MIC2291-15BML TR Micrel Inc, MIC2291-15BML TR Datasheet

IC LED DRIVER PHOTO FLASH 8-MLF

MIC2291-15BML TR

Manufacturer Part Number
MIC2291-15BML TR
Description
IC LED DRIVER PHOTO FLASH 8-MLF
Manufacturer
Micrel Inc
Type
Photo Flash LEDr
Datasheet

Specifications of MIC2291-15BML TR

Topology
PWM, Step-Up (Boost)
Number Of Outputs
1
Internal Driver
Yes
Type - Primary
Flash/Torch
Type - Secondary
White LED
Frequency
1.05MHz ~ 1.35MHz
Voltage - Supply
2.5 V ~ 10 V
Mounting Type
Surface Mount
Package / Case
8-MLF®, QFN
Operating Temperature
-40°C ~ 125°C
Current - Output / Channel
100mA
Internal Switch(s)
Yes
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Voltage - Output
-
Efficiency
-
Other names
MIC2291-15BMLTR
MIC2291-15BMLTR
General Description
The MIC2291 is a 1.2MHz Pulse Width Modulation (PWM),
boost-switching regulator that is optimized for high-current,
white LED photo flash applications. With a guaranteed
switch current of 1.2A, the MIC2291 easily drives a string
of 3 white LEDs in series at 100mA, ensuring a high level
of brightness and eliminating several ballast resistors.
The MIC2291 implements a constant frequency, 1.2MHz
PWM control scheme. The high frequency PWM operation
saves board space by reducing external component sizes.
The added benefit of the constant frequency PWM
scheme, in contrast to variable frequency topologies, is
much lower noise and input ripple injected back to the
battery source.
To optimize efficiency, the feedback voltage is set to only
95mV. This reduces the power dissipation in the current
set resistor, and allows the lowest total output voltage,
hence minimal current draw from the battery.
The MIC2291 is available with 2 levels of over-voltage
protection, 15V, and 34V. This allows designers to choose
the smallest possible external components with the
appropriate voltage ratings for their applications.
The MIC2291 is available in low-profile, Thin SOT23 5-pin
and 8-pin 2mm × 2mm MLF
MIC2291 has a junction temperature range of –40°C to
+125°C.
Data sheets and support documentation can be found on
Micrel’s web site at www.micrel.com.
Typical Application
PowerPAK is a trademark of Siliconix, Inc.
MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc.
May 2007
3V to 4.2V
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (
1-Cell
Li Ion
Thin SOT23 Flash LED Driver
1µF
5
4
MIC2291xD5
VIN
EN
10µH
GND
2
SW
FB
®
1
3
package options. The
95mV
100mA
0.22µF
ceramic
1
Features
• 2.5V to 10V input voltage
• Output voltage up to 34V
• 1.2A switch current
• 1.2MHz PWM operation
• 95mV feedback voltage
• Overvoltage protection (OVP)
• Stable with ceramic capacitors
• <1% line and load regulation
• 1µA shutdown current
• Over temperature protection
• UVLO
• Low-profile Thin SOT23-5 package option
• 2mm × 2mm MLF
• –40°C to +125°C junction temperature range
Applications
• Photo Flash LED driver
• Cell phones
• PDAs
• GPS systems
• Digital cameras
• IP phones
• LED flashlights
408
1.2A PWM Boost Regulator Photo Flash
) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
2mm x 2mm Flash LED Driver with Output OVP
3V to 4.2V
Options for 15V and 34V
1-Cell
Li Ion
1µF
®
MIC2291
LED Driver
package option
MIC2291-15xML
VIN
EN
10µH
GND
OVP
SW
FB
95mV
100mA
M9999-051507
0.22µF

Related parts for MIC2291-15BML TR

MIC2291-15BML TR Summary of contents

Page 1

... The MIC2291 is a 1.2MHz Pulse Width Modulation (PWM), boost-switching regulator that is optimized for high-current, white LED photo flash applications. With a guaranteed switch current of 1.2A, the MIC2291 easily drives a string of 3 white LEDs in series at 100mA, ensuring a high level of brightness and eliminating several ballast resistors. ...

Page 2

... Micrel, Inc. Ordering Information Part Number Marking* MIC2291BD5 SSAA MIC2291YD5 SSAA MIC2291-15BML STA MIC2291-15YML STA** MIC2291-34BML STC MIC2291-34YML STC** Notes: * Under bar / Over bar symbol may not be to scale. ** Over bar symbol located after Pin 1 identifier. Pin Configuration FB GND 5-Pin TSOT23 (D5) ...

Page 3

... I ≤ 40mA OUT 10V EN SW TURN ON TURN OFF V = 10V(6) EN MIC2291BML- 15 only MIC2291BML- 34 only Hysteresis , and the ambient temperature, TA. The maximum allowable power dissipation will result in excessive die (2) ).......................................... 2.5V to 10V IN ) ........................ –40°C to +125°C J 2x2 MLF-8 (θ ) .................................................93°C/W JA Thin SOT23-5 (θ ...

Page 4

... Micrel, Inc. Typical Characteristics May 2007 4 MIC2291 M9999-051507 ...

Page 5

... Micrel, Inc. Functional Characteristics May 2007 5 MIC2291 M9999-051507 ...

Page 6

... Functional Description The MIC2291 is a constant frequency, PWM current mode boost regulator. The block diagram is shown above. The MIC2291 is composed of an oscillator, slope compensation ramp generator, current amplifier, g amplifier, PWM generator, and a 500mA bipolar output transistor. The oscillator generates a 1.2MHz clock. The clock’ ...

Page 7

... If the feedback resistors are disconnected from the circuit or the feedback pin is shorted to ground, the feedback pin will fall to ground potential. This will cause the MIC2291 to switch at full duty-cycle in an attempt to maintain the feedback voltage result the output voltage will climb out of control ...

Page 8

... PWM dimming, and the other is continuous dimming. 1. PWM dimming control is implemented by applying a PWM signal on EN pin as shown in Figure 1. The MIC2291 is turned on and off by the PWM signal. With this method, the LEDs operate with either zero or full current. The average LED current is increased proportionally to the duty-cycle of the PWM signal ...

Page 9

... Micrel, Inc. Package Information May 2007 5-Pin Thin SOT23 (D5) ® 8-Pin 2mm x 2mm MLF (ML) 9 MIC2291 M9999-051507 ...

Page 10

... A Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully May 2007 indemnify Micrel for any damages resulting from such use or sale. © 2004 Micrel, Incorporated. 10 MIC2291 M9999-051507 ...

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