MAX1809EGI ,0.3-6V; 3A, 1MHz, DDR memory power supply. For DDR memory termination, active termination busesApplicationsDDR Memory Termination Pin ConfigurationsActive Termination BusesTOP VIEWTypical Operat ..
MAX1809EGI-T ,3A, 1MHz, DDR Memory Termination SupplyApplicationsDDR Memory Termination Pin ConfigurationsActive Termination BusesTOP VIEWTypical Operat ..
MAX1809ETI ,3A / 1MHz / DDR Memory Termination SupplyELECTRICAL CHARACTERISTICS (continued)(V = V = 3.3V, V = 1.1V, T = 0°C to +85°C, unless otherwise n ..
MAX1809ETI+ ,3A, 1MHz, DDR Memory Termination SupplyELECTRICAL CHARACTERISTICS (continued)(V = V = 3.3V, V = 1.1V, T = 0°C to +85°C, unless otherwise n ..
MAX1809ETI+T ,3A, 1MHz, DDR Memory Termination SupplyMAX180919-2142; Rev 1; 9/023A, 1MHz, DDR Memory Termination Supply
MAX180ACPL+ ,Complete, 100ksps, 8-Channel, 12-Bit Data Acquisition SystemsFeatures
urable for Unipolar (0V to
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MAX4666ESE+ ,5 Ohm, Quad, SPST, CMOS Analog SwitchesELECTRICAL CHARACTERISTICS—Dual Supplies(V+ = +15V, V- = -15V, V = +5V, V = +2.4V, V = +0.8V, T = T ..
MAX4667ESE+T ,2.5Ω, Dual, SPST, CMOS Analog SwitchesApplicationsMAX4667CPE 0°C to +70°C 16 Plastic DIPMAX4667ESE -40°C to +85°C 16 Narrow SOReed Relay ..
MAX466CWI ,Two-Channel, Triple/Quad RGB Video Switches and BuffersFeaturesThe MAX463–MAX470 series of two-channel, ' 100MHz Unity-Gain Bandwidthtriple/quad buffered ..
MAX4670ETJ+ ,Integrated T1/E1/J1 Short-Haul and Long-Haul Protection SwitchesApplications Pin ConfigurationOptical Multiplexers (ADMs, M13s, etc.)TOP VIEWEdge RoutersMultiservi ..
MAX4670ETJ+T ,Integrated T1/E1/J1 Short-Haul and Long-Haul Protection SwitchesELECTRICAL CHARACTERISTICS(V+ = +2.7V to +3.6V, T = T to T , unless otherwise noted. Typical values ..
MAX4674EEE ,3V/5V / 4 / Wideband Quad 2:1 Analog MultiplexerELECTRICAL CHARACTERISTICS—Single +5V Supply(V+ = +4.5V to +5.5V, V = 2.4V, V = 0.8V, T = T to T , ..
MAX1809EGI
0.3-6V; 3A, 1MHz, DDR memory power supply. For DDR memory termination, active termination buses
General DescriptionThe MAX1809 is a reversible energy flow, constant-off-
time, pulse-width modulated (PWM), step-down DC-DC
converter. It is ideal for use in notebook and subnote-
book computers that require 1.1V to 5V active
termination power supplies. This device features an
internal PMOS power switch and internal synchronous
rectifier for high efficiency and reduced component
count. The internal 90mΩPMOS power switch and
70mΩNMOS synchronous-rectifier switch easily deliver
continuous load currents up to 3A. The MAX1809 accu-
rately tracks an external reference voltage, produces
an adjustable output from 1.1V to VIN,and achieves
efficiencies as high as 93%.
The MAX1809 uses a unique current-mode, constant-
off-time, PWM control scheme that allows the output to
source or sink current. This feature allows energy to
return to the input power supply that otherwise would
be wasted. The programmable constant-off-time archi-
tecture sets switching frequencies up to 1MHz, allowing
the user to optimize performance trade-offs between
efficiency, output switching noise, component size, and
cost. The MAX1809 features an adjustable soft-start to
limit surge currents during startup, a 100% duty-cycle
mode for low-dropout operation, and a low-power shut-
down mode that disables the power switches and
reduces supply current below 1µA. The MAX1809 is
available in a 28-pin QFN with an exposed backside
pad, a 28-pin thin QFN, or a 16-pin QSOP.
ApplicationsDDR Memory Termination
Active Termination Buses
FeaturesSource/Sink 3A±1% Output AccuracyUp to 1MHz Switching Frequency93% EfficiencyInternal PMOS/NMOS Switches
90mΩ/70mΩOn-Resistance at VIN= 4.5V
110mΩ/80mΩOn-Resistance at VIN= 3V1.1V to VINAdjustable Output Voltage3V to 5.5V Input Voltage Range<1µA Shutdown Supply CurrentProgrammable Constant-Off-Time OperationThermal ShutdownAdjustable Soft-Start Inrush Current LimitingOutput Short-Circuit Protection
MAX1809
3A, 1MHz, DDR Memory Termination Supply
Pin Configurations
Ordering Information
Typical Operating Circuit19-2142; Rev 1; 9/02
*Contact factory for availability.
MAX1809
3A, 1MHz, DDR Memory Termination Supply
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICSStresses 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.
Note 1:LX has clamp diodes to PGND and IN. If continuous current is applied through these diodes, thermal limits must be
observed.
VCC, IN to GND........................................................-0.3V to +6V
IN to VCC.............................................................................±0.3V
GND to PGND.....................................................................±0.3VSHDN, SS, FB, TOFF, RREF,
EXTREF to GND.......................................-0.3V to (VCC+ 0.3V)
LX Current (Note 1).............................................................±4.7A
REF Short Circuit to GND Duration............................Continuous
Continuous Power Dissipation (TA= +70°C)
28-Pin QFN (derate 20mW/°C above +70°C;
part mounted on 1in2of 1oz copper)..............................1.6W
16-Pin QSOP (derate 12.5mW/°C above +70°C;
part mounted on 1in2of 1oz copper).................................1W
Operating Temperature Range...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
MAX1809
3A, 1MHz, DDR Memory Termination Supply
ELECTRICAL CHARACTERISTICS(VIN= VCC= 3.3V, VEXTREF= 1.1V, TA
= -40°C to +85°C, unless otherwise noted.) (Note 4)
Note 2:The output voltage will have a DC-regulation level lower than the feedback error comparator threshold by 50% of the ripple.
Note 3:Recommended operating frequency, not production tested.
Note 4:Specifications from 0°C to -40°C are guaranteed by design, not production tested.
ELECTRICAL CHARACTERISTICS (continued)(VIN= VCC= 3.3V, VEXTREF= 1.1V, TA
= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)
MAX1809
3A, 1MHz, DDR Memory Termination SupplyEFFICIENCY vs. OUTPUT CURRENT
(SOURCING)
MAX1809 toc01
OUTPUT CURRENT (A)
EFFICIENCY (%)21
EFFICIENCY vs. OUTPUT CURRENT
(SINKING)MAX1809 toc02
OUTPUT CURRENT (A)
EFFICIENCY (%)21
NORMALIZED OUTPUT ERROR
vs. OUTPUT CURRENT
MAX1809 toc03
OUTPUT CURRENT (A)
NORMALIZED OUTPUT ERROR (%)31456
NO-LOAD
SUPPLY CURRENT vs. SUPPLY VOLTAGEMAX1809 toc04
VIN (V)
NO-LOAD SUPPLY CURRENT (I
+ I
(mA))
OFF-TIME vs. RTOFF
MAX1809 toc05
RTOFF (kΩ)
tOFF
SWITCHING FREQUENCY
vs. OUTPUT CURRENT
MAX1809 toc06
OUTPUT CURRENT (A)
FREQUECNY (kHz)-1-20123
STARTUP AND SHUTDOWNMAX1809 toc07
1A/div
VOUT
1V/div
VSHDN
5V/div
IIN
1ms/div
VSS
2V/div
VIN = 3.3V, ROUT = 0.5Ω
LOAD-TRANSIENT RESPONSEMAX1809 toc08
50mV/div
IOUT
5A/div
V(LX)
5V/div
VOUT
(AC-COUPLED)
10µs/div
VEXTREF = 1.25V, VIN = 3.3V, IOUT = -2A to +2A to -2A
Typical Operating Characteristics(Circuit of Figure 1, VOUT= 1.25V, for VIN= 5V: L = 1µH, RTOFF= 130kΩ; for VIN= 3.3V: L = 0.68µH, RTOFF= 73.2kΩ.)
MAX1809
3A, 1MHz, DDR Memory Termination Supply
LOAD-TRANSIENT RESPONSEMAX1809 toc09
50mV/div
IOUT
5A/div
V(LX)
5V/div
VOUT
(AC-COUPLED)
10µs/div
VEXTREF = 1.25V, VIN = 3.3V, IOUT = -2A to +2A to -2A
LINE-TRANSIENT RESPONSEMAX1809 toc10
50mV/div
VIN
2V/div
VOUT
(AC-COUPLED)
20µs/div
IOUT = 2A, VIN = 5V to 3.3V to 5V
SWITCHING WAVEFORMS (SOURCING)MAX1809 toc11
50mV/div
V(LX)
5V/div
VOUT
(AC-COUPLED)
400ns/div
IOUT = 2A, VIN = 5V
I(LX)
2A/div
SWITCHING WAVEFORMS (SINKING)MAX1809 toc12
50mV/div
V(LX)
5V/div
VOUT
(AC-COUPLED)
400ns/div
IOUT = -2A, VIN = 5V
I(LX)
2A/div
Typical Operating Characteristics (continued)(Circuit of Figure 1, VOUT= 1.25V, for VIN= 5V: L = 1µH, RTOFF= 130kΩ; for VIN= 3.3V: L = 0.68µH, RTOFF= 73.2kΩ.)
