MAX1705EEE ,1- to 3-Cell / High-Current / Low-Noise / Step-Up DC-DC Converters with Linear RegulatorELECTRICAL CHARACTERISTICS(V = V = V = 3.6V, CLK/SEL = FB = LBN = LBO = ONA = ONB = TRACK = GND, RE ..
MAX1705EEE ,1- to 3-Cell / High-Current / Low-Noise / Step-Up DC-DC Converters with Linear RegulatorApplications __________Typical Operating CircuitDigital Cordless Phones PCS PhonesPersonal Communic ..
MAX1705EEE ,1- to 3-Cell / High-Current / Low-Noise / Step-Up DC-DC Converters with Linear Regulatorapplications. They use a syn-chronous rectifier pulse-width-modulation (PWM) boost' Step-Up Output ..
MAX1705EEE ,1- to 3-Cell / High-Current / Low-Noise / Step-Up DC-DC Converters with Linear RegulatorGeneral Description ________
MAX1705EEE+ ,1 to 3 Cell, High Current, Low-Noise, Step-Up DC-DC Converters with Linear RegulatorApplications __________Typical Operating CircuitDigital Cordless Phones PCS PhonesPersonal Communic ..
MAX1705EEE+T ,1 to 3 Cell, High Current, Low-Noise, Step-Up DC-DC Converters with Linear Regulatorapplications. They use a syn-chronous rectifier pulse-width-modulation (PWM) boost♦ Step-Up Output ..
MAX4524CUB+T ,Low-Voltage, Single-Supply Multiplexer and SwitchELECTRICAL CHARACTERISTICS—Single +5V Supply(V+ = 4.5V to 5.5V, GND = 0V, V = 2.4V, V = 0.8V, T = T ..
MAX4524CUB-T ,Low-Voltage, Single-Supply Multiplexer and SwitchApplicationsMAX4524EUB -40°C to +85°C 10 µMAX —Battery-Operated Equipment 10 TDFN-EP**MAX4524ETB -4 ..
MAX4524EUB ,Low-Voltage / Single-Supply Multiplexer and SwitchMAX4524/MAX452519-1332; Rev 0; 1/98Low-Voltage, Single-Supply Multiplexer and Switch ______________ ..
MAX4524EUB ,Low-Voltage / Single-Supply Multiplexer and SwitchELECTRICAL CHARACTERISTICS—Single +5V Supply(V+ = +4.5V to +5.5V, GND = 0V, V = 2.4V, V = 0.8V, T = ..
MAX4524EUB ,Low-Voltage / Single-Supply Multiplexer and SwitchELECTRICAL CHARACTERISTICS—Single +5V Supply(V+ = +4.5V to +5.5V, GND = 0V, V = 2.4V, V = 0.8V, T = ..
MAX4524EUB+ ,Low-Voltage, Single-Supply Multiplexer and SwitchFeaturesThe MAX4524/MAX4525 are low-voltage, single-supply ♦ Tiny 10-Pin TDFN PackageCMOS analog sw ..
MAX1705EEE-MAX1706EEE
1- to 3-Cell / High-Current / Low-Noise / Step-Up DC-DC Converters with Linear Regulator
_______________General DescriptionThe MAX1705/MAX1706 are high-efficiency, low-noise,
step-up DC-DC converters with an auxiliary linear-
regulator output. These devices are intended for use in
battery-powered wireless applications. They use a syn-
chronous rectifier pulse-width-modulation (PWM) boost
topology to generate 2.5V to 5.5V outputs from battery
inputs, such as 1 to 3 NiCd/NiMH cells or 1 Li-Ion cell.
The MAX1705 has an internal 1A N-channel MOSFET
switch. The MAX1706 has a 0.5A switch. Both devices
also have a built-in low-dropout linear regulator that
delivers up to 200mA.
With an internal synchronous rectifier, the MAX1705/
MAX1706 deliver 5% better efficiency than similar non-
synchronous converters. They also feature a pulse-
frequency-modulation (PFM) standby mode to improve
efficiency at light loads, and a 1µA shutdown mode. An
efficiency-enhancing track mode reduces the step-up
DC-DC converter output to 300mV above the linear-reg-
ulator output.
Both devices come in a 16-pin QSOP package, which
occupies the same space as an 8-pin SO. Other features
include two shutdown-control inputs for push-on/push-off
control, and an uncommitted comparator for use as a volt-
age monitor.
________________________ApplicationsDigital Cordless PhonesPCS Phones
Personal CommunicatorsWireless Handsets
Palmtop ComputersTwo-Way Pagers
Hand-Held Instruments
____________________________FeaturesUp to 96% Efficiency1.1VINGuaranteed Start-UpUp to 850mA Output (MAX1705)Step-Up Output (2.5V to 5.5V adjustable)Linear Regulator (1.25V to 5.0V adjustable)PWM/PFM Synchronous-Rectified Topology300kHz PWM Mode or Synchronizable1µA Shutdown ModeVoltage MonitorPushbutton On/Off Control
MAX1705/MAX1706
1- to 3-Cell, High-Current, Low-Noise,
Step-Up DC-DC Converters with Linear Regulator
__________________Pin Configuration
MAX1705/MAX1706
1- to 3-Cell, High-Current, Low-Noise,
Step-Up DC-DC Converters with Linear Regulator
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VOUT= VPOUT= VLBP= 3.6V, CLK/SEL = FB = LBN = LBO = ONA = ONB= TRACK = GND, REF = open (bypassed with 0.22µF),
LX = open, TA
= 0°C 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.
ONA, ONB, FBLDO, OUT, POUT to GND...................-0.3V to 6V
PGND to GND.....................................................................±0.3V
POUT to OUT......................................................................±0.3V
LX to PGND............................................-0.3V to (VPOUT+ 0.3V)
CLK/SEL, REF, FB, TRACK, LDO,
LBN, LBP, LBO to GND.......................-0.3V to (VOUT+ 0.3V)
LDO Short Circuit.......................................................Continuous
Continuous Power Dissipation (TA= +70°C)
QSOP (derate 8.70mW/°C above +70°C)...................696mW
Operating Temperature Range...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +160°C
Lead Temperature (soldering, 10sec).............................+300°C
MAX1705/MAX1706
1- to 3-Cell, High-Current, Low-Noise,
Step-Up DC-DC Converters with Linear Regulator
ELECTRICAL CHARACTERISTICS (continued)(VOUT= VPOUT= VLBP= 3.6V, CLK/SEL = FB = LBN = LBO = ONA = ONB= TRACK = GND, REF = open (bypassed with 0.22µF),
LX = open, TA
= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)
MAX1705/MAX1706
1- to 3-Cell, High-Current, Low-Noise,
Step-Up DC-DC Converters with Linear Regulator
ELECTRICAL CHARACTERISTICS (continued)(VOUT= VPOUT= VLBP= 3.6V, CLK/SEL = FB = LBN = LBO = ONA = ONB= TRACK = GND, REF = open (bypassed with 0.22µF),
LX = open, TA
= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)
ELECTRICAL CHARACTERISTICS(VOUT= VPOUT= VLBP= 3.6V, CLK/SEL = FB = LBN = LBO = ONA = ONB= TRACK = GND, REF = open (bypassed with 0.22µF),
LX = open, TA
= -40°C to +85°C, unless otherwise noted, Note 4.)
MAX1705/MAX1706
1- to 3-Cell, High-Current, Low-Noise,
Step-Up DC-DC Converters with Linear Regulator
ELECTRICAL CHARACTERISTICS (continued)
(VOUT= VPOUT= VLBP= 3.6V, CLK/SEL = FB = LBN = LBO = ONA = ONB= TRACK = GND, REF = open (bypassed with 0.22µF),
LX = open, TA= -40°C to +85°C, unless otherwise noted, Note 4.)
Note 1:Once the output is in regulation, the MAX1705/MAX1706 operate down to a 0.7V input voltage.
Note 2:The device is in start-up mode when VOUTis below this value (see Low-Voltage Start-Up Oscillatorsection).
Note 3:ONA and ONBinputs have a hysteresis of approximately 0.15VOUT.
Note 4:Specifications to -40°C to are guaranteed by design, not production tested.
MAX1705/MAX1706
1- to 3-Cell, High-Current, Low-Noise,
Step-Up DC-DC Converters with Linear Regulator
__________________________________________Typical Operating Characteristics
(Circuit of Figure 2, TA= +25°C, unless otherwise noted.)
MAX1705/MAX1706
1- to 3-Cell, High-Current, Low-Noise,
Step-Up DC-DC Converters with Linear Regulator
____________________________Typical Operating Characteristics (continued)
(Circuit of Figure 2, TA= +25°C, unless otherwise noted.)
1- to 3-Cell, High-Current, Low-Noise,
Step-Up DC-DC Converters with Linear Regulator
____________________________Typical Operating Characteristics (continued)
(Circuit of Figure 2, TA= +25°C, unless otherwise noted.)
MAX1705/MAX1706
1- to 3-Cell, High-Current, Low-Noise,
Step-Up DC-DC Converters with Linear Regulator
______________________________________________________________Pin Description
MAX1705/MAX1706
1- to 3-Cell, High-Current, Low-Noise,
Step-Up DC-DC Converters with Linear Regulator
_______________Detailed Description
The MAX1705/MAX1706 are designed to supply both
power and low-noise circuitry in portable RF and data-
acquisition instruments. They combine a linear regula-
tor, step-up switching regulator, N-channel power
MOSFET, P-channel synchronous rectifier, precision
reference, and low-battery comparator in a single 16-
pin QSOP package (Figure 1). The switching DC-DC
converter boosts a 1- or 2-cell input to an adjustable
output between 2.5V and 5.5V. The internal low-dropout
regulator provides linear post-regulation for noise-
sensitive circuitry, as well as outputs from 1.25V to
300mV below the switching-regulator output. The
MAX1705/MAX1706 start from a low, 1.1V input and
remain operational down to 0.7V.
These devices are optimized for use in cellular phones
and other applications requiring low noise during full-
power operation, as well as low quiescent current for
maximum battery life during standby and shutdown.
They feature constant-frequency (300kHz), low-noise
pulse-width-modulation (PWM) operation with 300mA or
730mA output capability from one or two cells, respec-
tively, with 3.3V output. A low-quiescent-current stand-
by pulse-frequency-modulation (PFM) mode offers an
output up to 60mA and 140µA, respectively, and
reduces quiescent power consumption to 500µW. In
shutdown mode, the quiescent current is further
reduced to just 1µA. Figure 2 shows the standard appli-
cation circuit for the MAX1705 configured in high-
power PWM mode.
Additional features include synchronous rectification for
high efficiency and improved battery life, and an
uncommitted comparator for low-battery detection. A
CLK/SEL input allows frequency synchronization to
reduce interference. Dual shutdown controls allow shut-
down using a momentary pushbutton switch and micro-
processor control.
Figure 1. Functional Diagram
