MAX1642EUA ,High-Efficiency / Step-Up DC-DC Converters for 1V InputsFeaturesThe MAX1642/MAX1643 are high-efficiency, low-voltage,' Built-In Synchronous Rectifierstep-u ..
MAX1643EUA ,High-Efficiency / Step-Up DC-DC Converters for 1V InputsELECTRICAL CHARACTERISTICS(V = V = 1.3V, I = 0mA, FB = GND, T = 0°C to +85°C, unless otherwise note ..
MAX1644 ,2A, Low-Voltage, Step-Down Regulator with Synchronous Rectification and Internal SwitchesELECTRICAL CHARACTERISTICS(V = V = +3.3V, FBSEL = GND, T = 0°C to +85°C, unless otherwise noted. Ty ..
MAX1644EAE ,2A, low-voltage, step-down regulator with synchronous rectification and intemal switchesfeatures internal' Internal PMOS and NMOS Switchessynchronous rectification for high efficiency and ..
MAX1644EAE+ ,2A, Low-Voltage, Step-Down Regulator with Synchronous Rectification and Internal SwitchesFeaturesThe MAX1644 constant-off-time, PWM step-down DC- ±1% Output AccuracyDC converter is ideal ..
MAX1644EAE+T ,2A, Low-Voltage, Step-Down Regulator with Synchronous Rectification and Internal SwitchesMAX164419-1457; Rev 2; 3/022A, Low-Voltage, Step-Down Regulator withSynchronous Rectification and I ..
MAX4392ESA ,Ultra-Small / Low-Cost / 85MHz Op Amps with Rail-to-Rail Outputs and DisableELECTRICAL CHARACTERISTICS—Single Supply(V = 5V, V = 0V, V = V /2, V = V /2, R = ∞ to V /2, DISABLE ..
MAX4392ESA+ ,Ultra-Small, Low-Cost, 85MHz Op Amps with Rail-to-Rail Outputs and Disableapplications). The MAX4389/MAX4390/• -59dBc Spurious-Free Dynamic RangeMAX4392–MAX4396 consume only ..
MAX4392ESA+T ,Ultra-Small, Low-Cost, 85MHz Op Amps with Rail-to-Rail Outputs and Disableapplications where an • 500V/μs Slew Rateinput or an output is exposed to the outside world, such a ..
MAX4392EUA ,Ultra-Small / Low-Cost / 85MHz Op Amps with Rail-to-Rail Outputs and Disableapplications27MHz 0.1dB Gain Flatness where an input or an output is exposed to the outside500V/µs ..
MAX4392EUA ,Ultra-Small / Low-Cost / 85MHz Op Amps with Rail-to-Rail Outputs and DisableApplications Ordering InformationSet-Top BoxesPIN- TOPPART TEMP RANGEPACKAGE MARKSurveillance Video ..
MAX4392EUA ,Ultra-Small / Low-Cost / 85MHz Op Amps with Rail-to-Rail Outputs and DisableELECTRICAL CHARACTERISTICS—Single Supply (continued)(V = 5V, V = 0V, V = V /2, V = V /2, R = ∞ to V ..
MAX1642EUA-MAX1643EUA
High-Efficiency / Step-Up DC-DC Converters for 1V Inputs
_______________General DescriptionThe MAX1642/MAX1643 are high-efficiency, low-voltage,
step-up DC-DC converters intended for devices pow-
ered by a single alkaline cell. They feature low quies-
cent supply currents and are supplied in the ultra-small
µMAX package, which is only 1.1mm high. The guaran-
teed start-up voltage is 0.88V.
Each device consists of an internal 1Ω, N-channel
MOSFET power switch; a built-in synchronous rectifier
that acts as the catch diode; an oscillator; a reference;
and pulse-frequency-modulation (PFM) control circuitry.
Both devices feature an independent undervoltage
comparator (PFI/PFO). The MAX1642 also includes a
2µA logic-controlled shutdown mode. The MAX1643
offers a dedicated low-battery detector (BATTLO) in
lieu of shutdown.
The output voltage for each device is preset to 3.3V
±4%, or can be adjusted from +2V to +5.2V using only
two resistors.
________________________ApplicationsPagers
Remote Controls
Pointing Devices
Personal Medical Monitors
Single-Cell Battery-Powered Devices
____________________________FeaturesBuilt-In Synchronous Rectifier0.88V Guaranteed Start-UpUltra-Small µMAX Package: 1.1mm High83% Efficiency4µA Quiescent Supply Current into BATT Pin2µA Logic-Controlled Shutdown (MAX1642)Two Undervoltage Detectors (MAX1643)2V to 5.2V Output Range20mA Output Current at 1.2V InputReverse Battery Protection
MAX1642/MAX1643
High-Efficiency, Step-Up
DC-DC Converters for 1V Inputs
_________________Pin Configurations
__________Typical Operating Circuit*Dice are tested at TA= +25°C.
Note: To order these devices shipped in tape and reel, add a -T
to the part number.
MAX1642/MAX1643
High-Efficiency, Step-Up
DC-DC Converters for 1V Inputs
ABSOLUTE MAXIMUM RATINGSBATT to GND...........................................................-0.3V to 6.0V
BATT Forward Current..........................................................0.5A
OUT to GND.............................................................-0.3V to 6.0V
OUT, LX Current.......................................................................1A
LX to GND................................................................-0.3V to 6.0VSHDN, FB, BATTLO, PFOto GND...........................-0.3V to 6.0V
PFI to GND............................................................-0.3V to VBATT
Reverse Battery Current (TA= +25°C) (Note 1)...............220mA
Continuous Power Dissipation
µMAX (derate 4.1mW/°C above 70°C)..........................330mW
Operating Temperature Range
MAX1642EUA/MAX1643EUA............................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +165°C
Lead Temperature (soldering, 10sec).............................+300°C
ELECTRICAL CHARACTERISTICS(VBATT= VSHDN= 1.3V, ILOAD= 0mA, FB = GND, TA
= 0°C to +85°C,unless otherwise noted. Typical values are at TA= +25°C.)
Note 1:The reverse battery current is measured from the Typical Operating Circuit’sinput terminal to GND when the battery is con-
nected backward. A reverse current of 220mA will not exceed package dissipation limits but, if left for an extended time
(more than 10 minutes), may degrade performance.
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.
MAX1642/MAX1643
High-Efficiency, Step-Up
DC-DC Converters for 1V Inputs
Note 2:Start-up guaranteed by correlation to measurements of device parameters (i.e., switch on-resistance, on-times, off-times, and
output voltage trip points).
Note 3:
Note 4:Specifications to -40°C are guaranteed by design, not production tested.
ELECTRICAL CHARACTERISTICS (VBATT= VSHDN= 1.3V, ILOAD= 0mA, FB = GND, TA
= -40°C to +85°C,unless otherwise noted.) (Note 4)
__________________________________________Typical Operating Characteristics(Circuit of Figure 4, VBATT= 1.2V, R1 + R2 = 1MW, TA = +25°C, unless otherwise noted.)
MAX1642/MAX1643
High-Efficiency, Step-Up
DC-DC Converters for 1V Inputs
____________________________Typical Operating Characteristics (continued)(Circuit of Figure 4, VBATT= 1.2V, R1 + R2 = 1MW, TA = +25°C, unless otherwise noted.)
MAX1642/MAX1643
High-Efficiency, Step-Up
DC-DC Converters for 1V Inputs
____________________________Typical Operating Characteristics (continued)(Circuit of Figure 4,VBATT= 1.2V, R1 + R2 = 1MW, TA = +25°C, unless otherwise noted.)
MAX1642/MAX1643
High-Efficiency, Step-Up
DC-DC Converters for 1V Inputs
______________________________________________________________Pin Description
_______________Detailed DescriptionThe MAX1642/MAX1643 each consist of an internal 1Ω,
N-channel MOSFET power switch, a built-in synchro-
nous rectifier that acts as the catch diode, an oscillator,
a reference, and PFM control circuitry (Figure 1).
These devices are optimized for applications with
power-management features that operate from one
alkaline cell, such as pagers, remote controls, and bat-
tery-powered instruments. They are designed to meet
the specific demands of the operating states character-
istic of such systems: Primary battery is good and the load is active:In
this state, the system draws tens of milliamperes,
and the MAX1642/MAX1643 typically offer 80% effi-
ciency. Primary battery is good and the load is sleeping:In
this state, the load is drawing hundreds of microam-
peres, and the DC-DC converter IC draws very low
quiescent current. In many applications, the load is
expected to be in this state most of the time.
Operating PrincipleThe MAX1642/MAX1643 employ a proprietary pulse-
frequency-modulation (PFM) control scheme that com-
bines the ultra-low quiescent current traditional of
pulse-skipping PFM converters with the high-load effi-
ciency of pulse-width-modulation (PWM) converters.
The on-time and minimum off-times are varied as a
function of the input and output voltages:
where K is typically 25V-µs. This enables the
MAX1642/MAX1643 to maintain high efficiency over a
wide range of loads and input/output voltages.The DC-
DC converter is powered from the OUT pin.
