MAX5904ESA+-MAX5904ESA+T-MAX5904ESA-T-MAX5904USA+-MAX5908EEE+-MAX5908UEE+-MAX5908UEE+T-MAX5909UEE+-MAX5909UEE+T Fast Delivery |IC PHOENIX CO.,LIMITED

MAX5904ESA-T ,Low-Voltage, Dual Hot-Swap Controllers/Power SequencersApplicationsPin Configurations®PCI-Express
MAX5904USA ,Low-Voltage / Dual Hot-Swap Controllers/Power SequencersELECTRICAL CHARACTERISTICS(V _ = +1V to +13.2V provided at least one supply is higher than +2.7V, V ..
MAX5904USA ,Low-Voltage / Dual Hot-Swap Controllers/Power SequencersMAX5904–MAX590919-2238; Rev 2; 11/03Low-Voltage, Dual Hot-Swap Controllers/PowerSequencers
MAX5904USA ,Low-Voltage / Dual Hot-Swap Controllers/Power SequencersApplicationsTOP VIEWBasestation Line CardsIN1 1 8 IN2Network Switches or RoutersSENSE1 2 7 SENSE2MA ..
MAX5904USA+ ,Low-Voltage, Dual Hot-Swap Controllers/Power Sequencersfeatures like startup current regulation and currentMAX5906UEE 0°C to +85°C 16 QSOP E16-1glitch p ..
MAX5905ESA ,+1V to +13.2V, Low-voltage, dual hot-swap controller/power sequenceFeaturesThe MAX5904–MAX5909 dual hot-swap controllers Safe Hot Swap for +1V to +13.2V Powerprovid ..
MAZ8068G ,Silicon planar typeelectrical characteristics WZ Zwithin part numbersReverse current I V Speciﬁed valuemAR R2*Tempera ..
MAZ8068GML , MAZ8xxxG Series Silicon planar type
MAZ8068GML , MAZ8xxxG Series Silicon planar type
MAZ8068GML+ , MAZ8xxxG Series Silicon planar type
MAZ8068-H ,Silicon planar typeelectrical characteristicsZ Zwithin part numbersReverse current I V ··············· Specified value ..
MAZ8068-L ,Silicon planar typeAbsolute Maximum Ratings T = 25°CaMarking SymbolParameter Symbol Rating UnitRefer to the list of t ..

MAX5904ESA+-MAX5904ESA+T-MAX5904ESA-T-MAX5904USA+-MAX5908EEE+-MAX5908UEE+-MAX5908UEE+T-MAX5909UEE+-MAX5909UEE+T
Low-Voltage, Dual Hot-Swap Controllers/Power Sequencers
General Description
The MAX5904–MAX5909 dual hot-swap controllers
provide complete protection for dual-supply systems.
These devices hot swap two supplies ranging from +1V
to +13.2V, provided one supply is at or above 2.7V,
allowing the safe insertion and removal of circuit cards
into live backplanes.
The discharged filter capacitors of the circuit card pro-
vide low impedance to the live backplane. High inrush
currents from the backplane to the circuit card can burn
up connectors and components, or momentarily col-
lapse the backplane power supply leading to a system
reset. The MAX5904 family of hot-swap controllers pre-
vents such problems by gradually ramping up the output
voltage and regulating the current to a preset limit when
the board is plugged in, allowing the system to stabilize
safely. After the startup cycle is completed, two on-chip
comparators provide VariableSpeed/BiLevel™ protec-
tion against short-circuit and overcurrent faults, as well
as immunity against system noise and load transients. In
the event of a fault condition, the load is disconnected.
The MAX5905/MAX5907/MAX5909 must be unlatched
after a fault, and the MAX5904/MAX5906/MAX5908 auto-
matically restart after a fault.
The MAX5904 family offers a variety of options to reduce
component count and design time. All devices integrate
an on-board charge pump to drive the gates of low-cost,
external n-channel MOSFETs. The devices offer integrat-
ed features like startup current regulation and current
glitch protection to eliminate external timing resistors and
capacitors. The MAX5906–MAX5909 provide an open-
drain status output, an adjustable startup timer, an
adjustable current limit, an uncommitted comparator,
and output undervoltage/overvoltage monitoring.
The MAX5904/MAX5905 are available in 8-pin SO pack-
ages. The MAX5906–MAX5909 are available in space-
saving 16-pin QSOP packages.
Applications
PCI-Express®Applications
Basestation Line Cards
Network Switches or Routers
Solid-State Circuit Breaker
Power-Supply Sequencing
Hot Plug-In Daughter Cards
RAID
FeaturesSafe Hot-Swap for +1V to +13.2V Power
Supplies
Requires One Input ≥2.7VLow 25mV Default Current-Limit ThresholdInrush Current Regulated at StartupCircuit Breaker FunctionAdjustable Circuit Breaker/Current-Limit
ThresholdVariableSpeed/BiLevel Circuit-Breaker ResponseAutoretry or Latched Fault ManagementOn/Off Sequence ProgrammingStatus Output Indicates Fault/Safe ConditionOutput Undervoltage and Overvoltage Monitoring
and/or Protection
MAX5904–MAX5909
Low-Voltage, Dual Hot-Swap Controllers/Power
Sequencers
GATE2GND
IN2
SENSE2SENSE1
GATE1
IN1
NARROW SO
TOP VIEW
MAX5904
MAX5905
Pin Configurations
Ordering Information
19-2238; Rev 3; 9/05EVALUATION KIT
AVAILABLE
PART TEMP RANGEPIN-
PACKAGE
PKG
CODE
MAX5904ESA*-40°C to +85°C8 SOS8-4
MAX5904USA 0°C to +85°C8 SOS8-4
MAX5905ESA*-40°C to +85°C8 SOS8-4
MAX5905USA 0°C to +85°C8 SOS8-4
MAX5906EEE*-40°C to +85°C16 QSOPE16-1
MAX5906UEE 0°C to +85°C16 QSOPE16-1
MAX5907EEE*-40°C to +85°C16 QSOPE16-1
MAX5907UEE 0°C to +85°C16 QSOPE16-1
MAX5908EEE*-40°C to +85°C16 QSOPE16-1
MAX5908UEE 0°C to +85°C16 QSOPE16-1
MAX5909EEE*-40°C to +85°C16 QSOPE16-1
MAX5909UEE 0°C to +85°C16 QSOPE16-1
Selector Guide and Typical Operating Circuits appear at end
VariableSpeed/BiLevel is a trademark of Maxim Integrated
Products, Inc.
PCI-Express is a registered trademark of PCI-SIG Corp.
Pin Configurations continued at end of data sheet.
*Contact factory for availability.
MAX5904–MAX5909
Low-Voltage, Dual Hot-Swap Controllers/Power
Sequencers
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN_ = +1V to +13.2V provided at least one supply is higher than +2.7V, VON= +2.7V, TA= 0°C to +85°C, unless otherwise noted.
Typical values are at VIN1= +5V, VIN2= +3.3V, and TA= +25°C.) (Note 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.
IN_ to GND...........................................................................+14V
GATE_ to GND..........................................+0.3V to (VIN_ + 6.2V)
ON, PGOOD, COMP+, COMPOUT, TIM
to GND.....-0.3V to the higher of (VIN1+ 0.3V) and (VIN2+ 0.3V)
SENSE_, MON_, LIM_ to GND...................-0.3V to (VIN_ + 0.3V)
Current into Any Pin .........................................................±50mA
Continuous Power Dissipation (TA= +70°C)
8-Pin Narrow SO (derate 5.9mW/°C above +70°C)......471mW
16-Pin QSOP (derate 8.3mW/°C above +70°C)............667mW
Operating Temperature Ranges:
MAX590_U_ _ .....................................................0°C to +85°C
MAX590_E_ _ ...................................................-40°C to +85°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
POWER SUPPLIES
IN_ Input Voltage Range (Note 2)VIN_Other VIN = +2.7V1.013.2V
Supply CurrentIINIIN1 + IIN21.22.9mA
CURRENT CONTROL
TA = +25°C 22.52527.5MAX5904/MAX5905TA = 0°C to +85°C20.527.5
LIM = GND22.52527.5
Slow-Comparator Threshold
(VIN - VSENSE) (Note 3)VSC,TH
MAX5906–MAX5909RLIM = 300kΩ80100125
1mV overdrive3msSlow-Comparator Response Time
(Note 4)tSCD50mV overdrive110µs
VSU,THVIN_ - VSENSE_; during startup2 x VSC, THFast-Comparator ThresholdVFC,THVIN_ - VSENSE_; normal operation4 x VSC, THmV
Fast-Comparator Response TimetFCD10mV overdrive, from overload condition260ns
SENSE Input Bias CurrentIB SENVSEN_ = VIN_0.036µA
MOSFET DRIVER
RTIM = 100kΩ7.110.815.5
RTIM = 4kΩ (minimum value)0.310.450.58Startup Period
(Note 5)tSTART
TIM floating for MAX5906–MAX5909
fixed for MAX5904/MAX59053.9916.0
Charging, VGATE = +5V, VIN = +10V
(Note 5)80100130µA
Weak discharge, during startup when current
limit is active or when 0.4V < VON < 0.8V100µAAverage Gate CurrentIGATE
Strong discharge, triggered by a fault or
when VON < 0.4V3mA
VGATE_ - VIN_, IGATE_ < 1µA, VIN ≥ 3V4.85.45.8Gate-Drive VoltageVDRIVEVGATE_ - VIN_, IGATE_ < 1µA, 2.7V ≤ VIN ≤ 3V4.25.35.8V
ON COMPARATOR
Low to high0.3750.40.425VFast Pulldown ON ThresholdVONFP,THHysteresis25mV
MAX5904–MAX5909
Low-Voltage, Dual Hot-Swap Controllers/Power
Sequencers
ELECTRICAL CHARACTERISTICS (continued)
(VIN_ = +1V to +13.2V provided at least one supply is higher than +2.7V, VON= +2.7V, TA= 0°C to +85°C, unless otherwise noted.
Typical values are at VIN1= +5V, VIN2= +3.3V, and TA= +25°C.) (Note 1)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
Low to high0.800.8250.85VChannel 1 ON ThresholdVON1,THHysteresis25mV
Low to high1.952.0252.07VChannel 2 ON ThresholdVON2,THHysteresis25mV
ON Propagation DelaytON10mV overdrive50µs
VON < 4.5V0.03
VON > 4.5V100ON Input Bias CurrentIBONVIN1 = VIN2 = +13.2V
VON = 4V0.031
ON Pulse-Width LowtUNLATCHTo unlatch after a latched fault100µs
DIGITAL OUTPUT (PGOOD)
Output Leakage CurrentVPGOOD = 13.2V1µA
Output-Voltage LowVOLISINK = 1mA0.4V
PGOOD DelaytPGDLYAfter tSTART, MON_ = VIN_0.75ms
OUTPUT VOLTAGE MONITORS (MON1, MON2)
Overvoltage655687710MON_ Trip ThresholdVMON_Undervoltage513543567mV
MON_ Glitch Filter20µs
MON_ Input Bias CurrentVMON_ = 600mV0.03µA
UNDERVOLTAGE LOCKOUT (UVLO)tar tup i s i ni ti ated w hen thi s thr eshol d i s r eached y V IN 1 or V IN 2 , V ON > 0.8V , V IN_ i ncr easi ng 2.12.42.67VUVLO ThresholdVUVLO
Hysteresis100mV
UVLO Glitch Filter Reset TimeVIN_ = 0V, to unlatch after a fault100µs
UVLO to Startup DelaytD,UVLOVIN_ step from 0 to 2.8V1837.564ms
SHUTDOWN RESTART
Autoretry DelaytRETRYDelay time to restart after a fault shutdown
MAX5904/MAX5906/MAX590864 x tSTARTms
UNCOMMITTED COMPARATOR
Low to high1.2061.251.290VINC+ Trip Threshold VoltageVC,THHysteresis10mV
Propagation Delay10mV overdrive50µs
OUTC Voltage LowVOLISINK = 1mA0.4V
INC+ Bias CurrentVINC+ = 5V0.021µA
OUTC Leakage CurrentIOUTCVOUTC = 13.2V0.021µA
MAX5904–MAX5909
Low-Voltage, Dual Hot-Swap Controllers/Power
Sequencers
ELECTRICAL CHARACTERISTICS
(VIN_ = +1V to +13.2V provided at least one supply is higher than +2.7V, VON= +2.7V, TA= -40°C to +85°C, unless otherwise noted.
Typical values are at VIN1= +5V, VIN2= +3.3V, and TA= +25°C.) (Note 1)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
POWER SUPPLIES
IN_ Input Voltage Range (Note 2)VIN_Other VIN = +2.7V1.013.2V
Supply CurrentIINIIN1 + IIN21.22.9mA
CURRENT CONTROL
TA = +25°C 22.52527.5MAX5904/MAX5905TA = -40°C to +85°C20.527.5
LIM = GND22.52527.5
Slow-Comparator Threshold
(VIN - VSENSE) (Note 3)VSC,TH
MAX5906–MAX5909RLIM = 300kΩ80100125
1mV overdrive3msSlow-Comparator Response Time
(Note 4)tSCD50mV overdrive110µs
VSU,THVIN_ - VSENSE_; during startup2 x VSC, THFast-Comparator ThresholdVFC,THVIN_ - VSENSE_; normal operation4 x VSC, THmV
Fast-Comparator Response TimetFCD10mV overdrive, from overload condition260ns
SENSE Input Bias CurrentIB SENVSEN_ = VIN_0.036µA
MOSFET DRIVER
RTIM = 100kΩ7.110.815.5
RTIM = 4kΩ (minimum value)0.310.450.58Startup Period
(Note 5)tSTART
TIM floating for MAX5906–MAX5909
fixed for MAX5904/MAX59053.9916.0
Charging, VGATE = +5V, VIN = +10V
(Note 5)80100130µA
Weak discharge, during startup when current
limit is active or when 0.4V < VON < 0.8V100µAAverage Gate CurrentIGATE
Strong discharge, triggered by a fault or
when VON < 0.4V3mA
VGATE_ - VIN_, IGATE_ < 1µA, VIN ≥ 3V4.85.45.8Gate-Drive VoltageVDRIVEVGATE_ - VIN_, IGATE_ < 1µA, 2.7V ≤ VIN ≤ 3V3.65.8V
ON COMPARATOR
Low to high0.3750.40.425VFast Pulldown ON ThresholdVONFP,THHysteresis25mV
Low to high0.790.8250.85VChannel 1 ON ThresholdVON1,THHysteresis25mV
Low to high1.932.0252.07VChannel 2 ON ThresholdVON2,THHysteresis25mV
ON Propagation DelaytON10mV overdrive50µs
MAX5904–MAX5909
Low-Voltage, Dual Hot-Swap Controllers/Power
Sequencers
ELECTRICAL CHARACTERISTICS (continued)
(VIN_ = +1V to +13.2V provided at least one supply is higher than +2.7V, VON= +2.7V, TA= -40°C to +85°C, unless otherwise noted.
Typical values are at VIN1= +5V, VIN2= +3.3V, and TA= +25°C.) (Note 1)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
VON < 4.5V0.03
VON > 4.5V100ON Input Bias CurrentIBONVIN1 = VIN2 = +13.2V
VON = 4V0.031
ON Pulse-Width LowtUNLATCHTo unlatch after a latched fault100µs
DIGITAL OUTPUT (PGOOD)
Output Leakage CurrentVPGOOD = 13.2V1µA
Output-Voltage LowVOLISINK = 1mA0.4V
PGOOD DelaytPGDLYAfter tSTART, MON_ = VIN_0.75ms
OUTPUT VOLTAGE MONITORS (MON1, MON2)
Overvoltage655687710MON_ Trip ThresholdVMON_Undervoltage513543567mV
MON_ Glitch Filter20µs
MON_ Input Bias CurrentVMON_ = 600mV0.03µA
UNDERVOLTAGE LOCKOUT (UVLO)tar tup i s i ni ti ated w hen thi s thr eshol d i s r eached y V IN 1 or V IN 2 , V ON > 0.8V , V IN_ i ncr easi ng 2.12.42.67VUVLO ThresholdVUVLO
Hysteresis100mV
UVLO Glitch Filter Reset TimeVIN_ = 0V, to unlatch after a fault100µs
UVLO to Startup DelaytD,UVLOVIN_ step from 0 to 2.8V1837.564ms
SHUTDOWN RESTART
Autoretry DelaytRETRYDelay time to restart after a fault shutdown
MAX5904/MAX5906/MAX590864 x tSTARTms
UNCOMMITTED COMPARATOR
Low to high1.2061.251.290VINC+ Trip Threshold VoltageVC,THHysteresis10mV
Propagation Delay10mV overdrive50µs
OUTC Voltage LowVOLISINK = 1mA0.4V
INC+ Bias CurrentVINC+ = 5V0.021µA
OUTC Leakage CurrentIOUTCVOUTC = 13.2V0.021µA
Note 1:Limits are 100% tested at TA= +25°C and +85°C. Limits at 0°C and -40°are guaranteed by characterization and are not produc-
tion tested.
Note 2:VINrising slew rate must be less than 0.2V/µs.
Note 3:The MAX5906–MAX5909 slow-comparator threshold is adjustable. VSC,TH= RLIMx 0.25µA + 25mV (see the Typical
Operating Characteristics).
Note 4:The current-limit slow-comparator response time is weighted against the amount of overcurrent; the higher the overcurrent
condition, the faster the response time. See the Typical Operating Characteristics.
Note 5:The startup period (tSTART) is the time during which the slow comparator is ignored and the device acts as a current limiter
by regulating the sense current with the fast comparator. See the Startup Periodsection.
MAX5904–MAX5909
Low-Voltage, Dual Hot-Swap Controllers/Power
Sequencers
Typical Operating Characteristics
(Typical Operating Circuits, Q1 = Q2 = Fairchild FDB7090L, VIN1= +5V, VIN2= +3.3V, TA= +25°C, unless otherwise noted. Channels
1 and 2 are identical in performance. Where characteristics are interchangeable, channels 1 and 2 are referred to as X and Y.)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX5904 toc01
VINX (V)
IIN
(mA)
VINY = VON = 2.7V
IINX + IINY
IINX
IINY
TOTAL SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX5904 toc02
VINX (V)
IIN
(mA)
VINY = 5.0V
A) VON = 3.3V
B) VON = 1.5V
C) VON = 0V
SUPPLY CURRENT
vs. TEMPERATURE
MAX5904 toc03
TEMPERATURE (°C)
IIN
(mA)
VON = VIN1
IIN1 + IIN2
IIN2
IIN1824101214
GATE-DRIVE VOLTAGE vs.
INPUT VOLTAGE
MAX5904 toc04
VINX (V)
GATE-DRIVE VOLTAGE (V)
VINY = 2.7V
GATE-CHARGE CURRENT
vs. GATE VOLTAGE
MAX5904 toc05
VGATEX (V)
GATE-CHARGE CURRENT (
VON = VINY = 2.7V
VINX = 13.2V
VINX = 5V
VINX = 1V
GATE-CHARGE CURRENT
vs. TEMPERATURE
MAX5904 toc06
TEMPERATURE (°C)
GATE-CHARGE CURRENT (VINX = 13.2V
VINX = 5V
VINX = 1V
VON = VINY = 2.7V
VGATEX = 0V
GATE WEAK DISCHARGE CURRENT
vs. GATE VOLTAGE
MAX5904 toc07
VGATEX (V)
GATE DISCHARGE CURRENT (
VON = 0.6V
VINY = 2.7V
VINX = 13.2VVINX = 5V
VINX = 1V
GATE WEAK DISCHARGE CURRENT
vs. TEMPERATURE
MAX5904 toc08
TEMPERATURE (°C)
GATE DISCHARGE CURRENT (
VON = 0.6V
VINX = 13.2VVINX = 5V
VINX = 1V
VINY = 2.7V
VGATEX = VINX + 6.2V
GATE STRONG DISCHARGE CURRENT
vs. GATE VOLTAGE
MAX5904 toc09
VGATEX (V)
GATE DISCHARGE CURRENT (mA)
VINX = 13.2VVINX = 5V
VINX = 1V
VON = 0V
VINY = 2.7V
VGATEX = VINX + 6.2V
MAX5904–MAX5909
Low-Voltage, Dual Hot-Swap Controllers/Power
Sequencers
GATE STRONG DISCHARGE CURRENT
vs. TEMPERATURE
MAX5904 toc10
TEMPERATURE (°C)
GATE DISCHARGE CURRENT (mA)
VINX = 13.2V
VINX = 5V
VINX = 1V
VON = 0V
VINY = 2.7V
VGATEX = VINX + 6.2V
TURN-OFF TIME vs. SENSE VOLTAGE
MAX5904 toc11
VIN - VSENSE (mV)
TURN-OFF TIME (ms)
SLOW-COMP. THRESHOLD
FAST-COMP. THRESHOLD
TURN-OFF TIME vs. SENSE VOLTAGE
(EXPANDED SCALE)
MAX5904 toc12
VIN - VSENSE (mV)
TURN-OFF TIME (ms)
SLOW-COMP. THRESHOLD
SLOW-COMPARATOR THRESHOLD
vs. RLIM
MAX5904 toc13
RLIM (kΩ)
SC, TH
(mV)
STARTUP PERIOD vs. RTIM
MAX5904 toc14
RTIM (kΩ)
tSTART
(ms)200300100400500600
VPGOOD
5V/div
VSENSE - VIN
100mV/div
VGATE
5V/div
TURN-OFF TIME
SLOW-COMPARATOR FAULT
MAX5904 toc15
1ms/div
VIN = 5.0V
tSCD
26mV STEPVPGOOD
5V/div
VSENSE - VIN
100mV/div
VGATE
5V/div
TURN-OFF TIME
FAST-COMPARATOR FAULT
MAX5904 toc16
400ns/div
VIN = 5.0V
tFCD
125mV STEP
VON
2V/div
VPGOOD
2V/div
IOUT
5A/div
VOUT
5V/div
VGATE
5V/div
STARTUP WAVEFORMS
FAST TURN-ON
MAX5904 toc17
1ms/div
VIN = 5.0V, RSENSE = 10mΩ,
RTIM = 27kΩ, CBOARD = 1000μF
Typical Operating Characteristics (continued)
(Typical Operating Circuits, Q1 = Q2 = Fairchild FDB7090L, VIN1= +5V, VIN2= +3.3V, TA= +25°C, unless otherwise noted. Channels
1 and 2 are identical in performance. Where characteristics are interchangeable, channels 1 and 2 are referred to as X and Y.)
MAX5904–MAX5909
Low-Voltage, Dual Hot-Swap Controllers/Power
Sequencers
Pin Description
PIN
MAX5904/
MAX5905
MAX5906–
MAX5909
NAMEFUNCTIONPGOODOpen-Drain Status Output. High impedance when startup is complete and no faults
are detected. Actively held low during startup and when a fault is detected.TIMStartup Timer Setting. Connect a resistor from TIM to GND to set the startup period.
Leave TIM unconnected for the default startup period of 9ms.IN1Channel 1 Supply Input. Connect to a supply voltage from 1V to 13.2V. Connect a
0.1µF ceramic bypass capacitor from IN1 to GND to filter high-frequency noise.SENSE1Channel 1 Current-Sense Input. Connect RSENSE1 from IN1 to SENSE1.GATE1Channel 1 Gate-Drive Output. Connect to gate of external n-channel MOSFET.GNDGroundLIM1Channel 1 Current-Limit Setting. Connect a resistor from LIM1 to GND to set
current-trip level. Connect to GND for the default 25mV threshold.MON1
Channel 1 Output Voltage Monitor. Window comparator input. Connect through a
resistive-divider from OUT1 to GND to set the channel 1 overvoltage and
undervoltage thresholds. Connect to IN1 to disable.MON2
Channel 2 Output Voltage Monitor. Window comparator input. Connect through a
resistive-divider from OUT2 to ground to set the channel 2 overvoltage and
undervoltage thresholds. Connect to IN2 to disable.
IOUT
5A/div
VOUT
5V/div
VGATE
5V/div
AUTORETRY DELAY
MAX5904 toc19
40ms/div
VIN = 5.0V, RSENSE = 10mΩ, RTIM = 47kΩ,
CBOARD = 1000μF, RBOARD = 1.4Ω
VON
2V/div
VPGOOD
2V/div
IOUT
5A/div
VOUT
5V/div
VGATE
5V/div
STARTUP WAVEFORMS
SLOW TURN-ON
MAX5904 toc18
1ms/div
VIN = 5.0V, RSENSE = 10mΩ, RTIM = 47kΩ,
CBOARD = 1000μF, CGATE = 22nF
Typical Operating Characteristics (continued)
(Typical Operating Circuits, Q1 = Q2 = Fairchild FDB7090L, VIN1= +5V, VIN2= +3.3V, TA= +25°C, unless otherwise noted. Channels
1 and 2 are identical in performance. Where characteristics are interchangeable, channels 1 and 2 are referred to as X and Y.)
Detailed Description
The MAX5904–MAX5909 are circuit breaker ICs for hot-
swap applications where a line card is inserted into a
live backplane. These devices hot swap supplies rang-
ing from +1V to +13.3V, provided one supply is at or
above 2.7V. Normally, when a line card is plugged into
a live backplane, the card’s discharged filter capacitors
provide low impedance that can momentarily cause the
main power supply to collapse. The MAX5904–
MAX5909 reside either on the backplane or on the
removable card to provide inrush current limiting and
short-circuit protection. This is achieved by using exter-
nal n-channel MOSFETs, external current-sense resis-
tors, and two on-chip comparators. Figure 1 shows the
MAX5906–MAX5909 functional diagram.
The MAX5904/MAX5905 have a fixed startup period
and current-limit threshold. The startup period and cur-
rent-limit threshold of the MAX5906–MAX5909 can be
adjusted with external resistors.
Startup Period
RTIMsets the duration of the startup period for the
MAX5906–MAX5909 from 0.4ms to 50ms (see the
Setting the Startup Period, RTIMsection). The duration
of the startup period is fixed at 9ms for the MAX5904/
MAX5905. The startup period begins after the following
three conditions are met:VIN1or VIN2exceeds the UVLO threshold (2.4V) for
the UVLO to startup delay (37.5ms).VONexceeds the channel 1 ON threshold (0.825V).
VONshould be delayed from the application of a
steep rising edge at IN_ by inserting a minimum RC
time delay of 20µs.The device is not latched or in its autoretry delay. (See
Latched and Autoretry FaultManagement section.)
The MAX5904–MAX5909 limit the load current if an
overcurrent fault occurs during startup. The slow com-
parator is disabled during the startup period and the
load current can be limited in two ways:Slowly enhancing the MOSFETs by limiting the
MOSFET gate charging currentLimiting the voltage across the external current-
sense resistor.
During the startup period, the gate drive current is typi-
cally 100µA and decreases with the increase of the
gate voltage (see the Typical Operating Character-
istics). This allows the controller to slowly enhance the
MOSFETs. If the fast comparator detects an overcur-
rent, the MAX5904–MAX5909 regulate the gate voltage
to ensure that the voltage across the sense resistor
does not exceed VSU,TH. This effectively regulates the
inrush current during startup. Figure 2 shows the start-
up waveforms. PGOOD goes high impedance 0.75ms
after the startup period if no fault condition is present.
VariableSpeed/BiLevel Fault Protection
VariableSpeed/BiLevel fault protection incorporates two
comparators with different thresholds and response
times to monitor the load current (Figure 9). During the
startup period, protection is provided by limiting the
load current. Protection is provided in normal operation
(after the startup period has expired) by discharging
both MOSFET gates with a strong 3mA pulldown cur-
rent in response to a fault condition. After a fault,
PGOOD is pulled low, the MAX5905/MAX5907/
MAX5909 stay latched off and the MAX5904/MAX5906/
MAX5908 automatically restart.
MAX5904–MAX5909
Low-Voltage, Dual Hot-Swap Controllers/Power
Sequencers
PIN
MAX5904/
MAX5905
MAX5906–
MAX5909
NAMEFUNCTION
—10LIM2Channel 2 Current-Limit Setting. Connect a resistor from LIM2 to GND to set
current-trip level. Connect to GND for the default 25mV threshold.
511ONOn Comparator Input
612GATE2Channel 2 Gate-Drive Output. Connect to gate of external n-channel MOSFET.
713SENSE2Channel 2 Current-Sense Input. Connect RSENSE2 from IN2 to SENSE2.
814IN2Channel 2 Supply Input. Connect to a supply voltage from 1V to 13.2V. Connect a
0.1µF ceramic bypass capacitor from IN2 to GND to filter high-frequency noise.
—15INC+Uncommitted Comparator Noninverting Input
—16OUTCUncommitted Comparator Open-Drain Output. Actively held low when VINC+ is less
than 1.236V.
Pin Description (continued)
MAX5904–MAX5909
Low-Voltage, Dual Hot-Swap Controllers/Power
Sequencers
UVLO
AST COMP
SLOW COMP
SLOW DISCHARGEF
AST DISCHARGE
OUT1
2.4V
2.4V
BIAS AND
REFERENCES
TIMING
OSCILLA
TOR
TUP
OSCILLA
TOR
TO ST
TUP
LOGIC BLOCKS
CHARGE
PUMP
DEVICE CONTROL
LOGIC
SC, TH
FS, TH
LIM1
SENSE1
IN1
TE1
SENSE1
LIM1
LIM2
3mA
687mV543mV
1.236V
MON1
INC+
OUTC
PGOOD
UVLO
AST COMP
SLOW COMP
SLOW DISCHARGEFAST DISCHARGE
OUT2
CHARGE PUMP
OSCILLA
TOR
TO ST
TUP
LOGIC BLOCKS
CHARGE
PUMP
CURRENT CONTROL
AND
TUP LOGIC
CURRENT CONTROL
AND
TUP LOGIC
SC, TH
FS, TH
SENSE2IN2GA
TE2
SENSE2
LIM2
3mA
687mV543mV
MON2
MAX5906MAX5907MAX5908MAX5909
2.025V0.825V
0.4V
TIM
TIM
Figure 1. MAX5906–MAX5909 Functional Diagram
Slow-Comparator Startup Period
The slow comparator is disabled during the startup
period while the external MOSFETs are turning on.
Disabling the slow comparator allows the device to
ignore the higher-than-normal inrush current charging
the board capacitors when a card is first plugged into a
live backplane.
Slow-Comparator Normal Operation
After the startup period is complete the slow compara-
tor is enabled and the device enters normal operation.
The comparator threshold voltage (VSC,TH)is fixed at
25mV for the MAX5904/MAX5905 and is adjustable
from 25mV to 100mV for the MAX5906–MAX5909. The
slow-comparator response time decreases to a mini-
mum of 110µs with a large overdrive voltage (Figure 9).
Response time is 3ms for a 1mV overdrive. The variable
speed response time allows the MAX5904–MAX5909 to
ignore low-amplitude momentary glitches, thus increas-
ing system noise immunity. After an extended overcur-
rent condition, a fault is generated, PGOOD is pulled
low, and the MOSFET gates are discharged with a
strong 3mA pulldown current.
Fast-Comparator Startup Period
During the startup period the fast comparator regulates
the gate voltage to ensure that the voltage across the
sense resistor does not exceed VSU,TH. The startup
fast-comparator threshold voltage (VSU,TH) is scaled to
two times the slow-comparator threshold (VSC,TH).
Fast-Comparator Normal Operation
In normal operation, if the load current reaches the fast-
comparator threshold, a fault is generated, PGOOD is
pulled low, and the MOSFET gates are discharged with
a strong 3mA pulldown current. This happens in the
event of a serious current overload or a dead short. The
fast-comparator threshold voltage (VFC,TH) is scaled to
four times the slow-comparator threshold (VSC,TH). This
comparator has a fast response time of 260ns (Figure 9).
Undervoltage Lockout (UVLO)
The undervoltage lockout prevents the MAX5904–
MAX5909 from turning on the external MOSFETs until
one input voltage exceeds the UVLO threshold (2.4V)
for tD,UVLO. The MAX5904–MAX5909 use power from
the higher input voltage rail for the charge pumps. This
allows for more efficient charge-pump operation. The
UVLO protects the external MOSFETs from an insuffi-
cient gate drive voltage. tD,UVLOensures that the board
is fully inserted into the backplane and that the input
voltages are stable. Any input voltage transient on both
supplies below the UVLO threshold will reinitiate the
tD,UVLOand the startup period.
Latched and Autoretry Fault Management
The MAX5905/MAX5907/MAX5909 latch the external
MOSFETs off when a fault is detected. Toggling ON
below 0.4V or one of the supply voltages below the
UVLO threshold for at least 100µs clears the fault latch
and reinitiates the startup period. Similarly, the
MAX5904/MAX5906/MAX5908 turn the external
MOSFETs off when a fault is detected then automatical-
ly restart after the autoretry delay that is internally set to
64 times tSTART. During the autoretry delay, toggling
ON below 0.4V does not clear the fault. The autoretry
can be overridden causing the startup period to begin
immediately by toggling one of the supply voltages
below the UVLO threshold.
MAX5904–MAX5909
Low-Voltage, Dual Hot-Swap Controllers/Power
Sequencers
tON
4.8V TO 5.8V
VGATE
VGATE
PGOOD
VTH
VOUT
VOUT
ILOAD
tSTART + tPGDLY
CBOARD = LARGE
CBOARD = 0
VSU,TH
RSENSE
Figure 2. Startup Waveforms
MAX5904–MAX5909
Low-Voltage, Dual Hot-Swap Controllers/Power
Sequencers
tPGDLY
VON_,TH
VON
VGATE_
VOUT_
INTERNAL SIGNAL
INTERNAL SIGNAL
PGOOD
tSTART
Figure 3. Power-Up with ON Pin Control (At Least One VIN_is > VUVLO)
Timing Diagrams

Partno	Mfg	Dc	Qty	Available	Descript
MAX5904ESA+ \|MAX5904ESA	MAXIM	N/a	7	avai	Low-Voltage, Dual Hot-Swap Controllers/Power Sequencers
MAX5904ESA+T \|MAX5904ESAT	MAX	N/a	2010	avai	Low-Voltage, Dual Hot-Swap Controllers/Power Sequencers
MAX5904ESA-T \|MAX5904ESAT	MAXIM	N/a	2270	avai	Low-Voltage, Dual Hot-Swap Controllers/Power Sequencers
MAX5904USA+	MAXIM	N/a	46	avai	Low-Voltage, Dual Hot-Swap Controllers/Power Sequencers
MAX5908EEE+ \|MAX5908EEE	MAX	N/a	20	avai	Low-Voltage, Dual Hot-Swap Controllers/Power Sequencers
MAX5908UEE+	MAX	N/a	184	avai	Low-Voltage, Dual Hot-Swap Controllers/Power Sequencers
MAX5908UEE+T	MAXIM	N/a	450	avai	Low-Voltage, Dual Hot-Swap Controllers/Power Sequencers
MAX5909UEE+ \|MAX5909UEE	MAX	N/a	30	avai	Low-Voltage, Dual Hot-Swap Controllers/Power Sequencers
MAX5909UEE+ \|MAX5909UEE	MAXIM	N/a	16	avai	Low-Voltage, Dual Hot-Swap Controllers/Power Sequencers
MAX5909UEE+T	MAXIM	N/a	560	avai	Low-Voltage, Dual Hot-Swap Controllers/Power Sequencers