MAX1651CSA ,5V/3.3V or Adjustable, High-Efficiency, Low-Dropout, Step-Down DC-DC ControllersGeneral Description ________
MAX1651CSA ,5V/3.3V or Adjustable, High-Efficiency, Low-Dropout, Step-Down DC-DC ControllersMAX1649/MAX165119-0305; Rev 2; 9/955V/3.3V or Adjustable, High-Efficiency,Low-Dropout, Step-Down DC ..
MAX1651CSA ,5V/3.3V or Adjustable, High-Efficiency, Low-Dropout, Step-Down DC-DC ControllersApplications MAX1651CPA 0°C to +70°C 8 Plastic DIPMAX1651CSA 0°C to +70°C 8 SOPDAsMAX1651C/D 0°C to ..
MAX1651CSA. ,5V/3.3V or Adjustable, High-Efficiency, Low-Dropout, Step-Down DC-DC ControllersApplicationsMAX1651ESA -40°C to +85°C 8 SOBattery-Powered
MAX1651CSA+ ,5V/3.3V or Adjustable, High-Efficiency, Low-Dropout, Step-Down DC-DC ControllerApplicationsMAX1651CPA 0°C to +70°C 8 Plastic DIPMAX1651CSA 0°C to +70°C 8 SOPDAsMAX1651C/D 0°C to ..
MAX1651CSA+T ,5V/3.3V or Adjustable, High-Efficiency, Low-Dropout, Step-Down DC-DC ControllerELECTRICAL CHARACTERISTICS(V+ = 5V, T = T to T , unless otherwise noted. Typical values are at T = ..
MAX4409ETP ,1.8 to 3.6 V, 80 mW, directdrive, stereo headphone amplifier with common-mode senseFeaturesThe MAX4409 stereo headphone amplifier combines ♦ No Bulky DC-Blocking Capacitors RequiredM ..
MAX4409ETP+ ,80mW, DirectDrive, Stereo Headphone Amplifier with Common-Mode SenseELECTRICAL CHARACTERISTICS(V = V = 3V, V = V = 0, SHDN = SV , C1 = C2 = 2.2µF, R = R = R1 = R2 = 10 ..
MAX4409ETP+T ,80mW, DirectDrive, Stereo Headphone Amplifier with Common-Mode SenseApplications Functional DiagramNotebooksDirectDrive OUTPUTS Desktop PCs ELIMINATE DC-BLOCKING MAX44 ..
MAX4409EUD+ ,80mW, DirectDrive, Stereo Headphone Amplifier with Common-Mode SenseFeaturesThe MAX4409 stereo headphone amplifier combines♦ No Bulky DC-Blocking Capacitors Required®M ..
MAX440CPI ,High-Speed Video Multiplixer/AmplifierELECTRICAL CHARACTERISTICS
(V+ = 5V, V- = -5V, VNS = -5V, RL = 1500, TA = +25'C. unless otherwise ..
MAX440EPI ,High-Speed Video Multiplixer/AmplifierFeatures
. 160MHz Unity Galn Bandwidth
. 110MHz Bandwidth (Av = 6dB)
. 0.037004% Differential ..
MAX1649CPA-MAX1649CSA-MAX1649ESA-MAX1651CPA-MAX1651CSA-MAX1651CSA.-MAX1651ESA
5V/3.3V or Adjustable, High-Efficiency, Low-Dropout, Step-Down DC-DC Controllers
_______________General DescriptionThe MAX1649/MAX1651 BiCMOS, step-down, DC-DC
switching controllers provide high efficiency over loads
ranging from 1mA to more than 2.5A. A unique, current-
limited pulse-frequency-modulated (PFM) control scheme
gives these devices the benefits of pulse-width-modula-
tion (PWM) converters (high efficiency at heavy loads),
while using only 100µA of supply current (vs. 2mA to
10mA for PWM converters). Dropout performance down
to 300mV is provided by a high switch duty cycle (96.5%)
and a low current-sense threshold (110mV).
A high switching frequency (up to 300kHz) allows these
devices to use miniature external components.
The MAX1649/MAX1651 have dropout voltages less
than 0.3V at 500mA and accept input voltages up to
16V. Output voltages are preset at 5V (MAX1649), or
3.3V (MAX1651). They can also be adjusted to any
voltage from 1.5V to the input voltage by using two
resistors.
These step-down controllers drive external P-channel
MOSFETs at loads greater than 12.5W. If less power is
required, use the MAX639/MAX640/MAX653 step-down
converters with on-chip FETs, which allow up to a
225mA load current.
________________________ApplicationsPDAs
High-Efficiency Step-Down Regulation
5V-to-3.3V Green PC Applications
Battery-Powered Applications
____________________________FeaturesMore than 90% Efficiency (10mA to 1.5A Loads)More than 12.5W Output PowerLess than 0.3V Dropout Voltage at 500mA100µA Max Quiescent Supply Current5µA Max Shutdown Supply Current16V Max Input Voltage5V (MAX1649), 3.3V (MAX1651), or Adjustable
Output VoltageCurrent-Limited Control SchemeUp to 300kHz Switching FrequencyUp to 96.5% Duty Cycle
______________Ordering Information* Dice are tested at TA= +25°C.
MAX1649/MAX1651
5V/3.3V or Adjustable, High-Efficiency,
Low-Dropout, Step-Down DC-DC Controllers
________________________________________________________________Maxim Integrated Products1
__________________Pin Configuration__________Typical Operating Circuit
Call toll free 1-800-998-8800 for free samples or literature.19-0305; Rev 2; 9/95
MAX1649/MAX1651
5V/3.3V or Adjustable, High-Efficiency,
Low-Dropout, Step-Down DC-DC Controllers_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(V+ = 5V, TA= TMINto TMAX, 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.
Supply Voltage, V+ to GND.......................................-0.3V, +17V
REF, SHDN, FB, CS, EXT, OUT.......................-0.3V, (V+ + 0.3V)
Continuous Power Dissipation (TA= +70°C)
Plastic DIP (derate 9.09mW/°C above +70°C).............727mW
SO (derate 5.88mW/°C above +70°C)..........................471mW
Operating Temperature Ranges
MAX1649C_A, MAX1651C_A..............................0°C to +70°C
MAX1649E_A, MAX1651E_A............................-40°C to +85°C
Storage Temperature Range.............................-65°C to +160°C
Lead Temperature (soldering, 10sec).............................+300°C
MAX1649/MAX1651
5V/3.3V or Adjustable, High-Efficiency,
Low-Dropout, Step-Down DC-DC Controllers
_______________________________________________________________________________________3
ELECTRICAL CHARACTERISTICS (continued)(V+ = 5V, TA= TMINto TMAX, unless otherwise noted. Typical values are at TA= +25°C.)
80
SUPPLY CURRENT vs. TEMPERATUREI+ (
MAX1649-TOC06
TEMPERATURE (°C)100-4008040120
SHUTDOWN CURRENT
vs. TEMPERATURE
I+ (
MAX1649-TOC05
TEMPERATURE (°C)100-4008040120
EXT RISE AND FALL TIMES
vs. TEMPERATURE (1nF)
MAX1649/51-01
TEMPERATURE (°C)
tRISE
& t
FALL
(ns)100-40080401201010k
LOAD CURRENT (mA)
EFFICIENCY (%)
1001k0.1
MAX1649/51-A1
EFFICIENCY
vs. LOAD CURRENT (VOUT = 5V)
__________________________________________Typical Operating Characteristics(TA = +25°C, unless otherwise noted.)
EXT RISE AND FALL TIMES
vs. TEMPERATURE (5nF)
MAX1649/51-02
TEMPERATURE (°C)
tRISE
& t
FALL
(ns)100-4008040120
2201010k
LOAD CURRENT (mA)
EFFICIENCY (%)
1001k0.1
MAX1649/51-A2
EFFICIENCY
vs. LOAD CURRENT (VOUT = 3.3V)
MAX1649/MAX1651
5V/3.3V or Adjustable, High-Efficiency,
Low-Dropout, Step-Down DC-DC Controllers_______________________________________________________________________________________SWITCH ON-TIME
vs. TEMPERATURE
MAX1649/51-03
TEMPERATURE (°C)
tON100-4008040120
SWITCH OFF-TIME
vs. TEMPERATURE
MAX1649/51-04
TEMPERATURE (°C)
tOFF100-4008040120
MAXIMUM DUTY CYCLE
vs. TEMPERATURE
MAX1649/51-05
TEMPERATURE (°C)
DUTY CYCLE (%)100-4008040120
CS TRIP LEVEL
vs. TEMPERATURE
MAX1649/51-06
TEMPERATURE (°C)
CS TRIP LEVEL (mV)100-4008040120
DROPOUT VOLTAGE
vs. LOAD CURRENT
MAX1649/51-A3
LOAD CURRENT (A)
DROPOUT VOLTAGE (mV)
REFERENCE OUTPUT RESISTANCE
vs. TEMPERATURE
REFERENCE OUTPUT RESISTANCE (
MAX1649-TOC07
TEMPERATURE (°C)100-4008040120
REFERENCE OUTPUT VOLTAGE
vs. TEMPERATURE
REFERENCE OUTPUT VOLTAGE (V)
MAX1649-TOC01
TEMPERATURE (°C)100-4008040120
____________________________Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
MAX1649/MAX1651
5V/3.3V or Adjustable, High-Efficiency,
Low-Dropout, Step-Down DC-DC Controllers
_______________________________________________________________________________________5
____________________________Typical Operating Characteristics (continued)(TA = +25°C, unless otherwise noted.)
MAX1649/MAX1651
5V/3.3V or Adjustable, High-Efficiency,
Low-Dropout, Step-Down DC-DC Controllers_______________________________________________________________________________________
_______________Detailed DescriptionThe MAX1649/MAX1651 are BiCMOS, step-down,
switch-mode power-supply controllers that provide
adjustable and fixed outputs of 5V and 3.3V, respec-
tively. Their unique control scheme combines the
advantages of pulse-frequency-modulation (low supply
current) and pulse-width-modulation (high efficiency at
high loads). An external P-channel power MOSFET
allows peak currents in excess of 3A, increasing the
output current capability over previous PFM devices.
Figure 2 is the block diagram.
The MAX1649/MAX1651 offer four main improvements
over prior solutions: The converters operate with miniature surface-mount
inductors, due to their 300kHz switching frequency.The current-limited PFM control scheme allows
greater than 90% efficiencies over a wide range of
load currents (10mA to 1.5A).Dropout voltage has been reduced to less than
300mV for many applications.The quiescent supply current is only 100µA.
PFM Control SchemeThe MAX1649/MAX1651 use a proprietary, current-limit-
ed PFM control scheme. As with traditional PFM con-
verters, the external power MOSFET is turned on when
the voltage comparator senses that the output is out of
regulation. However, unlike traditional PFM converters,
switching is accomplished through the combination of a
peak current limit and a pair of one-shots that set the
maximum switch on-time (32µs) and minimum switch
off-time (1.1µs). Once off, the off-time one-shot holds
the switch off for 1.1µs. After this minimum time, the
switch either 1) stays off if the output is in regulation, or
2) turns on again if the output is out of regulation.
The MAX1649/MAX1651 also limit the peak inductor cur-
rent, which allows them to run in continuous-conduction
mode and maintain high efficiency with heavy loads
(Figure 3). This current-limiting feature is a key compo-
nent of the control circuitry. Once turned on, the switch
stays on until either 1) the maximum on-time one-shot
turns it off (32µs later), or 2) the current limit is reached.
EXT swings from V+ to GND and provides the drive out-
put for an external P-channel power MOSFET.
______________________________________________________________Pin Description
