MAX1575ETE+-MAX1575ETE+T Fast Delivery |IC PHOENIX CO.,LIMITED

MAX1575ETE+ ,White LED 1x/1.5x Charge Pump for Main and Sub-DisplaysApplications+ Denotes lead-free package.Cell Phones with Main and Sub-DisplaysTypical Operating Cir ..
MAX1575ETE+T ,White LED 1x/1.5x Charge Pump for Main and Sub-DisplaysELECTRICAL CHARACTERISTICS(V = 3.6V, V = 0V, ENM = ENS = IN, R = 6.81kΩ, C = C1 = C2 = C = 1µF, T = ..
MAX1576ETG ,480mA White LED 1x/1.5x/2x Charge Pump for Backlighting and Camera FlashELECTRICAL CHARACTERISTICS (Voltages Referenced to V , T = – 40° to 130°C* unless otherwise indicat ..
MAX1576ETG+ ,480mA White LED 1x/1.5x/2x Charge Pump for Backlighting and Camera FlashELECTRICAL CHARACTERISTICS(V = 3.6V, V = V = V = 0V, ENM1 = ENM2 = ENF1 = ENF2 = IN, R = R = 6.8kΩ, ..
MAX1576ETG+T ,480mA White LED 1x/1.5x/2x Charge Pump for Backlighting and Camera FlashFeaturesThe MAX1576 charge pump drives up to 8 white LEDs♦ Powers Up to 8 LEDswith regulated consta ..
MAX1577ZETA+ ,1.2A White LED Regulating Charge Pump for Camera Flashes and Movie LightsApplicationsWhite LED Flashes, Strobes, and Movie LightsOrdering InformationLCD BacklightingPIN- TO ..
MAX423EPD ,【15 Volt Chopper Stabilized Operational Amplifierapplications. These devices offer input offset and drift specification superior to previous "preci ..
MAX4240EUK+ ,Single/Dual/Quad, +1.8V/10µA, SOT23, Beyond-the-Rails Op AmpsApplicationsMAX4242EUA -40°C to +85°C 8 µMAX —Two-Cell Battery- Strain GaugesMAX4242ESA -40°C to +8 ..
MAX4240EUK+T ,Single/Dual/Quad, +1.8V/10µA, SOT23, Beyond-the-Rails Op AmpsMAX4240–MAX424419-1343; Rev 3; 9/06Single/Dual/Quad, +1.8V/10µA, SOT23,Beyond-the-Rails Op Amps
MAX4240EUK-T ,Single/Dual/Quad / !.8V/10A / SOT23 / Beyond-the-Rails Op AmpsFeaturesThe MAX4240–MAX4244 family of micropower op amps' Ultra-Low-Voltage Operation:operate from ..
MAX4241ESA ,Single/Dual/Quad / !.8V/10A / SOT23 / Beyond-the-Rails Op AmpsApplicationsMAX4242EUA -40°C to +85°C 8 µMAX —Two-Cell Battery- Strain GaugesMAX4242ESA -40°C to +8 ..
MAX4241EUA ,Single/Dual/Quad / !.8V/10A / SOT23 / Beyond-the-Rails Op Ampsapplications.PIN- SOT PART TEMP. RANGEThe MAX4240 is offered in a space-saving 5-pin SOT23 PACKAGE ..

MAX1575ETE+-MAX1575ETE+T
White LED 1x/1.5x Charge Pump for Main and Sub-Displays
General Description
The MAX1575 charge pump drives up to four white
LEDs in the main display and up to two white LEDs in
the sub-display with regulated constant current for uni-
form intensity. By utilizing adaptive 1x/1.5x charge-
pump modes and very-low-dropout current regulators,
it achieves high efficiency over the full 1-cell lithium-
battery input voltage range. A 1MHz fixed-frequency
switching allows for tiny external components, and the
regulation scheme is optimized to ensure low EMI and
low input ripple.
The MAX1575 uses an external resistor to set the full-
scale 100% LED current. Two enable inputs, ENM and
ENS, are used for simple on/off controls for the main and
sub-displays, respectively. By repeatedly pulsing either
enable input, the LEDs can be dimmed in multiple steps
down to 5%. Once the desired brightness is set, the
MAX1575 maintains that brightness setting as long as
the enable input is kept high. If an enable input is kept
low for more than 2ms, the LED current for the respec-
tive display is set to zero. If both enable inputs are kept
low for more than 2ms, the MAX1575 enters shutdown.
The MAX1575 is available in a 16-pin 4mm x 4mm thin
QFN package (0.8mm max height).
Applications
Cell Phones with Main and Sub-Displays
PDAs/Smart Phones with Up to Six White LEDs
FeaturesPowers Main and Sub-Display LEDs85% Average Efficiency (PLED / PBATT) Over Li+
Battery Discharge2% LED Current MatchingUp to 30mA/LED Drive CapabilityAdaptive 1x/1.5x Mode SwitchoverLow Input Ripple and EMIIndividual 5% to 100% Dimming Through
Single-Wire Serial Pulse InterfaceLow 0.1µA Shutdown Current2.7V to 5.5V Supply Voltage RangeSoft-Start Limits Inrush CurrentOutput-Overvoltage ProtectionThermal-Shutdown Protection16-Pin Thin QFN 4mm x 4mm Package
MAX1575
White LED 1x/1.5x Charge Pump
for Main and Sub-Displays
Ordering Information
19-3097; Rev 2; 8/05
EVALUATION KIT
AVAILABLE
PARTTEMP RANGEPIN-PACKAGE
MAX1575ETE-40°C to +85°C16 Thin QFN 4mm x 4mm
MAX1575ETE+-40°C to +85°C16 Thin QFN 4mm x 4mm
C2P
OUT
SET
ENS
ENM5
LED66
LED57
LED48
LED3
LED2
LED1
GND
C1N1314
C2N15
C1P16
MAX1575
THIN QFN
4mm x 4mm
TOP VIEW
Pin Configuration
ENM
ENS
GND
LED1
LED2
LED3
LED4
OUT
C1PC1N
C2PC2N
2.7V TO 5.5V
1μF1μF
1μF
1μF
LED5
LED6
MAIN
SUB
SET
ENABLE MAIN
ON/OFF
AND DIMMING
ENABLE SUB
ON/OFF
AND DIMMING
RSET
MAX1575
Typical Operating Circuit
+ Denotes lead-free package.
MAX1575
White LED 1x/1.5x Charge Pump
for Main and Sub-Displays
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN= 3.6V, VGND = 0V, ENM = ENS = IN, RSET= 6.81kΩ, CIN = C1 = C2 = COUT = 1µF, TA = -40°C to +85°C, unless otherwise
noted. Typical values are at TA= +25°C.) (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, ENM, ENS to GND..................................-0.3V to +6.0V
SET, LED_, C1N, C2N to GND.....................-0.3V to (VIN + 0.3V)
C1P, C2P to GND.............................................................-0.3V to
the greater of (VOUT+ 1V) or (VIN + 1V)
OUT Short Circuit to GND..........................................Continuous
Continuous Power Dissipation (TA = +70°C)
16-Pin Thin QFN 4mm x 4mm
(derate 16.9 mW/°C above +70°C)............................1349mW
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
PARAMETERCONDITIONSMINTYPMAXUNITS
IN Operating Voltage2.75.5V
Undervoltage-Lockout ThresholdVIN falling2.252.452.60V
Undervoltage-Lockout Hysteresis35mV
OUT Overvoltage-Protection ThresholdVOUT rising5V
1MHz switching in 1.5x mode2No-Load Supply CurrentNo switching in 1x mode,10% setting0.5mA
Shutdown Supply CurrentENM = ENS = OUT = GND0.12µA
Soft-Start Time2ms
SET Bias Voltage0.6V
SET Leakage in ShutdownENM = ENS = GND0.011µA
TA = 0°C to +85°C10130SET Current RangeTA = -40°C to +85°C30130µA
SET-to-LED_ Current Ratio (ILED_ / ISET)100% setting234A/A
TA = +25°C to +85°C-8±2+8LED Current AccuracyTA = -40°C to +85°C-9.5+9.5%
TA = +25°C to +85°C-5±1.5+5LED-to-LED Current Matching (Note 2)TA = -40°C to +85°C-6.5+6.5%
Maximum LED_ Sink CurrentRSET = 4.53kΩ27.430.0mA
LED_ Dropout Voltage(Note 3)60100mV
LED_ 1x-to-1.5x Transition ThresholdVLED falling90100110mV
LED Leakage in ShutdownENM = ENS = GND, VLED_ = 5.5V0.011µA
Maximum OUT CurrentVIN ≥ 3.4V, VOUT = 3.9V, 100% setting120mA
1x mode (VIN - VOUT) / IOUT12.5Open-Loop OUT Resistance1.5x mode (1.5 x VIN - VOUT) / IOUT4.210Ω
Switching Frequency1MHz
OUT Pulldown ResistanceENM = ENS = GND5kΩ
ENM, ENS High VoltageVIN = 2.7V to 5.5V1.6V
ENM, ENS Low VoltageVIN = 2.7V to 5.5V0.4V
ENM, ENS Input CurrentVEN_ = 0V or 5.5V0.011µA
Shutdown DelayFrom falling edge of ENM and ENS1.023.3ms
MAX1575
White LED 1x/1.5x Charge Pump
for Main and Sub-Displays
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 current into the LED drops 10% from the LED current at
VLED_ = 0.2V.
ELECTRICAL CHARACTERISTICS (continued)
(VIN= 3.6V, VGND = 0V, ENM = ENS = IN, RSET= 6.81kΩ, CIN = C1 = C2 = COUT = 1µF, TA = -40°C to +85°C, unless otherwise
noted. Typical values are at TA= +25°C.) (Note 1)
PARAMETERCONDITIONSMINTYPMAXUNITS
tLO (ENM, ENS) (Figure 1)0.5500µs
tHI (ENM, ENS) (Figure 1)0.5µs
Initial tHI (ENM, ENS) (Figure 1)Only required for first EN_ pulse50µs
Thermal-Shutdown Threshold+160°C
Thermal-Shutdown Hysteresis20°C
Typical Operating Characteristics
(VIN= 3.6V, ENM = ENS = IN, circuit of Figure2, TA= +25°C, unless otherwise noted.)
EFFICIENCY vs. SUPPLY VOLTAGE
DRIVING SIX WHITE LEDs
MAX1575 toc01
SUPPLY VOLTAGE (V)
EFFICIENCY (%)
SUPPLY VOLTAGE FALLING
20mA/LED
8mA/LED2mA/LED
INPUT CURRENT vs. SUPPLY VOLTAGE
DRIVING SIX WHITE LEDs
MAX1575 toc02
SUPPLY VOLTAGE (V)
INPUT CURRENT (mA)
20mA/LED
8mA/LED
2mA/LED
SUPPLY VOLTAGE FALLING
INPUT CURRENT vs. SUPPLY VOLTAGE
DRIVING FOUR WHITE LEDs
MAX1575 toc03
SUPPLY VOLTAGE (V)
INPUT CURRENT (mA)
20mA/LED
8mA/LED
2mA/LED
SUPPLY VOLTAGE FALLING
INPUT CURRENT vs. SUPPLY VOLTAGE
DRIVING TWO WHITE LEDs
MAX1575 toc04
SUPPLY VOLTAGE (V)
INPUT CURRENT (mA)
20mA/LED
8mA/LED
2mA/LED
SUPPLY VOLTAGE FALLING
INPUT RIPPLE vs. SUPPLY VOLTAGE
DRIVING SIX WHITE LEDs
MAX1575 toc05
SUPPLY VOLTAGE (V)
INPUT RIPPLE (mV
P-P
20mA/LED
8mA/LED
2mA/LED
LED CURRENT MATCHING
vs. SUPPLY VOLTAGE
MAX1575 toc06
SUPPLY VOLTAGE (V)
LED CURRENT (mA)
2.75.5
MAX1575
White LED 1x/1.5x Charge Pump
for Main and Sub-Displays
OUTPUT CURRENT vs. SUPPLY VOLTAGE
DRIVING SIX LEDs AT 20mA EACH
MAX1575 toc07
SUPPLY VOLTAGE (V)
OUTPUT CURRENT (mA)
LED CURRENT vs. RSET
MAX1575 toc08
RSET (kΩ)
LED CURRENT (mA)
100% BRIGHTNESS SETTING
OPERATING WAVEFORMS (1x)
MAX1575 toc09
400ns/div
VOUT
VIN
IIN
200mV/div
AC-COUPLED
50mV/div
AC-COUPLED
50mA/div
0mA
OPERATING WAVEFORMS (1.5x)
MAX1575 toc10
400ns/div
VOUT
VIN
IIN
200mV/div
AC-COUPLED
50mV/div
AC-COUPLED
50mA/div
STARTUP WAVEFORMS
MAX1575 toc11
1ms/div
VOUT
VENM
AND VENS
IIN
5V/div
100mA/div
2V/div
MAIN STARTUP WITH SUB-DISPLAY ON
MAX1575 toc12
1ms/div
VOUT
VENM
IIN
5V/div
500mV/div
100mA/div
DIMMING RESPONSE
MAX1575 toc13
10ms/div
VOUT
VENM
AND VENS
IOUT
2V/div
2V/div
50mA/div
LINE TRANSIENT 3.8V TO 3.3V TO 3.8V
MAX1575 toc14
40μs/div
VOUT
VIN
IOUT
1V/div
50mA/div
0mA
1V/div
AC-COUPLED
Typical Operating Characteristics (continued)
(VIN= 3.6V, ENM = ENS = IN, circuit of Figure2, TA= +25°C, unless otherwise noted.)
Detailed Description
The MAX1575 charge pump drives up to four white
LEDs in the main display and up to two white LEDs in
the sub-display with regulated constant current for
uniform intensity. By utilizing adaptive 1x/1.5x charge-
pump modes and very-low-dropout current regulators, it
achieves high efficiency over the 1-cell lithium-battery
input voltage range. 1MHz fixed-frequency switching
allows for tiny external components and low input ripple.
1x to 1.5x Switchover
When VINis higher than VOUT, the MAX1575 operates in
1x mode and VOUTis pulled up to VIN. The internal cur-
rent regulators regulate the LED current. As VINdrops,
VLED_eventually falls below the switchover threshold of
100mV and the MAX1575 starts switching in 1.5x mode.
When the input voltage rises above VOUTby about 50mV,
the MAX1575 switches back to 1x mode.
Soft-Start
The MAX1575 includes soft-start circuitry to limit inrush
current at turn-on. When starting up, the output capacitor
is charged directly from the input with a ramped current
source (with no charge-pump action) until the output volt-
age approaches 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. During the soft-start time, the
output current is set to 5% of the maximum set by RSET.
In the case of 1.5x mode, soft-start operates until the low-
est of LED1–LED6 reaches regulation. If an overload con-
dition occurs, soft-start repeats every 2ms. If the output is
shorted to ground (or <1.25V), the part reverts to soft-
start and the ramped current source.
MAX1575
White LED 1x/1.5x Charge Pump
for Main and Sub-Displays
PINNAMEFUNCTIONC2PTransfer-Capacitor 2 Positive Connection. Connect a 1µF ceramic capacitor from C2P to C2N.OUTOutput. Connect a 1µF ceramic capacitor from OUT to GND. Connect OUT to the anodes of all the LEDs.
OUT is internally pulled down with 5kΩ during shutdown.SETCurrent-Set Input. Connect a resistor (RSET) from SET to GND to set the maximum LED current. ILED(MAX) =
234 × 0.6V / RSET. SET is internally biased to 0.6V. SET is high impedance during shutdown.ENS
Enable and Dimming Control for LED5 and LED6 (Sub-Display). The first time ENS goes high (50µs min),
LED5 and LED6 turn on at 100% brightness. P ul si ng E N S l ow d i m s the LE D s i n m ul ti p l e step s. If ENS is held
low for more than 2ms (typ), LED5 and LED6 turn off. When ENM and ENS are both held low for more than
2ms (typ), the IC goes into shutdown mode. See Figure 1.ENMnab l e and D i m m i ng C ontr ol for LE D 1–LE D 4 ( M ai n D i sp l ay) . The fi r st ti m e E N M g oes hi g h ( 50µs m i n) ,
LE D 1–LE D 4 tur n on at 100% b r i g htness. P ul si ng E N M l ow d i m s the LE D s i n m ul ti p l e step s. If E N M i s hel d l ow for or e than 2m s ( typ ) , LE D 1–LE D 4 tur n off. W hen E N M and E N S ar e b oth hel d l ow for m or e than 2m s ( typ ) , the IC oes i nto shutd ow n m od e. S ee Fi g ur e 1.LED6LED5
Sub-Display LEDs Cathode Connection. Current flowing into LED_ is described in the ENS and SET
descriptions above. The charge pump regulates the lowest-enabled LED_ voltage to 180mV. Connect LED_
to IN if the LED is not populated. LED_ is high impedance during shutdown.LED4LED3LED2LED1
Main-Display LEDs Cathode Connection. Current flowing into LED_ is described in the ENM and SET
descriptions above. The charge pump regulates the lowest-enabled LED_ voltage to 180mV. Connect LED_
to IN if the LED is not populated. LED_ is high impedance during shutdown.GNDGround. Connect GND as close as possible to system ground and to the ground of the input bypass
capacitor.C1NTransfer-Capacitor 1 Negative Connection. Connect a 1µF ceramic capacitor from C1P to C1N.INSupply Voltage Input. Connect a 1µF ceramic capacitor from IN to GND. The input voltage range is 2.7V to
5.5V. IN is high impedance during shutdown.C2NTransfer-Capacitor 2 Negative Connection. Connect a 1µF ceramic capacitor from C2P to C2N.C1PTransfer-Capacitor 1 Positive Connection. Connect a 1µF ceramic capacitor from C1P to C1N.EPExposed Paddle. Connect the exposed paddle to GND.
Pin Description
MAX1575
Setting the Output Current
The LED current at full (100%) brightness is set (up to
30mA) by a resistor, RSET, as follows:
ENM and ENS Dimming Controls
When the LEDs are enabled by driving ENM or ENS
high, the LED current initially goes to ILED_.
Dimming for the main display is done by pulsing ENM
low (500ns to 500µs pulse width). Dimming for the sub-
display is done by pulsing ENS low (500ns to 500µs
pulse width). Each pulse reduces the LED current by
10%, so after one pulse the LED current is 0.9 x ILED.
The 10th pulse reduces the current by 5% so the LED
current reduces from 0.1 x ILED_to 0.05 x ILED. The
11th pulse sets the LED current back to ILED_. Figure1
shows a timing diagram for EN_.
Because soft-start is longer than intitial tHI, apply dim-
ming pulses quickly upon startup (after initial tHI) to
avoid LED_ current transitioning through full brightness.
If dimming control is not required, EN_ work as simple
on/off controls. Drive ENM high to enable the main
LEDs, or drive ENM low to turn off the main LEDs. Drive
ENS high to enable the sub-LEDs, or drive ENS low to
turn off the sub-LEDs. Drive both ENM and ENS low to
put the IC in low-power shutdown mode.
Shutdown Mode
When both ENM and ENS are held low for 2ms or longer,
the MAX1575 is shut down and put in a low-current
mode. OUT is internally pulled to GND with 5kΩduring
shutdown.
Overvoltage Protection
If any LED fails as an open circuit, the output voltage is
limited to approximately 5V by gating on/off the charge
pump. In case any LED_ is floating or grounded, the
MAX1575 operates in the same overvoltage-protection
mode. To avoid overvoltage-protection mode when using
fewer than six LEDs, connect any unused LED_ to IN.
Thermal Shutdown
The MAX1575 includes a thermal-limit circuit that shuts
down the IC at approximately +160°C. The part turns
on after the IC cools by approximately 20°C.
Applications Information
Driving Fewer than Six LEDs
When driving fewer than six LEDs, connect any unused
LED_ directly to IN (Figure3). When connected in this
manner, the corresponding LED driver is disabled.
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. Alternately, increasing CINto 2.2µF
cuts input ripple in half with only a small increase in foot-
print. The 1x mode always has very low input ripple.VSETLED×06234.
White LED 1x/1.5x Charge Pump
for Main and Sub-Displays
ENM
OR ENS
ILED_SHDN
100%90%80%70%60%50%40%30%20%10%5%
100%90%
SHDN111098765432
tLOtSHDN
2ms (typ)
tSOFT-START
INITIAL tHI
≥50μs
tHI
500ns TO 500μs≥500ns
Figure1. EN_ Timing Diagram

Partno	Mfg	Dc	Qty	Available	Descript
MAX1575ETE+ \|MAX1575ETE	MAXIN	N/a	266	avai	White LED 1x/1.5x Charge Pump for Main and Sub-Displays
MAX1575ETE+ \|MAX1575ETE	MAXIM	N/a	90	avai	White LED 1x/1.5x Charge Pump for Main and Sub-Displays
MAX1575ETE+T	MAXIM	N/a	237	avai	White LED 1x/1.5x Charge Pump for Main and Sub-Displays