MAX1896EUT-MAX1896EUT+T Fast Delivery |IC PHOENIX CO.,LIMITED

MAX1896EUT+T ,1.4MHz SOT23 Current-Mode Step-Up DC-DC ConverterApplicationsHand-Held DevicesTypical Operating Circuit Pin ConfigurationINPUT2.6V TO 5.5VTOP VIEWOU ..
MAX1896EUT-T ,1.4MHz SOT23 Current-Mode Step-Up DC-DC ConverterApplicationsHand-Held DevicesTypical Operating Circuit Pin ConfigurationINPUT2.6V TO 5.5VTOP VIEWOU ..
MAX1896EUT-T ,1.4MHz SOT23 Current-Mode Step-Up DC-DC ConverterELECTRICAL CHARACTERISTICS(V = V = 3V, FB = GND, SS = open, T = 0°C to +85°C, unless otherwise note ..
MAX1897EGP ,4.0-28 V, quick-PWM slave controller for multiphase, step-down supplieApplicationsCM+ LX1 15Notebook ComputersCPU Core Supply CM- DH2 14Single-Stage (BATT to V ) Convert ..
MAX1897EGP ,4.0-28 V, quick-PWM slave controller for multiphase, step-down supplieFeaturesThe MAX1887/MAX1897 step-down slave controllers are Quick-PWM Slave Controllerintended for ..
MAX1897ETP ,4.0-28 V, quick-PWM slave controller for multiphase, step-down suppliefeatures.200kHz/300kHz/550kHz (MAX1897) SwitchingSynchronized to the master’s low-side gate driver, ..
MAX483ESA+ ,±15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 TransceiversApplications:state. The receiver input has a fail-safe feature that guar-MAX3440E–MAX3444E: ±15kV E ..
MAX483ESA+T ,±15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 TransceiversELECTRICAL CHARACTERISTICS(V = 5V ±5%, T = T to T , unless otherwise noted.) (Notes 1, 2)CC A MIN M ..
MAX483MJA ,Low-Power / Slew-Rate-Limited RS-485/RS-422 TransceiversGeneral Description ________
MAX483MSA/PR ,Low-Power, Slew-Rate-Limited RS-485/RS-422 TransceiversApplicationsguarantees a logic-high output if the input is open circuit.MAX3030E–MAX3033E: ±15kV E ..
MAX4840AEXT , Overvoltage-Protection Controllers with Status FLAG
MAX4840AEXT+T ,Overvoltage-Protection Controllers with Status FlagFeaturesThe MAX4838A/MAX4840A/MAX4842A are overvoltage- ♦ Overvoltage Protection Up to +28Vprotecti ..

MAX1896EUT-MAX1896EUT+T
1.4MHz SOT23 Current-Mode Step-Up DC-DC Converter
General Description
The MAX1896 step-up DC-DC converter incorporates
high-performance current-mode, fixed-frequency,
pulse-width modulation (PWM) circuitry and an internal
0.7ΩN-channel MOSFET to provide a highly efficient
regulator with fast response.
High switching frequency (1.4MHz) allows fast loop
response and easy filtering with small components. The
MAX1896 can produce an output voltage as high as
13V from an input as low as 2.6V. Soft-start is program-
mable with an external capacitor, which sets the input
current ramp rate. In shutdown mode, current con-
sumption is reduced to 0.01µA.
The MAX1896 is available in a space-saving 6-pin
SOT23 package. The ultra-small package and high
switching frequency allow cost and space-efficient
implementations.
Applications
Notebook Computers
LCD Displays
PCMCIA Cards
Portable Applications
Hand-Held Devices
Features>90% EfficiencyAdjustable Output Up to 13VGuaranteed 12V/120mA Output from 5V Input2.6V to 5.5V Input RangeLT1613 Pin Compatible0.01µA Shutdown CurrentProgrammable Soft-StartSpace-Saving 6-Pin SOT23 Package
MAX1896
1.4MHz SOT23 Current-Mode
Step-Up DC-DC Converter
GND
SHDNFBINSS
MAX1896
SOT23
TOP VIEW
Pin Configuration
OFF
MAX1896
INPUT
2.6V TO 5.5V
OUTPUT
UP TO 13V
UP TO 600mALXSHDNGND
Typical Operating Circuit
PARTTEMP RANGEPIN-PACKAGE
MAX1896EUT-T-40°C to +85°C6 SOT23-6
19-2221; Rev 1; 3/04
Ordering Information
MAX1896
1.4MHz SOT23 Current-Mode
Step-Up DC-DC Converter
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN= VSHDN= 3V, FB = GND, SS = open, TA= 0°C to +85°C, unless otherwise noted.)
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.
LX to GND..............................................................-0.3V to +14V
IN, SHDN, FB to GND...............................................-0.3V to +6V
SS to GND...................................................-0.3V to (VIN+ 0.3V)
RMS LX Pin Current..............................................................0.6A
Continuous Power Dissipation (TA= +70°C) (Note 1)
6-Pin SOT23 (derate 9.1mW/°C above +70°C)...........727mW
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
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
Input Supply RangeVIN2.65.5V
Output Voltage Adjust RangeVOUTCircuit of Figure 113V
VIN Undervoltage LockoutUVLOVIN rising, 50mV hysteresis2.252.42.55V
VFB = 1.3V, not switching0.20.4
Quiescent CurrentIINVFB = 1.0V, switching15mA
V SHDN = 0, TA = +25°C0.010.5Shutdown Supply CurrentV SHDN = 00.0110µA
ERROR AMPLIFIER
Feedback Regulation Set PointVFB1.21.241.25V
FB Input Bias CurrentIFBVFB = 1.24V2180nA
Line Regulation2.6V < VIN < 5.5V0.050.20%/V
OSCILLATOR
FrequencyfOSC100014001800kHz
Maximum Duty CycleDC8286%
POWER SWITCH
Current Limit (Note 2)ILIMVFB = 1V, duty cycle = 50%0.550.8A
On-ResistanceRON0.71Ω
VLX = 12V, TA = +25°C0.11
Leakage CurrentILXOFFVLX = 12V10µA
SOFT-START
Reset Switch Resistance100Ω
Charge CurrentVSS = 1.2V1.547.0µA
CONTROL INPUT
Input Low VoltageVILV SHDN, VIN = 2.6V to 5.5V0.3V
Input High VoltageVIHV SHDN, VIN = 2.6V to 5.5V1.0V
V SHDN = 3V2550SHDN Input CurrentISHDNV SHDN = 00.010.1µA
Note 1:Thermal properties are specified with product mounted on PC board with one square-inch of copper area and still air.
MAX1896
1.4MHz SOT23 Current-Mode
Step-Up DC-DC Converter
ELECTRICAL CHARACTERISTICS
(VIN= VSHDN= 3V, FB = GND, SS = open, TA= -40°C to +85°C, unless otherwise noted.) (Note 3)
Note 2:Current limit varies with duty cycle due to slope compensation. See the Output Current Capabilitysection.
Note 3:Specifications to -40°C are guaranteed by design and not production tested.
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
Input Supply RangeVIN2.65.5V
Output Voltage Adjust RangeVOUTCircuit of Figure 113V
VIN Undervoltage LockoutUVLOVIN rising, 50mV hysteresis.2.252.55V
VFB = 1.3V, not switching0.4Quiescent CurrentIINVFB = 1.0V, switching5mA
Shutdown Supply CurrentV SHDN = 010µA
ERROR AMPLIFIER
Feedback Regulation Set PointVFB1.21.25V
FB Input Bias CurrentIFBVFB = 1.24V80nA
Line Regulation2.6V < VIN < 5.5V0.20%/V
OSCILLATOR
FrequencyfOSC10001800kHz
Maximum Duty CycleDC82%
POWER SWITCH
Current Limit (Note 2)ILIMVFB = 1V, duty cycle = 50%0.55A
On-ResistanceRON1Ω
Leakage CurrentILXOFFVLX = 12V10µA
SOFT-START
Reset Switch Resistance100Ω
Charge CurrentVSS = 1.2V1.257.50µA
CONTROL INPUT
Input Low VoltageVILV SHDN = VIN = 2.6V to 5.5V0.3V
Input High VoltageVIHV SHDN = VIN = 2.6V to 5.5V1.0V
V SHDN = 3V50SHDN Input CurrentI SHDNV SHDN = 00.1µA
MAX1896
1.4MHz SOT23 Current-Mode
Step-Up DC-DC Converter
Typical Operating Characteristics
(Circuit of Figure 1, VIN= 3.3V, TA= +25°C, unless otherwise noted.)
EFFICIENCY vs. OUTPUT CURRENT
MAX1896 toc01
OUTPUT CURRENT (mA)
EFFICIENCY (%)70
VIN = 3.3V,
VOUT = 5V,
CIRCUIT OF FIGURE 1
EFFICIENCY vs. OUTPUT CURRENT
MAX1896 toc02
OUTPUT CURRENT (mA)
EFFICIENCY (%)70
VIN = 3.3V,
VOUT = 13V,
CIRCUIT OF FIGURE 3
EFFICIENCY vs. OUTPUT CURRENT
MAX1896 toc03
OUTPUT CURRENT (mA)
EFFICIENCY (%)70
VIN = 5V,
VOUT = 13V,
CIRCUIT OF FIGURE 3
NO LOAD SUPPLY CURRENT
vs. INPUT VOLTAGE
MAX1896 toc04
INPUT VOLTAGE (V)
NO LOAD SUPPLY CURRENT (mA)VOUT = 13V,
CIRCUIT OF FIGURE 3
OUTPUT VOLTAGE vs. OUTPUT CURRENT
MAX1896 toc05
OUTPUT CURRENT (mA)
OUTPUT VOLTAGE (V)10050150200
CIRCUIT OF FIGURE 3
TA = -40°C
TA = +85°C
TA = +25°C
LOAD
CURRENT
100mA/div
OUTPUT
VOLTAGE
AC-COUPLED
200mV/div
INDUCTOR
CURRENT
500mA/div
200µs/div
CFF = 100pF, COUT = 0.1µF CERAMIC + 10µF CERAMIC
LOAD TRANSIENT (VOUT = 13V)
MAX1896 toc06
LOAD
CURRENT
200mA/div
OUTPUT
VOLTAGE
AC-COUPLED
200mV/div
INDUCTOR
CURRENT
500mA/div
400µs/div
COUT = 0.1µF CERAMIC + 22µF TANTALUM
LOAD TRANSIENT (VOUT = 5V)
MAX1896 toc07SHDN
5V/div
OUTPUT
VOLTAGE
5V/div
INDUCTOR
CURRENT
500mA/div
100µs/div
VIN = 3.3V, COUT = 0.1µF CERAMIC + 3.3µF TANTALUM
CIRCUIT OF FIGURE 3
STARTUP WAVEFORM
WITHOUT SOFT-START
MAX1896 toc08SHDN
5V/div
OUTPUT
VOLTAGE
5V/div
IOUT = 10mA
INDUCTOR
CURRENT
500mA/div
2ms/div
VIN = 3.3V, CSS = 33nF,
COUT = 3.3µF TANTALUM + 0.1µF CERAMIC
STARTUP WAVEFORM
WITH SOFT-START
MAX1896 toc09
MAX1896
1.4MHz SOT23 Current-Mode
Step-Up DC-DC Converter
Pin Description
Typical Operating Characteristics (continued)
(Circuit of Figure 1, VIN= 3.3V, TA= +25°C, unless otherwise noted.)
SHDN
5V/div
OUTPUT
VOLTAGE
5V/div
IOUT = 100mA
INDUCTOR
CURRENT
500mA/div
2ms/div
VIN = 3.3V, CSS = 33nF,
COUT = 3.3µF TANTALUM + 0.1µF CERAMIC
CIRCUIT OF FIGURE 3
STARTUP WAVEFORM
WITH SOFT-START
MAX1896 toc10LX VOLTAGE
5V/div
OUTPUT
VOLTAGE
AC-COUPLED
200mV/div
INDUCTOR
CURRENT
500mA/div

400ns/div
VIN = 5V,
COUT = 0.1µF CERAMIC + 2.2µF CERAMIC
SWITCHING WAVEFORM
MAX1896 toc11
IOUT = 150mA
VOUT = 5V
VOUT = 12V
MAXIMUM OUTPUT CURRENT
vs. INPUT VOLTAGE
MAX1896 toc12
INPUT VOLTAGE (V)
MAXIMUM OUTPUT CURRENT (mA)
MAXIMUM OUTPUT
CURRENT DEFINED AT
90% OF NO LOAD
OUTPUT VOLTAGE
PINNAMEFUNCTION
1LXPower Switching Connection. Connect LX to the inductor and output rectifier. Connect components
as close to LX as possible.GNDGround
3FBFeedback Input. Connect a resistive voltage-divider from the output to FB to set the output voltage.
See the Setting the Output Voltage section.SHDN
Shutdown Input. Drive SHDN low to turn off the converter. To automatically start the converter,
connect SHDN to IN. Drive SHDN with a slew rate of 0.1V/µs or greater. Do not leave SHDN
unconnected. SHDN draws up to 50µA.
5SSSoft-Start Input. Connect a soft-start capacitor from SS to GND to soft-start the converter. Leave SS
open to disable the soft-start function. See the Soft-Start section.
6INInternal Bias Voltage Input. Connect IN to the input voltage source. Bypass IN to GND with a
1µF or greater capacitor as close to IN as possible.
MAX1896
1.4MHz SOT23 Current-Mode
Step-Up DC-DC Converter
Detailed Description
The MAX1896 is a highly efficient power supply that
employs a current-mode, fixed-frequency pulse-width
modulation (PWM) architecture for fast-transient response
and low-noise operation. The functional diagram is shown
in Figure 2. As the load varies, the error amplifier sets the
inductor peak current necessary to supply the load and
regulate the output voltage. To maintain stability at high
duty cycle, a slope-compensation signal is internally
summed with the current-sense signal.
At light loads, this architecture allows the MAX1896 to
skip cycles to prevent overcharging the output voltage.
In this region of operation, the inductor ramps up to a
peak value of about 100mA, discharges to the output
and waits until another pulse is needed again.
Output-Current Capability
The output-current capability of the MAX1896 is a func-
tion of current limit, input voltage, and inductor value.
Because of the slope compensation used to stabilize
the feedback loop, the duty cycle affects the current
limit. The output-current capability is governed by the
following equation:
where:
ILIM= current limit specified at 50% (see Electrical
Characteristics)
VDIODE= catch diode forward drop at ILIM, (V)
fOSC= oscillator frequency, (Hz)
L = inductor value, (H)= conversion efficiency, 0.85 nominal
VIN= input voltage, (V)
VOUT= output voltage, (V)
Soft-Start
The MAX1896 can be programmed for soft-start upon
power-up with an external capacitor. When the
MAX1896 is turned on, the soft-start capacitor (CSS) is
charged at a constant current of 4µA, ramping up to
0.5V. During this time, the SS voltage directly controls
the peak-inductor current, allowing 0A at VSS= 0.5V to
the full current limit at VSS= 1.5V. The maximum load
current is available after the soft-start cycle is complet-
ed. When the MAX1896 is turned off, the soft-start
capacitor is internally discharged to ground.
Shutdown
The MAX1896 shuts down to reduce the supply current
to 0.01µA when SHDNis low. In this mode, the internal
reference, error amplifier, comparators, biasing circuit,
and N-channel MOSFET are turned off. The step-up
converter’s output is still connected to IN via the exter-
nal inductor and output rectifier.
Applications Information
The MAX1896 operates well with a variety of external
components. The components in Figure 1 are suitable
for most applications. See the following sections to opti-
mize external components for a particular application.
Inductor Selection
Inductor selection depends on input voltage, output volt-
age, maximum current, size, and availability of inductor
values. Other factors can include efficiency and ripple
voltage. Inductors are specified by their inductance (L),
peak current (IPK), and resistance (RL). The following
step-up circuit equations are useful in choosing the
inductor values based on the application. They allow the
trading of peak current and inductor value while consid-
ering component availability and cost.
The equation used here assumes a constant LIR, which
is the ratio of the inductor peak-to-peak AC current to
average DC inductor current. A good compromise
between the size of the inductor versus loss and output
ripple is to choose an LIR of 0.3 to 0.5. The peak induc-
tor current is then given by:
where:
IOUT(MAX)= maximum output current, (A)
VIN(MIN)= minimum input voltage, (V)IxVxLIR
OUTMAXOUTMIN ()+η12
DUTYDUTYCYCLEVxRV
OUTINDIODE
OUTLIMONDIODE DutyxVV
OUTMAX
LIMxxDutyIN
OSCxL
OUT. . )) . −1450905

Partno	Mfg	Dc	Qty	Available	Descript
MAX1896EUT	MAXIM	N/a	1	avai	1.4MHz SOT23 Current-Mode Step-Up DC-DC Converter
MAX1896EUT+T	MAXIM	N/a	2899	avai	1.4MHz SOT23 Current-Mode Step-Up DC-DC Converter