MAX1945REUI ,2.6 V to 5.5 V, 1 MHz, 1% accurate, 6A internal switch step-down regulatorApplicationsLow-Voltage, High-Density Distributed PowerTypical Operating CircuitSuppliesASIC, CPU, ..
MAX1945REUI+ ,1MHz, 1% Accurate, 6A Internal Switch Step-Down RegulatorsApplicationsLow-Voltage, High-Density Distributed PowerTypical Operating CircuitSuppliesASIC, CPU, ..
MAX1945REUI+T ,1MHz, 1% Accurate, 6A Internal Switch Step-Down RegulatorsELECTRICAL CHARACTERISTICS(V = V = V = V = V = 3.3V, SYNC = GND, FBSEL = High-Z, V = 0.7V, C = 0.22 ..
MAX1946ETA ,Single USB Switch with Autoreset and Fault Blanking in Tiny TDFNApplications*EP = Exposed paddle.USB Ports and USB HubsNotebook and Desktop ComputersPDAs and Palmt ..
MAX1946ETA+ ,Single USB Switch with Autoreset and Fault Blanking in Tiny TDFNfeatures to pro-♦ 2.7V to 5.5V Input Voltage Rangetect the USB port. Built-in thermal-overload prot ..
MAX1946ETA+T ,Single USB Switch with Autoreset and Fault Blanking in Tiny TDFNELECTRICAL CHARACTERISTICS(V = 5V, C = 0.1µF, C = 1µF, T = 0°C to +85°C, unless otherwise noted. Ty ..
MAX4908ETD+TCFD ,Dual 3:1 Clickless Audio Multiplexers with Negative-Signal HandlingElectrical Characteristics(V = +2.7V to +5.5V, T = -40°C to +85°C, unless otherwise noted. Typical ..
MAX490CPA ,Low-Power / Slew-Rate-Limited RS-485/RS-422 TransceiversMAX481/MAX483/MAX485/MAX487–MAX491/MAX148719-0122; Rev 5; 2/96Low-Power, Slew-Rate-LimitedRS-485/RS ..
MAX490CPA+ ,Low-Power, Slew-Rate-Limited RS-485/RS-422 TransceiversApplicationsguarantees a logic-high output if the input is open circuit.MAX3030E–MAX3033E: ±15kV E ..
MAX490CSA ,Low-Power / Slew-Rate-Limited RS-485/RS-422 TransceiversELECTRICAL CHARACTERISTICS(V = 5V ±5%, T = T to T , unless otherwise noted.) (Notes 1, 2)CC A MIN M ..
MAX490CSA ,Low-Power / Slew-Rate-Limited RS-485/RS-422 TransceiversApplications ______________Ordering InformationLow-Power RS-485 TransceiversPART TEMP. RANGE PIN-PA ..
MAX490CSA ,Low-Power / Slew-Rate-Limited RS-485/RS-422 TransceiversMAX481/MAX483/MAX485/MAX487–MAX491/MAX148719-0122; Rev 5; 2/96Low-Power, Slew-Rate-LimitedRS-485/RS ..
MAX1945REUI
2.6 V to 5.5 V, 1 MHz, 1% accurate, 6A internal switch step-down regulator
General DescriptionThe MAX1945R/MAX1945S high-efficiency pulse-width
modulation (PWM) switching regulators deliver up to 6A
of output current. The devices operate from an input
supply range of 2.6V to 5.5V and provide selectable
output voltages of 1.8V, 2.5V, and adjustable output
voltages from 0.8V to 85% of the supply voltage. With
VCCat 3.3V/5V, the input voltage can be as low as
2.25V. The MAX1945R/MAX1945S are ideal for on-
board post-regulation applications. Total output voltage
error is less than ±1% over load, line, and temperature.
The MAX1945R/MAX1945S operate at a selectable
fixed frequency (500kHz or 1MHz) or can be synchro-
nized to an external clock (400kHz to 1.2MHz). The
high operating frequency minimizes the size of external
components. The high bandwidth of the internal error
amplifier provides excellent transient response. The
MAX1945R/MAX1945S have internal dual N-channel
MOSFETs to lower heat dissipation at heavy loads. Two
MAX1945R/MAX1945Ss can operate 180 degrees out-
of-phase of each other to minimize input capacitance.
The devices provide output voltage margining for
board-level testing. The MAX1945R provides a ±4%
voltage margining. The MAX1945S provides a ±9%
voltage margining.
The MAX1945R/MAX1945S are available in 28-pin
TSSOP-EP packages and are specified over the -40°C
to +85°C industrial temperature range. An evaluation kit
is available to speed designs.
ApplicationsLow-Voltage, High-Density Distributed Power
Supplies
ASIC, CPU, and DSP Core Voltages
RAM Power Supply
Base Station, Telecom, and Networking
Equipment Power Supplies
Server and Notebook Power Supplies
Features6A PWM Step-Down Regulator with 95%
Efficiency1MHz/500kHz Switching for Small External
Components0.76in2Complete 6A Regulator FootprintExternal Components’ Height <3mm±1% Output Accuracy over Load, Line, and
TemperatureOperate from 2.6V to 5.5V SupplyOperate from 2.5V Input with VCCat 3.3V/5VPreset Output Voltage of 1.8V or 2.5VAdjustable Output from 0.8V to 85% of InputVoltage Margining: ±4% (MAX1945R) or ±9%
(MAX1945S)Synchronize to External ClockSYNCOUT Provides 180-Degree Out-of-Phase
Clock OutputAll-Ceramic or Electrolytic Capacitor Designs
MAX1945R/MAX1945S
Step-Down Regulators
Ordering Information
Typical Operating Circuit19-2640; Rev 1; 7/04
*EP = Exposed pad.
Pin Configuration appears at end of data sheet.
MAX1945R/MAX1945S
1MHz, 1% Accurate, 6A Internal Switch
Step-Down Regulators
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VIN= VCC= VCTL1= VCTL2= VDD= 3.3V, SYNC = GND, FBSEL = High-Z, VFB= 0.7V, CREF= 0.22µF, TA
= 0°C to +85°C, unless otherwise noted. Typical values are at +25°C.)
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.
CTL1, CTL2, IN, SYNC, VCC, VDDto GND...............-0.3V to +6V
SYNCOUT, COMP, FB, FBSEL,
REF to GND............................................-0.3V to (VCC+ 0.3V)
LX Current (Note 1).....................................................-9A to +9A
BST to LX..................................................................-0.3V to +6V
PGND to GND.......................................................-0.3V to +0.3V
Continuous Power Dissipation (TA= +85°C)
(derate 23.8mW/°C above +70°C).............................1191mW
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.
MAX1945R/MAX1945S
1MHz, 1% Accurate, 6A Internal Switch
Step-Down Regulators
ELECTRICAL CHARACTERISTICS (continued)(VIN= VCC= VCTL1= VCTL2= VDD= 3.3V, SYNC = GND, FBSEL = High-Z, VFB= 0.7V, CREF= 0.22µF, TA
= 0°C to +85°C, unless
MAX1945R/MAX1945S
1MHz, 1% Accurate, 6A Internal Switch
Step-Down Regulators
ELECTRICAL CHARACTERISTICS (continued)
(VIN= VCC= VCTL1= VCTL2= VDD= 3.3V, SYNC = GND, FBSEL = High-Z, VFB= 0.7V, CREF= 0.22µF, TA
= 0°C to +85°C, unless
MAX1945R/MAX1945S
1MHz, 1% Accurate, 6A Internal Switch
Step-Down Regulators
ELECTRICAL CHARACTERISTICS (continued)
(VIN= VCC= VCTL1= VCTL2= VDD= 3.3V, SYNC = GND, FBSEL = High-Z, VFB= 0.7V, CREF= 0.22µF, TA= 0°C to +85°C, unless
ELECTRICAL CHARACTERISTICS
(VIN= VCC= VCTL1= VCTL2= VDD= 3.3V, SYNC = GND, FBSEL = High-Z, VFB= 0.7V, CREF= 0.22µF, TA= -40°C to +85°C, unless
otherwise noted.) (Note 2)
MAX1945R/MAX1945S
1MHz, 1% Accurate, 6A Internal Switch
Step-Down Regulators
ELECTRICAL CHARACTERISTICS (continued)
(VIN= VCC= VCTL1= VCTL2= VDD= 3.3V, SYNC = GND, FBSEL = High-Z, VFB= 0.7V, CREF= 0.22µF, TA= -40°C to +85°C, unless
otherwise noted.) (Note 2)
MAX1945R/MAX1945S
1MHz, 1% Accurate, 6A Internal Switch
Step-Down Regulators
ELECTRICAL CHARACTERISTICS (continued)
(VIN= VCC= VCTL1= VCTL2= VDD= 3.3V, SYNC = GND, FBSEL = High-Z, VFB= 0.7V, CREF= 0.22µF, TA= -40°C to +85°C, unless
otherwise noted.) (Note 2)
MAX1945R/MAX1945S
1MHz, 1% Accurate, 6A Internal Switch
Step-Down Regulators
Typical Operating Characteristics
(VIN= VCC= 5V, VOUT= 1.8V, IOUT= 6A, fSW= 500kHz, VDD= VCC, and TA= +25°C, unless otherwise noted.)
MAX1945R/MAX1945S
1MHz, 1% Accurate, 6A Internal Switch
Step-Down Regulatorsypical Operating Characteristics (continued)
(VIN= VCC= 5V, VOUT= 1.8V, IOUT= 6A, fSW= 500kHz, VDD= VCC, and TA= +25°C, unless otherwise noted.)
MAX1945R/MAX1945S
1MHz, 1% Accurate, 6A Internal Switch
Step-Down Regulators
Pin Descriptionypical Operating Characteristics (continued)
(VIN= VCC= 5V, VOUT= 1.8V, IOUT= 6A, fSW= 500kHz, VDD= VCC, and TA= +25°C, unless otherwise noted.)
