MAX1557ETB ,16 mA IQ, 1.2 A PWM step-down DC-DC converterFeaturesThe MAX1556/MAX1557 are low-operating-current ♦ Up to 97% Efficiency(16µA), fixed-frequency ..
MAX1557ETB+T ,16µA IQ, 1.2A PWM Step-Down DC-DC ConvertersELECTRICAL CHARACTERISTICS(V = V = V = 3.6V, T = -40°C to +85°C. Typical values are at T = +25°C, u ..
MAX1558ETB ,2.7 to 5.5 V, Dual, 3 mm x 3 mm, 1.2 A/programmable-current USB switches with autoresetApplications10 TDFNMAX1558HETB -40°C to +85°C AASUSB Ports and Hubs(3mm x 3mm)Notebook Computers an ..
MAX1558ETB+ ,Dual, 3mm x 3mm, 1.2A/Programmable-Current USB Switches with AutoresetApplications10 TDFNMAX1558HETB+ -40°C to +85°C AASUSB Ports and Hubs(3mm x 3mm)Notebook Computers a ..
MAX1558ETB+T ,Dual, 3mm x 3mm, 1.2A/Programmable-Current USB Switches with AutoresetELECTRICAL CHARACTERISTICS(V = V = 5V, V = V = 0V (MAX1558), V = V = 5V (MAX1558H), R = 26kΩ to GND ..
MAX1558HETB+ ,Dual, 3mm x 3mm, 1.2A/Programmable-Current USB Switches with AutoresetELECTRICAL CHARACTERISTICS (continued)(V = V = 5V, V = V = 0V (MAX1558), V = V = 5V (MAX1558H), R = ..
MAX4213ESA+T ,Miniature, 300MHz, Single-Supply, Rail-to-Rail Op Amps with EnableApplications Ordering InformationBattery-Powered InstrumentsTEMP PIN TOPPARTVideo Line Driver RANGE ..
MAX4213EUA ,Miniature, 300MHz, Single-Supply, Rail-to-Rail Op Amps with Enableapplications.' Space-Saving SOT23-5, µMAX, or QSOP PackagesThe MAX4212 comes in a miniature 5-pin S ..
MAX4213EUA+T ,Miniature, 300MHz, Single-Supply, Rail-to-Rail Op Amps with EnableMAX4212/MAX4213/MAX4216/MAX4218/MAX422019-1178; Rev 3; 10/03Miniature, 300MHz, Single-Supply, Rail- ..
MAX4214EUK ,High-Speed, Single-Supply, Gain of 2, Closed-Loop, Rail-to-Rail Buffers with EnableELECTRICAL CHARACTERISTICS(V = 5V, V = 0, IN_- = 0, EN_ = 5V, R = ∞ to 0, V = V /2, noninverting co ..
MAX4214EUK+ ,High-Speed, Single-Supply, Gain of 2, Closed-Loop, Rail-to-Rail Buffers with EnableELECTRICAL CHARACTERISTICS (continued)(V = 5V, V = 0, IN_- = 0, EN_ = 5V, R = ∞ to 0, V = V /2, non ..
MAX4214EUK+T ,High-Speed, Single-Supply, Gain of 2, Closed-Loop, Rail-to-Rail Buffers with EnableApplications __________________Pin ConfigurationsBattery-Powered InstrumentsTOP VIEWVideo Line Driv ..
MAX1556ETB-MAX1557ETB
16 mA IQ, 1.2 A PWM step-down DC-DC converter
General DescriptionThe MAX1556/MAX1557 are low-operating-current
(16µA), fixed-frequency step-down regulators. High effi-
ciency, low-quiescent operating current, low dropout,
and minimal (27µA) quiescent current in dropout make
these converters ideal for powering portable devices
from 1-cell Li-ion or 3-cell alkaline/NiMH batteries. The
MAX1556 delivers up to 1.2A; has pin-selectable 1.8V,
2.5V, and 3.3V outputs; and is also adjustable. The
MAX1557 delivers up to 600mA; has pin-selectable 1V,
1.3V, and 1.5V outputs; and is also adjustable.
The MAX1556/MAX1557 contain a low-on-resistance
internal MOSFET switch and synchronous rectifier to
maximize efficiency and dropout performance while
minimizing external component count. A proprietary
topology offers the benefits of a high fixed-frequency
operation while still providing excellent efficiency at
both light and full loads. A 1MHz PWM switching fre-
quency keeps components small. Both devices also
feature an adjustable soft-start to minimize battery tran-
sient loading.
The MAX1556/MAX1557 are available in a tiny 10-pin
TDFN (3mm x 3mm) package.
ApplicationsPDAs and Palmtop Computers
Cell Phones and Smart Phones
Digital Cameras and Camcorders
Portable MP3 and DVD Players
Hand-Held Instruments
FeaturesUp to 97% Efficiency95% Efficiency at 1mA Load CurrentLow 16µA Quiescent Current1MHz PWM SwitchingTiny 3.3µH InductorSelectable 3.3V, 2.5V, 1.8V, 1.5V, 1.3V, 1.0V, and
Adjustable Output1.2A Guaranteed Output Current (MAX1556)Voltage Positioning Optimizes Load-Transient
ResponseLow 27µA Quiescent Current in DropoutLow 0.1µA Shutdown CurrentNo External Schottky Diode RequiredAnalog Soft-Start with Zero Overshoot CurrentSmall, 10-Pin, 3mm x 3mm TDFN Package
MAX1556/MAX1557
16µA IQ, 1.2A PWM
Step-Down DC-DC Converters
Pin Configuration
Ordering Information
Typical Operating Circuit*EP = Exposed paddle.
MAX1556/MAX1557
16µA IQ, 1.2A PWM DC-DC
Step-Down Converters
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.
IN, INP, OUT, D2, SHDNto GND..........................-0.3V to +6.0V
SS, D1 to GND.............................................-0.3V to (VIN+ 0.3V)
PGND to GND.......................................................-0.3V to +0.3V
LX Current (Note 1)...........................................................±2.25A
Output Short-Circuit Duration.....................................Continuous
Continuous Power Dissipation (TA= +70°C)
10-Pin TDFN (derate 24.4mW/°C above +70°C).......1951mW
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
Note 1:LX has internal clamp diodes to GND and IN. Applications that forward bias these diodes should take care not to exceed
the IC’s package power-dissipation limits.
MAX1556/MAX1557
16µA IQ, 1.2A PWM DC-DC
Step-Down Converters
Note 2:For the MAX1556, 3.3V output accuracy is specified with a 4.2V input.
ELECTRICAL CHARACTERISTICS (continued)(VIN= VINP= VSHDN= 3.6V, TA = - 40°C to +85°C. Typical values are at TA = +25°C, unless otherwise noted.) (Note 1)
MAX1556/MAX1557
16µA IQ, 1.2A PWM DC-DC
Step-Down Converters
Typical Operating Characteristics(VIN= VINP= 3.6V, D1 = D2 = SHDN= IN, Circuits of Figures 2 and 3, TA= +25°C, unless otherwise noted.)
MAX1556/MAX1557
16µA IQ, 1.2A PWM DC-DC
Step-Down Converters
Typical Operating Characteristics (continued)(VIN= VINP= 3.6V, D1 = D2 = SHDN= IN, Circuits of Figures 2 and 3, TA= +25°C, unless otherwise noted.)
MAX1556/MAX1557
16µA IQ, 1.2A PWM DC-DC
Step-Down Converters
Detailed DescriptionThe MAX1556/MAX1557 synchronous step-down con-
verters deliver a guaranteed 1.2A/600mA at output volt-
ages from 0.75V to VIN. They use a 1MHz PWM
current-mode control scheme with internal compensation,
allowing for tiny external components and a fast transient
response. At light loads the MAX1556/MAX1557 automat-
ically switch to pulse-skipping mode to keep the quies-
cent supply current as low as 16µA. Figures 2 and 3
show the typical application circuits.
Control SchemeDuring PWM operation the converters use a fixed-fre-
quency, current-mode control scheme. The heart of the
current-mode PWM controller is an open-loop, multiple-
input comparator that compares the error-amp voltage
feedback signal against the sum of the amplified cur-
rent-sense signal and the slope-compensation ramp. At
the beginning of each clock cycle, the internal high-side
p-channel MOSFET turns on until the PWM comparator
trips. During this time the current in the inductor ramps
up, sourcing current to the output and storing energy in
the inductor’s magnetic field. When the p-channel turns
off, the internal low-side n-channel MOSFET turns on.
Now the inductor releases the stored energy while the
current ramps down, still providing current to the output.
The output capacitor stores charge when the inductor
current exceeds the load and discharges when the
inductor current is lower than the load. Under overload
conditions, when the inductor current exceeds the cur-
rent limit, the high-side MOSFET is turned off and the
low-side MOSFET remains on until the next clock cycle.
