MAX1971EEE ,Dual / 180 Out-of-Phase / 1.4MHz / 750mA Step- Down Regulator with POR and RSI/PFOELECTRICAL CHARACTERISTICS(V = V = V = 5V, R = 100kΩ to IN, R = 100kΩ to IN, V = 0, C = 0.1µF, FBSE ..
MAX1971EEE+ ,Dual, 180° Out-of-Phase, 1.4MHz, 750mA Step-Down Regulator with POR and RSI/PFOMAX1970/MAX1971/MAX197219-2297; Rev 1; 2/09Dual, 180° Out-of-Phase, 1.4MHz, 750mA Step-Down Regulat ..
MAX1972EEE ,Dual / 180 Out-of-Phase / 1.4MHz / 750mA Step- Down Regulator with POR and RSI/PFOFeaturesThe MAX1970/MAX1971/MAX1972 dual-output current- Current-Mode, 1.4MHz Fixed-Frequency PWMm ..
MAX1972EEE+ ,Dual, 180° Out-of-Phase, 1.4MHz, 750mA Step-Down Regulator with POR and RSI/PFOFeaturesThe MAX1970/MAX1971/MAX1972 dual-output current-♦ Current-Mode, 1.4MHz Fixed-Frequency PWMm ..
MAX1973EUB ,PLASTIC ENCAPSULATED DEVICESTable of Contents I. ........Device Description V. ........Quality Assurance Information II ..
MAX1973EUB+ ,Smallest 1A, 1.4MHz Step-Down RegulatorsApplications that forward bias these diodes should take care not to exceedthe IC package power diss ..
MAX494CSD+ ,Single/Dual/Quad, Micropower, Single-Supply, Rail-to-Rail Op AmpsGeneral Description ________
MAX494CSD+T ,Single/Dual/Quad, Micropower, Single-Supply, Rail-to-Rail Op AmpsApplications *Dice are specified at TA = +25°C, DC parameters only.__________Typical Operating Circ ..
MAX494CSD-T ,Single/Dual/Quad, Micropower, Single-Supply, Rail-to-Rail Op AmpsApplications *Dice are specified at TA = +25°C, DC parameters only.__________Typical Operating Circ ..
MAX494EPD ,Single/Dual/Quad, Micropower, Single-Supply Rail-to-Rail Op AmpsMAX492/MAX494/MAX49519-0265; Rev 2; 9/96Single/Dual/Quad, Micropower,Single-Supply Rail-to-Rail Op ..
MAX494ESD ,Single/Dual/Quad, Micropower, Single-Supply Rail-to-Rail Op AmpsFeatures' Low-Voltage Single-Supply Operation (+2.7V to +6V)The dual MAX492, quad MAX494, and singl ..
MAX494ESD+ ,Single/Dual/Quad, Micropower, Single-Supply, Rail-to-Rail Op Amps Not Recommended for New Designs The MAX495 was manufactured for Maxim by an outside wafer foundr ..
MAX1971EEE-MAX1972EEE
Dual / 180 Out-of-Phase / 1.4MHz / 750mA Step- Down Regulator with POR and RSI/PFO
General DescriptionThe MAX1970/MAX1971/MAX1972 dual-output current-
mode PWM buck regulators operate from 2.6V to 5.5V
input and deliver a minimum of 750mA on each output.
The MAX1970 and MAX1972 operate at a fixed 1.4MHz
(MAX1971 operates at 700kHz) to reduce output induc-
tor and capacitor size and cost. Switching the regula-
tors 180°out-of-phase also reduces the input capacitor
size and cost. Ceramic capacitors can be used for
input and output.
The output voltages are programmable from 1.2V to VIN
using external feedback resistors, or can be preset to
1.8V or 3.3V for output 1 and 1.5V or 2.5V for output 2.
When one output is higher than 1.2V, the second can
be configured down to sub-1V levels. Output accuracy
is better than ±1% over variations in load, line, and tem-
perature. Internal soft-start reduces inrush current dur-
ing startup.
All devices feature power-on reset (POR). The
MAX1971 includes a reset input (RSI), which forces
PORlow for 175ms after RSI goes low. The MAX1970
and MAX1972 include an open-drain power-fail output
(PFO) that monitors input voltage and goes high when
the input falls below 3.94V. For USB-powered xDSL
modems, this output can be used to detect USB power
failure. A minimum switching frequency of 1.2MHz
ensures operation outside the xDSL band.
Applications
FeaturesCurrent-Mode, 1.4MHz Fixed-Frequency PWM
Operation180°Out-of-Phase Operation Reduces Input
Capacitor±1% Output Accuracy Over Load, Line, and
Temperature Ranges750mA Guaranteed Output Current2.6V to 5.5V InputPower-On Reset Delay of 16.6ms (MAX1970) or
175ms (MAX1971 and MAX1972)Power-Fail Output (MAX1970 and MAX1972 Only)Power-On Reset Input (MAX1971 Only)Operation Outside xDSL BandUltra-Compact Design with Smallest External
ComponentsOutputs Adjustable from 0.8V to VINor 1.8V/3.3V
and 1.5V/2.5V PresetAll-Ceramic Capacitor ApplicationSoft-Start Reduces Inrush Current
MAX1970/MAX1971/MAX1972
Dual, 180°Out-of-Phase, 1.4MHz, 750mA Step-
Down Regulator with POR and RSI/PFO
Pin Configuration
Typical Operating Circuit19-2297; Rev 0; 1/02
xDSL Modems
xDSL Routers
Copper Gigabit SFP
and GBIC Modules
USB-Powered Devices
Dual LDO Replacement
Ordering Information
MAX1970/MAX1971/MAX1972
Dual, 180°Out-of-Phase, 1.4MHz, 750mA Step-
Down Regulator with POR and RSI/PFO
ABSOLUTE MAXIMUM RATINGSStresses 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, EN, FBSEL1, FBSEL2, PFO, POR,
RSI, VCCto GND...................................................-0.3V to +6V
COMP1, COMP2, FB1, FB2,
REF to GND.............................................-0.3V to (VCC+ 0.3V)
LX1, LX2 to PGND.......................................-0.3V to (VIN+ 0.3V)
PGND to GND.......................................................-0.3V to +0.3V
Continuous Power Dissipation (TA = +70°C)
16-pin QSOP (derate 8.3mW/°C above +70°C)...........667mW
Operating Temperature Range...........................-40°C to +85°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
ELECTRICAL CHARACTERISTICS(VIN= VCC= VEN= 5V, RPOR= 100kΩto IN, RPFO= 100kΩto IN, VRSI= 0, CREF= 0.1µF, FBSEL1 = unconnected, FBSEL2 =
MAX1970/MAX1971/MAX1972
Dual, 180°Out-of-Phase, 1.4MHz, 750mA Step-
Down Regulator with POR and RSI/PFO
ELECTRICAL CHARACTERISTICS (continued)(VIN= VCC= VEN= 5V, RPOR= 100kΩto IN, RPFO= 100kΩto IN, VRSI= 0, CREF= 0.1µF, FBSEL1 = unconnected, FBSEL2 =
unconnected, TA
= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)
MAX1970/MAX1971/MAX1972
Dual, 180°Out-of-Phase, 1.4MHz, 750mA Step-
Down Regulator with POR and RSI/PFO
ELECTRICAL CHARACTERISTICS (continued)(VIN= VCC= VEN= 5V, RPOR= 100kΩto IN, RPFO= 100kΩto IN, VRSI= 0, CREF= 0.1µF, FBSEL1 = unconnected, FBSEL2 =
unconnected, TA
= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)
ELECTRICAL CHARACTERISTICS(VIN= VCC= VEN= 5V, VFB1= VFB2= 1.15V, RPOR= 100kΩto IN, RPFO= 100kΩto IN, RSI = 0, CVCC= 0.1µF, CREF= 0.1µF,
MAX1970/MAX1971/MAX1972
Dual, 180°Out-of-Phase, 1.4MHz, 750mA Step-
Down Regulator with POR and RSI/PFO
ELECTRICAL CHARACTERISTICS (continued)(VIN= VCC= VEN= 5V, VFB1= VFB2= 1.15V, RPOR= 100kΩto IN, RPFO= 100kΩto IN, RSI = 0, CVCC= 0.1µF, CREF= 0.1µF,
MAX1970/MAX1971/MAX1972
Dual, 180°Out-of-Phase, 1.4MHz, 750mA Step-
Down Regulator with POR and RSI/PFO
ELECTRICAL CHARACTERISTICS (continued)(VIN= VCC= VEN= 5V, VFB1= VFB2= 1.15V, RPOR= 100kΩto IN, RPFO= 100kΩto IN, RSI = 0, CVCC= 0.1µF, CREF= 0.1µF,
FBSEL1 = unconnected, FBSEL2 = unconnected, TA
= -40°C to +85°C.) (Note 2)
Note 2:Specifications to -40°C are guaranteed by design and not production tested.
MAX1970/MAX1971/MAX1972
Dual, 180°Out-of-Phase, 1.4MHz, 750mA Step-
Down Regulator with POR and RSI/PFOEFFICIENCY vs. LOAD CURRENT
MAX1970TOC01
LOAD CURRENT (A)
EFFICIENCY (%)40
EFFICIENCY vs. LOAD CURRENT
MAX1970TOC02
LOAD CURRENT (A)
EFFICIENCY (%)40
EFFICIENCY vs. LOAD CURRENT
MAX1970TOC04
LOAD CURRENT (A)
EFFICIENCY (%)40
INPUT CURRENT vs. OUTPUT CURRENT
MAX1970TOC05
OUTPUT CURRENT (mA)
INPUT CURRENT (mA)
REFERENCE VOLTAGE vs.
REFERENCE LOAD CURRENT
MAX1970TOC06
REFERENCE LOAD CURRENT (µA)
REFERENCE VOLTAGE (V)
OSCILLATOR FREQUENCY
vs. INPUT VOLTAGE
MAX1970TOC07
INPUT VOLTAGE (V)
OSCILLATOR FREQUENCY (MHz)
CHANGE IN OUTPUT VOLTAGE
vs. LOAD CURRENT
MAX1970TOC08
LOAD CURRENT (mA)
CHANGE IN OUTPUT VOLTAGE (mV)
Typical Operating Characteristics(TA = +25°C, unless otherwise noted.)
MAX1970/MAX1971/MAX1972
Dual, 180°Out-of-Phase, 1.4MHz, 750mA Step-
Down Regulator with POR and RSI/PFOIOUT1
VOUT1
40µs/div
MAX1970TOC09
VIN = 5V
VOUT1 = 3.3V, 100mV/div
IOUT1 = 300mA TO 600mA
RC1 = 82kΩ, CC1 = 680pF
LOAD TRANSIENT RESPONSE
Typical Operating Characteristics (continued)(TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)(TA = +25°C, unless otherwise noted.)
MAX1970/MAX1971/MAX1972
Dual, 180°Out-of-Phase, 1.4MHz, 750mA Step-
Down Regulator with POR and RSI/PFO
MAX1970/MAX1971/MAX1972
Dual, 180°Out-of-Phase, 1.4MHz, 750mA Step-
Down Regulator with POR and RSI/PFO5ms/div
5V/div
MAX1970TOC17
SHUTDOWN RESPONSEMAX1970
VIN = 5V
VOUT1 = 3.3V, VOUT2 = 2.5V
IOUT1 = 375mA, IOUT2 = 375mA
Typical Operating Characteristics (continued)(TA = +25°C, unless otherwise noted.)
