MAX1561ETA+T ,High-Efficiency, 26V Step-Up Converters for Two to Six White LEDsFeaturesThe MAX1561/MAX1599 step-up converters drive up to ♦ Accurate Current Regulation for Unifor ..
MAX1561ETA-T ,High-Efficiency, 26V Step-Up Converters for Two to Six White LEDsApplicationsTOPPART TEMP RANGE PIN-PACKAGECell Phones and Smart PhonesMARKPDAs, Palmtops, and Wirel ..
MAX1561ETA-T ,High-Efficiency, 26V Step-Up Converters for Two to Six White LEDsApplicationsTOPPART TEMP RANGE PIN-PACKAGECell Phones and Smart PhonesMARKPDAs, Palmtops, and Wirel ..
MAX1562ESA ,Programmable 4A USB Current-Limited Switches with Autoreset and Fault BlankingELECTRICAL CHARACTERISTICS(V = +5V, C = 1µF, C = 4.7µF, T = 0°C to +85°C, unless otherwise noted. T ..
MAX1562ESA+ ,Programmable, 4A, USB, Current-Limited Switches with Autoreset and Fault BlankingFeaturesThe MAX1562/MAX1562H/MAX1563 single current-♦ Programmable Current Limit (1A to 4A) withlim ..
MAX1562HESA ,Programmable 4A USB Current-Limited Switches with Autoreset and Fault BlankingFeaturesThe MAX1562/MAX1562H/MAX1563 single current- Programmable Current Limit (1A to 4A) withlim ..
MAX4221CSE+ ,330MHz Buffered Video Switches Crosspoint Building BlocksApplicationsMAX4221CSE 0°C to +70°C 16 Narrow SOVideo-Router and Crosspoint ArraysBroadcast/HDTV-Qu ..
MAX4222ESD ,High-Speed / Single-Supply / Gain of @ / Closed-Loop / Rail-to-Rail Buffers with EnableELECTRICAL CHARACTERISTICS(V = +5V, V = 0V, IN_- = 0V, EN_ = 5V, R = ∞ to 0V, V = V /2, noninvertin ..
MAX4223ESA ,1GHz / Low-Power / SOT23 / Current-Feedback Amplifiers with ShutdownELECTRICAL CHARACTERISTICS(V = +5V, V = -5V, SHDN = 5V, V = 0V, R = ¥ , T = T to T , unless otherwi ..
MAX4223ESA ,1GHz / Low-Power / SOT23 / Current-Feedback Amplifiers with ShutdownELECTRICAL CHARACTERISTICS (continued)(V = +5V, V = -5V, SHDN = 5V, V = 0V, R = ¥ , T = T to T , un ..
MAX4223ESA+ ,1GHz, Low-Power, SOT23, Current Feedback Amplifiers with ShutdownFeaturesThe MAX4223–MAX4228 current-feedback amplifiers♦ Ultra-High Speed and Fast Settling Time:co ..
MAX4223EUT-T ,1GHz / Low-Power / SOT23 / Current-Feedback Amplifiers with ShutdownFeaturesThe MAX4223–MAX4228 current-feedback amplifiers' Ultra-High Speed and Fast Settling Time:co ..
MAX1561ETA+-MAX1561ETA+T-MAX1561ETA-T-MAX1599ETA+T
High-Efficiency, 26V Step-Up Converters for Two to Six White LEDs
neral DescriptionThe MAX1561/MAX1599 step-up converters drive up to
six white LEDs with a constant current to provide back-
light in cell phones, PDAs, and other hand-held
devices. The step-up converter topology allows series
connection of the white LEDs so the LED currents are
identical for uniform brightness. This configuration elim-
inates the need for ballast resistors and expensive fac-
tory calibration.
The MAX1561/MAX1599 include an internal, high-volt-
age, low-RDS(ON)N-channel MOSFET switch for high
efficiency and maximum battery life. A single Dual
Mode™ input provides a simple means of brightness
adjustment and on/off control. Fast 1MHz (500kHz for
the MAX1599) current-mode, pulse-width modulated
(PWM) operation allows for small input and output
capacitors and a small inductor while minimizing ripple
on the input supply/battery. Programmable soft-start
eliminates inrush current during startup.
Both devices are available in a space-saving, 8-pin 3mm
x 3mm thin DFN package with exposed paddle (EP).
ApplicationsCell Phones and Smart Phones
PDAs, Palmtops, and Wireless Handhelds
e-Books and Subnotebooks
White LED Display Backlighting
FeaturesAccurate Current Regulation for Uniform
IlluminationHigh Efficiency Up to 87%Flexible Analog or PWM Dimming ControlUp to 900mW Output Power with Internal 30V
MOSFET SwitchFast 1MHz (MAX1561) or 500kHz (MAX1599) PWM
OperationSmall, Low-Profile External Components2.6V to 5.5V Input Range26V (max) Output with Overvoltage ProtectionOptimized for Low 15mVP-PInput RippleSoft-Start with Zero Inrush Current0.3μA Shutdown CurrentTiny 8-Pin 3mm x 3mm Thin DFN Packageigh-Efficiency, 26V Step-Up Converte
for Two to Six White LEDs
3mm × 3mm
THIN DFNTOP VIEW
GND
COMPCS
PGNDIN
CTRL
OUT
MAX1561
MAX1599
PARTTEMP RANGEPIN-PACKAGETOP
MARK
MAX1561ETA-40°C to +85°C8 TDFN-EP*ACS
MAX1599ETA-40°C to +85°C8 TDFN-EP*AHG
Pin Configuration
Ordering InformationMAX1561
MAX1599
OUT
PGNDCOMP
GND
INPUT 2.6V TO 5.5V
PWM OR
ANALOG
DIMMING
CTRL
OUTPUT UP TO 6 LEDs
Typical Operating Circuit19-2731; Rev 1; 10/03
EVALUATION KIT
AVAILABLEDual Mode is a trademark of Maxim Integrated Products, Inc.
*EP = Exposed paddle.
igh-Efficiency, 26V Step-Up Converters for Two to Six White LEDs
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VIN= 3V, VOUT = 20V, COUT = 0.1μF, CCOMP = 0.15μF, RSENSE = 7.5Ω, VCTRL = 1.5V, Figure 1, TA = 0°C to +85°C,unless other-
wise 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 to GND.................................................................-0.3V to +6V
PGND to GND.......................................................-0.3V to +0.3V
LX, OUT to GND.....................................................-0.3V to +30V
CTRL to GND...................-0.3V to the lower of +6V or (VIN+ 2V)
COMP, CS to GND.........................................-0.3 to (VIN+ 0.3V)
ILX.............................................................................................1A
Continuous Power Dissipation (TA = +70°C)
3mm x 3mm 8-Pin TDFN
(derate 24.4mW/°C above +70°C).............................1950mW
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
PARAMETERCONDITIONSMINTYPMAXUNITSSupply Voltage2.65.5V
UVLO ThresholdVIN rising or falling2.102.382.55V
UVLO Hysteresis40mV
Quiescent CurrentNo switching0.380.55mA
TA = +25°C0.32Shutdown Supply CurrentCTRL = GND, VOUT = VINTA = +85°C1μA
OVLO ThresholdVOUT rising262729V
OVLO Hysteresis2V
VOUT = 26V, VCTRL > 0.24V102030OUT Input Bias CurrentVOUT = VIN, CTRL = GND0.011μA
Output Voltage Range(Note 1)(VIN - VD1)25.5V
ERROR AMPLIFIERCTRL to CS RegulationVCTRL = 1V, VIN = 2.6V to 5.5V0.0950.1000.105V
TA = +25°C0.011CS Input Bias CurrentVCS = VCTRL/10TA = +85°C0.03μA
CTRL Input ResistanceVCTRL ≤ 1.0V290500780kΩ
CTRL Dual-Mode Threshold100170240mV
CTRL Dual-Mode Hysteresis5mV
MAX15616.58.210.5CTRL Shutdown Enable Delay(Note 2)MAX159913.616.421.0ms
CS-to-COMP TransconductanceVCOMP = 1.0V325082μS
OSCILLATORMAX15610.801.01.25Operating FrequencyMAX15990.40.50.6MHz
PWM mode12Minimum Duty CyclePulse skipping0%
Maximum Duty CycleCTRL = IN, CS = GND9194%
igh-Efficiency, 26V Step-Up Converters for Two to Six White LEDs
ELECTRICAL CHARACTERISTICS (continued)(VIN= 3V, VOUT = 20V, COUT = 0.1μF, CCOMP = 0.15μF, RSENSE = 7.5Ω, VCTRL = 1.5V, Figure 1, TA = 0°C to +85°C,unless other-
wise noted. Typical values are at TA= +25°C.)
Note 1:VD1is the diode forward-voltage drop of diode D1 in Figure 1.
Note 2:Time from CTRL going below the dual-mode threshold to IC shutdown.
Note 3:Specifications to -40°C are guaranteed by design and not production tested.
PARAMETERCONDITIONSMINTYPMAXUNITS
N-CHANNEL SWITCHLX On-ResistanceILX = 190mA1.452.25Ω
TA = +25°C0.015LX Leakage CurrentVLX = 28V, CTRL = GNDTA = +85°C1μA
LX Current LimitDuty cycle = 90%450700950mA
ELECTRICAL CHARACTERISTICS(VIN= 3V, VOUT = 20V, COUT = 0.1μF, CCOMP = 0.15μF, RSENSE = 7.5Ω, VCTRL = 1.5V, Figure 1, TA = -40°C to +85°C,unless other-
wise noted.) (Note 3)
PARAMETERCONDITIONSMINTYPMAXUNITSSupply Voltage2.65.5V
UVLO ThresholdVIN rising or falling2.102.55V
Quiescent CurrentNo switching0.55mA
OVLO ThresholdVOUT rising2629V
VOUT = 26V, VCTRL > 0.24V1030OUT Input Bias CurrentVOUT = VIN, CTRL = GND1μA
Output Voltage Range(Note 1)(VIN - VD1)25.5V
ERROR AMPLIFIERCTRL to CS RegulationVCTRL = 1V, VIN = 2.6V to 5.5V0.0930.107V
CTRL Input ResistanceVCTRL ≤ 1.0V240780kΩ
CTRL Dual-Mode Threshold100240mV
MAX1561611CTRL Shutdown Enable Delay(Note 2)MAX15991322ms
CS-to-COMP TransconductanceVCOMP = 1.0V3285μS
OSCILLATORMAX15610.751.25Operating FrequencyMAX15990.370.63MHz
Maximum Duty CycleCTRL = IN, CS = GND91%
N-CHANNEL SWITCHLX On-Resistance2.25Ω
LX Current LimitDuty cycle = 90%450950mA
igh-Efficiency, 26V Step-Up Convertersfor Two to Six White LEDs
Typical Operating Characteristics(Circuit of Figure 1, VIN= 3.6V, ILED= 15mA, L1 = 22μH, CIN= 2.2μF, COUT= 0.1μF, CCOMP= 0.1μF, RSENSE= 7.5Ω, 4 LEDs, = +25°C, unless otherwise noted.)
MAX1561
EFFICIENCY vs. LED CURRENT
(vs. NUMBER of LEDs)
AX1561 toc01
LED CURRENT (mA)
(%
2 LEDs
4 LEDs
6 LEDs
MAX1561
EFFICIENCY vs. LED CURRENT
(vs. INPUT VOLTAGE)
X1561 toc02
LED CURRENT (mA)
(%
4.2VIN
3.6VIN
2.7VIN
MAX1561
EFFICIENCY vs. LED CURRENT
(vs. INDUCTANCE)
X1561 toc03
LED CURRENT (mA)
(%10µH
4.7µH47µH
22µH
MAX1599 EFFICIENCY vs. LED CURRENT
(vs. NUMBER OF LEDs)
AX1561 toc04
LED CURRENT (mA)
(%
6 LEDs
2 LEDs
4 LEDs
MAX1599 EFFICIENCY vs. LED CURRENT
(vs. INPUT VOLTAGE)
1561 toc05
LED CURRENT (mA)
(%
2.7VIN
3.6VIN
4.2VIN
MAX1599 EFFICIENCY vs. LED CURRENT
(vs. INDUCTANCE)
X1561 toc06
LED CURRENT (mA)
(%
47µH
22µH203040501060708090100
LED CURRENT vs. DIRECT-PWM
DIMMING DUTY CYCLEAX1561 toc09
DIRECT-PWM DIMMING DUTY CYCLE (%)
(m
VCTRL = SQUARE WAVE
200Hz < FREQ < 200kHz1015202553035404550
INPUT RIPPLE vs. INDUCTANCEAX1561 toc07
INDUCTANCE (µH)
(m23451678910
INPUT RIPPLE SPECTRUMX1561 toc08
FREQUENCY (MHz)
(m
igh-Efficiency, 26V Step-Up Converters for Two to Six White LEDs
Typical Operating Characteristics (continued)(Circuit of Figure 1, VIN= 3.6V, ILED= 15mA, L1 = 22μH, CIN= 2.2μF, COUT= 0.1μF, CCOMP= 0.1μF, RSENSE= 7.5Ω, 4 LEDs, = +25°C, unless otherwise noted.)
SWITCHING WAVEFORMSMAX1561 toc10
VIN
10mV/div
VOUT
100mV/div
VLX
10V/div
500ns/div
SOFT-START AND SHUTDOWN MAX1561 toc11
VCTRL
1V/div
IIN
50mA/div
VIN
50mV/div
VOUT
5V/div
0mA
20ms/div
VIN = 3.8V Li+ BATTERY
CTRL STEP RESPONSEMAX1561 toc12
VCTRL
1V/div
IIN
50mA/div
VIN
50mV/div
VOUT
5V/div
0mA
20ms/div
VIN = 3.8V Li+ BATTERY
DIRECT-PWM DIMMINGMAX1561 toc13
VCTRL
32kHz
1V/div
IIN
50mA/div
VIN
50mV/div
VOUT
5V/div
0mA
50µs/div
VIN = 3.8V Li+ BATTERY
LINE-TRANSIENT RESPONSEMAX1561 toc14
VIN
500mV/div
IIN
50mA/div
VCS
100mV/div
3.5V
0mA
50µs/div
igh-Efficiency, 26V Step-Up Converters for Two to Six White LEDs
Detailed DescriptionThe MAX1561/MAX1599s’ high efficiency and small size
make them ideally suited to drive up to six series-con-
nected LEDs. The device operates as a boost DC-DC
converter that regulates output current rather than volt-
age. The MAX1561/MAX1599 provide even illumination
by sourcing the same output current through each LED,
eliminating the need for expensive factory calibration.
The fast 1MHz (500kHz for the MAX1599) internal oscil-
lator allows for a small inductor and small input and out-
put capacitors while minimizing input and output ripple.
The single analog control input allows easy adjustment
of LED brightness and on/off control. This allows either
simple logic-level on/off control, analog voltage control,
or PWM duty-cycle control of both brightness and shut-
down. In shutdown, supply current is reduced to a low
0.3μA. A soft-start gradually illuminates the LEDs, elimi-
nating the inrush current during startup.
Soft-StartThe MAX1561/MAX1599 attain soft-start by charging
CCOMPgradually with a current source. When VCOMP
rises above 1.25V, the internal MOSFET begins switch-
ing at a reduced duty cycle. When VCOMPrises above
2.25V, the duty cycle is at its maximum. See the Typical
Operating Characteristicsfor an example of soft-start
operation.
ShutdownThe MAX1561/MAX1599 enter shutdown when VCTRLis
less than 100mV for more than 8.2ms (16.4ms for the
MAX1599). In shutdown, supply current is reduced to
0.3μA by powering down the entire IC except for the
CTRL voltage-detection circuitry. CCOMPis discharged
during shutdown, allowing the device to reinitiate soft-
start when it is enabled. Although the internal N-chan-
nel MOSFET does not switch in shutdown, there is still
a DC current path between the input and the LEDs
through the inductor and Schottky diode. The minimum
forward voltage of the LED array must exceed the max-
imum input voltage to ensure that the LEDs remain off
in shutdown. However, with two or more LEDs, the for-
ward voltage is large enough to keep leakage current
low, less than 1μA (typ). Typical shutdown timing char-
acteristics are shown in the Typical Operating
Characteristics.
Overvoltage ProtectionOvervoltage lockout (OVLO) occurs when VOUTis
above 27V. The protection circuitry stops the internal
MOSFET from switching and causes VCOMPto decay
to 0V. The device comes out of OVLO and into soft-
start when VOUTfalls below 25V.
PINNAMEFUNCTIONOUTOvervoltage Sense. When VOUT is greater than 27V, the internal N-channel MOSFET turns off until VOUT
drops below 25V, then the IC reenters soft-start. Connect a 0.1μF capacitor from OUT to PGND.INInput Voltage Supply. Input voltage range is 2.6V to 5.5V. Connect a 2.2μF capacitor from IN to PGND.CTRL
Brightness Control Input. LED brightness is controlled by the voltage applied to CTRL. Varying the voltage
from 0.24V to 1.62V adjusts the brightness from dim to bright, respectively. Any voltage above 1.62V does
not increase brightness. If CTRL is held below 100mV for more than 8.2ms (16.4ms for the MAX1599), the
IC shuts down.CSCurrent-Sense Feedback Input. Connect a resistor from CS to GND to set the LED bias current. The
voltage at CS regulates to VCTRL / 10 or 0.162V, whichever is lower.COMPCompensation Input. Connect a 0.1μF capacitor (CCOMP) from COMP to GND. CCOMP stabilizes the
converter and controls soft-start. CCOMP discharges to GND when in shutdown.GNDGround. Connect to PGND and the exposed pad directly under the IC.PGNDPower Ground. Connect to GND and the exposed pad directly under the IC.LXInductor Connection. This pin is high impedance during shutdown.
Exposed
PadEPGround. Connect directly to GND and PGND under the IC.
Pin Description
