MAX848ESE+T ,1-Cell-to-3-Cell, High-Power, Low-Noise, Step-Up DC-DC ConvertersApplicationstion ensures that the switching noise spectrum is limitedto the 300kHz fundamental and ..
MAX848ESE-T ,1-Cell-to-3-Cell, High-Power, Low-Noise, Step-Up DC-DC ConvertersFeaturesThe MAX848/MAX849 boost converters set a new stan- ♦ Up to 95% Efficiencydard of high effic ..
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 ..
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+-MAX848ESE+T-MAX848ESE-T
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.
aturesUp 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
-Cell to 3-Cell, High-Power,
Low-Noise, Step-Up DC-DC ConvertersAIN1
AIN2
AINSEL
DATA
ON1
ON2
CLK/SEL
POKIN
OUT
POUT
POK
MAX848
MAX849OUTPUTA/D CHANNEL 1 IN
A/D CHANNEL 2 IN
A/D CHANNEL SELECT
A/D OUTPUT
ON/OFF CONTROL
SYNC INPUT
INPUT
0.8V TO 5.5V
VOLTAGE MONITOR
OUTPUT
REFGNDPGND
Typical Operating Circuit19-1095; Rev 2; 12/97
PART
MAX848ESE
MAX849ESE-40°C to +85°C
-40°C to +85°C
TEMP. RANGEPIN-PACKAGE16 Narrow SO
16 Narrow SO
Ordering Information
Pin Configuration appears at end of data sheet.Dual Mode is a trademark of Maxim Integrated Products.
Typical Output Selector Guide
VIN
(V)
VOUT
(V)
MAX849 IOUT
(mA)
MAX848 IOUT
(mA)3.651000300
-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
300VIN= 1.2V
VOUT= 5V
130Output Current
VIN= 2.4V
IREF= 0mA
150VIN= 2.7V
Operating Current in Shutdown
kHz40300Frequency in Start-Up Mode0.91.1Minimum Start-Up Voltage (Note 5)-1.6
(Note 3)
Load Regulation (Note 4)1.231.251.27Reference Output Voltage
Current into OUT pin, VON2= 3.6V0.7
VOUT= 1.5V
Minimum Operating Voltage (Note 1)2.12.4
VFB= 1.25V
Output Voltage Lockout Range2.75.5
Adjustable output, CLK/SEL = OUT
Output Voltage Adjust Range200
-1μA < IREF< 50μA
FB Input Current1.2151.2401.265
2.5V < VOUT< 5V
FB Regulation Voltage515REF Load Regulation0.25
ILOAD< 1mA, TA> +25°C
REF Supply Rejection
VFB< 0.1V, CLK/SEL = OUTV3.173.343.40
CLK/SEL = OUT
Output Voltage (Note 2)
UNITSMINTYPMAXPARAMETERMAX848
MAX849
MAX848
MAX849
MAX848
MAX849
MAX848
MAX849
MAX848
MAX849
MAX848
MAX849
CONDITIONSVOUT= 3.3V
VOUT= 5V
VOUT= 3.3V
MAX849, VIN= 3.6V
VOUT= 5V
VOUT= 3.3V
VOUT= 5V
MAX848, VIN= 3.3V
DC-DC CONVERTER
REFERENCE
-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.)
Input Low Voltage1.2V < VOUT< 5.5V, ON1 and ON2(Note 8)0.2VOUT
Accuracy
Current into OUT pin, CLK/SEL = GND
VOUT= 2.7V, AINSEL and CLK/SEL
fCLK= 400kHz, 5ms conversion,
monotonic to 8 bits±4% FSR
0.2VOUT
Internal Trip Level
Rising VOUT, VPOKIN< 0.1V2.953.10V
External Trip Level
Input High Voltage
Rising VPOKIN1.2251.27512fCLK= 400kHz, VAIN1= VAIN2= 2.5VAIN1, AIN2 Input Current02.5AINSEL = OUTAIN2 Input Voltage Range0.6251.875AINSEL = GNDAIN1 Input Voltage RangeVOUT- 0.4
Data Output Voltage High0.4
ISOURCE= 1mA
Data Output Voltage LowISINK= 1mA
POK Low Voltage
1.2V < VOUT< 5.5V, ON1 and ON2(Note 8)
ISINK= 1mA, VOUT= 3.6V or
ISINK= 20μA, VOUT= 1V0.4V
POK High Leakage Current
0.8VOUT
VOUT= VPOK= 5.5V0.011μA
POKIN Leakage Current
VPOKIN= 1.5V50nA90
VOUT= 5.5V, AINSEL and CLK/SEL0.8VOUT
Operating Current in Low-Power
Mode (Note 6)
Logic Input Current ON1, ON2, AINSEL and CLK/SEL1μA
Internal Oscillator FrequencyCLK/SEL = OUT260300340kHz
Oscillator Maximum Duty Cycle808590%
External Clock Frequency Range200400kHz
CLK/SEL Pulse WidthNot tested200ns
CLK/SEL Rise/Fall TimeNot tested100ns
Current into OUT pin, CLK/SEL = OUT,
does not include switching lossesμA150300
UNITSMINTYPMAXCONDITIONSPARAMETEROperating Current in Low-Noise
Mode (Note 6)
VLX= 0V, VON2= VOUT= 5.5VμA0.120POUT Leakage Current
VLX= VON2= VOUT= 5.5VμA0.120LX Leakage Current
N-channel0.30.6CLK/SEL = GND
0.130.25CLK/SEL = OUT
P-channel
Switch On-Resistance
CLK/SEL = OUT
6008001000MAX848CLK/SEL = OUT110013501600MAX849
120200300MAX848VCLK/SEL= 0V (Note 7)
N-Channel Current Limit
MAX849
DC-DC SWITCHES
ADC
POWER-GOOD
LOGIC AND CONTROL INPUTS
-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.8090Oscillator Maximum Duty Cycle
kHz260340CLK/SEL = OUTInternal Oscillator Frequency1.2251.275Rising VPOKINExternal Trip Level2.953.10Rising VOUT, VPOKIN< 0.1VInternal Trip Level
% FSR±4fCLK= 400kHz, 5ms conversionAccuracy
250550MAX849CLK/SEL = GND (Note 7)
N-Channel Current Limit120300MAX848
PARAMETERCONDITIONSMINTYPMAXUNITS11001800MAX849CLK/SEL = OUT
6001100MAX848
0.5CLK/SEL = OUTP-channel
Switch On-Resistance0.25CLK/SEL = OUTN-channel
IREF= 0mAReference Output Voltage1.2251.275V
Output Voltage (Note 3)VFB< 0.1V, CLK/SEL = OUT,
includes load-regulation error 3.133.47V
FB Regulation VoltageAdjustable output, CLK/SEL = OUT1.211.27V
Output Voltage Lockout Range(Note 3)2.052.45V
0.6CLK/SEL = GND300CLK/SEL = OUT, does not include
switching losses
OUT Supply Current in Low-Noise
Mode (Note 6)90CLK/SEL = GNDOUT Supply Current in Low-Power
Mode (Note 6)
OUT Supply Current in ShutdownVON2= 3.6V20μA
REFERENCE
DC-DC CONVERTER
DC-DC SWITCHES
ADC
POWER-GOOD
LOGIC CONTROL INPUTS
-Cell to 3-Cell, High-Power,Low-Noise, Step-Up DC-DC Converters
Typical Operating Characteristics(TA = +25°C, unless otherwise noted.)
MAX849
EFFICIENCY vs. LOAD CURRENT
(VOUT = 3.3V)
848/9 TOC-01
LOAD CURRENT (mA)
(%
VIN = 2.4V
PFM
PWM
VIN = 0.9V
VIN = 1.2V
MAX849
EFFICIENCY vs. LOAD CURRENT
(VOUT = 5V)
848/9 TOC-02
LOAD CURRENT (mA)
(%
VIN = 1.2V
VIN = 2.4V
VIN = 3.6V
PFM
PWM
MAX848
EFFICIENCY vs. LOAD CURRENT
(VOUT = 3.3V)
848/9 TOC-03
LOAD CURRENT (mA)
(%
VIN = 2.4V
VIN = 1.2V
VIN = 0.9V
PFM
PWM23146
NO-LOAD BATTERY CURRENT
vs. INPUT VOLTAGEAX848/9 TOC
INPUT VOLTAGE (V)
(m
TA = +85°C
TA = +25°C
TA = -40°C
REFERENCE VOLTAGE
vs. TEMPERATURE
AX848/9 TOC
TEMPERATURE (°C)
(V
SHUTDOWN CURRENT
vs. INPUT VOLTAGE
AX848/9 TOC
(m
TA = +85°C
TA = +25°C
TA = -40°C
INCLUDES ALL EXTERNAL
COMPONENT LEAKAGES.
CAPACITOR LEAKAGE
DOMINATES AT
TA = +85°C
INPUT VOLTAGE (V)
START-UP VOLTAGE vs. LOAD CURRENT
(VOUT = 3.3V, PWM MODE)
AX848/9 TO
C-06
LOAD CURRENT (mA)
(V
TA = +85°C
TA = +25°C
TA = -40°C
REFERENCE VOLTAGE
vs. REFERENCE CURRENT
848/9 TO
C-08
REFERENCE CURRENT (mA)
(V
ADC LINEARITY ERROR
vs. FULL-SCALE INPUT VOLTAGE
848/9 TO
C-09
FULL-SCALE INPUT VOLTAGE (V)
(%
AIN1
AIN2
-Cell to 3-Cell, High-Power,Low-Noise, Step-Up DC-DC Converters
Typical Operating Characteristics (continued)(TA = +25°C, unless otherwise noted.)
VIN = 1.1V, IOUT = 200mA, VOUT = 3.3V
A = LX VOLTAGE, 2V/div
B = INDUCTOR CURRENT, 0.5A/div
C = VOUT RIPPLE, 50mV/div, AC COUPLED
HEAVY-LOAD SWITCHING WAVEFORMS
(VOUT = 3.3V)VOUTs/div
MAX848/9 TOC-10
VIN = 1.1V, VOUT = 3.3V
A = LOAD CURRENT, 0mA TO 200mA, 0.2A/div
B = VOUT RIPPLE, 50mV/div, AC COUPLED
LOAD-TRANSIENT RESPONSE200mA
2ms/div
MAX848/9 TOC-12
IOUT = 0mA, VOUT = 3.3V
A = VIN, 1.1V TO 2.1V, 1V/div
B = VOUT RIPPLE, 50mV/div, AC COUPLED
LINE-TRANSIENT RESPONSE5ms/div
MAX848/9 TOC-11
A = VON1, 2V/div
B = VOUT, 1V/div
C = INPUT CURRENT, 0.2A/div
POWER-ON DELAY
(PFM MODE)0mA
3.3V
5ms/div
MAX848/9 TOC-13
-Cell to 3-Cell, High-Power,Low-Noise, Step-Up DC-DC Converters
Typical Operating Characteristics (continued)(TA = +25°C, unless otherwise noted.)
VIN = 3.6V, VOUT = 5V, COUT = 440mF
A = VOUT RIPPLE, 200mV/div, AC COUPLED
B = LOAD CURRENT, 100mA TO 1A, 0.5A/div,
PULSE WIDTH = 577ms
MAX849
GSM LOAD-TRANSIENT RESPONSE1ms/div
MAX848/9 TOC-14
VIN = 1.2V, VOUT = 3.3V, COUT = 440mF
A = VOUT RIPPLE, 200mV/div, AC COUPLED
B = LOAD CURRENT, 50mA TO 400mA, 0.2A/div,
PULSE WIDTH = 416ms
MAX849
DECT LOAD-TRANSIENT RESPONSE3.3V
2ms/div
MAX848/9 TOC-15
0.1k1k10k100k1M
MAX849 NOISE SPECTRUM
(VOUT = 3.3V, VIN = 1.2V, RLOAD = 50W)AX848/9 TO
C-16
FREQUENCY (Hz)
(m
MAX849 INTERNAL OSCILLATOR
FREQUENCY vs. TEMPERATURE
848/9 TO
C-17
TEMPERATURE (°C)
. F
(kH
VOUT = 5V
VOUT = 3.3V
MAX849 PEAK INDUCTOR CURRENT
vs. OUTPUT VOLTAGE
848/9 TO
C-18
OUTPUT VOLTAGE (V)
IN
(A
1.5
-Cell to 3-Cell, High-Power,Low-Noise, Step-Up DC-DC Converters
Pin DescriptionADC’s Input Channel Selector. Pull low to select AIN1 and drive high to select AIN2.AINSEL9
ADC’s Serial Output. Pulsed output, RZ format. Full scale is fOSC/2 (fCLK/2in external sync mode). The
DATA output is low when VCLK/SEL= 0V (PFM mode).DATA10
External Clock Input/Regulator’s Switching Mode Selector.
CLK/SEL = low: low-power, low-quiescent PFM mode. Delivers 100mW of output power.
CLK/SEL = high: low-noise, high-power PWM mode, switching at a constant frequency (300kHz).
CLK/SEL = driven with external clock: low-noise, high-power, synchronized PWM mode. The internal
oscillator is synchronized to the external clock (200kHz ~ 400kHz). Turning the DC-DC converter on with
VCLK/SEL= 0V also serves as a soft-start function, since the peak inductor current is limited to 30% of the
nominal value.
CLK/SEL11
Source of the Internal N-Channel Power MOSFET. Connect to high-current ground path.PGND12
Drain of the Internal N-Channel Power MOSFET and P-Channel Synchronous RectifierLX13
Output Sense Input. The IC is powered from OUT. Bypass to GND with a 0.1μF ceramic capacitor. Connect
OUT to POUT through a 10Ωseries resistor.OUT5
Power-Good Comparator Input. Connect to GND for fixed threshold (VOUTx 0.9). To adjust the threshold,
connect to a resistor divider from OUT to GND.POKIN6
Dual Mode DC-DC Converter Feedback Input. Connect to GND for fixed 3.3V output voltage. Connect to
a resistor divider from OUT to GND to adjust the output voltage. Minimize noise coupling from switching
signals to FB.7
Power-Good Output. This open-drain output is pulled low when the output voltage (VOUT) drops below
the internally set threshold (fixed threshold), or when the voltage at POKIN drops below VREF(adjustable
threshold).
POK8
Ground. Use for low-current ground paths. Connect to PGND with a short trace.GND4
Reference Output. Bypass with a 0.22μF capacitor to GND.REF3
PINADC’s Channel 2 Input. Analog input voltage range is 0V to 2.5V.AIN22
ADC’s Channel 1 Input. Analog input voltage range is 0.625V to 1.875V.AIN11
FUNCTIONNAMEPOUTSource of the Internal P-Channel Synchronous Rectifier MOSFET. Connect an external Schottky diode from
LX to POUT. Bypass to PGND with a 0.1μF ceramic capacitor as close to the IC as possible.ON2OFF Control Input. When ON1 = 0 and ON2= 1, the IC is off.ON1ON Control Input. When ON1 = 1 or ON2= 0, the IC is on.
