MAX17067EUA+ ,Low-Noise Step-Up DC-DC ConverterFeaturesThe MAX17067 boost converter incorporates high-♦ 90% Efficiencyperformance (at 1.2MHz), cur ..
MAX1706EEE ,1- to 3-Cell / High-Current / Low-Noise / Step-Up DC-DC Converters with Linear RegulatorFeaturesThe MAX1705/MAX1706 are high-efficiency, low-noise, ' Up to 96% Efficiencystep-up DC-DC con ..
MAX1706EEE ,1- to 3-Cell / High-Current / Low-Noise / Step-Up DC-DC Converters with Linear RegulatorMAX1705/MAX170619-1198; Rev 0; 4/971- to 3-Cell, High-Current, Low-Noise, Step-Up DC-DC Converters ..
MAX1706EEE ,1- to 3-Cell / High-Current / Low-Noise / Step-Up DC-DC Converters with Linear RegulatorApplications __________Typical Operating CircuitDigital Cordless Phones PCS PhonesPersonal Communic ..
MAX1706EEE+ ,1 to 3 Cell, High Current, Low-Noise, Step-Up DC-DC Converters with Linear RegulatorELECTRICAL CHARACTERISTICS(V = V = V = 3.6V, CLK/SEL = FB = LBN = LBO = ONA = ONB = TRACK = GND, RE ..
MAX17075ETG+ ,Boost-Regulator with Integrated Charge Pumps, Switch Control, and High-Current Op AmpELECTRICAL CHARACTERISTICS(V = +5V, Circuit of Figure 1, V = V = +13V, T = 0°C to +85°C, unless oth ..
MAX4525CUB+ ,Low-Voltage, Single-Supply Multiplexer and SwitchMAX4524/MAX452519-1332; Rev 2; 6/07Low-Voltage, Single-Supply Multiplexer and Switch ______________ ..
MAX4525CUB+T ,Low-Voltage, Single-Supply Multiplexer and SwitchMAX4524/MAX452519-1332; Rev 2; 6/07Low-Voltage, Single-Supply Multiplexer and Switch ______________ ..
MAX4525EUB ,Low-Voltage / Single-Supply Multiplexer and SwitchELECTRICAL CHARACTERISTICS—Single +5V Supply (continued)(V+ = +4.5V to +5.5V, GND = 0V, V = 2.4V, V ..
MAX4525EUB ,Low-Voltage / Single-Supply Multiplexer and SwitchGeneral Description ________
MAX4525EUB+T ,Low-Voltage, Single-Supply Multiplexer and SwitchGeneral Description ________
MAX4525EUB+T ,Low-Voltage, Single-Supply Multiplexer and SwitchELECTRICAL CHARACTERISTICS—Single +5V Supply (continued)(V+ = 4.5V to 5.5V, GND = 0V, V = 2.4V, V = ..
MAX17067EUA+
Low-Noise Step-Up DC-DC Converter
General DescriptionThe MAX17067 boost converter incorporates high-
performance (at 1.2MHz), current-mode, fixed-frequency,
pulse-width modulation (PWM) circuitry with a built-in
0.15Ωn-channel MOSFET to provide a highly efficient
regulator with fast response.
High switching frequency (640kHz or 1.2MHz selectable)
allows for easy filtering and faster loop performance. An
external compensation pin provides the user flexibilityin
determining loop dynamics, allowing the use of small,
low equivalent-series-resistance (ESR) ceramic output
capacitors. The device can produce an output voltage
as high as 18V.
Soft-start is programmed with an external capacitor, which
sets the input-current ramp rate. The MAX17067 is avail-
able in a space-saving 8-pin μMAX®package. The ultra-
small package and high switching frequency allow the
total solution to be less than 1.1mm high.
ApplicationLCD Displays
Features90% EfficiencyAdjustable Output from VINto 18V2.4A, 0.15Ω, 22V Power MOSFET+2.6V to +4.0V Input RangePin-Selectable 640kHz or 1.2MHz Switching
FrequencyProgrammable Soft-StartSmall 8-Pin µMAX PackageIntegrated Input Voltage Clamp Circuit
MAX17067
Low-Noise Step-Up DC-DCConverterGND
FREQFB
COMP
μMAX
TOP VIEW
MAX17067SHDN
VIN
2.6V TO 4V
GNDFREQ
VOUT
COMP
SHDN
MAX17067
ON/OFF
Typical Operating Circuit19-3106; Rev 0; 1/08
Pin Configuration
Ordering Information
EVALUATION KIT
AVAILABLE
PART TEMP RANGE PIN-
PACKAGE
PKG
CODE MAX17067EUA+ -40°C to +85°C 8 μMAX U8+1
+ Denotes a lead-free package.
MAX17067
Low-Noise Step-Up DC-DCConverter
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VIN= SHDN= 3V, FREQ = 3V, TA
= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)
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 +22V
SHDN, FREQ to GND............................................-0.3V to +7.5V
IN to GND (Note 1)...................................................-0.3V to +6V
SS, COMP, FB to GND................................-0.3V to (VIN+ 0.3V)
RMS LX Pin Current..............................................................1.2A
Continuous Power Dissipation (TA= +70°C)
8-Pin μMAX (derate 4.1mW/°C above +70°C)............330mW
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
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSInput Supply Range VIN VOUT < 18V 2.6 4.0 V
Output Voltage 18 V
Input Supply Clamp Voltage Use external limiting resistor; RIN = 100,
VIN = 10V (Note 3) 6.05 6.40 6.60 V
VIN Undervoltage Lockout UVLO VIN rising, typical hysteresis is 50mV, LX
remains off below this level 2.30 2.45 2.57 V
VFB = 1.3V, not switching 0.3 0.6 Quiescent Current IINVFB = 1.0V, switching 1.5 2.5 mA
SHDN = GND, TA = +25°C 30 60 Shutdown Supply Current IINSHDN = GND, TA = +85°C 30 μA
ERROR AMPLIFIERFeedback Voltage VFB Level to produce VCOMP = 1.24V 1.23 1.24 1.25 V
FB Input Bias Current IFB VFB = 1.24V 50 125 200 nA
Feedback-Voltage Line
Regulation
Level to produce VCOMP = 1.24V,
2.6V < VIN < 5.5V 0.05 0.15 %/V
Transconductance gmI = 5μA 100 240 440 μS
Voltage Gain AV 3800 V/V
OSCILLATOR FREQ = GND 500 640 780 Frequency fOSC
FREQ = IN 1000 1200 1400
kHz
Maximum Duty Cycle DC FREQ = GND, FREQ = IN 89 92 95 %
n-CHANNEL SWITCH Current Limit ILIM VFB = 1V, duty cycle = 68% (Note 4) 1.8 2.4 3.4 A
On-Resistance RON 150 275 m
Leakage Current ILXOFF VLX = 20V 10 20 μA
Current-Sense Transresistance RCS 0.2 0.3 0.4 V/A
SOFT-STARTReset Switch Resistance 100
Charge Current VSS = 1.2V 2.5 4.5 6.5 μA
MAX17067
Low-Noise Step-Up DC-DCConverter
ELECTRICAL CHARACTERISTICS(VIN= SHDN= 3V, FREQ = 3V, TA
= -40°C to +85°C, unless otherwise noted.) (Note 2)
ELECTRICAL CHARACTERISTICS (continued)(VIN= SHDN= 3V, FREQ = 3V, TA
= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
CONTROL INPUTS Input Low Voltage VILSHDN, FREQ, VIN = 2.6V to 4.0V 0.3 x
VINV
Input High Voltage VIHSHDN, FREQ, VIN = 2.6V to 4.0V 0.7 x
VIN V
Hysteresis SHDN, FREQ 0.1 x
VIN V
FREQ Pulldown Current IFREQ 3 6 9 μA
SHDN = GND, TA = +25°C -1 +1 SHDN Input Current ISHDNSHDN = GND, TA = +85°C 0 μA
Temperature rising 160 Thermal Shutdown
Hysteresis 20 °C
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSInput Supply Range VIN VOUT < 18V 2.6 4.0 V
Output Voltage Range 18 V
Input Supply Clamp Voltage Use external limiting resistor;
RIN = 100, VIN = 10V (Note 3) 6.03 6.60 V
VIN Undervoltage Lockout UVLO VIN rising, typical hysteresis is 80mV, LX
remains off below this level 2.30 2.57 V
VFB = 1.3V, not switching 0.6 Quiescent Current IINVFB = 1.0V, switching 2.5 mA
ERROR AMPLIFIERFeedback Voltage VFB Level to produce VCOMP = 1.24V 1.227 1.253 V
FB Input Bias Current IFB VFB = 1.24V 200 nA
Feedback-Voltage Line
Regulation
Level to produce VCOMP = 1.24V,
2.6V < VIN < 4.0V 0.15 %/V
Transconductance gmI = 5μA 100 440 μS
OSCILLATORFREQ = GND 450 830 Frequency fOSCFREQ = IN 950 1500 kHz
Maximum Duty Cycle DC FREQ = GND, FREQ = VIN 89 95 %
Typical Operating Characteristics(Circuit of Figure 1, VIN= 3.3V, fOSC= 640kHz, TA= +25°C, unless otherwise noted.)
MAX17067
Low-Noise Step-Up DC-DCConverter
ELECTRICAL CHARACTERISTICS (continued)(VIN= SHDN= 3V, FREQ = 3V, TA
= -40°C to +85°C, unless otherwise noted.) (Note 1)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
n-CHANNEL SWITCHCurrent Limit ILIM VFB = 1V, duty cycle = 68% (Note 4) 1.8 3.4 A
On-Resistance RON VIN = 3V 275
Current-Sense Transresistance RCS 0.19 0.40 V/A
SOFT-STARTReset Switch Resistance 100
Charge Current VSS = 1.2V 2.5 6.5 μA
CONTROL INPUTSInput Low Voltage VILSHDN, FREQ, VIN = 2.6V to 4.0V 0.3 x
VINV
Input High Voltage VIHSHDN, FREQ, VIN = 2.6V to 4.0V 0.7 x
VIN V
Note 1:Limit on IN absolute maximum ratings is for operation without the use of an external resistor for the internal clamp circuit.
See the IN Supply Clamp Circuitsection for IN voltage limits during clamping circuit operation.
Note 2:Limits are 100% production tested at TA= +25°C. Maximum and minimum limits over temperature are guaranteed by design
and characterization.
Note 3:See the IN Supply Clamp Circuitsection to properly size the external resistor.
Note 4:Current limit varies with duty-cycle slope compensation. See the Output-Current Capabilitysection.
MAX17067 toc01100010010
EFFICIENCY vs. L0AD CURRENT
(VIN = 3.3V, VOUT = 9V)LOAD CURRENT (mA)
EFFICIENCY (%)
fOSC = 1.2MHz
L = 3.3μH
fOSC = 640kHz
L = 4.7μH
STEP-UP CONVERTER
LOAD REGULATION
MAX17067 toc02
LOAD CURRENT (mA)
REGULATION (%)
L = 3.3μH
INPUT VOLTAGE (V)
SWITCHING FREQUENCY
vs. INPUT VOLTAGE
MAX17067 toc03
SWITCHING FREQUENCY (kHz)
FREQ = IN
FREQ = GND
MAX17067
Low-Noise Step-Up DC-DCConverterSUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX17067 toc04
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
NONSWITCHING
SWITCHING
VOUT
5V/div
INDUCTOR
CURRENT
1A/div
SOFT-START
(RLOAD = 18Ω)MAX17067 toc05
2ms/div
LOAD-TRANSIENT RESPONSE
(ILOAD = 10mA TO 200mA)MAX17067 toc06
100μs/div
L = 3.3μH
RCOMP = 39kΩ
CCOMP1 = 620pF
IOUT
200mA/div
10mA
VOUT
500mA/div
AC-COUPLED
INDUCTOR
CURRENT
500mA/div
IOUT
1A/div
0.1A
INDUCTOR
CURRENT
1A/div
VOUT
200mV/div
AC-COUPLED
10μs/div
PULSED LOAD-TRANSIENT RESPONSE
(ILOAD = 40mA TO 1.1A)MAX17067 toc07
L = 3.3μH
RCOMP = 39kΩ
CCOMP1 = 620pF
Typical Operating Characteristics (continued)(Circuit of Figure 1, VIN= 3.3V, fOSC= 640kHz, TA= +25°C, unless otherwise noted.)
5V/div
INDUCTOR
CURRENT
1A/div
SWITCHING WAVEFORMS
(ILOAD = 500mA)MAX17067 toc08
MAX17067
Low-Noise Step-Up DC-DCConverter
Pin DescriptionSwitch Pin. Connect the inductor/catch diode to LX and minimize the trace area for lowest EMI.LX5
Supply Pin. Bypass IN with at least a 1μF ceramic capacitor directly to GND.IN6
Frequency Select Input. When FREQ is low, the oscillator frequency is set to 640kHz. When FREQ is high,
the frequency is 1.2MHz. This input has a 5μA pulldown current.FREQ7
Soft-Start Control Pin. Connect a soft-start capacitor (CSS) to this pin. Leave open for no soft-start. The soft-
start capacitor is charged with a constant current of 4μA. Full current limit is reached after t = 2.5 x105CSS.
The soft-start capacitor is discharged to ground when SHDNis low. When SHDNgoes high, the soft-start
capacitor is charged to 0.5V, after which soft-start begins.8
GroundGND4
Active-Low Shutdown Control Input. Drive SHDNlow to turn off the MAX17067. SHDN3
PINFeedback Pin. Reference voltage is 1.24V nominal. Connect an external resistor-divider tap to FB and
minimize the trace area. Set VOUTaccording to: VOUT= 1.24V (1 + R1 / R2). See Figure 1.FB2
Compensation Pin for Error Amplifier. Connect a series RC from COMP to ground. See the Loop
Compensationsection for component selection guidelines.COMP1
FUNCTIONNAME
Detailed DescriptionThe MAX17067 is a highly efficient power supply that
employs a current-mode, fixed-frequency PWM architec-
ture for fast-transient response and low-noise operation.
The device regulates the output voltage through a com-
bination of an error amplifier, two comparators, and sev-
eral signal generators (Figure 2). The error amplifier
compares the signal at FB to 1.24V and varies the
COMP output. The voltage at COMP determines the cur-
rent trip point each time the internal MOSFET turns on.
As the load varies, the error amplifier sources or sinks
current to the COMP output accordingly to produce the
inductor peak current necessary to service the load. To
maintain stability at high duty cycle, a slope-compensa-
tion signal is summed with the current-sense signal.
At light loads, this architecture allows the ICs to “skip”
cycles to prevent overcharging the output voltage. In
this region of operation, the inductor ramps up to a fixed
peak value, discharges to the output, and waits until
another pulse is needed again.
VIN
2.6V TO 4.0V
GNDFREQ
VOUT
COMP
SHDN
0.027μF
MAX17067COUT
10μF
6.3V
RCOMP
CCOMP
CCOMP2
MBRS130LT1
CIN
640kHz
1.2MHz
ON/OFF
VIN
Figure 1. Typical Application Circuit
MAX17067
Low-Noise Step-Up DC-DCConverter
IN Supply Clamp CircuitThe MAX17067 features an internal clamp to allow appli-
cations where there is overvoltage stress on the supply
line. In many cases, high-voltage spikes happen on pro-
duction lines and are difficult to protect against. The
MAX17067’s internal clamp circuit can solve this prob-
lem. The internal clamp circuit limits the voltage at the IN
pin to 6.4V (typ) to protect the IN pin from a continuous
or transient overvoltage stress condition on the supply
line. To use the clamp circuit, put a series resistor (RIN)
between supply and IN, and a decoupling capacitor
(1μF typical) from IN to GND. To properly size the exter-
nal resistor, several factors should be considered:The maximum current for the clamp is 40mA, and the
clamp voltage at the IN pin is 6.05V (min). Therefore,
the external resistor is:Power dissipation in the clamp is in addition to the
total power loss.The external resistor causes a DC voltage drop in
the IN supply line. The voltage at the IN pin has to
be properly maintained when clamping is used. The
worst-case quiescent current of the IN pin is 2.5mA;
therefore, the worst-case voltage drop is 2.5mA
multiplied by RIN.
Output-Current CapabilityThe output-current capability of the MAX17067 is a
function of current limit, input voltage, operating fre-
quency, and inductor value. Because of the slope com-
pensation used to stabilize the feedback loop, the duty
cycle affects the current limit. The output-current capa-
bility is governed by the following equation:
IOUT(MAX)= [ILIMx (1.26 - 0.4 x Duty) -
0.5 x Duty x VIN/(fOSCx L)] x ηx VIN/VOUT
where:
ILIM= current limit specified at 68% (see the Electrical
Characteristics):
Duty = duty cycle = (VOUT- VIN+ VDIODE)/
(VOUT- ILIMx RON+ VDIODE)
VDIODE= catch diode forward voltage at ILIM= conversion efficiency, 85% nominalININ≥()⎡⎣⎤⎦-605004..Ω
GND
FREQ
COMP
4μA
5μA
ERROR
COMPARATOR
ERROR
AMPLIFIER
SKIP
COMPARATOR
CLOCK
SKIP
BIAS
SHDN
MAX17067CURRENT
SENSE
CONTROL
AND DRIVER
LOGIC
SOFT-
START
SLOPE
COMPEN-
SATION
OSCILLATOR
1.24V
Figure 2. Functional Diagram
