MAX1556ETB+-MAX1556ETB+T-MAX1557ETB+T Fast Delivery |IC PHOENIX CO.,LIMITED

MAX1556ETB+T ,16µA IQ, 1.2A PWM Step-Down DC-DC ConvertersFeaturesThe MAX1556/MAX1556A/MAX1557 are low-operating- ♦ Up to 97% Efficiencycurrent (16µA), fixed ..
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 ..
MAX4212EUK-T ,Miniature, 300MHz, Single-Supply, Rail-to-Rail Op Amps with Enableapplications.♦ High-Output Impedance in Off StateThe MAX4212 comes in a miniature 5-pin SOT23 pack- ..
MAX4213ESA ,Miniature, 300MHz, Single-Supply, Rail-to-Rail Op Amps with EnableApplicationsRANGE PACKAGEMARKBattery-Powered InstrumentsMAX4212EUK -40°C to +85°C 5 SOT23-5 ABAFVid ..
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 ..

MAX1556ETB+-MAX1556ETB+T-MAX1557ETB+T
16µA IQ, 1.2A PWM Step-Down DC-DC Converters
General Description
The MAX1556/MAX1556A/MAX1557 are low-operating-
current (16µA), fixed-frequency step-down regulators.
High efficiency, 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/MAX1556A/MAX1557contain a low-on-
resistance internal MOSFET switch and synchronous
rectifier to maximize efficiency and dropout perfor-
mance while minimizing external component count. A
proprietary topology offers the benefits of a high fixed-
frequency operation while still providing excellent effi-
ciency at both light and full loads. A 1MHz PWM
switching frequency keeps components small. Both
devices also feature an adjustable soft-start to minimize
battery transient loading.
The MAX1556/MAX1556A/MAX1557are available in a
tiny 10-pin TDFN (3mm x 3mm) package.
Applications
PDAs 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, 1.2V, 1.0V,
and Adjustable Output1.2A Guaranteed Output Current
(MAX1556/MAX1556A)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/MAX1556A/MAX1557
16µA IQ, 1.2A PWM
Step-Down DC-DC Converters
TOP VIEW
OUT
SHDN6
INP
GND
PGND
TDFN
MAX1556
MAX1556A
MAX1557
Pin Configuration
Ordering InformationON
OFFSHDN
GND
INPUT
2.6V TO 5.5V
VOLTAGE
SELECT
OUTPUT
0.75V TO VIN
PGND
OUT
INP
MAX1556
MAX1556A
MAX1557
Typical Operating Circuit
19-3336; Rev 3; 1/11
EVALUATION KIT
AVAILABLE
PARTTEMP RANGEPIN-PACKAGETOP
MARK
MAX1556ETB+-40°C to +85°C10 TDFN-EP*ACQ
MAX1556ETB/V+T-40°C to +85°C10 TDFN-EP*AWS
MAX1556AETB+-40°C to +85°C10 TDFN-EP*AUJ
MAX1557ETB+-40°C to +85°C10 TDFN-EP*ACR
*EP = Exposed paddle.
+Denotes a lead(Pb)-free/RoHS-compliant package.
/V denotes an automotive qualified part.= Tape and reel.
MAX1556/MAX1556A/MAX1557
16µA IQ, 1.2A PWM DC-DC
Step-Down Converters
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN= VINP= VSHDN= 3.6V, TA = -40°C to +85°C. Typical values are at TA = +25°C, unless otherwise noted.) (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.
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
Soldering Temperature (reflow).......................................+260°C
PARAMETERCONDITIONSMINTYPMAXUNITS
Input Voltage2.65.5V
Undervoltage-Lockout ThresholdVIN rising and falling, 35mV hysteresis (typ)2.202.352.55V
No switching, D1 = D2 = GND1625Quiescent Supply CurrentDropout2742µA
TA = +25°C0.11Shutdown Supply CurrentSHDN = GNDTA = +85°C0.1µA
Output Voltage Range0.75VINV
No load-0.25+0.75+1.75
300mA load-0.750+0.75
600mA load-1.5-0.750
1200mA load, MAX1556-2.75-2.25-1.25
TA = 0°C to +85°C
(Note 3)
1200mA load, MAX1556A-2.25
No load-0.75+2.25
300mA load-1.5+1.5
600mA load-2.25+0.50
Output Accuracy
TA = -40°C to +85°C
(Note 3)
1200mA load, MAX1556-4.0-1.0
MAX1556/MAX1556A1200Maximum Output CurrentMAX1557600mA
TA = +25°C0.010.1D1 = D2 = GND
MAX1556/MAX1557TA = +85°C0.01OUT Bias Current
For preset output voltages34.5
No load-0.50+0.75+1.75
300mA load-1.20+1.2
600mA load-1.75-0.75+0.25
D1 = D2 = GND,
VOUT = 0.75V at
300mA (typ),
TA = 0°C to +85°C
MAX1556/MAX15571200mA load, MAX1556 only-3.25-2.25-1.25
No load-1.25+2.25
300mA load-1.75+1.50
600mA load-2.75+0.25
FB Threshold AccuracyD1 = D2 = GND,
VOUT = 0.75V
at 300mA (typ),
TA = -40°C to +85°C1200mA load, MAX1556 only-4.25-1.00
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/MAX1556A/MAX1557
16µA IQ, 1.2A PWM DC-DC
Step-Down Converters
Note 2:All units are 100% production tested at TA= +25°C. Limits over the operating range are guaranteed by design.
Note 3: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 2)
PARAMETERCONDITIONSMINTYPMAXUNITS
VIN = 2.6V to 3.6V-0.37MAX1556,
D1 = IN, D2 = GND;
MAX1556A
D1 = D2 = IN
VIN = 3.6V to 5.5V0.33
VIN = 2.6V to 3.6V-0.1
Line Regulation
MAX1557,
D1 = IN, D2 = GNDVIN = 3.6V to 5.5V0.09
VIN = 3.6V0.190.35MAX1556/MAX1556AVIN = 2.6V0.23
VIN = 3.6V0.350.7p-Channel On-Resistance
MAX1557VIN = 2.6V0.42
VIN = 3.6V0.270.48n-Channel On-ResistanceVIN = 2.6V0.33Ω
MAX1556/MAX1556A1.51.82.1p-Channel Current-Limit
ThresholdMAX15570.81.01.2A
n-Channel Zero Crossing
Threshold203545mA
MAX1556/MAX1556A1.8RMS LX Output CurrentMAX15571.0ARMS
TA = +25°C0.110LX Leakage CurrentVIN = 5.5V, LX =
GND or INTA = +85°C0.1µA
Maximum Duty Cycle100%
Minimum Duty Cycle0%
Internal Oscillator Frequency0.911.1MHz
SS Output Impedance∆VSS / ISS for ISS = 2µA130200300kΩ
SS Discharge ResistanceSHDN = GND, 1mA sink current90200Ω
Thermal-Shutdown Threshold+160°C
Thermal-Shutdown Hysteresis15°C
LOGIC INPUTS (D1, D2, SHDN)
Input-Voltage High2.6V ≤ VIN ≤ 5.5V1.4V
Input-Voltage Low0.4V
TA = +25°C0.11Input LeakageTA = +85°C0.1µA
MAX1556/MAX1556A/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.)
EFFICIENCY vs. LOAD CURRENT
WITH 3.3V OUTPUT
MAX1556/7 toc01
LOAD CURRENT (mA)
EFFICIENCY (%)
0.1100010,000
VIN = 5V
VIN = 3.6V
VIN = 4.2V
EFFICIENCY vs. LOAD CURRENT
WITH 2.5V OUTPUT
MAX1556/7 toc02
LOAD CURRENT (mA)
EFFICIENCY (%)
0.1100010,000
VIN = 3.6V
VIN = 3V
VIN = 2.6V
VIN = 5V
EFFICIENCY vs. LOAD CURRENT
WITH 1.8V OUTPUT
MAX1556/7 toc03
LOAD CURRENT (mA)
EFFICIENCY (%)
0.1100010,000
VIN = 5V
VIN = 3.6V
VIN = 3V
VIN = 2.6V
EFFICIENCY vs. LOAD CURRENT
WITH 1.0V OUTPUT (MAX1557)
MAX1556/7 toc04
LOAD CURRENT (mA)
EFFICIENCY (%)
VIN = 5VVIN = 3.6V
VIN = 3V
VIN = 2.6V
OUTPUT VOLTAGE
vs. LOAD CURRENT
MAX1556/7 toc05
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
TA = -45°C
TA = +25°C
TA = +85°C
OUTPUT VOLTAGE vs. INPUT VOLTAGE
WITH 600mA LOAD
MAX1556/7 toc06
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
TA = -40°C
TA = +25°C
TA = +85°C
OUTPUT VOLTAGE vs. INPUT VOLTAGE
WITH NO LOAD
MAX1556/7 toc07
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
TA = -40°C
TA = +25°C
TA = +85°C
SUPPLY CURRENT vs. INPUT VOLTAGE
MAX1556/7 toc08
INPUT VOLTAGE (V)
SUPPLY CURRENT (432
HEAVY-LOAD SWITCHING WAVEFORMS
MAX1556/7 toc09
VOUT
AC-COUPLED
10mV/div
VLX
ILX
2V/div400ns
500mA/div
ILOAD = 750mA
MAX1556/MAX1556A/MAX1557
16µA IQ, 1.2A PWM DC-DC
Step-Down Converters
LIGHT-LOAD SWITCHING WAVEFORMS
MAX1556/7 toc10
20mV/div
AC-COUPLED
VLX
VOUT
ILX
2V/div
4µs/div
200mA/div
EXTERNAL FEEDBACK
SWITCHING WAVEFORMS
MAX1556/7 toc10b
VLX
ILX
2V/div
2µs/div
200mA/div
VIN = 5V, VOUT = 3.3V, IOUT = 500mA
SOFT-START/SHUTDOWN WAVEFORMS
MAX1556/7 toc11
5V/div
ILX
VSHDN
VOUT
IIN
500mA/div0
100μs/div
1V/div0
500mA/div
CSS = 470pF
RLOAD = 4Ω
SOFT-START RAMP TIME vs. CSS
MAX1556/7 toc12
CSS (pF)
SOFT-START RAMP TIME (ms)
LOAD TRANSIENT
MAX1556/7 toc13
50mV/div
AC-COUPLED
500mA/div
VOUT
IOUT
20μs/div
IOUTMIN = 20mA
LOAD TRANSIENT
MAX1556/7 toc14
50mV/div
AC-COUPLED
500mA/div
VOUT
IOUT
20μs/div
IOUTMIN = 180mA
LINE TRANSIENT
MAX1556/7 toc15
10mV/div
AC-COUPLED
VIN
VOUT
ILX
3.5V
40μs/div
200mA/div
BODE PLOT
MAX1556/7 toc16
FREQUENCY (kHz)
GAIN (dB)
PHASE (DEGREES)
0dB
PHASE MARGIN = 53°
COUT = 22µF, RLOAD = 4Ωypical Operating Characteristics (continued)
(VIN= VINP= 3.6V, D1 = D2 = SHDN= IN, Circuits of Figures 2 and 3, TA= +25°C, unless otherwise noted.)
MAX1556/MAX1556A/MAX1557
16µA IQ, 1.2A PWM DC-DC
Step-Down Converters
Detailed Description
The 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
Control Scheme
During 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.
Pin Description
PINNAMEFUNCTIONINSupply Voltage Input. Connect to a 2.6V to 5.5V source.GNDGround. Connect to PGND.
3SS
Soft-Start Control. Connect a 1000pF capacitor (CSS) from SS to GND to eliminate input-current
overshoot during startup. CSS is required for normal operation of the MAX1556/MAX1557. For greater
than 22µF total output capacitance, increase CSS to COUT / 22,000 for soft-start. SS is internally
discharged through 200Ω to GND in shutdown.OUT
Output Sense Input. Connect to the output of the regulator. D1 and D2 select the desired output
voltage through an internal feedback resistor-divider. The internal feedback resistor-divider remains
connected in shutdown.SHDNShutdown Input. Drive SHDN low to enable low-power shutdown mode. Drive high or connect to IN
for normal operation.D2OUT Voltage-Select Input. See Table 1.PGNDPower Ground. Connect to GND.
8LXInductor Connection. Connected to the drains of the internal power MOSFETs. High impedance in
shutdown mode.INPSupply Voltage, High-Current Input. Connect to a 2.6V to 5.5V source. Bypass with a 10µF ceramic
capacitor to PGND.D1OUT Voltage-Select Input. See Table 1.
—EPExposed Paddle. Connect to ground plane. EP also functions as a heatsink. Solder to circuit-board
ground plane to maximize thermal dissipation.D2MAX1556
VOUT
MAX1556A
VOUT
MAX1557
VOUT
Adjustable
(VFB = 0.75V)
from 0.75V to
VIN
3.3V
Adjustable
(VFB = 0.75V)
from 0.75V to
VIN13.3V1.5V1.5V02.5V1.2V1.3V11.8V2.5V1.0V
Table 1. Output-Voltage-Select Truth Table
A zero represents D_ being driven low or connected to GND.
A 1 represents D_ being driven high or connected to IN.

Partno	Mfg	Dc	Qty	Available	Descript
MAX1556ETB+	MAXIM	N/a	850	avai	16µA IQ, 1.2A PWM Step-Down DC-DC Converters
MAX1556ETB+T \|MAX1556ETBT	MAXIM	N/a	15000	avai	16µA IQ, 1.2A PWM Step-Down DC-DC Converters
MAX1557ETB+T	MAXIM	N/a	265	avai	16µA IQ, 1.2A PWM Step-Down DC-DC Converters