MAX1759EUB ,Buck/Boost Regulating Charge Pump in レMAXFeaturesThe MAX1759 is a buck/boost regulating charge pump Regulated Output Voltage (Fixed 3.3V or ..
MAX1759EUB+ ,Buck/Boost Regulating Charge Pump in µMAXFeaturesThe MAX1759 is a buck/boost regulating charge pump♦ Regulated Output Voltage (Fixed 3.3V or ..
MAX1759EUB+T ,Buck/Boost Regulating Charge Pump in µMAXApplications MAX1759EUB -40°C to +85°C 10 µMAXMiniature EquipmentBackup Battery Boost ConvertersTra ..
MAX1760EUB ,0.8A, Low-Noise, 1MHz, Step-Up DC-DC ConverterELECTRICAL CHARACTERISTICS(CLK/SEL = ON = FB = PGND = GND, ISET = REF, OUT = POUT, V = 3.6V, T = 0° ..
MAX1760EUB ,0.8A, Low-Noise, 1MHz, Step-Up DC-DC ConverterApplicationsDigital Cordless Phones PCS PhonesWireless Handsets Hand-Held InstrumentsPalmtop Comput ..
MAX1760EUB ,0.8A, Low-Noise, 1MHz, Step-Up DC-DC Converterapplications requiring PWM Synchronous Rectified Topologythe longest possible battery life. Low- ..
MAX4583CUE ,Low-Voltage, CMOS Analog Multiplexers/SwitchesELECTRICAL CHARACTERISTICS—Dual Supplies(V = 4.5V to 5.5V, V = -4.5V to -5.5V, V = 2.4V, V = 0.8V, ..
MAX4583CUE+ ,Low-Voltage, CMOS Analog Multiplexers/SwitchesFeatures♦ MAX4582 Available in AEC-Q100 QualifiedThe MAX4581/MAX4582/MAX4583 are low-voltage,Versio ..
MAX4583EEE ,Low-voltage, CMOS analog switch (three SPDT switches).Applications♦ +2V to +12V Single-Supply OperationBattery-Operated Equipment±2V to ±6V Dual-Supply O ..
MAX4583EEE ,Low-voltage, CMOS analog switch (three SPDT switches).FeaturesThe MAX4581/MAX4582/MAX4583 are low-voltage, ♦ Pin Compatible with Industry-Standard CMOS a ..
MAX4583EEE+ ,Low-Voltage, CMOS Analog Multiplexers/SwitchesMAX4581/MAX4582/MAX458319-1328; Rev 6; 3/12Low-Voltage, CMOS AnalogMultiplexers/Switches___________ ..
MAX4583EPE ,Low-voltage, CMOS analog switch (three SPDT switches).ELECTRICAL CHARACTERISTICS—Dual Supplies(V = 4.5V to 5.5V, V = -4.5V to -5.5V, V = 2.4V, V = 0.8V, ..
MAX1759EUB
Buck/Boost Regulating Charge Pump in レMAX
General DescriptionThe MAX1759 is a buck/boost regulating charge pump
that generates a regulated output voltage from a single
lithium-ion (Li+) cell, or two or three NiMH or alkaline
cells for small hand-held portable equipment. The
MAX1759 operates over a wide +1.6V to +5.5V input
voltage range and generates a fixed 3.3V or adjustable
(2.5V to 5.5V) output (Dual Mode™). Maxim’s unique
charge-pump architecture allows the input voltage to be
higher or lower than the regulated output voltage.
Despite its high 1.5MHz operating frequency, the
MAX1759 maintains low 50µA quiescent supply current.
Designed to be an extremely compact buck/boost con-
verter, this device requires only three small ceramic
capacitors to build a complete DC-DC converter capa-
ble of generating a guaranteed 100mA (min) output
current from a +2.5V input. For added flexibility, the
MAX1759 also includes an open-drain power-OK
(POK) output that signals when the output voltage is in
regulation.
The MAX1759 is available in a space-saving 10-pin
µMAX package that is 1.09mm high and half the size of
an 8-pin SO.
ApplicationsLi+ Battery-Powered Applications
Miniature Equipment
Backup Battery Boost Converters
Translators
FeaturesRegulated Output Voltage (Fixed 3.3V or
Adjustable 2.5V to 5.5V)100mA Guaranteed Output Current +1.6V to +5.5V Input Voltage RangeLow 50µA Quiescent Supply Current1µA Shutdown ModeLoad Disconnected from Input in ShutdownHigh 1.5MHz Operating FrequencyUses Small Ceramic CapacitorsShort-Circuit Protection and Thermal ShutdownSmall 10-Pin µMAX Package
MAX1759
Buck/Boost Regulating
Charge Pump in µMAX
Typical Operating Circuit19-1600; Rev 0; 1/00
Pin Configuration
Ordering InformationDual Mode is a trademark of Maxim Integrated Products.
MAX1759
Buck/Boost Regulating
Charge Pump in µMAX
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(Circuit of Figure 1, VIN= VSHDN= 2V, FB = PGND = GND, CIN= 10µF, CX= 0.33µF, COUT= 10µF, TA
= 0°C to +85°C, unless oth-erwise 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.
IN, OUT, FB, POK, SHDNto GND............................-0.3V to +6V
PGND to GND.....................................................................±0.3V
CXN to GND................................................-0.3V to (VIN+ 0.3V)
CXP to GND..............................................-0.3V to (VOUT+ 0.3V)
OUT Short to GND.........................................................Indefinite
Continuous Power Dissipation (TA= +70°C)
10-Pin µMAX (derate 5.6mW/°C above +70°C).........444mW
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
MAX1759
Buck/Boost Regulating
Charge Pump in µMAX
ELECTRICAL CHARACTERISTICS(Circuit of Figure 1, VIN= VSHDN= 2V, FB = PGND = GND, CIN= 10µF, CX= 0.33µF, COUT= 10µF, TA
= -40°C to +85°C, unless oth-erwisenoted.) (Note 1)
Note 1:Specifications to -40°C are guaranteed by design and are not production tested.
MAX1759
Buck/Boost Regulating
Charge Pump in µMAX
Typical Operating Characteristics(Circuit of Figure 1, CIN= 10µF, CX= 0.33µF, COUT= 10µF, VOUT= 3.3V, VIN= 2.5V, TA= +25°C, unless otherwise noted.)
MAX1759
Buck/Boost Regulating
Charge Pump in µMAX
Typical Operating Characteristics (continued)(Circuit of Figure 1, CIN= 10µF, CX= 0.33µF, COUT= 10µF, VOUT= 3.3V, VIN= 2.5V, TA= +25°C, unless otherwise noted.)
Pin Description
MAX1759
Buck/Boost Regulating
Charge Pump in µMAX
Detailed Description The MAX1759’s unique charge-pump architecture
allows the input voltage to be higher or lower than the
regulated output voltage. Internal circuitry senses VIN
and VOUTand determines whether VINmust be
stepped up or stepped down to produce the regulated
output. When VINis lower than VOUT, the charge pump
operates as a regulated step-up voltage doubler. When
VINis higher than VOUT, the charge pump operates as
a step-down gated switch.
In voltage step-down mode (i.e., the input voltage is
greater than the output voltage) with a light load, the
controller connects CXN to PGND, and shuttles charge
to the output by alternately connecting CXP from IN to
OUT (see Figures 1 and 2). Although VINis greater than
VOUT, this scheme may not allow the MAX1759 to regu-
late the output under heavy loads. In this case, the
MAX1759 will automatically switch to step-up mode.In
step-upmode, the output is kept in regulation by modu-
lating the charge delivered by the transfer capacitor
(CX) to the load (see Figure 2). When lightly loaded, the
charge pump switches only as necessary to supply the
load, resulting in low quiescent current. Output voltage
ripple does not increase with light loads.
Shutdown ModeDriving SHDNlow places the MAX1759 in shutdown
mode. This disables the charge-pump switches, oscil-
lator, and control logic, reducing quiescent current to
1µA. The output is high impedance in shutdown and is
disconnected from the input. The POK output is high
impedance in shutdown.
Undervoltage Lockout The MAX1759 undervoltage lockout feature deactivates
the device when the input voltage falls below 1V.
Power-OK OutputPOK is an open-drain output that sinks current when
the regulator feedback voltage falls below 1.1V. The
feedback voltage can be either the internal resistor-
divider feedback voltage when in fixed output mode
(FB tied to GND) or an external feedback voltage from
an external resistive divider in adjustable output mode.
A 10kΩto 1MΩpull-up resistor from POK to OUT may
be used to provide a logic output. Connect POK to GND
or leave unconnectedif not used.
Soft-Start and Short-Circuit ProtectionThe MAX1759 features foldback short-circuit protec-
tion. This circuitry provides soft-start by limiting inrush
current during startup and limits the output current to
110mA (typ) if the output is short-circuited to ground.
Thermal ShutdownThe MAX1759 features thermal shutdown with tempera-
ture hysteresis. When the die temperature exceeds
160°C, the device shuts down. When the die cools by
20°C, the MAX1759 turns on again. If high die tempera-
ture is caused by output overload and the load is not
removed, the device will turn off and on, resulting in a
pulsed output.
Design Procedure
Setting the Output VoltageThe MAX1759 dual-mode feedback controller selects
between the internally set 3.3V regulated output or an
external resistive divider that allows adjustment of the
output voltage from 2.5V to 5.5V. Connect FB to GND
for a regulated 3.3V output. For an adjustable output,
connect a resistive divider between OUT and GND. To
ensure feedback-loop stability and to minimize error due
to FB pin bias currents, the resistivedivider current
should be approximately 15µA. In the following equa-
tion, choose R2 in the 50kΩto 100kΩrange, and calcu-
late R1 from the following formula (Figure 3):
R1 = R2 [(VOUT / VFB) - 1]
and
VOUT= VFB(R1 + R2) / R2
where VOUTis the desired output voltage from 2.5V to
5.5V, and VFBis the internal regulation voltage, nomi-
nally 1.235V.
The circuit of Figure 3 generates a regulated 2.5V, using
external standard 1% resistor values. Surface-mount
resistors should be placed close to the MAX1759, less
than 5mm away from FB (see the PC Board Layout
section).
