MAX5944ESE-MAX5944ESE+ Fast Delivery |IC PHOENIX CO.,LIMITED

MAX5944ESE ,Dual FireWire Current Limiter and Low-Drop ORing Switch ControllerApplications Ordering InformationFireWire Desktop/Notebook PortPART TEMP RANGE PIN-PACKAGEFireWire ..
MAX5944ESE+ ,Dual FireWire Current Limiter and Low-Drop ORing Switch ControllerELECTRICAL CHARACTERISTICS(V = 7.5V to 37V, GND = 0V, and T = -40°C to +85°C, unless otherwise note ..
MAX5945CAX ,Quad Network Power Controller for Power-Over-LANapplications. The MAX5945 is pin ♦ Wide Digital Power Input, V , Common-ModeDIGand function compati ..
MAX5945EAX ,Quad Network Power Controller for Power-Over-LANApplicationsMIDSPAN 2 35 AUTOINT 3 34 OUT1Power-Sourcing Equipment (PSE)SCL 4 33 GATE1SDAOUT 5 32 S ..
MAX5945EAX+ ,Quad Network Power Controller for Power-Over-LANapplications. The MAX5945 is pin ♦ Wide Digital Power Input, V , Common-ModeDIGand function compati ..
MAX5946AETX ,Dual PCI Express, Hot-Plug Controllerapplications. The device provides hot-♦ Hot Swaps 12V, 3.3V, and 3.3V Auxiliary for 2 plug control ..
MAZ8150G ,Silicon planar typeFeatures Package Extremely low noise voltage caused from the diode (2.4 V to Code 39V, 1/3 to 1 ..
MAZ8150-H ,Silicon planar typeZener DiodesMAZ8000 SeriesSilicon planar typeUnit : mmFor stabilization of power supplyKA
MAZ8150-L ,Silicon planar typeFeatures•Extremely low noise voltage caused from the diode (2.4V to 39V,1/3 to 1/10 of our conventi ..
MAZ8150-M ,Silicon planar typeAbsolute Maximum Ratings T = 25°CaMarking SymbolParameter Symbol Rating UnitRefer to the list of t ..
MAZ8160-H ,Silicon planar typeElectrical Characteristics T = 25°CaParameter Symbol Conditions Min Typ Max UnitForward voltage V ..
MAZ8160-L ,Silicon planar typeZener DiodesMAZ8000 SeriesSilicon planar typeUnit : mmFor stabilization of power supplyKA

MAX5944ESE-MAX5944ESE+
Dual FireWire Current Limiter and Low-Drop ORing Switch Controller
General Description
The MAX5944 is a dual, current limiter/low-drop ORing,
switch controller power-management IC for FireWire®
applications. Each independent channel controls two
external power MOSFETs to regulate current from the
input power supply to the load and performs low-voltage-
drop power-supply ORing. The MAX5944 operates over
the 7.5V to 37V input range and provides inrush and out-
put current limit in addition to diode ORing functions suit-
able for FireWire applications.
The MAX5944 allows the safe insertion and removal of
FireWire peripherals into a live FireWire port by providing
inrush current control and output current-limiting func-
tions. The MAX5944 features a current-limit function that
actively limits the current drawn by the load with a 2ms
timeout. Its autoretry function then automatically restarts
after the 259ms autoretry delay time.
The ORing feature provides a very efficient way to pro-
tect the FireWire port when connected to another
FireWire peripheral that sources a higher voltage. By
turning off the external MOSFETS, the MAX5944 provides
a true bidirectional load disconnect. Each channel has
an independent ON/OFF control that results in less than
10µA supply current per channel.
The MAX5944 operates over the -40°C to +85°C
extended temperature range and is available in a
16-pin SO package.
Applications
FireWire Desktop/Notebook Port
FireWire Peripheral Device Current Limit
FireWire Hub
Hot Swap
FeaturesProvides Safe Hot-Swap for 7.5V to 37V Power
SuppliesDual-Channel Hot-SwapLow-Drop Power ORing with Ultra-Fast Turn-OffActive Current Limit±5% Current-Limit Sensing Accuracy2ms Current-Limit TimeoutFast Current-Limit Response to Output
Short-Circuit ConditionsDrives External n-Channel Power MOSFETsIndependent Overcurrent Fault Status Outputs259ms Autoretry Period10μA (Per Channel) Shutdown CurrentIndependent ON/OFF Control Allows
Undervoltage Lockout ProgrammingFast Load Disconnect Control Through
ON/OFF InputsBidirectional Load DisconnectPower Routing from One Port to Another
MAX5944
Dual FireWire Current Limiter and Low-Drop
ORing Switch Controller
INASENSEA
GATE1A
GATE2A
OUTA
GND
FAULTB
ONB
INB
TOP VIEW
MAX5944
ONA
FAULTA
GATE2B
ONQ1
OUTB
GATE1B
SENSEB
Pin Configuration
Ordering Information
19-3426; Rev 0; 10/04
EVALUATION KITAVAILABLE
Typical Operating Circuit appears at end of data sheet.
FireWire is a registered trademark of Apple Computer, Inc.
PARTTEMP RANGEPIN-PACKAGE
MAX5944ESE-40°C to +85°C16 SO
MAX5944
Dual FireWire Current Limiter and Low-Drop
ORing Switch Controller
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN= 7.5V to 37V, GND = 0V, and TA= -40°C to +85°C, unless otherwise noted. Typical values are at VIN_= 12V, 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.
(Voltages referenced to GND, unless otherwise noted.)
IN_..........................................................................-0.3V to +80V
OUT_......................................................................-0.3V to +80V
SENSE_ to IN_..........................................................-1V to +0.3V
GATE1_ to SENSE_..................................................-0.3V to +8V
GATE2_ to OUT_......................................................-0.3V to +8V
FAULT_...................................................................-0.3V to +85V
ON_ONQ1...................................................................-0.3V to +85V
Continuous Power Dissipation (TA= +70°C)
16-Pin SO (derate 9.1mW/°C above +70°C)................728mW
Operating Temperature Range...........................-40°C to +85°C
Maximum Junction Temperature.....................................+150°C
Storage Temperature Range.............................-60°C to +150°C
ESD Rating (Human Body Model)......................................2000V
Lead Temperature (soldering, 10s).................................+300°C
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
SUPPLIES
Supply Voltage RangeVIN_7.537V
Supply CurrentIINVON_ = 3V, no load, per channel1.32.3mA
Shutdown CurrentISDVON_ = 0.4V, per channel510µA
IN_ Default Undervoltage
LockoutVUVLOVIN_ rising, ON_ = IN_6.26.56.8V
IN_ Default Undervoltage-
Lockout Hysteresis0.35V
ON_ Undervoltage-Lockout
ThresholdVON_REFVON_ rising1.201.241.275V
ON_ Undervoltage-Lockout-
Threshold Hysteresis70mV
ON_ Input Bias CurrentION1µA
GATE2_ (Current-Limit Control)
GATE2_ Pullup Current (Note 2)IG2U364554µA
7.5V ≤ VIN ≤ 8V4.255.56.50GATE2_ High VoltageVG2VGATE2_ - VOUT_8V ≤ VIN ≤ 37V4.55.56.5V
Current-Limit Threshold VoltageVTHVIN_ - VSENSE_47.55052.5mV
Fast Pulldown Current-Limit
Threshold Voltage (Note 3)VTHFVIN_ - VSENSE_707580mV
GATE2_ Pulldown CurrentIG2DVTH < (VIN_ - VSENSE_) < VTHF335435535µA
GATE2_ Fast Pulldown Current
(Note 3)IG2DF(VIN_ - VSENSE_) > VTHF,
VGATE2_ = (VOUT_ + 4.5V)80125200mA
MAX5944
Dual FireWire Current Limiter and Low-Drop
ORing Switch Controller
ELECTRICAL CHARACTERISTICS (continued)
(VIN= 7.5V to 37V, GND = 0V, and TA= -40°C to +85°C, unless otherwise noted. Typical values are at VIN_= 12V, TA= +25°C.)
(Note 1)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
GATE2_ Peak Pulldown CurrentIG2DP(VIN_ - VSENSE_) = 1V1.0A
GATE2_ Pulldown Current During
Any GATE2_ Turn-Off Condition
(Note 4)
IG2OFFVGATE2_ = (VOUT_ + 4.5V)80125200mA
GATE1_ (ORing Control)
ORing Switch Turn-On-Current
Threshold VoltageVOR(VIN_ - VSENSE_) rising357mV
ORing Switch Turn-On-Current
Threshold Voltage Hysteresis(VIN_ - VSENSE_) falling0.5mV
GATE1_ Pullup Current (Note 5)IG1U364554µA
7.5V ≤ VIN ≤ 8V4.255.56.50
GATE1_ High VoltageVG1VGATE_ - VSENSE_8V ≤ VIN ≤ 37V4.55.56.5V
GATE1_ Turn-Off Switch On-
ResistanceRG1PDMeasured between GATE1_ and SENSE_
when (VIN_ - VSENSE_) < VOR23Ω
LOGIC INPUTS
ONQ1 Input-Logic Low VoltageVILVON_ > VON_REF0.7V
ONQ1 Input-Logic High VoltageVIHVON_ > VON_REF1.8V
ONQ1 Input CurrentIIH1µA
FAULT_ Output Low VoltageVOLLow-impedance state, IFAULT_ = 5mA0.120.25V
FAULT_ Output High Leakage
CurrentIOHHigh-impedance state, VFAULT_ = 37V1µA
OUT_ Input CurrentIOUTVON_ = GND1µA
MAX5944
Dual FireWire Current Limiter and Low-Drop
ORing Switch Controller
ELECTRICAL CHARACTERISTICS (continued)
(VIN= 7.5V to 37V, GND = 0V, and TA= -40°C to +85°C, unless otherwise noted. Typical values are at VIN_= 12V, TA= +25°C.)
(Note 1)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
TIMING
Current-Limit TimeouttILIMCurrent-limit mode1.782.022.26ms
Automatic Restart Delay After
Current-Limit Timeout (Note 7)tOFF240259278ms
GATE1_ Turn-Off Time
(ORing Response Time)tORFrom VOR trigger until
(VGATE1_ - VIN_) < 1V, CGATE1_ = 10nF100ns
Turn-Off Response Time
(Note 7)tON_OFF
Time from VON_ < (VON_OFF - Hysteresis)
until (VGATE2_ - VOUT_) < 1V,
for CGATE2_ = open
0.340.6µs
Minimum Delay from ON_ Low to
Low-Current Shutdown ModetSDON_ step from 1.3V to 0.4V50µs
Note 1:All min/max parameters are tested at +25°C and +85°C. Limits at -40°C are guaranteed by design.
Note 2:Measured at both VGATE2= VOUT= 0V and VGATE2= VOUT= VIN.
Note 3:The typical value of parameter VTHFis 1.5 x VTH.
Note 4:Current-Limit Timeout. IN_ or ON_ low.
Note 5:See the Typical Operating Circuit. Measured at VGATE_= VSENSE_.
Note 6:The tristate (“floating”) logic condition will be entered if the pin current is within these limits.
Note 7:If the ON_ voltages go below VON_REF- Hysteresis, then GATE2_ goes low immediately to disconnect power from the load
quickly (within tON_OFF).
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX5944 toc01
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)3020251510
TA = +85°C
TA = +25°C
TA = -40°C
SHUTDOWN SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX5944 toc02
SUPPLY VOLTAGE (V)
SHUTDOWN SUPPLY CURRENT (3020251510
CURRENT-LIMIT/CIRCUIT-BREAKER
THRESHOLD VOLTAGE vs. TEMPERATURE
MAX5944 toc03
TEMPERATURE (°C)
THRESHOLD VOLTAGE (mV)3510-15
VIN = 32V
VIN = 12V
VIN = 7.5V
Typical Operating Characteristics
(VIN_= +12V, TA= +25°C, unless otherwise noted.)
MAX5944
Dual FireWire Current Limiter and Low-Drop
ORing Switch Controller
CURRENT-LIMIT TIMEOUT
vs. TEMPERATURE
MAX5944 toc04
TEMPERATURE (°C)
CURRENT-LIMIT TIMEOUT (ms)3510-15
ORing THRESHOLD VOLTAGE
vs. TEMPERATURE
MAX5944 toc05
TEMPERATURE (°C)
ORing THRESHOLD VOLTAGE (mV)3510-15
GATE CURRENTS vs. TEMPERATURE
MAX5944 toc06
TEMPERATURE (°C)
GATE CURRENTS (3510-15-4085
GATE2
GATE1
GATE1 DRIVE VOLTAGE
vs. TEMPERATURE
MAX5944 toc07
TEMPERATURE (°C)
GATE1 DRIVE VOLTAGE (V)3510-15
GATE2 DRIVE VOLTAGE
vs. TEMPERATURE
MAX5944 toc08
TEMPERATURE (°C)
GATE2 DRIVE VOLTAGE (V)3510-15
ON HIGH VOLTAGE vs. TEMPERATURE
MAX5944 toc09
TEMPERATURE (°C)
ON HIGH VOLTAGE (V)3510-15
ON LOW VOLTAGE vs. TEMPERATURE
MAX5944 toc10
TEMPERATURE (°C)
ON LOW VOLTAGE (V)3510-15-4085
FAULT LOW VOLTAGE
vs. TEMPERATURE
MAX5944 toc11
TEMPERATURE (°C)
FAULT LOW VOLTAGE (mV)3510-15-4085
IFAULT = 5mA
Typical Operating Characteristics (continued)
(VIN_= +12V, TA= +25°C, unless otherwise noted.)
MAX5944
Dual FireWire Current Limiter and Low-Drop
ORing Switch Controller
Typical Operating Characteristics (continued)
(VIN_= +12V, TA= +25°C, unless otherwise noted.)
ORing THRESHOLD RESPONSE TIME
MAX5944 toc12
IIN
500mA/div
VOUT
5V/div
(VGATE - VSENSE)
5V/div
VIN
10V/div
100µs/div
TURN-OFF RESPONSE TIME
MAX5944 toc13
IIN
1A/div
VOUT
10V/div
VGATE2
10V/div
VON
2V/div
200ns/div
SHORT-CIRCUIT EVENT
(VIN = 37V)
MAX5944 toc14
IIN
1A/div
VOUT
50V/div
VGATE2
50V/div
VIN
50V/div
400µs/div
VFAULT
50V/div
SHORT-CIRCUIT EVENT
(VIN = 37V)
MAX5944 toc15
IIN
10A/div
VOUT
50V/div
VGATE2
50V/div
VIN
50V/div
100ns/div
VFAULT
50V/div
SHORT-CIRCUIT RESPONSE
(VIN = 8V)
MAX5944 toc16
IIN
1A/div
VOUT
10V/div
VGATE2
10V/div
VIN
10V/div
400µs/div
VFAULT
10V/div
SHORT-CIRCUIT RESPONSE
(VIN = 8V)
MAX5944 toc17
IIN
10A/div
VOUT
10V/div
VGATE2
10V/div
VIN
10V/div
100ns/div
VFAULT
10V/div
MAX5944
Dual FireWire Current Limiter and Low-Drop
ORing Switch Controller
Typical Operating Characteristics (continued)
(VIN_= +12V, TA= +25°C, unless otherwise noted.)
ORing SWITCHOVER WAVEFORM
MAX5944 toc18
IINA
500mA/div
VOUT
1V/div
200µs/div
IINB
500mA/div
VINA = 12VVONA RISING = 12V
VINB = 12.8VCOUT = 0
ORing SWITCHOVER WAVEFORM
(VINB RISING ABOVE VINA)
MAX5944 toc19
IINA
500mA/div
VOUT
1V/div
10µs/div
IINB
500mA/div
VINA = 12VVONB RISING = 12V
VINB = 13VCOUT = 0
ORing SWITCHOVER WAVEFORM
(VINB FALLING BELOW VINA)
MAX5944 toc20
IINA
500mA/div
VOUT
1V/div
20µs/div
IINB
500mA/div
VINA = 12VVONB FALLING = 12V
VINB = 13VCOUT = 0
HOT PLUG-IN LOAD CAPACITANCE
INTO ACTIVE PORT (NO FAULT)
MAX5944 toc21
IIN
2A/div
VFAULT
10V/div
400µs/div
VOUT
10V/div
CLOAD = 220µF
VGATE2
10V/div
HOT PLUG-IN LOAD CAPACITANCE INTO
ACTIVE PORT (CURRENT-LIMIT TIMEOUT)
MAX5944 toc22
IIN
1A/div
VFAULT
10V/div
400µs/div
VOUT
10V/div
CLOAD = 470µF
VGATE2
10V/div
MAX5944
Dual FireWire Current Limiter and Low-Drop
ORing Switch Controller
Pin Description
PINNAMEFUNCTIONINAChannel A Input Power and Current-Sense Positive Input. Connect INA to the other end of the current-
sense resistor and to the power source (see the Typical Operating Circuit).ONA
Channel A On/Off Control Input. ONA sets the undervoltage lockout threshold and resets the part after a
fault latch. Drive ONA high to enable the device. Drive ON_ low to disable the device. Connect ONA to INA
for the default undervoltage lockout threshold. Connect a resistor-divider from INA to ONA and to GND to
program the desired undervoltage lockout threshold.FAULTAChannel A Current-Fault Status Output. FAULTA is an open-drain output. FAULTA goes low after a current-
limit fault has exceeded the 2ms (typ) current-limit timeout period (see the FAULT_ section).ONQ1
ORing Switch Manual Turn-On Input. Drive ONQ1 low to enable power-supply ORing for channels A and B.
Drive ONQ1 high to set GATE1A to GATE1B high to allow reverse-current flow. ONQ1 is disabled for the
respective channel when VIN is below the UVLO threshold, VON_ is below the undervoltage lockout
threshold and after a current-limit fault.OUTBChannel B Output-Voltage Sense. Connect to the output.GATE2B
Channel B Current-Limiter Switch Gate-Drive Output. Referenced to OUTB. Connect GATE2B to the gate of
the 2nd n-channel MOSFET. GATE2B is a charge pump with a 50µA pullup current to 5.5V (typ) above
OUTB when active (see the Typical Operating Circuit).GATE1B
Channel B ORing Switch Gate-Drive Output. Referenced to SENSEB. Connect GATE1B to the gate of the
1st n-channel MOSFET. GATE1B is a charge pump with a 50µA pullup current to 5.5V (typ) above SENSEB
when active (see the Typical Operating Circuit).SENSEBChannel B Current-Sense Negative Input. Connect current-sense resistor, RSENSE, from INB to SENSEB.INBChannel B Input Power and Current-Sense Positive Input. Connect INB to the other end of the current-
sense resistor and to the power source.ONB
Channel B On/Off Control Input. ONB sets the undervoltage lockout threshold and resets the part after a
fault latch. Drive ONB high to enable the device. Drive ON_ low to disable the device. Connect ONB to INB
for the default undervoltage lockout threshold. Connect a resistor-divider from INB to ONB and to GND to
program the desired undervoltage lockout threshold.FAULTBChannel B Current-Fault Status Output. FAULTB is an open-drain output. FAULTB goes low after a current-
limit fault has exceeded the 2ms (typ) current-limit timeout period (see the FAULT_ section).GNDGroundOUTAChannel A Output-Voltage Sense. Connect to the output.GATE2A
Channel A Current-Limiter Switch Gate-Drive Output. Referenced to OUTA. Connect GATE2A to the gate of
the 2nd n-channel MOSFET. GATE2A is a charge pump with a 50µA pullup current to 5.5V (typ) above
OUTA when active.GATE1A
Channel A ORing Switch Gate-Drive Output. Referenced to SENSEA. Connect GATE1A to the gate of the
1st n-channel MOSFET. GATE1A is a charge pump with a 50µA pullup current to 5.5V (typ) above SENSEA
when active.SENSEAChannel A Current-Sense Negative Input. Connect current-sense resistor, RSENSEA, from INA to SENSEA
(see the Typical Operating Circuit).

Partno	Mfg	Dc	Qty	Available	Descript
MAX5944ESE	MAXIM	N/a	94	avai	Dual FireWire Current Limiter and Low-Drop ORing Switch Controller
MAX5944ESE+	MAXIM	N/a	12	avai	Dual FireWire Current Limiter and Low-Drop ORing Switch Controller