUT and GND) ...........................................................20mA .....................................-0.3V to the highest of V - V or V Continuous Power Dissipation (T = +70C) IN1 IN3 CC A SET1, SET2, SET3 ....................................................-0.3V to +6V 16-Pin 4mm x 4mm Thin QFN GATE1, GATE2, GATE3 .........................................-0.3V to +12V (derate 16.9mW/C above +70C).............................1349mW OUT1, OUT2, OUT3 .................................................-0.3V to +6V 24-Pin 4mm x 4mm Thin QFN LTCH/RTR, TRK/SEQ, MARGIN ...............................-0.3V to +6V (derate 20.8mW/C above +70C).............................1667mW FAULT, PG/RST, EN/UV ...........................................-0.3V to +6V Operating Temperature Range ...........................-40C to +85C DELAY, SLEW, TIMEOUT.........................................-0.3V to +6V Storage Temperature Range .............................-65C to +150C OUT Current....................................................................50mA Maximum Junction Temperature .....................................+150C GND Current.....................................................................50mA 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 (V , IN1, IN2, or IN3 = +2.7V to +5.5V, EN/UV = MARGIN = ABP, T = -40C to +85C, unless otherwise specified. Typical values CC A are at T = +25C, unless otherwise noted.) (Note 1) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Voltage on ABP (the highest of V or IN ) CC to ensure that PG/RST and FAULT are valid 1.4 and GATE = 0V Operating Voltage Range V V CC Voltage on ABP (the highest of V or IN ) CC 2.7 5.5 to ensure the device is fully operational Supply Current I V = 5.5V , IN 1 = IN 2 = IN 3 = 3.3V , no loa d 1.1 1.8 mA CC C C o SET falling, T = +25 C 0.4925 0.5 0.5075 A SET Threshold Range V V TH o o SET falling, T = -40 C to +85 C 0.4875 0.5 0.5125 A SET Threshold Hysteresis V SET rising 0.5 % TH HYS SET Input Current I SET = 0.5V -100 +100 nA SET V Input rising 1.286 EN R EN/UV Input Voltage V V Input falling 1.22 1.25 1.28 EN F EN/UV Input Current I -5 +5 A EN EN/UV Input Pulse Width t EN/UV falling, 100mV overdrive 7 s EN DELAY, TIMEOUT Output Current I (Notes 2, 3) 2.12 2.5 2.88 A D DELAY, TIMEOUT Threshold V = 3.3V 1.25 V C C Voltage SLEW Output Current (Note 4) I 22.5 25 27.5 A S Track/Sequence Slew-Rate SR C = 200pF (Note 4) -15 +15 % SLEW Timebase Accuracy Timebase/C Ratio 100pF < C < 1nF (Note 4) 104 k SLEW SLEW S l ew- Rate Accurac y dur i ng P ow er - C = 200pF, ABP = 5.5V (Note 4) -50 +50 % SLEW U p and P ow er - D own Power-Good Threshold V V falling 91.5 92.5 93.5 % TH PG OUT 2 MAX6877/MAX6878/MAX6879