MAX849ESE ,1-Cell to 3-Cell / High-Power / Low-Noise / Step-Up DC-DC ConvertersMAX848/MAX84919-1095; Rev 2; 12/971-Cell to 3-Cell, High-Power,Low-Noise, Step-Up DC-DC Converters
MAX8505EEE ,3A, 1MHz, 1% Accurate, Internal Switch Step-Down Regulator with Power-OKfeatures 1% accurate output over load,line, and temperature variations. Adjustable soft-start is♦ F ..
MAX8505EEE+ ,3A, 1MHz, 1% Accurate, Internal Switch Step-Down Regulator with Power-OKfeatures current-limit, short-circuit, andthermal-overload protection and enables a ruggeddesign. O ..
MAX8505EEE+T ,3A, 1MHz, 1% Accurate, Internal Switch Step-Down Regulator with Power-OKMAX85056mPmOxS19-2992; Rev 1; 9/103A, 1MHz, 1% Accurate, Internal Switch Step-Down Regulator with P ..
MAX8507ETE ,PWM Step-Down DC-DC Converters with 75m? Bypass FET for WCDMA and cdmaOne HandsetsELECTRICAL CHARACTERISTICS(V = V = 3.6V, SHDN = SKIP = BATT, HP = GND, V = 1.932V (MAX8506), V = 1. ..
MAX850ESA ,Low-Noise / Regulated / Negative Charge-Pump Power Supplies for GaAsFET Bias
MB81C81A-35 ,CMOS 256K-BIT HIGH-SPEED SRAMMay 1990 00
Edition1.0 FUJITSU
M38 1 C8 1A-25/-35
CMOS 256K-BI T HIGH-SPEED SRAM
256K Words ..
MB81F643242C-10FN ,4 x 512K x 32 bit synchronous dynamic RAMFUJITSU SEMICONDUCTORADVANCED INFO. AE0.1EDATA SHEETMEMORYCMOS4 · 512 K · 32 BITSYNCHRONOUS DYNAMIC ..
MB81F643242C-10FN ,4 x 512K x 32 bit synchronous dynamic RAMfeatures a fully synchronous operation referenced to a positive edge clock whereby all operations a ..
MB81N643289-60FN ,8 x 256K x 32 bit double data rate FCRAMapplications where large memory density and high effective bandwidth arerequired and where a simple ..
MB8264A-10 , MOS 65536-BIT DYNAMIC RANDOM ACCESS MEMORY
MB8264A-10 , MOS 65536-BIT DYNAMIC RANDOM ACCESS MEMORY
MAX848ESE-MAX849ESE
1-Cell to 3-Cell / High-Power / Low-Noise / Step-Up DC-DC Converters
General DescriptionThe MAX848/MAX849 boost converters set a new stan-
dard of high efficiency and high integration for noise-
sensitive power-supply applications, such as portable
phones and small systems with RF data links. The heart
of the these devices is a synchronous boost-topology
regulator that generates a fixed 3.3V output (or 2.7V to
5.5V adjustable output) from one to three NiCd/NiMH
cells or one Li-Ion cell.
Synchronous rectification provides a 5% efficiency
improvement over similar nonsynchronous boost regu-
lators. In standby mode, pulse-skipping PFM operation
keeps the output voltage alive with only 150µW quies-
cent power consumption. Fixed-frequency PWM opera-
tion ensures that the switching noise spectrum is limited
to the 300kHz fundamental and its harmonics, allowing
easy post-filtering noise reduction. For even tighter
noise spectrum control, synchronize to a 200kHz to
400kHz external clock.
Battery monitoring is provided by a two-channel, volt-
age-to-frequency analog-to-digital converter (ADC).
One channel is intended for a single-cell battery input
(0.625V to 1.875V range), while the other channel is for
monitoring higher voltages (0V to 2.5V range).
Two control inputs are provided for push-on, push-off
control via a momentary pushbutton switch. Upon
power-up, an internal comparator monitors the output
voltage to generate a power-good output (POK).
The devices differ only in the current limit of the
N-channel MOSFET power switch: 0.8A for the
MAX848, and 1.4A for the MAX849.
FeaturesUp to 95% Efficiency
(see Typical Output Selector Guidebelow)3.3V Dual Mode™or 2.7V to 5.5V Adj. Output0.7V to 5.5V Input Range0.15mW Standby Mode300kHz PWM Mode or SynchronizableTwo-Channel ADC with Serial OutputPower-Good Function
ApplicationsDigital Cordless PhonesPCS Phones
Cellular PhonesHand-Held Instruments
Palmtop ComputersPersonal Communicators
Local 3.3V to 5V Supplies
MAX848/MAX849
1-Cell to 3-Cell, High-Power,
Low-Noise, Step-Up DC-DC Converters
Typical Operating Circuit19-1095; Rev 2; 12/97
Pin Configuration appears at end of data sheet.Dual Mode is a trademark of Maxim Integrated Products.
ypical Output Selector Guide
MAX848/MAX849
1-Cell to 3-Cell, High-Power,
Low-Noise, Step-Up DC-DC Converters
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VOUT= 3.6V, GND = PGND = CLK/SEL = ON1 = ON2= AINSEL = AIN1 = AIN2 = FB = POKIN, POUT = OUT, TA= 0°C to +85°C,
unless otherwise noted.)
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.
ON1, ON2, OUT, POUT to GND..................................-0.3V, +6V
PGND to GND..........................................................-0.3V, +0.3V
LX to PGND...............................................-0.3V, (VPOUT+ 0.3V)
CLK/SEL, DATA, POKIN, REF,
AINSEL, AIN1, AIN2, FB, POK to GND.....-0.3V, (VOUT+ 0.3V)
Continuous Power Dissipation (TA= +70°C)
Narrow SO (derate 8.7mW/°C above +70°C)................696mW
Operating Temperature Range
MAX848ESE/MAX849ESE.................................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature.........................................-65°C to +160°C
Lead Temperature (soldering, 10sec).............................+300°C
MAX848/MAX849
1-Cell to 3-Cell, High-Power,
Low-Noise, Step-Up DC-DC Converters
ELECTRICAL CHARACTERISTICS (continued)
(VOUT= 3.6V, GND = PGND = CLK/SEL = ON1 = ON2= AINSEL = AIN1 = AIN2 = FB = POKIN, POUT = OUT, TA= 0°C to +85°C,
unless otherwise noted.)
MAX848/MAX849
1-Cell to 3-Cell, High-Power,
Low-Noise, Step-Up DC-DC Converters
ELECTRICAL CHARACTERISTICS
(VOUT= 3.6V, GND = PGND = CLK/SEL = ON1 = ON2= AINSEL = AIN1 = AIN2 = FB = POKIN, POUT = OUT, TA= -40°C to +85°C,
unless otherwise noted.) (Note 9)
Note 1:Minimum operating voltage. Because the MAX848/MAX849 are bootstrapped to the output, it will operate down to a 0.7V input.
Note 2:In low-power mode (CLK/SEL = GND), the output voltage regulates 1% higher than in low-noise mode (CLK/SEL = OUT or
synchronized).
Note 3:The part is in start-up mode until it reaches this voltage level. Do not apply full-load current.
Note 4:Load regulation is measured from no load to full load, where full load is determined by the N-channel switch current limit.
Note 5:Start-up is tested with Figure 2’s circuit. Output current is measured when the input and output voltages are applied.
Note 6:Supply current from the 3.34V output is measured between the 3.34V output and the OUT pin. This current correlates directly
with actual battery supply current, but is reduced in value according to the step-up ratio and efficiency. VOUT= 3.6V to keep
the internal switch open when measuring the current into the device.
Note 7:When VCLK/SEL= 0V, the inductor is forced into constant-peak-current, discontinuous operation. This is guaranteed by
testing in Figure 2’s circuit.
Note 8:ON1 and ON2inputs have approximately 0.15VOUT hysteresis.
Note 9:Specifications to -40°C are guaranteed by design, not production tested.
MAX848/MAX849
1-Cell to 3-Cell, High-Power,
Low-Noise, Step-Up DC-DC Converters
Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
MAX848/MAX849
1-Cell to 3-Cell, High-Power,
Low-Noise, Step-Up DC-DC Converters
Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
MAX848/MAX849
1-Cell to 3-Cell, High-Power,
Low-Noise, Step-Up DC-DC Converters
Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
MAX848/MAX849
1-Cell to 3-Cell, High-Power,
Low-Noise, Step-Up DC-DC Converters
Pin Description
