MAX1705 Fast Delivery |IC PHOENIX CO.,LIMITED

MAX1705 ,1 to 3 Cell, High Current, Low-Noise, Step-Up DC-DC Converters with Linear RegulatorApplications __________Typical Operating CircuitDigital Cordless Phones PCS PhonesPersonal Communic ..
MAX17058G+T10 ,1-Cell/2-Cell Li+ ModelGauge ICsFeatures and BenefitsThe MAX17058/MAX17059 ICs are tiny fuel gauges S MAX17058: 1 Cell, MAX17059: 2 ..
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 ________
MAX4524CUB ,Low-Voltage / Single-Supply Multiplexer and SwitchMAX4524/MAX452519-1332; Rev 0; 1/98Low-Voltage, Single-Supply Multiplexer and Switch ______________ ..
MAX4524CUB+ ,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 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 = ..

MAX1705
1 to 3 Cell, High Current, Low-Noise, Step-Up DC-DC Converters with Linear Regulator
General Description
The 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.
________________________Applications
Digital Cordless PhonesPCS Phones
Personal CommunicatorsWireless Handsets
Palmtop ComputersTwo-Way Pagers
Handheld Instruments
FeaturesUp to 96% Efficiency1.1VINGuaranteed StartupUp 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
LBPPOUT
ONA
ONB
PGND
CLK/SEL
LBO
LDO
TOP VIEW
MAX1705
MAX1706
QSOP
LBN
REF
OUT
TRACK
GND
FBLDO
Pin Configuration
POUT
OUT
STEP-UP OUTPUT
CLK/SEL
ONA
ONB
TRACK
INPUT 0.7V TO 5.5V
PGNDGND
LDO
FBLDO
LBP
LBO
LBN
REF
MAX1705
MAX1706
LINEAR
REGULATOR
OUTPUT
LOW-BATTERY
DETECTION
ON/OFF CONTROL
HIGH
EFFICIENCY
LOW
NOISE
__________Typical Operating Circuit
19-1198; Rev 1; 8/00
PART
MAX1705C/D
MAX1705EEE
MAX1706C/D0°C to +70°C
-40°C to +85°C
0°C to +70°C
TEMP RANGEPIN-PACKAGE
Dice*
16 QSOP
Dice*
EVALUATION KIT AVAILABLE
Ordering Information
*Dice are tested at TA= +25°C, DC parameters only.
MAX1706EEE-40°C to +85°C16 QSOP
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, 10s).................................+300°C
CLK/SEL = OUT
-1µA < IREF< 50µA
(Note 1)
IREF= 0µA
CLK/SEL = GND, VFB= VFBLDO= 1.5V,
no load
ONA = GND, ONB= OUT, measure IOUT
(Note 2)
VPOUT= VOUT= 1.5V
VFB= 1.5V
MAX1705, 0A ≤ILX≤0.5A;
MAX1706, 0A ≤ILX≤0.25A;
CLK/SEL = OUT
TRACK = VLDO> 2.3V
CLK/SEL = OUT
CONDITIONS415Reference Load Regulation1.2381.2501.262Reference Output Voltage180360
IOUTSupply Current in
Low-Noise Mode1.2191.2331.247FB Regulation Voltage0.7Minimum Operating Battery
Voltage100190IOUTSupply Current in
Low-Power Mode120IOUTSupply Current in Shutdown2.002.152.30Startup to Normal Mode
Transition Voltage
kHz40150300fLXFrequency in Startup Mode0.0150FB Input Current2.55.5OUT Adjust Range0.651.25Load RegulationVLDOVLDO VLDO
+ 0.2+ 0.3 + 0.4OUT Voltage in Track Mode
UNITSMINTYPMAXSYMBOLPARAMETER= +25°C, ILOAD< 1mA, Figure 2V0.91.1Minimum Startup Voltage
2.5V < VOUT< 5.5VmV0.25Reference Supply Regulation
DC-DC CONVERTER
REFERENCE
VFB= VFBLDO= 1.5V, no load
FB = GND (LX switching)2.1mA
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.)
f = 300kHz
VOUT= 5.5V, CLK/SEL, TRACK
VLBO= VOUT= 5V
ISINK= 1mA, VOUT= 2.5V, LBP = GND,
LBN = OUT
1.2V < VOUT< 5.5V, ONA, ONB(Note 3)
VOUT= 2.5V, CLK/SEL, TRACK
VLBN= VLBP= 1V
VLBN= 0.5V and 1.5V (at least one input must
be within this range)
Hysteresis approximately 10°C
LBP falling
1.2V < VOUT< 5.5V, ONA, ONB(Note 3)
LBP rising
CONDITIONS1Input Leakage Current
(CLK/SEL, ONA, ONB, TRACK)
0.8VOUTV0.8VOUTInput High Level
0.2VOUTV0.2VOUTInput Low Level38AC Power-Supply Rejection1LBO High Leakage0.4LBO Output Low Voltage0.0150LBN, LBP Input Current0.51.5LBN, LBP Common-Mode
Input Range155Thermal Shutdown-5+5LBN, LBP Offset16LBN, LBP Hysteresis
UNITSMINTYPMAXSYMBOLPARAMETER2070120p-Channel Synchronous-
Rectifier Turn-Off Current
VLX= 0V, VONB= VOUT= 5.0VµA0.120POUT Leakage Current
CLK/SEL = GND
CLK/SEL = GND250435550
CLK/SEL = OUT
ILIMn-Channel MOSFET
Current Limit
MAX1705
MAX1705
MAX1706
MAX1706250435550
FBLDO = LDO, ILOAD= 1mAV1.2381.2501.262FBLDO Regulation Voltage
VFBLDO= 1.5VnA0.0150FBLDO Input Current
FBLDO = GNDmA220300500Short-Circuit Current Limit
VFBLDO= 1V, ILDO= 200mAΩ0.51.2Dropout Resistance
100µA < ILDO< 200mA, FBLDO = LDO%0.41.2Load Regulation
2.5V < VOUT< 5.5V, FBLDO = LDO,
ILDO= 1mA%0.10.5Line Regulation
p-channel, ILX= 100mA 0.270.50
n-channel, ILX= 100mAΩ
Switch On-Resistance0.160.28
CLK/SEL = GND
CLK/SEL = OUT
VLX= VONB= VOUT= 5.0VµA0.120LX Leakage Current1.255.0LDO Adjust Range
CONTROL INPUTS
LOW-BATTERY COMPARATOR
LINEAR REGULATOR
DC-DC SWITCHES
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)
noted. (Note 4) LX = open, TA= -40°C to +85°C, unless otherwise noted. (Note 4)
PARAMETERSYMBOLMINTYPMAXUNITS
Minimum CLK/SEL Pulse
Internal Oscillator Frequency260300340kHz
200ns
Maximum CLK/SEL
Rise/Fall Time100ns
CONDITIONS
CLK/SEL = OUT
Supply Current in
Low-Power ModeIOUT190µACLK/SEL = 0V, FB = FBLDO = 1.5V, no load
Supply Current in ShutdownIOUT20µAONA = 0V, ONB= OUT, measure IOUT
OUT Voltage in Track ModeVLDO+ VLDO+
0.20.4VTRACK = OUT, VLDO> 2.3V
250570MAX1706
MAX1706
CLK/SEL = OUT
CLK/SEL = 0V
MAX1705
CLK/SEL = OUT
CLK/SEL = 0V
MAX1705
Switch On-Resistance
0.45n-channel, ILX= 100mA
550950n-Channel MOSFET
Current LimitILIM
CLK/SEL = OUT
CLK/SEL = 0V
p-channel, ILX= 100mA
PARAMETERSYMBOLMINTYPMAX
p-Channel Synchronous-
Rectifier Turn-Off Current
UNITSCONDITIONS120mA
Startup to Normal Mode
Transition Voltage2.02.3V
FB Regulation Voltage1.215 1.251VCLK/SEL = OUT
Reference Output Voltage1.2351.265VIREF= 0µA
Oscillator Maximum Duty Cycle808690%
External Oscillator
Synchronization Range200400kHz
Supply Current in
Low-Noise ModeIOUT360µACLK/SEL = OUT, VFB = VFBLDO= 1.5V,
no load
DC-DC CONVERTER
REFERENCE
DC-DC CONVERTER
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.)
PARAMETERSYMBOLMINTYPMAXUNITS
LBN, LBP Common-Mode
Input Range0.51.5V
CONDITIONS
LBN = 0.5V and 1.5V (at least one input must
be within this range)
LBO High Leakage1µALBO = OUT = 5V
Input Low Level0.15VOUTV1.2V < VOUT< 5.5V, ONA, ONB(Note 2)
0.85VOUT1.2V < VOUT< 5.5V, ONA, ONB(Note 2)
Internal Oscillator Frequency260340kHzCLK/SEL = OUT
External Oscillator
Synchronization Range200400kHz
0.85VOUTVOUT= 5.5V, CLK/SEL, TRACK
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 startup mode when VOUTis below this value (see Low-Voltage Startup 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.
Input High Level
VOUT= 2.5V, CLK/SEL, TRACK0.15VOUT
LBN, LBP Offset-5+5mVLBP falling
FBLDORegulation Voltage1.2331.268VFBLDO = LDO, ILOAD= 1mA
Short-Circuit Current Limit220600mAFBLDO = LDO = GND
FBLDOInput Current0.0150nAVFBLDO= 1.5V
Dropout Resistance1.2ΩVFBLDO= 1V, ILDO= 200mA
LINEAR REGULATOR
CONTROL INPUTS
LOW-BATTERY COMPARATOR
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
EFFICIENCY vs. OUTPUT CURRENT
(VOUT = 5V)
MAX1705/6 TOC02
OUTPUT CURRENT (mA)
EFFICIENCY (%)40
L = 10μH
VOUT = 5V
A: VIN = 0.9V
C: VIN = 2.4V
E: VIN = 3.6V
1: PFM MODE
2: PWM MODE
A.1
A.2
C.1
C.2B.2B.1
MAX1705
EFFICIENCY vs. OUTPUT CURRENT
(VOUT = 3.3V)
MAX1705/6 TOC01
OUTPUT CURRENT (mA)
EFFICIENCY (%)40
L = 10μH
VOUT = 3.3V
A: VIN = 0.9V
B: VIN = 2.7V
1: PFM MODE
2: PWM MODE
B.1
B.2A.1
A.2
MAX1705
MAXIMUM OUTPUT CURRENT
vs. INPUT VOLTAGE
MAX1705/6 TOC03
INPUT VOLTAGE (V)
MAXIMUM OUTPUT CURRENT (mA)
L = 10μH
PWM MODE
PFM MODE
VOUT = 3.3V
VOUT = 3.3V
VOUT = 5V
VOUT = 5V
MAX1706
EFFICIENCY vs. OUTPUT CURRENT
(VOUT = 3.3V)
MAX1705/6 TOC04
OUTPUT CURRENT (mA)
EFFICIENCY (%)40
B.2
A.2
A.1
B.1
L = 22μH
VOUT = 3.3V
A: VIN = 0.9V
B: VIN = 2.7V
1: PFM MODE
2: PWM MODE
MAX1705
STARTUP INPUT VOLTAGE
vs. OUTPUT CURRENT
MAX1705/6 TOC07
STARTUP INPUT VOLTAGE (V)
NO-LOAD STARTUP:
1.0V AT -40°C
0.79 AT +25°C
0.64V AT +85°C
CONSTANT-CURRENT LOAD
VOUT = 3.3V
L = 10μH
D1 = MBR0520L
TA = -40°C
TA = +25°C
TA = +85°C
MAX1706
EFFICIENCY vs. OUTPUT CURRENT
(VOUT = 5V)
MAX1705/6 TOC05
OUTPUT CURRENT (mA)
EFFICIENCY (%)40
A.1A.2
C.2B.2
C.1
B.1
L = 22μH
VOUT = 5V
A:VIN = 0.9V
B: VIN = 2.4V
C: VIN = 3.6V
1: PFM MODE
2: PWM MODE0
MAX1706
MAXIMUM OUTPUT CURRENT
vs. INPUT VOLTAGE
MAX1705/6 TOC06
INPUT VOLTAGE (V)
MAXIMUM OUTPUT CURRENT (mA)
PWM MODE
L = 22μH
PFM MODE
VOUT = 5V
VOUT = 5V
VOUT = 3.3V
VOUT = 3.3V
NO-LOAD SUPPLY CURRENT
vs. INPUT VOLTAGE
MAX1705/6 TOC8
NO-LOAD SUPPLY CURRENT (mA)
PFM MODE
PWM MODE
VOUT = 3.3V
L = 10μH
LINEAR-REGULATOR DROPOUT
VOLTAGE vs. LOAD CURRENT
MAX1705/6 TOC09
DROPOUT VOLTAGE (mV)
VLDO = 3.3V
VLDO = 2.5V
VLDO = 5V
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.)
10010k100k1M1k10M
LINEAR-REGULATOR POWER-SUPPLY
REJECTION RATIO vs. FREQUENCY
MAX1705/6 TOC10
FREQUENCY (Hz)
PSRR (dB)
VOUT = 4V TO 5V
VLDO = 3.3V
ILDO = 200mA
C5 = 0.33μF
LINEAR-REGULATOR
REGION OF STABLE C6 ESR
vs. LOAD CURRENT
MAX1705/6 TOC11
LOAD CURRENT (mA)
C6 ESR (
STABLE REGION
C2 = 22pF (FEED FORWARD)
UNCOMPENSATED
C6 = 22μF10k100k1M10M
MAX1705
NOISE SPECTRUM AT POUT
(VOUT = 4.5V, VIN = 1.2V, 200mA LOAD)
MAX1705/6 TOC13
FREQUENCY (Hz)
NOISE (5mV
RMS/
div)10k100k1M10M
MAX1705
LINEAR-REGULATOR OUTPUT NOISE SPECTRUM
(VLDO = 3.3V, VOUT = 4.5V, VIN = 1.2V, ILDO = 200mA)
MAX1705/6 TOC14
NOISE (50
V/div)
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.)
200μs/div
MAX1705
LINE-TRANSIENT RESPONSE
MAX1705/6 TOC15
IOUT = 0mA, VOUT = 3.3V
A = VIN, 1.5V TO 2.0V, 200mV/div
B = VOUT, 10mV/div, 3.3V DC OFFSET
2ms
MAX1705
POWER-ON DELAY
(PWM MODE)
MAX1705/6 TOC17
VIN = 1.2V, LOAD = 1kΩ, ONB TIED TO OUT
A = ONA, 2V/div
B = VLDO, 2V/div
C = VOUT, 2V/div
D = INDUCTOR CURRENT, 500mA/div
2.5V
3.3V
0mA
1μs/div
MAX1705
PWM SWITCHING WAVEFORMS
MAX1705/6 TOC18
VIN = 1.2V, VOUT = 4.5V, VLDO = 3.3V, ILDO = 200mA
A = INDUCTOR CURRENT, 500mA/div
B = LX VOLTAGE, 5V/div
C = VOUT RIPPLE, 50m/div AC-COUPLED
D = VLDO RIPPLE, 5m/div AC-COUPLED
C5 = 0.33μF
VOUT
VLDO
2μs/div
MAX1705
PFM SWITCHING WAVEFORMS
MAX1705/6 TOC19
VIN = 1.2V, VOUT = 4.5V, VLDO = 3.3V, ILDO = 40mA
A = INDUCTOR CURRENT, 500mA/div
B = LX VOLTAGE, 5V/div
C = VOUT RIPPLE, 50mV/div AC-COUPLED
D = VLDO RIPPLE, 5mV/div AC-COUPLED
C5 = 0.33μF
0mA
VOUT
VLDO
1ms/div
MAX1705
LINEAR-REGULATOR
OUTPUT NOISE
MAX1705/6 TOC20
VLDO IS AC-COUPLED, 1mv/div
ILDO = 200mA
C5 = 0.33μF
VLDO
DC TO 500kHz
200μs/div
MAX1705
LOAD-TRANSIENT RESPONSE
MAX1705/6 TOC16
VIN = 1.2V, VOUT = 3.3V
A = VOUT, 50mV/div, 3.3V DC OFFSET
B = IOUT, 0mA TO 200mA, 200mA/div
MAX1705/MAX1706
1- to 3-Cell, High-Current, Low-Noise,
Step-Up DC-DC Converters with Linear Regulator
Pin Description
Boost DC-DC Converter Power Output. POUT is the source of the p-channel synchronous-rectifier MOSFET
switch. Connect an external Schottky diode from LX to POUT. The output current available from POUT is
reduced by the current drawn from the LDO linear-regulator output.
POUT16
On-Control Input. When ONA = high or ONB= low, the IC turns on. Connect ONA to OUT for normal
operation (Table 2).ONA15
Off-Control Input. When ONB= high and ONA = low, the IC is off. Connect ONBto GND for normal
operation (Table 2).ONB14
Inductor Connection to the Drains of the p-Channel Synchronous Rectifier and n-Channel SwitchLX13
Power Ground for the Source of the n-channel power MOSFET switchPGND12
Low-Dropout Linear-Regulator Output. LDO sources up to 200mA. Bypass to GND with a 22µF capacitor.LDO9
Low-Battery Comparator Output. This open-drain, n-channel output is low when LBP < LBN.
Input hysteresis is 16mV.LBO10
Switching-Mode Selection and External-Clock Synchronization Input:CLK/SEL = low: low-power, low-quiescent-current PFM mode.CLK/SEL = high: low-noise, high-power PWM mode. Switches at a constant frequency (300kHz). Full
output power is available.CLK/SEL = driven with an external clock: low-noise, high-power synchronized PWM mode.
Synchronizes to an external clock (from 200kHz to 400kHz).
Turning on the DC-DC converter with CLK/SEL = GND also serves as a soft-start function,
since peak inductor current is reduced.
CLK/SEL11
GroundGND5
Step-Up Converter Feedback Input, Used During Track Mode. IC power and low-dropout linear-regulator
input. Bypass OUT to GND with a 0.1µF ceramic capacitor placed as close to the IC as possible.OUT6
Step-Up DC-DC Converter Feedback Input. Connect FB to a resistor voltage-divider between POUT and
GND to set the output voltage between 2.5V and 5.5V. FB regulates to 1.233V.FB7
Low-Dropout Linear-Regulator Feedback Input. Connect FBLDO to a resistor voltage-divider between LDO
to GND to set the output voltage from 1.25V to VOUT- 0.3V (5.0V max). FBLDO regulates to 1.250V.FBLDO8
Track-Mode Control Input for DC-DC Converter. In track mode, the boost-converter output is sensed at
OUT and set 0.3V above LDO to improve efficiency. Set TRACK to OUT for track mode. Connect TRACK to
GND for normal operation.
TRACK4
1.250V Reference Output. Bypass REF with a 0.33µF capacitor to GND. REF can source up to 50µA.REF3
PIN
Low-Battery Comparator Inverting Input. Common-mode range is 0.5V to 1.5V.LBN2
Low-Battery Comparator Noninverting Input. Common-mode range is 0.5V to 1.5V.LBP1
FUNCTIONNAME

Partno	Mfg	Dc	Qty	Available	Descript
MAX1705		N/a	15	avai	1 to 3 Cell, High Current, Low-Noise, Step-Up DC-DC Converters with Linear Regulator