MAX1842EEE ,1A/2.7A / 1MHz / Step-Down Regulators with Synchronous Rectification and Internal SwitchesFeaturesThe MAX1742/MAX1842 constant-off-time, pulse-width- ±1% Output Accuracymodulated (PWM) ste ..
MAX1842EEE+ ,1A/2.7A, 1MHz, Step-Down Regulators with Synchronous Rectification and Internal SwitchesApplications that forward-bias these diodes should take care not to exceedthe IC’s package power di ..
MAX1842EEE+T ,1A/2.7A, 1MHz, Step-Down Regulators with Synchronous Rectification and Internal SwitchesFeaturesThe MAX1742/MAX1842 constant-off-time, pulse-width-♦ ±1% Output Accuracymodulated (PWM) ste ..
MAX1842EEE-T ,1A/2.7A, 1MHz, Step-Down Regulators with Synchronous Rectification and Internal Switchesapplications requir-♦ 100% Duty Cycle During Low-Dropout Operationing small external component size ..
MAX1842EEE-T ,1A/2.7A, 1MHz, Step-Down Regulators with Synchronous Rectification and Internal SwitchesApplicationsTypical Configuration5V or 3.3V to Low-Voltage ConversionCPU I/O Ring OUTPUTINPUTIN 1.1 ..
MAX1842EEE-T ,1A/2.7A, 1MHz, Step-Down Regulators with Synchronous Rectification and Internal SwitchesELECTRICAL CHARACTERISTICS(V = V = 3.3V, FBSEL = GND, T = 0°C to +85°C, unless otherwise noted. Typ ..
MAX4736EUB ,0.8 / Low-Voltage / Single-Supply / Dual SPDT Analog SwitchApplicationsPower RoutingOrdering InformationBattery-Powered SystemsPART TEMP RANGE PIN-PACKAGEAudi ..
MAX4736EUB ,0.8 / Low-Voltage / Single-Supply / Dual SPDT Analog SwitchELECTRICAL CHARACTERISTICS—Single 3V Supply(V+ = 2.7V to 3.6V, V = 1.4V, V = 0.5V, T = T to T , unl ..
MAX4736EUB+ ,0.6 Ohm, Low-Voltage, Single-Supply, Dual SPDT Analog SwitchElectrical Characteristics—Single 3V Supply(V+ = 2.7V to 4.2V, V = 1.4V, V = 0.5V, T = T to T , unl ..
MAX4736EUB+T ,0.6 Ohm, Low-Voltage, Single-Supply, Dual SPDT Analog Switchfeatures ● 1.8V CMOS Logic Compatible (3V Supply)low 0.6Ω on-resistance (R), with 0.1Ω R matching O ..
MAX4737EBE+T ,4.5 Ohm Quad SPST Analog Switches in UCSPApplications● Battery-Operated Equipment● Audio/Video-Signal Routing● Low-Voltage Data-Acquisition ..
MAX4737ETE ,+1.8 to +5.5 V, quad 4.5 om SPST analog switcheApplicationsOrdering InformationBattery-Operated EquipmentPIN/BUMP- TOPPART TEMP RANGEPACKAGE MARKA ..
MAX1842EEE
1A/2.7A / 1MHz / Step-Down Regulators with Synchronous Rectification and Internal Switches
MAX1742/MAX1842
1A/2.7A, 1MHz, Step-Down Regulators with
Synchronous Rectification and Internal Switches19-1760; Rev 1; 2/02
General DescriptionThe MAX1742/MAX1842 constant-off-time, pulse-width-
modulated (PWM) step-down DC-DC converters are ideal
for use in 5V and 3.3V to low-voltage conversion neces-
sary in notebook and subnotebook computers. These
devices feature internal synchronous rectification for high
efficiency and reduced component count. They require
no external Schottky diode. The internal 90mΩPMOS
power switch and 70mΩNMOS synchronous-rectifier
switch easily deliver continuous load currents up to 1A.
The MAX1742/MAX1842 produce a preset 2.5V, 1.8V, or
1.5V output voltage or an adjustable output from 1.1V to
VIN. They achieve efficiencies as high as 95%.
The MAX1742/MAX1842 use a unique current-mode,
constant-off-time, PWM control scheme, which includes
Idle Mode™ to maintain high efficiency during light-load
operation. The programmable constant-off-time architec-
ture sets switching frequencies up to 1MHz, allowing the
user to optimize performance trade-offs between effi-
ciency, output switching noise, component size, and
cost. Both devices are designed for continuous output
currents up to 1A. The MAX1742 uses a peak current
limit of 1.3A (min) and is suitable for applications requir-
ing small external component size and high efficiency.
The MAX1842 has a higher current limit of 3.1A (min)
and is intended for applications requiring an occasional
burst of output current up to 2.7A. Both devices also fea-
ture an adjustable soft-start to limit surge currents during
startup, a 100% duty cycle mode for low-dropout opera-
tion, and a low-power shutdown mode that disconnects
the input from the output and reduces supply current
below 1µA. The MAX1742/MAX1842 are available in 16-
pin QSOP packages.
For similar devices that provide continuous output cur-
rents up to 2A and 3A, refer to the MAX1644 and
MAX1623 data sheets.
Applications5V or 3.3V to Low-Voltage Conversion
CPU I/O Ring
Chipset Supplies
Notebook and Subnotebook Computers
Features±1% Output Accuracy95% EfficiencyInternal PMOS and NMOS Switches
90mΩOn-Resistance at VIN= 4.5V
110mΩOn-Resistance at VIN= 3VOutput Voltage
2.5V, 1.8V, or 1.5V Pin Selectable
1.1V to VINAdjustable3V to 5.5V Input Voltage Range600µA (max) Operating Supply Current<1µA Shutdown Supply CurrentProgrammable Constant-Off-Time Operation1MHz (max) Switching FrequencyIdle-Mode Operation at Light LoadsThermal Shutdown Adjustable Soft-Start Inrush Current Limiting100% Duty Cycle During Low-Dropout OperationOutput Short-Circuit Protection16-Pin QSOP Package
Ordering InformationIdle Mode is a trademark of Maxim Integrated Products.
Typical Configuration
Pin Configuration appears at end of data sheet.
MAX1742/MAX1842
1A/2.7A, 1MHz, Step-Down Regulators with
Synchronous Rectification and Internal Switches
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.
VCC, IN to GND........................................................-0.3V to +6V
IN to VCC.............................................................................±0.3V
GND to PGND.....................................................................±0.3V
All Other Pins to GND.................................-0.3V to (VCC+ 0.3V)
LX Current (Note 1).............................................................±4.7A
REF Short Circuit to GND Duration............................Continuous
ESD Protection.....................................................................±2kV
Continuous Power Dissipation (TA= +70°C)
SSOP (derate 16.7mW/°C above +70°C;
part mounted on 1 in.2of 1oz. copper)...............................1W
Operating Temperature Range...........................-40°C to +85°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s)................................+300°C
Note 1:LX has internal clamp diodes to PGND and IN. Applications that forward-bias these diodes should take care not to exceed
the IC’s package power dissipation limits.
MAX1742/MAX1842
1A/2.7A, 1MHz, Step-Down Regulators with
Synchronous Rectification and Internal Switches
ELECTRICAL CHARACTERISTICS (continued)(VIN= VCC= 3.3V, FBSEL = GND, TA
= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)
MAX1742/MAX1842
1A/2.7A, 1MHz, Step-Down Regulators with
Synchronous Rectification and Internal Switches
ELECTRICAL CHARACTERISTICS
Typical Operating Characteristics(Circuit of Figure 1, TA = +25°C, unless otherwise noted.)
MAX1742/MAX1842
1A/2.7A, 1MHz, Step-Down Regulators with
Synchronous Rectification and Internal SwitchesMAX1742
EFFICIENCY vs. OUTPUT CURRENT
(VIN = 5.0V, L = 6.0µH)
MAX1742 toc01
OUTPUT CURRENT (A)
EFFICIENCY (%)
MAX1742
EFFICIENCY vs. OUTPUT CURRENT
(VIN = 3.3V, L = 3.9µH)
MAX1742 toc02
OUTPUT CURRENT (A)
EFFICIENCY (%)
MAX1742
EFFICIENCY vs.OUTPUT CURRENT
(fPWM = 270kHz)
MAX1742 toc03
OUTPUT CURRENT (A)
EFFICIENCY (%)
MAX1742
NORMALIZED OUTPUT ERROR
vs. OUTPUT CURRENT
MAX1742 toc04
OUTPUT CURRENT (A)
NORMALIZED OUTPUT ERROR (%)
MAX1742
SWITCHING FREQUENCY
vs. OUTPUT CURRENT
MAX1742 toc05
OUTPUT CURRENT (A)
FREQUENCY (kHz)
MAX1742/MAX1842
1A/2.7A, 1MHz, Step-Down Regulators with
Synchronous Rectification and Internal Switches
MAX1742
STARTUP AND SHUTDOWNIINPUT
1A/div
VOUTPUT
1V/div
VSS
2V/div
MAX1742 toc06
1ms/div
VSHDN
5V/div
MAX1742
LOAD-TRANSIENT RESPONSEVOUTPUT
AC-COUPLED,
50mV/div
0.5A/div
MAX1742 toc07
10µs/div
MAX1742
LINE-TRANSIENT RESPONSEVINPUT
2V/div
VOUTPUT
20mV/div
AC-COUPLED
MAX1742 toc08
20µs/div
IOUT = 1A, VOUT = 1.5V, RTOFF = 100kΩ, L = 6µH
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX1742 toc09
VIN (V)
NO-LOAD SUPPLY CURRENT, I
+ I
CC
SHUTDOWN SUPPLY CURRENT, I
+ I
CC
(nA)
Typical Operating Characteristics (continued)(Circuit of Figure 1, TA = +25°C, unless otherwise noted.)
MAX1742/MAX1842
1A/2.7A, 1MHz, Step-Down Regulators with
Synchronous Rectification and Internal Switchesypical Operating Characteristics (continued)
MAX1742/MAX1842
1A/2.7A, 1MHz, Step-Down Regulators with
Synchronous Rectification and Internal Switches
Pin Descriptionypical Operating Characteristics (continued)(Circuit of Figure 1, TA = +25°C, unless otherwise noted.)
