MAX6877 MAXIM [Maxim Integrated Products], MAX6877 Datasheet
MAX6877
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MAX6877 Summary of contents
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... During voltage-tracking mode, the voltage at the GATE of each MOSFET is increased to slowly bring up all supplies at a controlled slew rate. The MAX6877/ MAX6878/MAX6879 feature an autoretry or latch-off mode with capacitor-adjusted timing. These devices also provide a controlled power-down (tracking mode) when the system shuts off in an orderly manner ...
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Dual-/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 CC ABP .....................................-0.3V to the highest of V SET1, SET2, SET3 ....................................................-0.3V to +6V GATE1, GATE2, GATE3 .........................................-0.3V to ...
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Dual-/Triple-Voltage, Power-Supply ELECTRICAL CHARACTERISTICS (continued) , IN1, IN2, or IN3 = +2.7V to +5.5V, EN/UV = MARGIN = ABP are +25°C, unless otherwise noted.) (Note 1) A PARAMETER SYMBOL Power-Good Threshold Hysteresis V GATE_ ...
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Dual-/Triple-Voltage, Power-Supply Trackers/Sequencers/Supervisors EN/UV V EN_R EN/UV IN1 = 2.5V IN2 = 1.8V IN3 = 0.7V IN_ CAPACITOR- ADJUSTED SLEW RATE OUT_ t DELAY PG/RST t TIMEOUT Figure 1. Tracking Timing Diagram in Normal Mode 4 _______________________________________________________________________________________ BUS VOLTAGE MONITORED ...
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Dual-/Triple-Voltage, Power-Supply EN/UV V EN_R IN1 = 2.5V IN2 = 1.8V IN3 = 0.7V IN_ CAPACITOR- ADJUSTED SLEW RATE OUT_ t DELAY t TIMEOUT PG/RST FAULT = HIGH FORCED INTO QUICK SHUTDOWN AFTER NORMAL SHUTDOWN WHEN IN1 GOES BELOW ITS ...
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Dual-/Triple-Voltage, Power-Supply Trackers/Sequencers/Supervisors EN/UV V EN_R IN1 = 2.5V IN2 = 1.8V IN3 = 0.7V IN_ CAPACITOR- ADJUSTED SLEW RATE OUT_ t DELAY PG/RST Figure 3. Sequencing in Normal Mode 6 _______________________________________________________________________________________ BUS VOLTAGE MONITORED THROUGH EN/UV INPUT MONITORED THROUGH ...
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Dual-/Triple-Voltage, Power-Supply EN/UV V EN_R IN1 = 2.5V IN2 = 1.8V IN3 = 0.7V IN_ CAPACITOR- ADJUSTED SLEW RATE OUT_ t DELAY PG/RST FAULT FORCED INTO QUICK SHUTDOWN WHEN OUT1 FALLS BELOW 92.5% of IN1 Figure 4. Sequencing in Fast ...
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Dual-/Triple-Voltage, Power-Supply Trackers/Sequencers/Supervisors EN/UV V EN_R IN1 = 2.5V IN2 = 1.8V IN3 = 0.7V IN_ CAPACITOR- ADJUSTED SLEW RATE OUT_ t DELAY PG/RST = LOW *ANY POWER-DOWN CONDITION BEFORE t Figure 5. Timing Diagram (Aborted Tracking) 8 _______________________________________________________________________________________ EN/UV ...
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Dual-/Triple-Voltage, Power-Supply EN/UV BUS VOLTAGE MONITORED THROUGH EN/UV INPUT V EN_R IN1 = 2.5V IN2 = 1.8V IN3 = 0.7V IN_ CAPACITOR- ADJUSTED SLEW RATE OUT_ t DELAY PG/RST = LOW *ANY POWER-DOWN CONDITION BEFORE t Figure 6. Timing Diagram ...
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Dual-/Triple-Voltage, Power-Supply Trackers/Sequencers/Supervisors EN/UV V EN_R OUT2 AND OUT3 ARE WAITING OUT1 IS SLOW OUT_ t DELAY t FAULT FAULT t AND t NOT TO SCALE FAULT RETRY OR IN_ ≥ 2.7V ALL SET_ > 0.5V AND V CC Figure ...
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Dual-/Triple-Voltage, Power-Supply = 200pF MARGIN = ABP 2.7V to 5.5V, C CC_ SLEW V SUPPLY CURRENT CC vs. INPUT VOLTAGE 1.4 1 +85°C A 1.2 1 +25° ...
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... GATE SOURCE CURRENT (µA) MAX6877 toc13 EN/UV 2V/div OUT1 OUT2 1V/div OUT3 FAST SHUTDOWN WITH RETRY MAX6877 toc15 100ms/div TRACKING MODE MAX6877 toc12 3.0 10ms/div FAST SHUTDOWN MAX6877 toc14 EN/UV 2V/div OUT1 OUT2 1V/div OUT3 FAULT 2V/div 40ms/div OUT1 2V/div THRESHOLD ERROR AT OUT1, OUT1 PULLED BELOW 92.5% OF IN1 ...
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... Dual-/Triple-Voltage, Power-Supply Trackers/Sequencers/Supervisors PIN MAX6877 MAX6878 MAX6879 1 1 — — — 16, 17, — — — — ______________________________________________________________________________________ NAME Optional Supply Voltage Input. Connect V supply if desired. Leave V ...
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... Dual-/Triple-Voltage, Power-Supply Trackers/Sequencers/Supervisors PIN MAX6877 MAX6878 MAX6879 14 14 — — — 17 — — — — ______________________________________________________________________________________ NAME Power-Good Output, Open-Drain. PG_RST asserts high t PG/RST OUT_ voltages exceed the V Tracking Fault Alert Output, Active Low, Open-Drain ...
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... Dual-/Triple-Voltage, Power-Supply Trackers/Sequencers/Supervisors IN1 MAX6877 SET1 IN2 COMP SET2 IN3 COMP SET3 V BUS COMP EN/UVLO COMP V REF MARGIN GND ______________________________________________________________________________________ V IN2 IN3 CC IN1 ABP INTERNAL V /UVLO CC RAMP GENERATOR CONTROL LOGIC TRACKING MONITORS DELAY SLEW C SLEW FAULT TRK/SEQ LTCH/RTR Functional Diagram ...
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... The channel exclusion feature adds more flexibili- 16 ______________________________________________________________________________________ ty to the device in a variety of different applications example, the MAX6877 can track or sequence two voltages using IN1 and IN2 while IN3 is left disabled. MAX6877/MAX6878/MAX6879 These devices derive power from either the IN1, IN2, or IN3 voltage inputs or V (see the Functional Diagram) ...
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... IN_ supply is set with an external resistor-divider from each IN_ to SET_ to ground. Undervoltage Lockout Threshold Inputs (SET_) The MAX6877 features three and the MAX6878/ MAX6879 feature two externally adjustable IN_ under- voltage lockout (UVLO) thresholds (SET1, SET2, SET3) to enable sequencing/tracking functionality. The undervolt- ...
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... Connect EN/ external resistor-divider network to set the external undervoltage = 3.5s, RETRY lockout threshold. The MAX6877 monitors three and MAX6878/MAX6879 monitor two OUT_ outputs to control the tracking/ sequencing performance. After the internal supply (ABP) exceeds the minimum voltage (2.7V) require- ments, EN/UV > V FORMULAS ...
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... OUT_ is enabled to help discharge load capacitance (100Ω is connected for fast power-down control). The MAX6877/MAX6878/MAX6879 feature up to three GATE_ outputs to drive up to three external n-channel FET gates. The following conditions must be met before GATE_ begins enhancing the external n-channel FET_: 1) All SET_ inputs (SET1– ...
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... If V RETRY all IN_ are cycled below 2.7V, the device tries to power- up immediately. Power-Good Output (PG/ RST ) The MAX6877/MAX6878 include a power-good (PG/RST) output. PG/RST is an open-drain output and requires an external pullup resistor. All the OUT_ outputs must exceed their IN_ referenced thresholds (IN_ x V ...
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... Dual-/Triple-Voltage, Power-Supply Trackers/Sequencers/Supervisors IN1 IN2 IN3 V BUS ______________________________________________________________________________________ Typical Application Circuit 0.1µF 0.1µF 0.1µF IN1 IN2 IN3 GATE1 GATE2 SET1 SET2 MAX6877 SET3 EN/ LTCH/RTR ABP SLEW GND TRK/SEQ DELAY TIMEOUT 1µF OUT1 OUT2 OUT3 GATE3 OUT1 OUT2 OUT3 FAULT ...
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Dual-/Triple-Voltage, Power-Supply Trackers/Sequencers/Supervisors Ordering Information (continued) PART TEMP RANGE MAX6878ETG+* -40°C to +85°C 24 Thin QFN MAX6878ETG* -40°C to +85°C 24 Thin QFN MAX6879ETE+ -40°C to +85°C 16 Thin QFN MAX6879ETE -40°C to +85°C 16 Thin QFN *Future product—contact factory ...
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Dual-/Triple-Voltage, Power-Supply (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information www.maxim-ic.com/packages.) ______________________________________________________________________________________ Trackers/Sequencers/Supervisors Package Information PACKAGE OUTLINE, 12, 16, 20, 24, 28L THIN QFN, 4x4x0.8mm 1 ...
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Dual-/Triple-Voltage, Power-Supply Trackers/Sequencers/Supervisors (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information www.maxim-ic.com/packages.) Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied ...