MAQ3203

MAQ3203 MICREL | Alldatasheet

Document overview

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• PDF pages: 23

Technical content

Features

• AEC-Q100 qualified
• 4.5V to 42V input voltage range
• High efficiency ( >90%)
• ±5% LED current accuracy
• Dither enabled for low EMI
• High-side current sense
• Dedicated dimming control input
• Hysteretic control (no compensation!)
• Up to 1.5MHz switching frequency
• Adjustable constant LED current
• Over-temperature protection
• −40°C to +125°C junction temperature range

Applications

• Automotive lighting
• Industrial lighting Typical Application MAQ3203 Step-down LED Driver March 2011 M9999-032411-A

Micrel, Inc. MAQ3203 March 2011 2 M9999-032411-A Ordering Information (1) Part Number Marking Junction Temperature Range Package PWM MAQ3203YM MAQ3203YM −40°C to +125°C 8-Pin SOIC Dither Note: 1. YM is a GREEN RoHS compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free. Pin Configuration 8-Pin SOIC MAQ3203 Pin Description Pin Number Pin Name Pin Function

1 VCC

Voltage Regulator Output. The VCC pin supplies the power to the internal circuitry. The VCC in the output of a linear regulator which is powered from VIN. A 1µF ceramic capacitor is recommended for bypassing and should be placed as close as possible to the VCC and AGND pins. Do not connect to an external load. 2 CS Current-Sense Input. The CS pin provides the high-side current sense to set the LED current with an external sense resistor.

3 VIN

Input Power Supply. VIN is the input supply pin to the internal circuitry and the positive input to the current sense comparator. Due to the high frequency switching noise, a 10µF ceramic capacitor is recommended to be placed as close as possible to VIN and the power ground (PGND) pin for bypassing. Please refer to layout recommendations. 4 AGND Ground pin for analog circuitry. Internal signal ground for all low power sections. 5 EN Enable Input. The EN pin provides a logic level control of the output and the voltage has to be 2.0V or higher to enable the current regulator. The output stage is gated by the DIM pin. When the EN pin is pulled low, the regulator goes to off state and the supply current of the device is greatly reduced (below 1µA). In the off state, during this period the output drive is placed in a "tri-stated" condition, where MOSFET is in an “off” or non-conducting state. Do not drive the EN pin above the supply voltage.

6 DIM

PWM Dimming Input. The DIM pin provides the control for brightness of the LED. A PWM input can be used to control the brightness of LED. DIM high enables the output and its voltage has to be at least 2.0V or higher. DIM low disables the output, regardless of EN “high” state.

7 PGND

Power Ground Pin for Power FET. Power Ground (PGND) is for the high-current switching with hysteretic mode. The current loop for the power ground should be as small as possible and separate from the Analog ground (AGND) loop. Refer to the layout considerations for more details.

8 DRV

Gate-Drive Output. Connect to the gate of an external N-channel MOSFET. The drain of the external MOSFET connects directly to the inductor and provides the switching current necessary to operate in hysteretic mode. Due to the high frequency switching and high voltage associated with this pin, the switch node should be routed away from sensitive nodes.

Micrel, Inc. MAQ3203 March 2011 3 M9999-032411-A Absolute Maximum Ratings (1) ESD Ratings (3) Operating Ratings (2) Junction Thermal Resistance Electrical Characteristics (4) VIN = VEN = VDIM = 12V; CVCC = 1.0µF; TJ = 25°C, bold values indicate −40°C ≤ TA ≤ +125°C; unless noted. Symbol Parameter Condition Min. Typ. Max. Units Input Supply VIN Input Voltage Range (VIN) 4.5 42 V IS Supply Current DRV = open 1 3 mA ISD Shutdown Current VEN = 0V 1 µA UVLO V IN UVLO Threshold VIN rinsing 3.2 4 4.5 V UVLOHYS V IN UVLO Hysteresis 500 mV VCC Supply VCC V CC Output Voltage VIN = 12V, ICC = 10mA 4.5 5 5.5 V Current Limit 201.4 212 222.6 mV VCS(MAX) Current Sense Upper Threshold VCS(MAX ) = VIN − VCS 199 212 225 mV 168 177 186 mV VCS(MIN) Sense Voltage Threshold Low VCS(MIN ) = VIN − VCS 165 177 189 mV VCSHYS V CS Hysteresis 35 mV VCS Rising 50 ns Current Sense Response Time VCS Falling 70 ns CS Input Current VIN − VCS = 220mV 0.5 10 µA Frequency FMAX Switching Frequency 1.5 MHz Dithering (MAQ3203) VDITH V CS Hysteresis Dithering Range(5) ±6 mV FDITHER Frequency Dithering Range (5) % of Switching Frequency ±12 %

Micrel, Inc. MAQ3203 March 2011 4 M9999-032411-A Electrical Characteristics (4) (Continued) VIN = VEN = VDIM = 12V; CVCC = 1.0µF; TJ = 25°C, bold values indicate −40°C ≤ TJ ≤ +125°C; unless noted. Symbol Parameter Condition Min. Typ. Max. Units Enable Input ENHI EN Logic Level High 2.0 V ENLO EN Logic Level Low 0.4 V VEN = 12V 60 µA EN Bias Current VEN = 0V 1 µA Start-Up Time From EN Pin going high to DRV going high 30 µs Dimming Input DIMHI DIM Logic Level High 2.0 V DIMLO DIM Logic Level Low 0.4 V 20 50 DIM Bias Current VDIM = 0V 1 µA DIM Delay Time From DIM Pin going high to DRV going high 450 ns FDIM Maximum Dimming Frequency 20 kHz External FET Driver Pull Up, ISOURCE = 10mA 2 DRV On-Resistance Pull Down, ISINK = -10mA 1.5 Ω Rise Time, CLOAD = 1000pF 13 DRV Transition Time Fall Time, CLOAD = 1000pF 7 ns Thermal Protection TLIM Over-Temperature Shutdown TJ Rising 160 TLIMHYS Over-Temperature Shutdown Hysteresis 20 °C Notes: 1. Exceeding the absolute maximum rating may damage the device. 2. The device is not guaranteed to function outside its operating rating. 4. Specification for packaged product only. 5. Guaranteed by design.

Micrel, Inc. MAQ3203 March 2011 5 M9999-032411-A Typical Characteristics Efficiency vs Input Voltage 100 0 5 10 15 20 25 30 35 40 45 INPUT VOLTAGE (V) EFFICIENCY (%) L=150µH ILED=1A 4LED 6LED 8LED 10LED Efficiency vs Input Voltage 100 0 5 10 15 20 25 30 35 40 45 INPUT VOLTAGE (V) EFFICIENCY (%) L=68µH ILED=1A 4LED 6LED 8LED 10LED Normalized LED Currents vs Input Voltage 0.97 0.98 0.99 1.01 1.02 1.03 0 5 10 15 20 25 30 35 40 45 INPUT VOLTAGE (V) LED CURRENTS (A) L=150µH ILED=1A 4LED 6LED 8LED 10LED 1LED 2LED Normalized LED Currents vs. Input Voltage 0.97 0.98 0.99 1.01 1.02 1.03 0 5 10 15 20 25 30 35 40 45 INPUT VOLTAGE (V) LED CURRENTS (A) L=68µH ILED=1A 4LED 6LED 8LED 10LED 1LED 2LED Frequency vs. Input Voltage 100 150 200 250 300 350 0 5 10 15 20 25 30 35 40 45 INPUT VOLTAGE (V) FREQUENCY (kHz) L=150µH ILED=1A 4LED 6LED 8LED 10LED 1LED 2LED Frequency vs. Input Voltage 100 200 300 400 500 600 700 0 5 10 15 20 25 30 35 40 45 INPUT VOLTAGE (V) FREQUENCY (kHz) L=68µH ILED=1A 4LED 6LED 8LED 10LED 1LED 2LED Duty Cycle vs. Input Voltage 100 0 5 10 15 20 25 30 35 40 45 INPUT VOLTAGE (V) DUTY CYCLE (%) L=150µH ILED=1A 4LED 6LED 8LED 10LED 1LED 2LED Duty Cycle vs Input Voltage 100 0 5 10 15 20 25 30 35 40 45 INPUT VOLTAGE (V) DUTY CYCLE (%) L=68µH ILED=1A 4LED 6LED 8LED 10LED 1LED 2LED Supply Current vs. Input Voltage 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 0 5 10 15 20 25 30 35 40 45 INPUT VOLTAGE (V) SUPPLY CURRENT (mA) TA = 25°C ILED = 0A

Micrel, Inc. MAQ3203 March 2011 6 M9999-032411-A Typical Characteristics (Continued) VCC vs. Input Voltage 0.0 1.0 2.0 3.0 4.0 5.0 6.0 0 5 10 15 20 25 30 35 40 45 INPUT VOLTAGE (V) VCC (V) TA = 25°C ILED = 0A ICC = 0A Enable Threshold vs. Input Voltage 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 0 5 10 15 20 25 30 35 40 45 INPUT VOLTAGE (V) ENABLE THRESHOLD (V) TA=25°C 1LED ILED=1A Current-Sense Voltage vs. Input Voltage 100 150 200 250 0 5 10 15 20 25 30 35 40 45 INPUT VOLTAGE (V) CURRENT SENSE VOLTAGE (mV) VCS_MAX VCS_MIN L=100µA ILED=1A Shutdown Current vs. Input Voltage 0 5 10 15 20 25 30 35 40 45 INPUT VOLTAGE (V) SHUTDOWN CURRENT (µA) TA=25°C ILED=0A Enable Current vs. Enable Voltage 100 120 140 160 0 5 10 15 20 25 30 35 40 45 ENABLE VOTLAGE (V) ENABLE CURRENT (µA) TA=25°C ICC Limit vs. Input Voltage 100 120 140 160 180 200 0 5 10 15 20 25 30 35 40 45 INPUT VOLTAGE (V) ICC LIMIT (mA) TA=25°C VCC=4.2V ILED=0A Supply Current vs. Temperature 0.0 0.2 0.4 0.6 0.8 1.0 1.2 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) SUPPLY CURRENT (mA) VIN=12V ILED=0A VCC vs. Temperature 0.0 1.0 2.0 3.0 4.0 5.0 6.0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) VCC (V) VIN=12V ILED=0A ICC=0A Enable Threshold vs. Temperature 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) ENABLE THRESHOLD (V) ON OFF 1LED ILED=1A

Micrel, Inc. MAQ3203 March 2011 7 M9999-032411-A Typical Characteristics (Continued) Shutdown Current vs. Temperature 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) SHUTDOWN CURRENT (uA) VIN=12V EN=0V Enable Current vs. Temperature -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) ENABLE CURRENT (uA) VIN=12V VEN=VIN Current-Sense Voltage vs. Temperature 100 150 200 250 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) CURRENT SENSE VOLTAGE (mV) VCS_MAX VCS_MIN 1LED ILED=1A D_VCS Switching Frequency vs. Temperature 100 120 140 160 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) SWITCHING FREQUENCY (kHz) VIN=12V 1LED ILED=1A L=100µH UVLO Threshold vs. Temperature 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) UVLO THRESHOLD (V) OF ON L=100µA ILED=1A Thermal Shutdown vs. Input Voltage 100 120 140 160 180 0 5 10 15 20 25 30 35 40 45 INPUT VOLTAGE (V) THERMAL SHUTDOWN (°C) OF ON

Micrel, Inc. MAQ3203 Functional Characteristics March 2010 8 M9999-031811-A

Micrel, Inc. MAQ3203 Functional Characteristics (Continued) March 2010 9 M9999-031811-A

Figure 1. MAQ3203 Block Diagram regulates the LED current over wide input voltage range. current through inductor and LEDs starts decreasing.

Micrel, Inc. MAQ3203 March 2011 11 M9999-032411-A

Application Information

The internal block diagram of the MAQ3203 is shown in Figure 1. The MAQ3203 is composed of a current-sense control scheme very popular for certain applications. Table 1. RCS for LED Current VL is the voltage across inductor L which varies by supply.

• V D is Schottky diode forward drop
• V LED is total LEDs voltage drop
• V IN is input voltage
• I LED is average LED current

make the operating frequency no higher than 1.5MHz. Table 2. Inductor for VIN = 12V, 1 LED Table 3. Inductor for VIN = 24V, 4 LEDs Table 4. Inductor for VIN = 36V, 8 LEDs determined by its RMS and peak current rating. L is inductor average current. higher than the peak current. voltage, output LED current and switching frequency. maximum voltage rating for high reliability requirements. currents as well as meets the cost requirement.

Micrel, Inc. MAQ3203 March 2011 13 M9999-032411-A The switching loss occurs during the MOSFET turn-on and turn-off transition and can be found by: GATE DRV DRV gd 2 gs DRV SWLED IN ) TRAN ( LOSS R V= I ) Q + Q ( ×I F × I × V=P where: RGATE is total MOSFET resistance, Q gs2 and Q gd can be found in a MOSFET manufacturer datasheet. The total power loss is: ) TRAN ( LOSS) CON ( LOSS) TOT ( LOSS P +P =P The MOSFET junction temperature is given by: A JAθ) TOT ( LOSSJ T + R ×P = T The TJ must not exceed maximum junction temperature under any conditions. Snubber A RC voltage snubber is used to damp out high frequency ringing on the switch node caused by parasitic inductance and capacitance. The capacitor is used to slow down the switch node rise and fall time and the resistor damps the ringing. Excessive ringing can cause the MAQ3203 to operate erratically by prematurely tripping its current limit comparator circuitry. The snubber is connected across the Schottky diode as shown in the evaluation board schematic. Capacitor C S (C4) is used to block the DC voltage across the resistor, minimizing the power dissipation in the resistor. This capacitor value should be between two to five times the parasitic capacitance of the MOSFET C OSS and the Schottky diode junction capacitance C j. A capacitor that is too small will have high impedance and prevent the resistor from damping the ringing. A capacitor that is too large causes unnecessary power dissipation in the resistor, which lowers efficiency. The snubber components should be placed as close as possible to the Schottky diode. Placing the snubber too far from the diode or using an etch that is too long or too thin adds inductance to the snubber and diminishes its effectiveness. Proper snubber design requires the parasitic inductance and capacitance be known. A method of determining these values and calculating the damping resistor value is outlined below: 1. Measure the ringing frequency at the switch node which is determined by parasitic L P and C P. Define this frequency as f1. 2. Add a capacitor C S (normally at least 3 times as big as the COSS of the diode) across the diode and measure the new ringing frequency. Define this new (lower) frequency as f2. LP and C P can now be solved using the values of f1, f2 and CS. 3. Add a resistor R S i n s e r i e s w i t h CS to generate critical damping. If the snubber resistance is equal to the characteristic impedance of the resonant circuit (1/sqrt(L PCP)), the resonant circuit will be critically damped and have no ringing. Step 1: First measure the ringing frequency on the switch node voltage when the high-side MOSFET turns on. This ringing is characterized by the equation: P P C L 2π where: CP and LP are the parasitic capacitance and inductance. Step 2: Add a capacitor, C S, in parallel with the Schottky diode. The capacitor value should be approximately 3 times the COSS of D1. Measure the frequency of the switch node ringing, f2. ) C (C L 2π P S P + × Define f’ as: f ff' = Combining the equations for f 1, f 2 and f’ to derive C P, the parasitic capacitance: − × 1 ) (f 2 CC 2 , SP

Micrel, Inc. MAQ3203 March 2011 14 M9999-032411-A LP is solved by re-arranging the equation for f1: () ( ) 2 1 P f C 2π × × Step 3: Calculate the damping resistor. Critical damping occurs at Q = 1: 1C C L R P S P S =+= Solving for R P S P S C C LR += The snubber capacitor, C S, is charged and discharged each switching cycle. The energy stored in C S is dissipated by the snubber resistor, R S, two times per switching period. This power is calculated in the equation below: IN S SSNUBBER V C fP × × = where: fS is the switching frequency for each phase. V IN is the DC input voltage. An alternate method to reduce the switch node ringing is to place a 2.2 Ω resistor in series with the n-channel MOSFETs gate pin. This will slow down both the rising and falling edge of the switch node waveform. Freewheeling Diode The diode provides a conduction path for the inductor current during the switch o ff time. The reverse voltage rating of the diode should be at least 1.2 times the maximum input voltage. A Schottky diode is recommend for highest efficiency. The Schottky diode can be the major source of power loss, especially at the maximum input voltage. The current through the diode is equal to the LED current with a duty cycle of (V IN – VLED)/VIN. The diode dissipation is given by: f IN LEDIN LED D VV ) V (VI P ×−× = Vf is the forward voltage of the diode at I LED. A Schottky diode forward voltage is typically 0.6V at its full rated current. It is normal design practice to use a diode rated at 1.5 to 2 times output current to maintain efficiency. This derating allows V f to drop to approximately 0.5V. When calculating the “worst case” power dissipation, use the maximum input voltage and the actual diode forward voltage drop at the maximum operating temperature; otherwise the calculated power dissipation will be artificially high. The forward voltage drop of a diode decrease as ambient temperature is increased, at a rate of −1.0mV/°C. Input Capacitor The ceramic input capacitor is selected by voltage rating and ripple current rating. To determine the input current ripple rating, the RMS value of the input capacitor can be found by: () D 1 D II LEDCIN(RMS) − × × = The power loss in the input capacitor is: ESRINCIN(RMS) LOSS(CIN) C I P ×= The input capacitor current rating can be considered as ILED/2 under the worst condition D = 50%. LED Ripple Current The LED current is the same as inductor current. If LED ripple current needs to be reduced then place a 4.7µF/50V ceramic capacitor across LED.

Figure 2. Output Voltage Frequency Spectrum

Micrel, Inc. MAQ3203 March 2011 16 M9999-032411-A PCB Layout Guidelines Warning!!! To minimize EMI and output noise, follow these layout recommendations. PCB Layout is critical to achieve reliable, stable and efficient performance. A ground plane is required to control EMI and minimize the inductance in power, signal and return paths. The following guidelines should be followed to insure proper operation of the MAQ3203 regulator. IC Use thick traces to route the input and output power lines. Signal and power grounds should be kept separate and connected at only one location. Input Capacitor Place the input capacitors on the same side of the board and as close to the IC as possible. Keep both the VIN and PGND traces as short as possible. Place several vias to the ground plane close to the input capacitor ground terminal, but not between the input capacitors and IC pins. Use either X7R or X5R dielectric input capacitors. Do not use Y5V or Z5U type capacitors. Do not replace the ceramic input capacitor with any other type of capacitor. Any type of capacitor can be placed in parallel with the input capacitor. If a Tantalum input capacitor is placed in parallel with the input capacitor, it must be recommended for switching regulator applications and the operating voltage must be derated by 50%. In “Hot-Plug” applications, a Tantalum or Electrolytic bypass capacitor must be placed in parallel to ceramic capacitor to limit the over-voltage spike seen on the input supply with power is suddenly applied. In this case an additional Tantalum or Electrolytic bypass input capacitor of 22µF or higher is required at the input power connection if necessary. Inductor Keep the inductor connection to the switch node (MOSFET drain) short. Do not route any digital lines underneath or close to the inductor. To minimize noise, place a ground plane underneath the inductor. Output Capacitor If LED ripple current needs to be reduced then place a 4.7µF/50V capacitor across LED. The capacitor must be placed as close to the LED as possible. MOSFET Place the MOSTET as close as possible to the MAQ3203 to avoid the trace inductance. Provide sufficient copper area on MOSFET ground to dissipate the heat. Diode Place the Schottky diode on the same side of the board as the IC and input capacitor. The connection from the Schottky diode’s Anode to the switching node must be as short as possible. The diode’s Cathode connection to the RCS must be keep as short as possible. RC Snubber If a RC snubber is needed, place the RC snubber on the same side of the board and as close to the Schottky diode as possible. RCS (Current-Sense Resistor) VIN pin and CS pin must be as close as possible to R CS. Make a Kelvin connection to the VIN and CS pin respectively for current sensing. Trace Routing Recommendation Keep the power traces as short and wide as possible. One current flowing loop is during the MOSFET ON time, the traces connecting the input capacitor C IN, R CS, LEDs, Inductor, the MOSFET and back to C IN. The other current flowing loop is during the MOSFET OFF time, the traces connecting R CS, LED, inductor, free wheeling diode and back to R CS. These two loop areas should kept as small as possible to minimize the noise interference, Keep all analog signal traces away from the switching node and its connecting traces.

grounding clip, or a long wire with an alligator clip. erroneously inject it into the measured output ripple. input and output supplies and their respective grounds. ripple measurements can be obtained. Figure 3. Low Noise Measurement

Micrel, Inc. MAQ3203 March 2011 18 M9999-032411-A Evaluation Board Schematic

Micrel, Inc. MAQ3203 March 2011 19 M9999-032411-A Bill of Materials Item Part Number Manufacturer Description Qty. 12105C475KAZ2A AVX (1) C1, C5 GRM32ER71H475KA88L Murata (2) 4.7µF/50V, Ceramic Capacitor, X7R, Size 1210 2 12105C475KAZ2A AVX (1) GRM32ER71H475KA88L Murata (2) C2 C3225X7S1H475M TDK (3) 4.7µF/50V, Ceramic Capacitor, X5R, Size 1210 1 08053D105KAT2A AVX (1) 1µF/25V, Ceramic Capacitor, X5R, Size 0805 1 GRM21BR71E105KA99L Murata (2) C3 C2012X7R1E105K TDK (3) 1µF/25V, Ceramic Capacitor, X7R, Size 0805 1 (Open) 08055A271JAT2A AVX(1) C4 (Open) GRM2165C2A271JA01D Murata(2) 270pF/50V, Ceramic Capacitor NPO, Size 0805 1 SK36-TP MCC (4) SK36 Fairchild (5) D1 SK36-7-F Diodes, Inc.(6) 60V, 3A, SMC, Schottky Diode 1 L1 SLF10145T-680M1R2 TDK(3) 68µH, 1.2A, 0.14Ω, SMT, Power Inductor 1 M1 FDS5672 Fairchild(7) MOSFET, N-CH, 60V, 12A, SO-8 1 R1 CSR 1/2 0.2 1% I Stackpole Electronics, Inc(8) 0.2Ω Resistor, 1/2W, 1%, Size 1206 1 R2, R3 CRCW08051003FKEA Vishay(9) 100k Ω Resistor, 1% , Size 0805 2 R4 CRCW08050000FKEA Vishay(9) 0 Ω Resistor, 1%, Size 0805 1 R5 (Open) CRCW08052R20FKEA Vishay(9) 2.2Ω Resistor, 1%, Size 0805 1 R6 CRCW08051002FKEA Vishay(9) 10k Ω Resistor, 1% , Size 0805 1 U1 MAQ3203YM Micrel, Inc.(10) High-Brightness LED Driver Controller with High-Side Current Sense 1 Notes: 1. AVX: www.avx.com. 2. Murata: www.murata.com. 3. TDK: www.tdk.com. 4. MCC: www.mccsemi.com. 5. Fairchild: www.fairchildsemi.com. 7. Fairchild : www.Fairchildsemi.com. 8. Stackpole Electronics: www.seielect.com. 9. Vishay: www.vishay.com.

Micrel, Inc. MAQ3203 March 2011 20 M9999-032411-A PCB Layout Recommendation Top Assembly Top Layer

Micrel, Inc. MAQ3203 March 2011 21 M9999-032411-A PCB Layout Recommendation (Continued) Bottom Layer

Micrel, Inc. MAQ3203 March 2011 22 M9999-032411-A

Package Information

Micrel, Inc. MAQ3203 March 2011 23 M9999-032411-A Recommended Landing Pattern 8-Pin SOIC MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. This information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry, specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellectual property rights is granted by this document. Except as provided in Micrel’s terms and conditions of sale for such products, Micrel assumes no liability whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. 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 indemnify Micrel for any damages resulting from such use or sale. © 2011 Micrel, Incorporated.