MAX1791EUB ,High-Efficiency, 10-Pin レMAX, Step-Down Controllers for NotebooksELECTRICAL CHARACTERISTICS(V = 15V, VL enabled, C = 1µF, C = 0.1µF, T = 0 to +85°C, unless otherwis ..
MAX1791EUB ,High-Efficiency, 10-Pin レMAX, Step-Down Controllers for NotebooksELECTRICAL CHARACTERISTICS(V = 15V, VL enabled, C = 1µF, C = 0.1µF, T = 0 to +85°C, unless otherwis ..
MAX1791EUB ,High-Efficiency, 10-Pin レMAX, Step-Down Controllers for NotebooksFeaturesThe MAX1762/MAX1791 PWM step-down controllers High Operating Frequency (300kHz)provide hig ..
MAX1791EUB+ ,High-Efficiency, 10-Pin µMAX, Step-Down Controllers for NotebooksApplicationsPART TEMP RANGE PIN-PACKAGENotebooks Handy-TerminalsMAX1762EUB -40°C to +85°C 10 µMAXS ..
MAX1792EUA15 ,500mA Low-Dropout Linear Regulator in レMAXFeaturesThe MAX1792 low-dropout linear regulator operates Guaranteed 500mA Output Currentfrom a +2 ..
MAX1792EUA15 ,500mA Low-Dropout Linear Regulator in レMAXFeaturesThe MAX1792 low-dropout linear regulator operates Guaranteed 500mA Output Currentfrom a +2 ..
MAX4621CSE ,Dual / 5 Analog SwitchesApplicationswhere current switching is required. They have lowReed Relay Replacement Military Radio ..
MAX4621EPE ,Dual / 5 Analog SwitchesELECTRICAL CHARACTERISTICS—Dual Supplies(V+ = +15V, V- = -15V, V = +5V, GND = 0, V = +2.4V, V = +0. ..
MAX4622CPE ,Dual / 5 Analog SwitchesFeaturesThe MAX4621/MAX4622/MAX4623 are precision, dual, ♦ Low On-Resistance: 3Ω (typ), 5Ω (max)hig ..
MAX4622CSE ,Dual / 5 Analog SwitchesMAX4621/MAX4622/MAX462319-1497; Rev 0; 8/99Dual, 5Ω Analog Switches
MAX4622CSE ,Dual / 5 Analog SwitchesFeaturesThe MAX4621/MAX4622/MAX4623 are precision, dual, ♦ Low On-Resistance: 3Ω (typ), 5Ω (max)hig ..
MAX4622CSE+ ,Dual, 5Ω Analog SwitchesApplicationswhere current switching is required. They have lowReed Relay Replacement Military Radio ..
MAX1762EUB-MAX1791EUB
High-Efficiency, 10-Pin レMAX, Step-Down Controllers for Notebooks
General DescriptionThe MAX1762/MAX1791 PWM step-down controllers
provide high efficiency, excellent transient response,
and high DC output accuracy needed for stepping
down high-voltage batteries to generate low-voltage
CPU core, I/O, and chipset RAM supplies in notebook
computers and PDAs.
Maxim’s proprietary Quick-PWM™pulse-width modula-
tor is a free-running constant on-time type with input
feed-forward. Its high operating frequency (300kHz)
allows small external components to be utilized in PC
board area-critical applications such as subnotebook
computers and smart phones. PWM operation occurs
at heavy loads, and automatic switchover to pulse-skip-
ping operation occurs at lighter loads. The external
high-side P-channel and low-side N-channel MOSFETs
require no bootstrap components. The MAX1762/
MAX1791 are simple, easy to compensate, and do not
have the noise sensitivity of conventional fixed-frequen-
cy current-mode PWMs.
These devices achieve high efficiency at a reduced
cost by eliminating the current-sense resistor found in
traditional current-mode PWMs. Efficiency is further
enhanced by their ability to drive synchronous-rectifier
MOSFETs. The MAX1762/MAX1791 come in a 10-pin
µMAX package and offer two fixed voltages (Dual
Mode™) for each device, 1.8V/2.5V/adj (MAX1762)and
3.3V/5.0V/adj (MAX1791).
________________________ApplicationsNotebooksHandy-Terminals
SubnotebooksPDAs
Digital CamerasSmart Phones
1.8V/2.5V Logic
and I/O Supplies
FeaturesHigh Operating Frequency (300kHz)No Current-Sense ResistorAccurate Current Limit±1% Total DC Error over Line and During
Continuous ConductionDual Mode Fixed Output
1.8V/2.5V/adj (MAX1762)
3.3V/5.0V/adj (MAX1791)0.5V to 5.5V Output Adjust Range5V to 20V Input Range Automatic Light-Load Pulse Skipping OperationFree-Running On-Demand PWMFoldback Mode™UVLOPFET/NFET Synchronous Buck4.65V at 25mA Linear Regulator Output5µA Shutdown Supply Current230µA Quiescent Supply Current10-Pin µMAX Package
MAX1762/MAX1791
High-Efficiency, 10-Pin µMAX,Step-Down
Controllers for Notebooks19-1923; Rev 0; 1/01
Ordering Information
Typical Operating Circuit
Pin ConfigurationQuick-PWM, Dual Mode, and Foldback Mode are a trade-
marks of Maxim Integrated Products.
MAX1762/MAX1791
High-Efficiency, 10-Pin µMAX,Step-Down
Controllers for Notebooks
ABSOLUTE MAXIMUM RATINGSVP, SHDNto GND..................................................-0.3V to +22V
VP to VL..................................................................-0.3V to +22V
OUT, VL to GND.......................................................-0.3V to +6V
DL, FB, REF to GND....................................-0.3V to (VL + 0.3V)
DH to GND....................................................-0.3V to (VP + 0.3V)
CS to GND....................................................-2.0V to (VP + 0.3V)
REF Short Circuit to GND...........................................Continuous
Continuous Power Dissipation (TA= +70°C)
10-Pin µMAX (derate 5.6mW/°C above +70°C)...........444mW
Operating Temperature.......................................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature.........................................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
ELECTRICAL CHARACTERISTICS(VVP= 15V, VL enabled, CVL= 1µF, CREF= 0.1µF, TA
= 0 to +85°C,unless otherwise noted. Typical values are at TA= +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.
MAX1762/MAX1791
High-Efficiency, 10-Pin µMAX,Step-Down
Controllers for Notebooks
ELECTRICAL CHARACTERISTICS (continued)(VVP= 15V, VL enabled, CVL= 1µF, CREF= 0.1µF, TA
= 0 to +85°C,unless otherwise noted. Typical values are at TA= +25°C.)
MAX1762/MAX1791
High-Efficiency, 10-Pin µMAX,Step-Down
Controllers for Notebooks
ELECTRICAL CHARACTERISTICS
MAX1762/MAX1791
High-Efficiency, 10-Pin µMAX,Step-Down
Controllers for Notebooks
Note 1:Specifications to -40°C are guaranteed by design, not production tested.
Note 2:One-shot times are measured at the DH pin (VP = 15V, CDH= 400pF, 90% point to 90% point; see drawing below for
measurement details).
ELECTRICAL CHARACTERISTICS (continued)
MAX1762/MAX1791
High-Efficiency, 10-Pin µMAX,Step-Down
Controllers for Notebooks
Typical Operating Characteristics(TA = +25°C, unless otherwise noted.)
High-Efficiency, 10-Pin µMAX,Step-Down
Controllers for Notebooks
Typical Operating Characteristics (continued)(TA = +25°C, unless otherwise noted.)
MAX1762/MAX1791
High-Efficiency, 10-Pin µMAX,Step-Down
Controllers for Notebooks
Standard Application CircuitThe standard application circuit (Figure 1) generates a
low-voltage output for general-purpose use in notebook
computers (I/O supply, fixed CPU, core supply, and
DRAM supply). This DC-DC converter steps down bat-
tery voltage from 5V to 20V with high efficiency and
accuracy to a fixed voltage of 1.8V/2.5V/adj (MAX1762)
or 3.3V/5.0V/adj (MAX1791). Both the MAX1762 and
MAX1791 can be configured for adjustable output volt-
ages (VOUT > 1.25V), using a resistive voltage-divider
from VOUTto FB to adjust the output voltage (Figure 2).
Similarly, Figure 3 shows an application circuit for VOUT
< 1.25V, where a resistive voltage-divider from REF to
FB is used to set the output voltage. Figure 4 shows
how to set the regulator’s current limit with an external
sense resistor from CS to GND. Table 1 lists the com-
ponents for each application circuit, and Table 2 con-
tains contact information for the component
manufacturers.
Detailed DescriptionThe MAX1762/MAX1791 step-down controllers are tar-
geted at low-voltage chipsets and RAM power supplies
for notebook and subnotebook computers, with addi-
tional applications in digital cameras, PDAs, and
handy-terminals. Maxim’s proprietary Quick-PWM
pulse-width modulator (Figure 5) is specifically
designed for handling fast load steps while maintaining
a relatively constant operating frequency (300kHz) over
a wide range of input voltages (5V to 20V). The
MAX1762 has fixed 1.8V or 2.5V outputs, while the
MAX1791 has fixed 3.3V or 5.0V output voltages. Using
an external resistive divider, VOUTcan be set between
0.5V and 5.5V on either device. Quick-PWM architec-
ture circumvents the poor load-transient response of
fixed-frequency current-mode PWMs. This type of
design avoids the problems commonly encountered
with conventional constant-on-time and constant-off-
time PWM schemes.
MAX1762/MAX1791
High-Efficiency, 10-Pin µMAX,Step-Down
Controllers for Notebooks
MAX1762/MAX1791
High-Efficiency, 10-Pin µMAX,Step-Down
Controllers for Notebooks
