MAX1573ETE-MAX1573ETE+-MAX1573ETE+T Fast Delivery |IC PHOENIX CO.,LIMITED

MAX1573ETE+ ,White LED 1x/1.5x Charge Pump in UCSP and Thin QFNApplicationsCell Phones, Smart PhonesOrdering InformationPDAs, Digital Cameras, CamcordersPART TEMP ..
MAX1573ETE+T ,White LED 1x/1.5x Charge Pump in UCSP and Thin QFNApplicationsCell Phones, Smart PhonesOrdering InformationPDAs, Digital Cameras, CamcordersPART TEMP ..
MAX1573ETE+T ,White LED 1x/1.5x Charge Pump in UCSP and Thin QFNMAX157319-2847; Rev 2; 8/05White LED 1x/1.5x Charge Pump in UCSP and Thin QFN
MAX1574ETB ,180mA / 1x/2x / White LED Charge Pump in 3mm x 3mm TDFNELECTRICAL CHARACTERISTICS(V = 3.6V, V = 0V, EN = IN, R = 13.7kΩ, T = -40°C to +85°C, unless otherw ..
MAX1574ETB ,180mA / 1x/2x / White LED Charge Pump in 3mm x 3mm TDFNApplicationsOrdering InformationLCD BacklightingPIN- TOPPART TEMP RANGEPACKAGE MARKCamera Strobes/F ..
MAX1574ETB+ ,180mA, 1x/2x, White LED Charge Pump in 3mm x 3mm TDFNELECTRICAL CHARACTERISTICS(V = 3.6V, V = 0V, EN = IN, R = 13.7kΩ, T = -40°C to +85°C, unless otherw ..
max4237EUT-T ,SOT23 / Very High Precision / 3V/5V Rail-to-Rail Op AmpsELECTRICAL CHARACTERISTICS (SO-8 and µMAX-8)(V = +2.4V to +5.5V, V = 0, V = 0, V = V /2, R = 100kΩ ..
MAX4238ASA ,Ultra-Low Offset/Drift / Low-Noise / Precision SOT23 AmplifiersApplications 0.1µA Shutdown ModeThermocouples Rail-to-Rail Output (R = 1kΩ )LStrain Gauges Low 6 ..
MAX4238ASA+ ,Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 AmplifiersGeneral Description Beneits and
MAX4238ASA+T ,Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 AmplifiersApplications• 0.1µA Shutdown Mode● Thermocouples● Strain GaugesPin Configurations appear at end of ..
MAX4238ASA+T ,Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 AmplifiersApplications• 0.1µA Shutdown Mode● Thermocouples● Strain GaugesPin Configurations appear at end of ..
MAX4238ATT+T ,Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 AmplifiersMAX4238/MAX4239 Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 Ampliiers

MAX1573ETE-MAX1573ETE+-MAX1573ETE+T
White LED 1x/1.5x Charge Pump in UCSP and Thin QFN
General Description
The MAX1573 fractional charge pump drives up to four
white LEDs with regulated constant current for uniform
intensity. By utilizing proprietary adaptive 1x/1.5x
modes and ultra-low-dropout current regulators, it
maintains the highest possible efficiency over the full
1-cell Li+ battery input voltage range. The 1MHz fixed-
frequency switching allows for tiny external compo-
nents and the regulation scheme is optimized to ensure
low EMI and low input ripple.
An external resistor sets the full-scale LED current, while
two digital inputs control on/off and select amongst three
levels of brightness. A pulse-width modulation (PWM)
signal can also be used to modulate LED brightness,
requiring no additional components.
The MAX1573 is available in the tiny chip-scale UCSP™
(4 x 4 grid) and 16-pin thin QFN packages.
Applications
Cell Phones, Smart Phones
PDAs, Digital Cameras, Camcorders
MP3 Players
Other Handhelds with Color Displays
FeaturesProprietary Adaptive 1x/1.5x ModesHigh Efficiency (PLEDs/PBATT), Up to 92%0.2% LED Current Matching28mA/LED Drive CapabilityLow Input Ripple and EMIEliminates Ballast ResistorsLogic or PWM Dimming ControlLow 0.1µA Shutdown Current2.7V to 5.5V Input Voltage RangeSoft-Start Limits Inrush CurrentOutput Overvoltage ProtectionThermal Shutdown ProtectionNo External Schottky Diode RequiredTiny UCSP (2.1mm x 2.1mm x 0.6mm) and Thin
QFN (4mm x 4mm) Packages
MAX1573
White LED 1x/1.5x Charge Pump in
UCSP and Thin QFN
TOP VIEW
MAX157310934
N.C.GNDLED3LED4
LED1
LED2
SET
EN2
C2N
C1P
C2P
OUT
EN1
N.C.
CIN
THIN QFN
4mm × 4mm
A "+" SIGN WILL REPLACE THE FIRST PIN INDICATOR ON LEAD-FREE PACKAGES.
Pin Configurations
Ordering Information
MAX1573
VIN
2.7V TO 5.5V
RSET
ON/OFF
AND
DIMMING
CONTROL
SET
GND
C1NC1PC2NC2P
OUT
LED1
LED2
LED3
LED4
EN1
1μF1μF
1μF1μF
VOUT
UP TO 4 LEDS
EN2
Typical Operating Circuit
19-2847; Rev 2; 8/05
PARTTEMP RANGEPIN-PACKAGE
MAX1573EBE-T-40°C to +85°C14 UCSP (4 x 4)
MAX1573ETE-40°C to +85°C16 Thin QFN
MAX1573ETE+-40°C to +85°C16 Thin QFN
UCSP is a trademark of Maxim Integrated Products, Inc.
Pin Configurations continued at end of data sheet.
+ Denotes lead-free package.
MAX1573
White LED 1x/1.5x Charge Pump in
UCSP and Thin QFN
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN= VEN1= VEN2= 3.6V, CIN= C1 = C2 = COUT= 1µF, TA= -40°C to +85°C. Typical values are at TA= +25°C, unless otherwise
noted.) (Note 1)
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, EN1, EN2 to GND...................................-0.3V to +6.0V
SET, LED1, LED2, LED3, LED4 to GND......-0.3V to (VIN+ 0.3V)
C1N, C2N to GND..........................................-0.3V to (VIN+ 1V)
C1P, C2P to GND............................................-0.3V to greater of
.............................................................(VOUT+ 1V) or (VIN+ 1V)
OUT Short Circuit to GND..........................................Continuous
Continuous Power Dissipation (TA= +70°C)
14-Bump UCSP (derate 7.36mW/°C above +70°C)....589mW
16-Pin Thin QFN (derate 16.9mW/°C above +70°C).1349mW
Operating Temperature Range...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
PARAMETERCONDITIONSMINTYPMAXUNITS
IN Operating Voltage2.75.5V
Undervoltage Lockout ThresholdVIN rising or falling, 35mV hysteresis2.252.452.60V
Supply CurrentSwitching, no load, ISET = 130µA24mA
Shutdown Supply CurrentEN1 = EN2 = OUT = GND, TA = +25°C0.110µA
Soft-Start Completion Time2.1ms
SET Bias Voltage0.5700.60.630V
SET Leakage in ShutdownEN1 = EN2 = GND, TA = +25°C0.011µA
SET Current Range40130µA
EN1 = EN2 = IN190219245
EN1 = IN, EN2 = GND586674SET to LED_ Current Ratio (ILED/ISET)ISET = 60µA
EN1 = GND, EN2 = IN19.52225.0
A/A
LED_ Current AccuracyE N 1 = EN 2 = IN , RS E T = 4.64kΩ , TA = 0°C to + 85°C ±0.6%
LED_ Current MatchingISET = 130µA, TA = 0°C to +85°C (Note 2)±0.2%
Maximum LED_ Sink CurrentISET = 130µA, EN1 = EN2 = IN25.928mA
LED_ Dropout VoltageISET = 87µA (Note 3)4080mV
LED_ Minimum Regulation Voltage (1.5x Mode)EN1 = EN2 = IN, ISET = 87µA100150200mV
LED Leakage in ShutdownEN1 = EN2 = GND, VLED = 5.5V, TA = +25°C0.011µA
Maximum OUT CurrentVIN ≥ 3.4V, VOUT ≥ 3.9V, EN1 = EN2 = IN120mA
1x mode (1 x VIN - VOUT) / IOUT1.5Open-Loop OUT Resistance1.5x mode (1.5 x VIN - VOUT) / IOUT10Ω
Switching Frequency1MHz
EN1, EN2 Logic High VoltageVIN = 2.7V to 5.5V1.6V
EN1, EN2 Logic Low VoltageVIN = 2.7V to 5.5V0.4V
EN1, EN2 Input CurrentVEN_ = GND or 5.5V, TA = +25°C0.011µA
Thermal-Shutdown Threshold20°C hysteresis160°C
Note 1:Specifications to -40°C are guaranteed by design and not production tested.
Note 2:LED_ current matching is defined as: (ILED- IAVG) / IAVG.
Note 3:Dropout voltage is defined as the LED_ to GND voltage at which the LED_ current drops 10% from the value at VLED= 200mV.
MAX1573
White LED 1x/1.5x Charge Pump in
UCSP and Thin QFN
EFFICIENCY (PLEDs/PBATT)
vs. Li+ BATTERY DISCHARGE
MAX1573 toc01
Li+ BATTERY VOLTAGE, TIME-WEIGHTED (V)
EFFICIENCY (%)
FULL
3/10
1/10
EFFICIENCY (PLEDs/PBATT)
vs. SUPPLY VOLTAGE
MAX1573 toc02
SUPPLY VOLTAGE (V)
1/103/10FULL
EFFICIENCY (%)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX1573 toc03
SUPPLY VOLTAGE (V)
BATTERY CURRENT (mA)
FULL
1/10
3/10
INPUT RIPPLE vs. SUPPLY VOLTAGE
MAX1573 toc04
SUPPLY VOLTAGE (V)
INPUT RIPPLE (mV
RMS
FULL
3/10
1/10
LED CURRENT vs. SUPPLY VOLTAGE
MAX1573 toc05
SUPPLY VOLTAGE (V)
LED CURRENT (mA)
LED4LED2
LED1LED317.5
LED CURRENT vs. TEMPERATURE
MAX1573 toc06
TEMPERATURE (°C)
LED CURRENT (mA)867101112131415
LED CURRENT vs. RSET
MAX1573 toc07
RSET (kΩ)
LED CURRENT (mA)
FULL
1/10
3/10
Typical Operating Characteristics
(VIN= 3.6V, EN1 = EN2 = IN, CIN= C1 = C2 = COUT= 1µF, RSET= 7.50kΩ, TA= +25°C, unless otherwise noted.)
500ns/div
20mV/
div
10mA/
div
20mV/
div
VIN
IIN
VOUT
TYPICAL OPERATING WAVEFORMS
IN 1x MODE
MAX1573 toc08
3.6V Li+ BATTERY INPUT
500ns/div
20mV/
div
10mA/
div
20mV/
div
VIN
IIN
VOUT
TYPICAL OPERATING WAVEFORMS
IN 1.5x MODE
MAX1573 toc09
3.4V Li+ BATTERY INPUT
MAX1573
White LED 1x/1.5x Charge Pump in
UCSP and Thin QFNypical Operating Characteristics (continued)
(VIN= 3.6V, EN1 = EN2 = IN, CIN= C1 = C2 = COUT= 1µF, RSET= 7.50kΩ, TA= +25°C, unless otherwise noted.)
STARTUP AND SHUTDOWN RESPONSE
MAX1573 toc10
500μs/div
5V/
div
2V/
div
50mA/
div
VEN_
VOUT
IIN
LED_ = 4 ✕ 17mA
EN1 = EN2
DIMMING RESPONSE
MAX1573 toc11
5μs/div
2V/
div
50mA/
div
VENI1
IOUT
EN2 = IN
Pin Description
PIN
TQFNUCSP
NAMEFUNCTIONB2C2PTransfer Capacitor 2 Positive Connection. See the Component Selection section for capacitor value.A2OUTOutput. Bypass to GND with a 1µF ceramic capacitor. Connect to the anodes of all the LEDs. OUT is
high impedance during shutdown.A3EN1Enable, Dimming Control Input 1. EN1 and EN2 control shutdown and the LED current. See Table 1.—N.C.No ConnectionA4EN2Enable, Dimming Control Input 2. EN1 and EN2 control shutdown and the LED current. See Table 1.B4SETBias-Current Set Input. Connect a resistor from SET to GND to set the LED bias current (ISET). ISET =
600mV/RSET.C4LED2
LED2 Cathode Connection and Charge-Pump Feedback. The charge pump regulates to the lowest
voltage on any of the LED_ inputs. Connect LED2 to the cathode of one output LED. Connect LED2 to
IN if this LED is not populated.D4LED1
LED1 Cathode Connection and Charge-Pump Feedback. The charge pump regulates to the lowest
voltage on any of the LED_ inputs. Connect LED1 to the cathode of one output LED. Connect LED1 to
IN if this LED is not populated.C3LED4
LED4 Cathode Connection and Charge-Pump Feedback. The charge pump regulates to the lowest
voltage on any of the LED_ inputs. Connect LED4 to the cathode of one output LED. Connect LED4 to
IN if this LED is not populated.D3LED3
LED3 Cathode Connection and Charge-Pump Feedback. The charge pump regulates to the lowest
voltage on any of the LED_ inputs. Connect LED3 to the cathode of one output LED. Connect LED3 to
IN if this LED is not populated.D2GNDGround—N.C.No Connection
Detailed Description
The MAX1573 is a complete charge-pump buck-boost
converter requiring only four small ceramic capacitors.
The MAX1573 utilizes a proprietary 1x/1.5x fractional
charge-pump topology to drive up to four white LEDs
with regulated constant current for uniform intensity.
The MAX1573 operates with a 1MHz fixed frequency.
An external resistor (RSET) programs the full-scale LED
current, while two digital inputs control on/off and pro-
vide brightness control.
Output Regulation
The MAX1573 operates in 1x mode until just above
dropout. Then the MAX1573 switches to 1.5x charge-
pump mode to regulate the lowest of LED1–LED4 to
150mV and maintain constant LED brightness even at
very low battery voltages. Using this topology, there is
no LED brightness change during the 1x/1.5x switchover,
which guarantees no flicker on the display. The
switchover scheme has low hysteresis, minimizing
operation in the less-efficient 1.5x mode. The 1x mode
produces almost no ripple, while the 1.5x mode regu-
lates the output voltage by controlling the rate at which
the transfer capacitors are charged. In this way, the
switching frequency remains constant for reduced input
ripple and stable noise spectrum.
Soft-Start
The MAX1573 includes soft-start circuitry to limit inrush
current at turn-on. When starting up with an output
voltage that is not near the input voltage, the output
capacitor is charged directly from the input with a DAC-
ramped current source (with no charge-pump action)
until the output voltage is near the input voltage. Once
this occurs, the charge pump determines if 1x or 1.5x
mode is required. In the case of 1x mode, the soft-start
is terminated and normal operation begins. In the case
of 1.5x mode, soft-start operates until the lowest of
LED1–LED4 reaches regulation. If an overload condi-
tion occurs, soft-start repeats every 2.1ms. If the output
is shorted to ground, the output current is limited by
the MAX1573 fractional-switching technique.
MAX1573
White LED 1x/1.5x Charge Pump in
UCSP and Thin QFN
Pin Description (continued)
PIN
TQFNUCSP
NAMEFUNCTIOND1C1NTransfer Capacitor 1 Negative Connection. See the Component Selection section for capacitor value.C1INSupply Voltage Input. IN supplies power for the IC. Bypass IN to GND with a 1µF ceramic capacitor.B1C2NTransfer Capacitor 2 Negative Connection. See the Component Selection section for capacitor value.A1C1PTransfer Capacitor 1 Positive Connection. See the Component Selection section for capacitor value.P
MAX1573
0.6V
SET
EN2
EN1
C1P
0.15V
BRIGHTNESS
CONTROL
MINIMUM
SELECT
1x/1.5x REGULATED CHARGE PUMP
C1NC2PC2N
1.25V
OUT
LED1
LED2
LED3
LED4
GND
LDO CURRENT
REGULATOR
LDO CURRENT
REGULATOR
LDO CURRENT
REGULATOR
LDO CURRENT
REGULATOR
Block Diagram
True Shutdown™ Mode
When EN1 and EN2 are grounded, the MAX1573 is in
shutdown, and the charge pump examines whether the
input voltage is greater than or less than the output volt-
age and shorts the transfer capacitor nodes to either IN
or OUT as necessary. The output is high impedance in
either case.
Thermal Shutdown
The MAX1573 includes a thermal-limit circuit that shuts
down the IC at about +160°C. Turn-on occurs after the
IC cools by approximately 20°C.
Setting the Output Current
SET controls the LED bias current. Current flowing into
LED1, LED2, LED3, and LED4 is a multiple of the current
flowing out of SET. Set the output current as follows:
where K = 22, 66, or 219 (depending upon EN1 and
EN2, see Table 1), and RSETis the resistor connected
between SET and GND (see the Typical Operating
Circuit).
Applications Information
Dimming Using EN1 and EN2
Use EN1 and EN2 inputs as a digital 2-bit number to
control on/off, 1/10, 3/10, and full current (see Table 1).
RSETprograms the full current level (see the Setting the
Output Currentsection).
Dimming Using PWM into EN1
Use EN2 for shutdown and drive EN1 with a PWM sig-
nal. Current can be varied from 1/10 to full. The wave-
forms in the Typical Operating Characteristics show the
response time of dimming. EN2 keeps the part on, elimi-
nating any soft-start delay that would impede PWM con-
trol, allowing a PWM frequency up to 50kHz (Figure 1).
Dimming Using a Filtered PWM Signal
Use a high-frequency PWM signal to drive an R-C-R fil-
ter on the SET pin (Figure 2). A 0% PWM duty cycle
corresponds to 18.7mA/LED, while a 100% PWM duty
cycle corresponds to 0mA/LED. At PWM frequencies
above 5kHz, C3 may be reduced.
Input Ripple
For LED drivers, input ripple is more important than out-
put ripple. Input ripple depends on the source supply’s
impedance. Adding a lowpass filter to the input further
reduces input ripple. Figure 3 shows a C-R-C filter used
to reduce input ripple to less than 2mVP-Pwhen driving
a 75mA load. Alternately, increasing CINto 2.2µF or
4.7µF yields input ripple of 17mVP-Por 9mVP-P, respec-
tively, with only a small increase in footprint. The 1x
mode always has very low input ripple.xVLEDSET_.=⎛⎜⎞⎟06
MAX1573
White LED 1x/1.5x Charge Pump in
UCSP and Thin QFN
LED1
LED2
LED3
LED4
1μF
GND
EN1
EN2
SET
1μF
VIN
MAX1573
OUT0 TO 18.7mA/LED
1μF
14.3kΩ
14.3kΩ
RSET
9.09kΩ
PWM
INPUT
0 TO
2.5V
C1PC1N
1μF
C2PC2N
1μF
Figure 2. Dimming Using Filtered PWM Signal
Table 1. EN1/EN2 States
EN1/EN2 STATESBRIGHTNESSLED CURRENT
EN1 = low, EN2 = lowShutdownILED = 0
EN1 = low, EN2 = high1/10 BrightnessILED = 22 x ISET
EN1 = high, EN2 = low3/10 BrightnessILED = 66 x ISET
EN1 = high, EN2 = highFull BrightnessILED = 219 x ISET
LED1
LED2
LED3
LED4
GND
C1PC1N
1μF
C2PC2N
1μF
EN2
EN1
SET
RSET
1μF1μF
VIN
MAX1573
PWM INPUT
OUT
Figure 1. Dimming Using PWM Signal into EN1
True Shutdown is a trademark of Maxim Integrated Products, Inc.

Partno	Mfg	Dc	Qty	Available	Descript
MAX1573ETE+T \|MAX1573ETET	MAX	N/a	5396	avai	White LED 1x/1.5x Charge Pump in UCSP and Thin QFN
MAX1573ETE+T	MAXIM	N/a	273	avai	White LED 1x/1.5x Charge Pump in UCSP and Thin QFN
MAX1573ETE	MAXIM	N/a	502	avai	White LED 1x/1.5x Charge Pump in UCSP and Thin QFN
MAX1573ETE+	MAXIM	N/a	8827	avai	White LED 1x/1.5x Charge Pump in UCSP and Thin QFN