MAX1763EEE+ ,1.5A, Low-Noise, 1MHz, Step-Up DC-DC Converterapplicationsthat require constant-frequency operation at all load Digital Cordless Hand-Heldcurrent ..
MAX1765EEE ,800mA, Low-Noise, Step-Up DC-DC Converter with 500mA Linear RegulatorApplicationslimit functions to permit optimization of efficiency, exter-Wireless Handsets Personaln ..
MAX1765EEE+ ,800mA, Low-Noise, Step-Up DC-DC Converter with 500mA Linear RegulatorApplicationslimit functions to permit optimization of efficiency, exter-Wireless Handsets Personaln ..
MAX1765EUE+T ,800mA, Low-Noise, Step-Up DC-DC Converter with 500mA Linear RegulatorELECTRICAL CHARACTERISTICS(V = V = V = V = V = 3.6V, CLK/SEL = FBL = ONB = TRACK = PGND = GND, ISET ..
MAX176ACPA ,Serial-Output, 250Ksps 12-Bit ADC with T/H and RefernceELECTRICAL CHARACTERISTICS
(VDD = +5V i5%_ Vss = -11 4V to -IS75V, fCLK = 4MHE for MAX176_C/E an ..
MAX176ACPA+ ,Serial Output, 250ksps, 12-Bit ADC with Track/Hold and ReferenceGeneral Description
The MAX176 is a complete analog-to-digital converter
(ADC) that achieves a ..
MAX4590CAE+ ,1.25Ω, Dual SPST, CMOS Analog SwitchesMAX4580/MAX4590/MAX460019-1394; Rev 1; 6/031.25Ω, Dual SPST,CMOS Analog Switches
MAX4590EAE ,1.25 / Dual SPST / CMOS Analog Switchesapplications and arethe preferred solution over mechanical relays in automat- ' Rail-to-Rail Signal ..
MAX4590EAE+ ,1.25Ω, Dual SPST, CMOS Analog SwitchesELECTRICAL CHARACTERISTICS–Dual Supplies(V+ = +15V, V- = -15V, V = +5V, V = +2.4V, V = +0.8V, T = T ..
MAX4590EWE ,1.25 / Dual SPST / CMOS Analog SwitchesMAX4580/MAX4590/MAX460019-1394; Rev 0; 10/981.25Ω, Dual SPST,CMOS Analog Switches
MAX4591CPE ,High-Speed / Single-Supply / Quad / SPST Analog SwitchesApplicationsMAX4591CUE 0°C to +70°C 16 TSSOPMAX4591CSE 0°C to +70°C 16 Narrow SOTest Equipment Samp ..
MAX4591CSE ,High-Speed / Single-Supply / Quad / SPST Analog SwitchesELECTRICAL CHARACTERISTICS—Single +12V Supply(V+ = +12V, V- = GND = 0, V = 5V, V = 0.8V, T = T to T ..
MAX1763EEE+
1.5A, Low-Noise, 1MHz, Step-Up DC-DC Converter
General DescriptionThe MAX1763 is a high-efficiency, low-noise, step-up
DC-DC converter intended for use in battery-powered
wireless applications. This device maintains exception-
ally low quiescent supply current (110µA) despite its
high 1MHz operating frequency. Small external compo-
nents and a tiny package make this device an excellent
choice for small hand-held applications that require the
longest possible battery life.
The MAX1763 uses a synchronous-rectified pulse-
width-modulation (PWM) boost topology to generate
2.5V to 5.5V outputs from a wide range of input
sources, such as one to three alkaline or NiCd/NiMH
cells or a single Lithium-ion (Li+) cell. Maxim's propri-
etary Idle Mode™ circuitry significantly improves effi-
ciency at light load currents while smoothly transitioning
to fixed-frequency PWM operation at higher load cur-
rents to maintain excellent full-load efficiency. Low-
noise, forced-PWM mode is available for applications
that require constant-frequency operation at all load
currents. The MAX1763 may also be synchronized to
an external clock to protect sensitive frequency bands
in communications equipment.
The MAX1763 includes an on-chip linear gain block
that can be used to build a high-power external linear
regulator or as a low-battery comparator. Soft-start and
current limit functions permit optimization of efficiency,
external component size, and output voltage ripple.
The MAX1763 is available in a space-saving 16-pin
QSOP package or a high-power (1.5W) 16-pin TSSOP-
EP package.
FeaturesUp to 94% Efficiency+0.7V to +5.5V Input Voltage Range1.1V Guaranteed Startup Input VoltageUp to 1.5A OutputFixed 3.3V Output or Adjustable (2.5V to 5.5V)1MHz PWM Synchronous-Rectified Topology1µA Logic-Controlled ShutdownAnalog Gain Block for Linear-Regulator or Low-
Battery ComparatorAdjustable Current Limit and Soft-Start1.5W TSSOP Package Available
MAX1763
1.5A, Low-Noise, 1MHz, Step-Up
DC-DC Converter
Pin Configuration19-1698; Rev 2; 4/11
Ordering Information+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad
Idle Mode is a trademark of Maxim Integrated Products.
PARTTEMP RANGEPIN-PACKAGE
MAX1763EEE+-40°C to +85°C16 QSOP
MAX1763EUE+-40°C to +85°C16 TSSOP-EP*
Digital Cordless
Phones
PCS Phones
Wireless Handsets
Hand-Held
Instruments
Palmtop Computers
Personal
Communicators
Typical Operating CircuitOFF
PWM
OFFONONB
ONA
POUT
OUT
CLK/SEL
GNDPGNDFB
ISET
REF
MAX1763
OR NORMAL
AINLBI OR GAIN
BLOCK INPUT
1.5μHIN
0.7V TO 5.5V
LBO OR
GAIN BLOCK OUTPUT
OUT
3.3V AT 1.5A
________________________ApplicationsONAONB
POUT
POUT
PGND
PGND
CLK/SEL
TOP VIEW
MAX1763
QSOP
TSSOP-EPISET
REF
OUT
GND
AIN
EVALUATION KIT
AVAILABLE
MAX1763
1.5A, Low-Noise, 1MHz, Step-Up
DC-DC Converter
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(CLK/SEL = ONB= FB = PGND = GND, ISET = REF, OUT = POUT, VONA= VAIN= VOUT= 3.6V, TA
= 0°C to +85°C, unless other-wise 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.
ONA, ONB, AO, OUT to GND.......................................0.3V, +6V
PGND to GND.....................................................................±0.3V
LX to PGND............................................-0.3V to (VPOUT+ 0.3V)
CLK/SEL, REF, FB, ISET, POUT,
AIN to GND.........................................-0.3V to (VOUT+ 0.3V)
POUT to OUT......................................................................±0.3V
Continuous Power Dissipation
16-Pin QSOP (derate 8.7mW/°C above +70°C)...........667mW
16-Pin TSSOP-EP (derate 19mW/°C above +70°C)...........1.5W
Operating Temperature Range...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
Soldering Temperature (reflow).......................................+260°C
PARAMETERCONDITIONSMINTYPMAXUNITS
DC-DC CONVERTERInput Voltage Range (Note 1)0.75.5V
Minimum Startup Voltage
(Note 2)ILOAD < 1mA, TA = +25°C0.91.1V
Temperature Coefficient of
Startup VoltageILOAD < 1mA-2mV/°C
Frequency in Startup ModeVOUT = 1.5V1255001000kHz
Internal Oscillator FrequencyCLK/SEL = OUT0.811.2MHz
Oscillator Maximum Duty Cycle
(Note 3)808690%
External Clock Frequency Range0.51.2MHz
Output VoltageVFB < 0.1V, CLK/SEL = OUT, includes load regulation
for 0 < ILX < 1.1A3.173.33.38V
FB Regulation VoltageAdjustable output, CLK/SEL = OUT, includes load
regulation for 0 < ILX < 1.1A1.2151.2451.270V
FB Input CurrentVFB = 1.35V0.01100nA
Load RegulationCLK/SEL = OUT, 0 < ILX < 1.1A-1.0%
Output Voltage Adjust Range2.55.5V
Output Voltage Lockout
Threshold (Note 4)Rising edge2.002.152.30V
ISET Input Leakage CurrentVISET = 1.25V0.0150nA
Supply Current in ShutdownV ONB = 3.6V, VONA = 0V110µA
No-Load Supply Current, Low-
Power Mode (Note 5)CLK/SEL = GND, AIN = OUT110200µA
No-Load Supply Current, Low-
Noise ModeCLK/SEL = OUT2.5mA
Gain Block Supply CurrentVAIN < (VOUT - 1.4V), gain block enabled2550µA
MAX1763
1.5A, Low-Noise, 1MHz, Step-Up
DC-DC Converter
ELECTRICAL CHARACTERISTICS (continued)(CLK/SEL = ONB= FB = PGND = GND, ISET = REF, OUT = POUT, VONA= VAIN= VOUT= 3.6V, TA
= 0°C to +85°C, unless other-wise noted. Typical values are at TA= +25°C.)
PARAMETERCONDITIONSMINTYPMAXUNITS
DC-DC SWITCHESPOUT Leakage CurrentVLX = 0V, VOUT = 5.5V0.110µA
LX Leakage CurrentVLX = V ONB = VOUT = 5.5V, VONA = 0V0.110µA
N channel0.0750.13Switch On-ResistanceP channel0.130.25Ω
N-Channel Current Limit2.02.53.4A
P-Channel Turn-Off CurrentCLK/SEL = GND10120240mA
REFERENCEReference Output VoltageIREF = 0A1.2301.2501.270V
Reference Load Regulation-1µA < IREF < 50µA515mV
Reference Supply Rejection2.5V < VOUT < 5V0.25mV
GAIN BLOCKAIN Reference VoltageIAO = 20µA910938970mV
AIN Input CurrentVAIN = 1.5V±0.01±30nA
TransconductanceVAO = 1V, 10µA < IAO < 100µA51016mS
AO Output Low VoltageVAIN = 0.5V, IAO = 100µA0.10.4V
AO Output High LeakageVAIN = 1.5V, VAO = 5.5V0.011µA
Gain-Block Enable Threshold
(VOUT - VAIN) (Note 6)1.4V
Gain-Block Disable Threshold
(VOUT - VAIN) (Note 6)0.2V
LOGIC INPUTSCLK/SEL Input Low Level2.5V ≤ VOUT ≤ 5.5V(0.2)
VOUTV
CLK/SEL Input High Level2.5 V ≤ VOUT ≤ 5.5V(0.8)
VOUTV
1.1 V ≤ VOUT ≤ 1.8V0.2ONA and ONB Input Low Level
(Note 7)1.8 V ≤ VOUT ≤ 5.5V0.4V
1.1 V ≤ VOUT ≤ 1.8VVOUT
- 0.2VONA and ONB Input High Level
(Note 7)
1.8 V ≤ VOUT ≤ 5.5V1.6
Input Leakage CurrentCLK/SEL, ONA, ONB0.011µA
Minimum CLK/SEL Pulse Width100ns
Maximum CLK/SEL
Rise/Fall Time100ns
MAX1763
1.5A, Low-Noise, 1MHz, Step-Up
DC-DC Converter
ELECTRICAL CHARACTERISTICS(CLK/SEL = ONB= FB = PGND = GND, ISET = REF, OUT = POUT, VONA= VAIN= VOUT= 3.6V, TA
= -40°C to +85°C, unless other-wise noted.) (Note 8)
PARAMETERCONDITIONSMINMAXUNITS
DC-DC CONVERTERInput Voltage Range (Note 1)5.5Vi ni m um S tartup V ol tag e ( N ote 2) ILOAD < 1mA, TA = +25°C1.1V
Frequency in Startup ModeVOUT = 1.5V1251000kHz
Internal Oscillator FrequencyCLK/SEL = OUT0.751.25MHz
Oscillator Maximum Duty Cycle
(Note 3)8091%xter nal C l ock Fr eq uency Rang e0.61.2MHz
Output VoltageVFB < 0.1V, CLK/SEL = OUT, includes load regulation
for 0 < ILX < 1.1A3.173.38V
FB Regulation VoltageAdjustable output, CLK/SEL = OUT, includes load
regulation for 0 < ILX < 1.1A
1.2151.270V
FB Input CurrentVFB = 1.35V100nA
Output Voltage Adjust Range2.55.5V
Output Voltage Lockout
Threshold (Note 4)Rising edge2.002.30V
ISET Input Leakage CurrentVISET = 1.25V50nA
Supply Current in ShutdownV ONB = 3.6V, VONA = 0V10µA
No-Load Supply Current, Low-
Power Mode (Note 5)CLK/SEL = GND, AIN = OUT200µA
Gain Block Supply CurrentVAIN < (VOUT - 1.4V), gain block enabled50µA
DC-DC SWITCHESPOUT Leakage CurrentVLX = 0V, VOUT = 5.5V10µA
LX Leakage CurrentVLX = V ONB = VOUT = 5.5V, VONA = 0V10µA
N-channel0.13Switch On-ResistanceP-channel0.25Ω
N-Channel Current Limit2.03.4A
P-Channel Turn-Off CurrentCLK/SEL = GND10240mA
REFERENCEReference Output VoltageIREF = 0A1.2201.270V
Reference Load Regulation-1µA < IREF < 50µA15mV
Reference Supply Rejection2.5V < VOUT < 5V5mV
GAIN BLOCKAIN Reference VoltageIAO = 20µA910970mV
AIN Input CurrentVAIN = 1.5V±30nA
TransconductanceVAO = 1V, 10µA < IAO < 100µA516mS
AO Output Low VoltageVAIN = 0.5V, IAO = 100µA0.4V
AO Output High LeakageVAIN = 1.5V, VAO = 5.5V1µA
MAX1763
1.5A, Low-Noise, 1MHz, Step-Up
DC-DC Converter
ELECTRICAL CHARACTERISTICS (continued)(CLK/SEL = ONB= FB = PGND = GND, ISET = REF, OUT = POUT, VONA= VAIN= VOUT= 3.6V, TA
= -40°C to +85°C, unless other-wise noted.) (Note 8)
PARAMETERCONDITIONSMINMAXUNITS
LOGIC INPUTSGain-Block Enable Threshold
(VOUT - VAIN) (Note 6)1.4V
Gain-Block Disable Threshold
(VOUT - VAIN) (Note 6)0.2V
CLK/SEL Input Low Level2.5 V ≤ VOUT ≤ 5.5V(0.2)
VOUTV
CLK/SEL Input High Level2.5 V ≤ VOUT ≤ 5.5V(0.8)
VOUTV
1.1 V ≤ VOUT ≤ 1.8V0.2ONA and ONB Input Low Level
(Note 7)1.8 V ≤ VOUT ≤ 5.5V0.4V
1.1 V ≤ VOUT ≤ 1.8VVOUT
- 0.2VONA and ONB Input High Level
(Note 7)1.8V ≤ VOUT ≤ 5.5V1.6
Input Leakage CurrentCLK/SEL, ONA, ONB1µA
Note 1:Operating voltage. Because the regulator is bootstrapped to the output, once started, the MAX1763 will operate down to
0.7V input. For conditions where VINmight exceed the set VOUT, or where VOUTis set above 4V, an external Schottky diode
must be connected from LX to POUT.
Note 2:Startup is tested with the circuit of Figure 2.
Note 3:Defines low-noise mode maximum step-up ratio.
Note 4:The regulator is in startup mode until this voltage is reached. Do not apply full load current until the output exceeds 2.3V.
Note 5:Supply current from the 3.3V output is measured between the 3.3V output and the OUT pin. This current correlates directly
to the actual battery-supply current, but is reduced in value according to the step-up ratio and efficiency. The gain block is
disabled.
Note 6:Connect AIN to OUT to disable gain block.
Note 7:ONA and ONBhave hysteresis of approximately 0.15 ✕VOUT.
Note 8:Specifications to -40°C are guaranteed by design and not production tested.
MAX1763
1.5A, Low-Noise, 1MHz, Step-Up
DC-DC Converter
Typical Operating Characteristics(Circuit of Figure 2, VIN = +3.6V, VOUT = +5V, TA = +25°C, unless otherwise noted.)
EFFICIENCY vs. OUTPUT CURRENT
(VOUT = 3.3V)
MAX1763 toc01
OUTPUT CURRENT (A)
EFFICIENCY (%)40B
A: VIN = 2.4V
B: VIN = 1.2V
C: VIN = 0.9V
= NORMAL MODE
= FPWM MODE
EFFICIENCY vs. OUTPUT CURRENT
(VOUT = 5V)
MAX1763 toc02
OUTPUT CURRENT (A)
EFFICIENCY (%)40A
A: VIN = 3.6V
B: VIN = 2.4V
C: VIN = 1.2V
= NORMAL MODE
= FPWM MODE
MAXIMUM OUTPUT CURRENT
vs. INPUT VOLTAGE
MAX1763 toc03
INPUT VOLTAGE (V)
OUTPUT CURRENT (A)
VOUT = 3.3V
VOUT = 5V
NO-LOAD INPUT
vs. INPUT VOLTAGE
MAX1763 toc04
INPUT VOLTAGE (V)
INPUT CURRENT (A)
= INPUT VOLTAGE INCREASING
= INPUT VOLTAGE DECREASING
INPUT VOLTAGE (V)
SHUTDOWN CURRENT (
SHUTDOWN CURRENT
vs. INPUT VOLTAGE35
MAX1763 toc05
INTERNAL OSCILLATOR FREQUENCY
vs. TEMPERATURE
MAX1763 toc06
TEMPERATURE (°C)
FREQUENCY (MHz)
VIN = 3.6V, VOUT = 5V
VIN = 2.4V, VOUT = 3.3V
STARTUP VOLTAGE
vs. OUTPUT CURRENT
MAX1763 toc07
OUTPUT CURRENT (A)
STARTUP VOLTAGE (V)
PEAK INDUCTOR CURRENT vs. VISET
MAX1763 toc08
ISET VOLTAGE (V)
PEAK INDUCTOR CURRENT (A)
HEAVY-LOAD SWITCHING WAVEFORMSMAX1763 toc09
400ns/div
VIN = 2.4V, VOUT = 3.3V, IOUT = 1.5A
A: INDUCTOR CURRENT, 500mA/div
B: VLX, 2V/div
MAX1763
1.5A, Low-Noise, 1MHz, Step-Up
DC-DC Converter
LIGHT-LOAD SWITCHING WAVEFORMSMAX1763 toc10
200ns/div
VIN = 1.1V, VOUT = 3.3V, IOUT = 20mA
A: LX NODE, 5V/div
B: INDUCTOR CURRENT, 0.1A/div, AC COUPLED
C: OUTPUT RIPPLE, 0.1V/div, AC COUPLED
LOAD-TRANSIENT RESPONSEMAX1763 toc11
100μs/div
VIN = 2.4V, VOUT = 3.3V, IOUT = 0.2A TO 1.35A
A: IOUT, 0.5A/div
B: VOUT, 100mV/div, AC-COUPLED
LINE-TRANSIENT RESPONSEMAX1763 toc12
40μs/div
VIN = 2.4V TO 1.4V, IOUT = 70mA
A: VIN, 1V/div
B: VOUT, 5mV/div, AC-COUPLED
POWER-ON DELAYMAX1763 toc13
100μs/div
ONA
5V/div
IIN
0.5A/div
VOUT
2V/div
IL = 10mA
STARTUP WAVEFORMS
NO SOFT-STARTMAX1763 toc14
2ms/div
VIN = 1.2V, VOUT = 3.3V, RLOAD = 3kΩ
VOUT
2V/div
ONA
5V/div
IIN
1A/div
STARTUP WAVEFORMS
USING SOFT-STARTMAX1763 toc15
2ms/div
VIN = 1.2V, VOUT = 3.3V, RSS = 510kΩ, CSS = 0.1μF, RLOAD = 3kΩ
VOUT
2V/div
ONA
5V/div
IIN
1A/div
NOISE SPECTRUM
MAX1763 toc16
FREQUENCY (MHz)
NOISE (mV
RMS
VIN = 2.4V
VOUT = 3.3V
ypical Operating Characteristics (continued)(Circuit of Figure 2, VIN = +3.6V, VOUT = +5V, TA = +25°C, unless otherwise noted.)
MAX1763
Detailed DescriptionThe MAX1763 is a highly-efficient, low-noise power
supply for portable RF and hand-held instruments. It
combines a boost switching regulator, N-channel
power MOSFET, P-channel synchronous rectifier, preci-
sion reference, shutdown control, and a versatile gain
block (Figure 1).
The DC-DC converter boosts a one-cell to three-cell bat-
tery voltage input to a fixed 3.3V or adjustable voltage
required for output voltages greater than 4V. The
MAX1763 guarantees startup with an input voltage as
low as 1.1V and remains operational down to an input of
just 0.7V. It is optimized for use in cellular phones and
other applications requiring low noise and low quiescent
current for maximum battery life. It features constant-fre-
quency (1MHz), low-noise PWM operation with up to
1.5A output capability. A CLK input allows frequency
synchronization to control the output noise spectrum.
See Table 1 for typical available output current.
1.5A, Low-Noise, 1MHz, Step-Up
DC-DC Converter
Pin Description
PINNAMEFUNCTIONONAOn Control Input. When ONA = high or ONB = low, the IC turns on. Connect ONA to OUT for normal
operation (Table 3).ISET
N-Channel Current Limit Control. For maximum current limit, connect to REF. To reduce current,
supply a voltage between REF and GND by means of a resistive voltage-divider. If soft-start is
desired, connect a capacitor from ISET to GND. When ONA = low and ONB = high, or VREF < 80% of
nominal value, an on-chip switched resistor (100kΩ typ) discharges this pin to GND.REF1.250V Voltage Reference Bypass Pin. Connect a 0.22µF ceramic bypass capacitor to GND. Up to
50µA of external REF load current is allowed.GNDGround. Connect to PGND with short trace.
5FB
DC-DC Converter Feedback Input. To set fixed output voltage of +3.3V, connect FB to ground. For
adjustable output of 2.5V to 5.5V, connect to a resistive divider placed from OUT to GND. FB set
point is 1.245V (Figure 6).OUTIC Power, Supplied from the Output. Bypass to GND with a 1.0µF ceramic capacitor, and connect to
POUT with a series 4.7Ω resistor (Figure 2).AIN
Gain-Block Input. The nominal transconductance from AIN to AO is 10mS. An external P-channel
pass device can be used to build a linear regulator. The gain block can also be used as a low-battery
comparator with a threshold of 0.938V. The gain block and its associated quiescent current are
disabled by connecting AIN to OUT.
8AOGain-Block Output. This open-drain N-channel output sinks current when VAIN < (0.75)(VREF). AO is
high-Z when the device is shut down, or when AIN = OUT.CLK/SEL
Clock Input for the DC-DC Converter. Also serves to program the operating mode of the switcher as
follows:
CLK/SEL = LO: Normal; operates at a fixed frequency, automatically switching to low-power mode ifload is minimized.
CLK/SEL = HI: Forced PWM mode; operates in low-noise, constant-frequency mode at all loads.
CLK/SEL = Clocked: Forced PWM mode with the internal oscillator synchronized to CLK in 500kHzto 1200kHz range.
10, 12PGNDSource of N-Channel Power MOSFET Switch. Connect both PGND pins together close to the device.
11, 14LXInductor Connection. Connect the LX pins together close to the device.
13, 15POUTPower Output. P-channel synchronous rectifier source.ONBOff Control Input. When ONB = high and ONA = low, the IC is off. Connect ONB to GND for normal
operation (Table 3).EPExposed Pad (TSSOP Only). Connect EP to a large ground plane to maximize thermal performance.
In its normal mode of operation (CLK/SEL = low), the
MAX1763 offers fixed-frequency PWM operation through
most of its load range. At light loads (less than 25% of full
load), the device automatically optimizes efficiency by
switching only as needed to supply the load. Shutdown
reduces quiescent current to just 1µA. Figure 2 shows
the standard application circuit for the MAX1763. (An
external Schottky diode is needed for output voltages
greater than 4V, or to assist low-voltage startup.)
Additional features include synchronous rectification for
high efficiency and increased battery life, and a gain
block that can be used to build a linear regulator using
block can also function as a voltage-monitoring com-
parator. The MAX1763 is available in a 16-pin QSOP
package or a 1.5W 16-pin TSSOP-EP package for high-
temperature or high-dissipation applications.
MAX1763
1.5A, Low-Noise, 1MHz, Step-Up
DC-DC Converter Figure 1. Functional Diagram
Figure 2. PFM/PWM Automode Connection
GAIN
BLOCK
AIN
2.15V
IC POWER
1.25V
DUAL
MODE/
REFERENCE
UNDERVOLTAGE LOCKOUT
STARTUP
OSCILLATOR
1MHz
OSCILLATOR
CONTROLLERD
POUT
PGND
OSC
MODEQREF
ISET
GND
CLK/SELRDY
REF
0.938V
ONB
ONA
OUT
MAX1763
ISET
GNDPGND
POUT
OUT
AIN
MBR0520L
VIN
0.7V TO 5.5V
2 x 100µF
OUT
3.3V
1.5µHREF
CLK/SEL
ONA
ONB
ISET
0.22µF
1.0µF
NOTE: HEAVY LINES INDICATE HIGH-CURRENT PATHS. 4.7ΩMAX1763
47µF
Table 1. Typical Available Output Current
NUMBER
OF CELLS
INPUT
VOLTAGE
(V)
OUTPUT
VOLTAGE
(V)
OUTPUT
CURRENT
(mA)1 NiCd/NiMH1.23.3675
2 NiCd/NiMH
1 Li+2.7 (min)3.31300
1 Li+2.7 (min)5.01100
3 NiCd/NiMH3.65.01600
