mic4801 Micrel Semiconductor, mic4801 Datasheet

no-image

mic4801

Manufacturer Part Number
mic4801
Description
Manufacturer
Micrel Semiconductor
Datasheet
General Description
The MIC4801 is a high efficiency White LED (WLED)
driver designed to drive a single LED up to 600mA. The
MIC4801 constant current driver is designed to drive high
power LED’s in various lighting applications. The MIC4801
provides the highest possible efficiency as this architecture
has no switching losses present in traditional charge
pumps or inductive boost circuits. It features a typical
dropout of 130mV at 400mA. This allows the LEDs to be
driven directly from the voltage source eliminating
switching noise/losses present with the use of boost
circuitry. The high accuracy (±1% typical) current regulated
WLED channel ensures uniform display illumination under
all conditions. The brightness is controlled through an Ultra
Fast PWM™ Control interface operating down to less than
1% duty cycle.
The MIC4801 is available in an 8-pin SOIC package with a
junction temperature range of -40°C to +125°C.
Datasheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
____________________________________________________________________________________________________________
Typical Application
Ultra Fast PWM is a trademark of Micrel, Inc.
January 2011
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (
High Current Lighting Schematic
Features
• High Efficiency (no Voltage Boost losses)
• Ultra Fast PWM™ control (200Hz to 500kHz)
• Input voltage range: 3.0V to 5.5V
• Dropout of 130mV at 400mA
• Programmable LED current with external resistor
• Current accuracy of ±1% typical
Applications
• Bill board displays
• Marquee displays
• Instrument displays
• Architectural lighting
408
) 944-0800 • fax + 1 (408) 474-1000 •
High Efficiency 600mA Single Channel
Ultra Fast PWM™ Control
Linear WLED Driver with
MIC4801
http://www.micrel.com
M9999-011811-A

Related parts for mic4801

mic4801 Summary of contents

Page 1

... The brightness is controlled through an Ultra Fast PWM™ Control interface operating down to less than 1% duty cycle. The MIC4801 is available in an 8-pin SOIC package with a junction temperature range of -40°C to +125°C. Datasheets and support documentation can be found on Micrel’s web site at: www.micrel.com. ...

Page 2

... LED1 driver input. Connect LED anode to VIN and cathode to this pin. All D1 pins must be connected to the LED LED1 driver input. Connect LED anode to VIN and cathode to this pin. All D1 pins must be connected to the LED. January 2011 Temperature Range –40°C to +125°C 8-Pin SOIC (M) (Top View) 2 MIC4801 Package 8-Pin SOIC M9999-011811-A ...

Page 3

... ....................................... ........................ –40°C to +125°C J SOIC-8L (θ )..................................................98.9°C/W JA ≤ 125°C; unless noted. J Min Typ 374 416 130 2.2 0.01 1.2 0. 0 MIC4801 IN IN Max Units 458 mA 250 mV 2 µA 0 µA 60 µs µs µs µs µ M9999-011811-A ...

Page 4

... DUTY CYCLE (%) Typical I vs. V LED LED 2 VIN = 5.0V 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 2.4 2.6 2.8 3 3.2 3.4 3.6 LED FORWARD VOLTAGE (V) 4 MIC4801 Supply Bias Current vs. LED Anode Voltage 6 5.5 VIN = 3.0V VIN = 5.5V 5 4.5 4 3.5 3 2.5 2 VIN = 2.5V 1 4.64kΩ SET 0 5.5 5 4.5 4 3.5 3 2.5 LED ANODE VOLTAGE (V) LED Current vs. PWM Duty Cycle ...

Page 5

... Micrel Inc. Functional Characteristics January 2011 5 MIC4801 M9999-011811-A ...

Page 6

... Micrel Inc. Functional Diagram Functional Description The MIC4801 is a single channel linear LED driver with a maximum 600mA current capability. The LED driver is designed to maintain proper current regulation with LED current accuracy of ±10%. The dropout is 130mV at 400mA. The low dropout of the linear drivers allows the ...

Page 7

... EN The EN pin is equivalent to the enable pin for the linear drivers on the MIC4801. It can also be used for dimming by applying a PWM signal. See the PWM Dimming Interface in the Application Information section for details. Pulling the EN low for more than 40ms puts the MIC4801 into a low I sleep mode ...

Page 8

... WLED current response when a PWM signal is applied to the EN pin (1) From the low I sleep mode higher PWM frequencies require a logic Q high enable signal for 60μs to first enable the MIC4801 prior to PWM dimming. LED Current vs. PWM Duty Cycle 900 VIN = 5V ...

Page 9

... Figure 8. PWM Signal at 50% Duty Cycle (I Figure 9. PWM Signal at 80% Duty Cycle (I January 2011 Thermal Consideration The MIC4801 thermal considerations involve calculating the junction temperature based on the voltage drop across the package and the LED current. The voltage drop across the package is equal to the voltage at D1 with respect to ground times the LED current ...

Page 10

... Micrel Inc. MIC4801 Typical Application Circuit Bill of Materials Item Part Number C1608X5R0J225K 06036D225KAT2A C1 GRM188R60J225KE19D VJ0603G225KXYAT LED R42180 R1 CRCW060312K1FKEA U1 MIC4801YM Notes: 1. TDK: www.tdk.com 2. AVX: www.avx.com 3. Murata: www.murata.com 4. Vishay: www.vishay.com 5. Seoul Semi: http://www.acriche.com/en 6. Micrel, Inc.: www.micrel.com January 2011 Manufacturer (1) TDK (2) AVX Ceramic Capacitor, 2.2µF, 6.3V, X5R, Size 0603 ...

Page 11

... Micrel Inc. Layout Recommendations January 2011 Top Layer Bottom Layer 11 MIC4801 M9999-011811-A ...

Page 12

... 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 January 2011 8-Pin SOIC (M) indemnify Micrel for any damages resulting from such use or sale. © 2010 Micrel, Incorporated. 12 http://www.micrel.com M9999-011811-A MIC4801 ...

Related keywords