MAX1916EZT+-MAX1916EZT+T Fast Delivery |IC PHOENIX CO.,LIMITED

MAX1916EZT+T ,Low-Dropout, Constant-Current Triple White LED Bias SupplyFeaturesThe MAX1916 low-dropout bias supply for white LEDs♦ Low 200mV Dropout at 9mAis a high-perfo ..
MAX1917EEE ,Tracking / Sinking and Sourcing / Synchronous Buck Controller for DDR Memory and Termination SuppliesELECTRICAL CHARACTERISTICS(V+ = 12V, V = V = 2.5V, C = 4.7µF, C = 1µF, C = 0.22µF, V = 0, ILIM = VL ..
MAX1917EEE+ ,Tracking, Sinking and Sourcing, Synchronous Buck Controller for DDR Memory and Termination SuppliesApplicationsDDR Memory Power Notebook ComputersOrdering InformationSupplyDesktop ComputersPART TEMP ..
MAX1917EEE+T ,Tracking, Sinking and Sourcing, Synchronous Buck Controller for DDR Memory and Termination SuppliesMAX191719-2335; Rev 1; 6/02Tracking, Sinking and Sourcing, Synchronous BuckController for DDR Memor ..
MAX1917EEE+T ,Tracking, Sinking and Sourcing, Synchronous Buck Controller for DDR Memory and Termination SuppliesFeaturesThe MAX1917 provides a complete power-manage-♦ 25A Sourcing and Sinking Currentment solutio ..
MAX1917EEE-T ,Tracking, Sinking and Sourcing, Synchronous Buck Controller for DDR Memory and Termination SuppliesELECTRICAL CHARACTERISTICS(V+ = 12V, V = V = 2.5V, C = 4.7µF, C = 1µF, C = 0.22µF, V = 0, ILIM = VL ..
MAX487ECSA-T ,±15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 TransceiversApplications:ate from a single +5V supply.MAX3293/MAX3294/MAX3295: 20Mbps, +3.3V,Drivers are short- ..
MAX487EEPA ,15kV ESD-Protected / Slew-Rate-Limited / Low-Power / RS-485/RS-422 TransceiversFeaturesThe MAX481E, MAX483E, MAX485E, MAX487E–MAX491E, ' ESD Protection: ±15kV—Human Body Modelan ..
MAX487EEPA+ ,±15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 TransceiversELECTRICAL CHARACTERISTICS(V = 5V ±5%, T = T to T , unless otherwise noted.) (Notes 1, 2)CC A MIN M ..
MAX487EESA ,15kV ESD-Protected / Slew-Rate-Limited / Low-Power / RS-485/RS-422 TransceiversApplicationsIndustrial-Control Local Area Networks__Selection TableRECEIVER/ QUIESCENT NUMBER OFPAR ..
MAX487EESA ,15kV ESD-Protected / Slew-Rate-Limited / Low-Power / RS-485/RS-422 Transceiversapplications. For
MAX487EESA ,15kV ESD-Protected / Slew-Rate-Limited / Low-Power / RS-485/RS-422 TransceiversApplicationsMAX481EESA -40°C to +85°C 8 SOLow-Power RS-485 TransceiversOrdering Information continu ..

MAX1916EZT+-MAX1916EZT+T
Low-Dropout, Constant-Current Triple White LED Bias Supply
MAX1916
Low-Dropout, Constant-Current riple White LED Bias Supply
19-2067; Rev 0; 7/01
General Description
The MAX1916 low-dropout bias supply for white LEDs
is a high-performance alternative to the simple ballast
resistors used in conventional white LED designs. The
MAX1916 uses a single resistor to set the bias current
for three LEDs, which are matched to 0.3%. The
MAX1916 consumes only 40µA of supply current when
enabled and 0.05µA when disabled.
The MAX1916’s advantages over ballast resistors
include significantly better LED-to-LED bias matching,
much lower bias variation with supply voltage variation,
significantly lower dropout voltage, and in some appli-
cations, significantly improved efficiency. The MAX1916
requires a 200mV dropout at a 9mA load on each out-
put to match the LED brightness.
The MAX1916 is available in a space-saving 6-pin Thin
SOT23 package.
Applications
Next-Generation Wireless Handsets
PDAs, Palmtops, and Handy Terminals
Digital Cameras, Camcorders
Battery-Powered Equipment
FeaturesLow 200mV Dropout at 9mAUp to 60mA/LED Bias Current0.3% LED Current MatchingSimple LED Brightness ControlLow 40µA Supply CurrentLow 0.05µA Shutdown Current2.5V to 5.5V Supply Voltage RangeThermal Shutdown ProtectionTiny 6-Pin Thin SOT23 Package (1mm High)
GND
LED3SETLED1LED2
MAX1916
THIN SOT23-6
TOP VIEW
Pin Configuration
MAX1916OFF
GND
SETLED1LED2LED3
VCTRLV+
Typical Operating Circuit
Ordering Information
PARTTEMP. RANGEPIN-
PACKAGE
TOP
MARK
MAX1916EZT-40°C to +85°C 6 Thin SOT23AAAG
MAX1916
Low-Dropout, Constant-Current riple White LED Bias Supply
ABSOLUTE MAXIMUM RATINGS
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.
Note 1:Limits are 100% production tested at TA= +25°C. Limits over the operating temperature range are guaranteed through
correlation using statistical quality control (SQC) methods.
Note 2:Dropout Voltage is defined as the LED_ to GND voltage at which current sink into LED_ drops 20% from the value at
VLED= 1V.
Note 3:Dropout Voltage is defined as the LED_ to GND voltage at which current sink into LED_ drops 10% from the value at
VLED= 1V.
EN, SET, LED1, LED2, LED3 to GND .....................-0.3V to +6V
Continuous Power Dissipation (TA= +70°C)
6-Pin Thin SOT23 (derate 9.1mW/°C above +70°C) ...727mW
Operating Temperature Range .........................-40°C to +85°C
Storage Temperature Range ...........................-65°C to +150°C
Lead Temperature (soldering, 10s)...................................300°C
ELECTRICAL CHARACTERISTICS
(VEN= 3.3V, VLED1= VLED2= VLED3= 1V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
Operating Voltage RangeVENEN is the power-supply input2.55.5V
VEN rising2.22.47VUndervoltage Lockout
ThresholdVUVLOHysteresis85mV
SET Input Current RangeISET5260μA
SET to LED_ Current RatioILED/ISET, ISET = 42μA207230253A/A
SET Bias VoltageVSETISET = 42μA1.1541.2151.276V
TA = -40°C to +25°C0.011SET Leakage Current
in Shutdown
EN = GND,
VSET = 3.3VTA = -40°C to +85°C5μA
LED_-to-LED_ Current MatchingISET = 42μA0.35%
Maximum LED_ Sink CurrentILED_Each LED_60mA
ISET = 22μA (Note 2)100180
ISET = 42μA (Note 3)200360LED_ Dropout Voltage
ISET = 84μA (Note 3)230410
LED_ Leakage Current
in Shutdown
VLED1 = VLED2 =
VLED3 = 5.5V, EN =
GND, each LED_
TA = +25°C0.011μA
Input High VoltageVIHVEN > VIH for enable2.5
Input Low VoltageVILVEN < VIL for disable2.2V
VEN = 2.5V to 5.5V, EN is the power-supply
input40100EN Input Bias CurrentIEN
VEN = 0.4VTA = +25°C0.051
Thermal Shutdown Temperature170°C
Thermal Shutdown Hysteresis10°C
MAX1916
Low-Dropout, Constant-Current riple White LED Bias Supply
LED CURRENT vs.
V+ BIAS VOLTAGE
MAX1916 toc01
V+ BIAS VOLTAGE (V)
LED CURRENT (mA)356
LED3
LED2
LED1
UNMATCHED LEDS
OUTPUT CURRENT
vs. VEN SUPPLY VOLTAGE
MAX1916 toc02
VEN SUPPLY VOLTAGE (V)
OUTPUT CURRENT (mA)
LED CURRENT vs.
TEMPERATURE
MAX1916 toc03
TEMPERATURE (°C)
LED CURRENT (mA)
LED CURRENT
vs. RSET
MAX1916 toc04
RSET (kΩ)
LED CURRENT (mA)
VCTRL = 5.0V
VCTRL = 3.3V
VCTRL = 2.5V
VCTRL = 1.8V
LED CURRENT (ILED)
vs. VCTRL
MAX1916 toc05
VCTRL (V)
LED CURRENT (mA)
A: RSET = 10kΩ
B: RSET = 15kΩ
C: RSET = 22kΩ
D: RSET = 33kΩ
E: RSET = 47kΩ
F: RSET = 68kΩ
G: RSET = 100kΩ
LED DROPOUT VOLTAGE
vs. CURRENT
MAX1916 toc06
LED CURRENT (mA)
LED DROPOUT VOLTAGE (mV)
Typical Operating Characteristics
(VEN= 3.3V, VCTRL= 3.3V, RSET= 24.9kΩ, V+ = 5V, TA= +25°C, unless otherwise noted.) (Circuit of Figure 1)
MAX1916
Low-Dropout, Constant-Current riple White LED Bias Supply
ENABLE AND SHUTDOWN RESPONSE
MAX1916 toc08
20mA
ILED
20mA/div
VEN
2V/div
40μs/div
IEN SUPPLY CURRENT
vs. VEN SUPPLY VOLTAGE
MAX1916 toc07
VEN SUPPLY VOLTAGE (V)
IEN
SUPPLY CURRENT (
VCTRL TRANSIENT RESPONSE
MAX1916 toc09
20mA
10mA
ILED
10mA/div
VCTRL
1V/div
10μs/div
V+ TRANSIENT RESPONSE
MAX1916 toc10
20mA
10mA
ILED
10mA/div
1V/div
20μs/div
Typical Operating Characteristics (continued)
(VEN= 3.3V, VCTRL= 3.3V, RSET= 24.9kΩ, V+ = 5V, TA= +25°C, unless otherwise noted.) (Circuit of Figure 1)
Detailed Description
The MAX1916 provides constant-current bias supply
for white LED designs. The MAX1916 uses a single
resistor to set the bias current for up to three LEDs.
LED bias currents are matched to 0.3% by the
MAX1916’s unique current-matching architecture
(Figure 1). Supply current (IEN) is a low 40µA in normal
operation and 0.05µA when disabled.
The MAX1916 offers several advantages over using
ballast resistors, such as improved LED-to-LED bright-
ness matching, lower bias variation with supply voltage
changes, significantly lower dropout voltage, and in
some applications, significantly improved efficiency.
The MAX1916 achieves a 200mV dropout with a 9mA
load on each output.
For circuits requiring only one or two LEDs, leave
unused LED outputs unconnected.
Enable Input
EN powers the input of the MAX1916. Drive EN high
(> 2.5V) to enable the device; drive EN low (< 2.2V) to
disable the device. When driven high, EN draws 40µA
to power the IC. Driving EN low forces LED1, LED2,
LED3, and SET into a high-impedance state.
MAX1916
Low-Dropout, Constant-Current riple White LED Bias Supply
PINNAMEFUNCTION
1EN
Enable Input/Power Input. Drive high (> 2.5V) to enable; drive low (< 2.2V) to disable. When
disabled, SET, LED1, LED2, and LED3 are high impedance. When enabled, EN is the power input
for the MAX1916.GNDGroundSETBias Current Set Input. The current flowing into SET sets the bias current into each LED by
ILED_= 230 x ISET. VSET is internally biased to 1.215V. SET is high impedance when EN is low.LED3LED 3 Cathode Connection. Current flowing into LED3 is 230 times the current flowing into SET.
LED3 is high impedance when EN is low.LED2LED 2 Cathode Connection. Current flowing into LED2 is 230 times the current flowing into SET.
LED2 is high impedance when EN is low.LED1LED 1 Cathode Connection. Current flowing into LED1 is 230 times the current flowing into SET.
LED1 is high impedance when EN is low.
Pin Description
MAX1916
OFF
THERMAL
SHUTDOWN
GND
SETLED1LED2LED3
VCTRLV+
230X230X
1.215V
RSET
UVLOREF
230X
Figure 1. MAX1916 Simplified Functional Diagram
MAX1916
Setting the Output Current
SET controls the LED bias current. Current flowing into
LED1, LED2, and LED3 is 230 times greater than the
current flowing into SET. Set the output current as fol-
lows:
where VSET= 1.215V, VCTRLis an external voltage
between 1.8V and 5.5V, and RSETis the resistor con-
nected between VCTRLand SET (Figure 1).
Applications InformationVery Low-Cost, High-Efficiency Solution (Figure 2).
A battery (single Li+ or three NiMH cells) powers
the LEDs directly. This is the least expensive and
most efficient architecture. Due to the high forward
voltage of white LEDs (3.3V), the LED brightness
may dim slightly at the end of battery life. The
MAX1916’s current-regulating architecture and low
dropout greatly minimize this effect compared to
using simple ballast resistors. The enable function
of the MAX1916 turns on and off the LEDs. An exist-
ing low-dropout regulator is used as VCTRL.Brightness Adjustment Using a DAC (Figure 3). A
DAC is used as VCTRLsuch that the LED brightness
may be dynamically adjusted to eliminate factory
calibration. A battery (single Li+ or three NiMH
cells) or a regulated power source drives the LEDs.Existing 5V Supply (Figure 4). Use an existing sys-
tem regulator, such as the MAX684, to provide the
required LED voltage and provide power to other
circuits. Due to the high forward voltage of white
LEDs (3.3V), use a 3.6V to 5.5V regulated supply to
provide enough voltage headroom such that the
LEDs will maintain constant brightness for any bat-
tery voltage. Use the existing regulated supply as
VCTRL.
Chip Information
TRANSISTOR COUNT: 220
PROCESS: BiCMOSVVLEDCTRLSET
SET_()=−230
Low-Dropout, Constant-Current riple White LED Bias Supply
MAX1916OFF
EXISTING
LDO
GND
SETLED1LED2LED3
VCTRL
TO OTHER
CIRCUITS
Figure 2. Very Low-Cost, High-Efficiency Solution
MAX1916OFF
DAC
GND
SETLED1LED2LED3
VCTRL
Figure 3. Brightness Adjust Using DAC
MAX1916OFF
EXISTING
REGULATOR
GND
SETLED1LED2LED3
VBATT5.0VTO OTHER
CIRCUITS
Figure 4. Existing 5V Supply Circuit

Partno	Mfg	Dc	Qty	Available	Descript
MAX1916EZT+	MAIXM	N/a	2500	avai	Low-Dropout, Constant-Current Triple White LED Bias Supply
MAX1916EZT+T	MAXIM	N/a	5000	avai	Low-Dropout, Constant-Current Triple White LED Bias Supply