MIC23155 3MHz PWM 2A Buck Regulator with HyperLight Load® and Power Good General Description Features The MIC23155 is a high efficiency 3MHz 2A synchronous buck regulator with HyperLight Load® mode, Power Good output indicator, and programmable soft start. HyperLight Load® provides very high efficiency at light loads and ultra fast transient response which makes the MIC23155 perfectly suited for supplying processor core voltages. An additional benefit of this proprietary architecture is very low output ripple voltage throughout the entire load range with the use of small output capacitors. The tiny 2.5mm x 2.5mm Thin MLF® package saves precious board space and requires only four external components. The MIC23155 is designed for use with a very small inductor, down to 0.47µH, and an output capacitor as small as 2.2 µF that enables a total solution size, less than 1mm in height. The MIC23155 has a very low quiescent current of 22µA and achieves a peak efficiency of 94% in continuous conduction mode. In discontinuous conduction mode, the MIC23155 can achieve 85% efficiency at 1mA. The MIC23155 is available in a 10-pin 2.5mm x 2.5mm Thin MLF® package with an operating junction temperature range from –40°C to +125°C. Datasheets and support documentation can be found on Micrel’s web site at: www.micrel.com. • • • • • • • • • • • • • • • • • Input voltage: 2.7V to 5.5V Output voltage: fixed or adjustable (down to 0.7V) Up to 2A output current Up to 94% peak efficiency 85% typical efficiency at 1mA Power Good output Programmable Soft Start 22µA typical quiescent current 3MHz PWM operation in continuous conduction mode Ultra fast transient response Active output discharge when disabled Low output voltage ripple Fully integrated MOSFET switches 0.01µA shutdown current Thermal shutdown and current limit protection 10-pin 2.5mm x 2.5mm Thin MLF® –40°C to +125°C junction temperature range Applications • • • • • • Solid State Drives (SSD) Smart phones Tablet PCs Mobile handsets Portable devices (PMP, PND, UMPC) WiFi/WiMax/WiBro applications ____________________________________________________________________________________________________________ Typical Application Fixed Output Voltage Adjustable Output Voltage HyperLight Load is a registered trademark of Micrel, Inc. MLF and MicroLeadFrame are registered trademarks Amkor Technology, Inc. Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com April 2011 M9999-041811-A Micrel Inc. MIC23155 Ordering Information Part Number Marking Code Nominal Output Voltage Junction Temp. Range Package MIC23155-GYMT QLG 1.8V –40°C to +125°C 10-Pin 2.5mm x 2.5mm Thin MLF® MIC23155YMT QLA Adjustable –40°C to +125°C 10-Pin 2.5mm x 2.5mm Thin MLF® Notes: 1. Other fixed output voltage options available. Contact Micrel Marketing for details. 2. Thin MLF® is a GREEN RoHS compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free. 3. Thin MLF® ▲ = Pin 1 identifier. Pin Configuration 2.5mm x 2.5mm Thin MLF® (MT) Fixed Output Voltage (Top View) 2.5mm x 2.5mm Thin MLF® (MT) Adjustable Output Voltage (Top View) Pin Description Pin Number Pin Number (Fixed) (Adjustable) 1 1 SW Output Switch Node 2 2 EN Enable: Logic high enables operation of the regulator. Logic low will shut down the device. Do not leave floating. 3 3 SNS 4 - NC Pin Name Pin Function Output voltage sensing pin. When disabled, provides output discharge. Not internally connected. - 4 FB Feedback connection for output voltage sensing 5 5 PG Power good indicator. Open drain output 6 6 SS Programmable soft start pin. Do not leave floating 7 7 AGND 8,9 8,9 VIN 10 10 PGND EPAD EPAD HS PAD April 2011 Analog Ground. Ground path for bias and control circuitry. Input Voltage Supply. Power Ground. Ground path for high current circuitry Exposed heat sink pad. Connect to PGND 2 M9999-041811-A Micrel Inc. MIC23155 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VIN)... …………………………..2.7V to 5.5V Enable Input Voltage (VEN) .. ……………………….0V to VIN Sense Voltage (VSNS) .......................................... 0.7V to VIN Junction Temperature Range (TJ)... ….-40°C ≤ TJ ≤ +125°C Thermal Resistance 2.5mm x 2.5mm Thin MLF-10 (θJA) ...................90°C/W 2.5mm x 2.5mm Thin MLF-10 (θJC) ...................63°C/W Supply Voltage (VIN) ........................................... -0.3V to 6V Sense Voltage (VSNS) .........................................-0.3V to VIN Output Switch Voltage (VSW) ..............................-0.3V to VIN Enable Input Voltage (VEN).. ..............................-0.3V to VIN Power Good Voltage (VPG).................................-0.3V to VIN Storage Temperature Range .. ……………-65°C to +150°C Lead temperature (soldering, 10 sec.) ....................... 260°C ESD Rating(3) ................................................. ESD Sensitive Electrical Characteristics(4) TA = 25°C; VIN = VEN = 3.6V; L = 1.0µH; COUT = 4.7µF unless otherwise specified. Bold values indicate –40°C ≤ TJ ≤ +125°C, unless noted. Parameter Condition Min. Supply Voltage Range Under Voltage Lockout Threshold 2.7 Rising 2.45 Under Voltage Lockout Hysteresis 2.55 IOUT = 0mA , SNS > 1.2 * VOUTNOM Shutdown Current VEN = 0V; VIN = 5.5V VIN = 3.6V if VOUTNOM < 2.5V, ILOAD = 20mA VIN = 4.5V if VOUTNOM ≥ 2.5V, ILOAD = 20mA 2.65 5 µA +2.5 % 0.6355 V -2.5 Current Limit SNS = 0.9*VOUTNOM Output Voltage Line Regulation VIN = 3.6V to 5.5V if VOUTNOM < 2.5V, ILOAD = 20mA VIN = 4.5V to 5.5V if VOUTNOM ≥ 2.5V, ILOAD = 20mA 20mA < ILOAD < 500mA, VIN = 3.6V if VOUTNOM < 2.5V 20mA < ILOAD < 500mA, VIN = 5.0V if VOUTNOM ≥ 2.5V 20mA < ILOAD < 1A, VIN = 3.6V if VOUTNOM < 2.5V 20mA < ILOAD < 1A, VIN = 5.0V if VOUTNOM ≥ 2.5V ISW = 100mA PMOS 0.20 ISW = -100mA NMOS 0.19 Switching Frequency IOUT = 180mA Soft Start Time Soft Start Current 0.6045 2.2 V mV 0.01 IFB 0.62 1 nA 3.3 A 0.3 %/V 0.3 % 0.7 % Ω 3 MHz VOUT = 90%, CSS = 470pF 320 µs VSS = 0V 2.7 µA Power Good Threshold (Rising) 85 Power Good Threshold Hysteresis Rising Power Good Pull Down Resistance Enable Input Voltage V µA Feedback Bias Current Power Good Delay Time 5.5 45 ILOAD = 20mA PWM Switch RDSON Units 22 Feedback Regulation Voltage Output Voltage Load Regulation Max. 75 Quiescent Current Output Voltage Accuracy (Fixed) Typ. 91 95 7 % 68 µs 165 Ω Logic Low 0.5 Logic High V V 1.2 Enable Input Current % 0.1 2 µA 165 Ω Over-temperature Shutdown 160 °C Shutdown Hysteresis 20 °C Output Discharge Resistance April 2011 EN=0V 3 M9999-041811-A Micrel Inc. MIC23155 Notes: 1. Exceeding the absolute maximum rating may damage the device. 2. The device is not guaranteed to function outside its operating rating. 3. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5kΩ in series with 100pF. 4. Specification for packaged product only. April 2011 4 M9999-041811-A Micrel Inc. MIC23155 Typical Characteristics Efficiency (VOUT = 3.3V) vs. Output Current 100 90 80 80 70 V IN = 5.0V 60 V IN = 4.2V 50 40 30 90 80 70 V IN = 5.0V 60 V IN = 4.2V 50 V IN = 3.6V 40 30 20 20 COUT=4.7µF L=1µH 10 0 1 10 1000000 100 1000 10 100 1000 1 10 100 1000 VOUT Rise Time vs. CSS Current Limit vs. Input Voltage Quiescent Current vs. Input Voltage 1000 4.0 3.5 3.0 2.5 2.0 1.5 VOUTNOM = 1.8V 1.0 COUT = 4.7µF 0.5 VOUTNOM = 1.8V COUT = 4.7µF 0.0 10 1000 10000 3.0 CSS (pF) Shutdown Current vs. Input Voltage 3.5 4.0 4.5 5.0 5.5 5 4.0 4.5 INPUT VOLTAGE (V) 5.0 5.5 15 T=-45°C 10 No Switching SNS > VOUTNOM * 1.2 5 COUT = 4.7µF 3.0 3.5 4.0 4.5 5.0 Line Regulation (HLL) 2.00 5.5 1.95 1.90 1.85 IOUT = 300mA IOUT = 1A 1.80 1.75 1.70 VOUTNOM = 1.8V 1.90 IOUT = 80mA 1.85 IOUT = 20mA 1.80 1.75 IOUT = 1mA 1.70 VOUTNOM = 1.8V 1.65 COUT = 4.7µF 1.60 3.5 20 Line Regulation (CCM) 1.65 0 25 INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 10 T=25°C 2.5 1.95 15 T=125°C 30 INPUT VOLTAGE (V) 2.00 20 35 0 2.5 100000 1000000 10000 40 QUIESCENT CURRENT (µA) CURRENT LIMIIT (A) RISE TIME (µs) COUT=4.7µF L=1µH OUTPUT CURRENT (mA) 100 SHUTDOWN CURRENT (nA) 30 OUTPUT CURRENT (mA) 10000 April 2011 V IN =3.6V 40 OUTPUT CURRENT (mA) 100000 3.0 V IN =4.2V 50 10000 4.5 2.5 V IN =2.7V 10 5.0 100 V IN =5.0V 60 0 1 10000 70 20 COUT=4.7µF L=1µH 10 0 Efficiency (VOUT = 1.8V) vs. Output Current 100 EFFICIENCY (%) 90 EFFICIENCY (%) EFFICIENCY (%) 100 Efficiency (VOUT = 2.5V) vs. Output Current COUT = 4.7µF 1.60 2.5 3.0 3.5 4.0 4.5 INPUT VOLTAGE (V) 5 5.0 5.5 2.5 3.0 3.5 4.0 4.5 5.0 5.5 INPUT VOLTAGE (V) M9999-041811-A Micrel Inc. MIC23155 Typical Characteristics (Continued) Load Regulation (HLL) 2.00 2.00 VOUTMAX vs. VIN 5.0 1.85 1.80 1.75 1.70 VIN = 3.6V COUT = 4.7µF 1.60 0 0.65 40 80 120 160 1.75 1.70 VIN = 3.6V COUT = 4.7µF OUTPUT CURRENT (A) Feedback Voltage vs. Temperature Switching Frequency vs. Temperature VIN = 3.6V 0.60 VOUTNOM= 1.8V 0.59 0 20 40 60 80 TEMPERATURE (°C) 100 120 IOUT = 400mA 3.5 3.0 IOUT = 1.2A 2.5 2.0 1.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 INPUT VOLTAGE (V) Switching Frequency vs. Output Current 5 0.61 IOUT = 100mA 4.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 OUTPUT CURRENT (A) 0.62 4.5 1.5 VOUTNOM = 1.8V 1.60 0.63 April 2011 1.80 200 0.64 -40 -20 1.85 1.65 VOUTNOM =1.8V 1.65 1.90 5.0 4.5 SWITCHING FREQUENCY (MHz) 1.90 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1.95 SWITCHING FREQUENCY (MHz) OUTPUT VOLTAGE (V) 1.95 FEEBACK VOLTAGE (V) Load Regulation (CCM) 4.0 4 L=0.47µH 3.5 3.0 3 2.5 L=1.0µH 2.0 2 VIN = 3.6V VOUTNOM = 1.8V 1 COUT = 4.7µF 1.5 1.0 0.5 0.0 0 -40 -20 0 20 40 60 80 TEMPERATURE (°C) 6 100 120 0.1 1 10 100 1000 10000 OUTPUT CURRENT (mA) M9999-041811-A Micrel Inc. MIC23155 Functional Characteristics April 2011 7 M9999-041811-A Micrel Inc. MIC23155 Functional Characteristics (Continued) April 2011 8 M9999-041811-A Micrel Inc. MIC23155 Functional Characteristics (Continued) April 2011 9 M9999-041811-A Micrel Inc. MIC23155 Functional Diagram Figure 1. Simplified MIC23155 Functional Block Diagram – Fixed Output Voltage Figure 2. Simplified MIC23155 Functional Block Diagram – Adjustable Output Voltage April 2011 10 M9999-041811-A Micrel Inc. MIC23155 Functional Description VIN The input supply (VIN) provides power to the internal MOSFETs for the switch mode regulator along with the internal control circuitry. The VIN operating range is 2.7V to 5.5V. An input capacitor with a minimum voltage rating of 6.3V is recommended. Due to the high switching speed, a minimum 2.2µF bypass capacitor placed close to VIN and the power ground (PGND) pin is required. Refer to the layout recommendations for details. PGND The power ground pin is the ground path for the high current in PWM mode. The current loop for the power ground should be as small as possible and separate from the analog ground (AGND) loop as applicable. Refer to the layout recommendations for more details. PG The power good (PG) pin is an open drain output which indicates when the output voltage is within regulation. This is indicated by a logic high signal when the output voltage is above the PG threshold. Connect a pull up resistor greater than 5kΩ from PG to VOUT. EN A logic high signal on the enable pin activates the output voltage of the device. A logic low signal on the enable pin deactivates the output and reduces supply current to 0.01µA. MIC23155 features external soft start circuitry via the SS pin that reduces inrush current and prevents the output voltage from overshooting at start up. Do not leave the EN pin floating. SS The SS pin is used to control the output voltage ramp up time. The approximate equation for the ramp time in milliseconds is 270x103 x ln(10) x CSS. For example, for a CSS = 470pF, TRISE ≈ 300µs. Refer to the “VOUT Rise Time vs. CSS” graph in the Typical Characteristics section. The minimum recommended value for CSS is 200pF. SW The switch (SW) connects directly to one end of the inductor and provides the current path during switching cycles. The other end of the inductor is connected to the load, SNS pin, and output capacitor. Due to the high speed switching on this pin, the switch node should be routed away from sensitive nodes whenever possible. FB The feedback (FB) pin is provided for the adjustable voltage option. This is the control input for setting the output voltage. A resistor divider network is connected to this pin from the output and is compared to the internal 0.62V reference within the regulation loop. The output voltage can be calculated using the following equation: SNS The sense (SNS) pin is connected to the output of the device to provide feedback to the control circuitry. The SNS connection should be placed close to the output capacitor. Refer to the layout recommendations for more details. The SNS pin also provides the output active discharge circuit path to pull down the output voltage when the device is disabled. R1 ⎞ ⎛ VOUT = VREF ⋅ ⎜1 + ⎟ R2 ⎝ ⎠ Recommended feedback resistor values: AGND The analog ground (AGND) is the ground path for the biasing and control circuitry. The current loop for the signal ground should be separate from the power ground (PGND) loop. Refer to the layout recommendations for more details. April 2011 11 VOUT R1 R2 1.2V 274k 294k 1.5V 316k 221k 1.8V 301k 158k 2.5V 324k 107k 3.3V 309k 71.5k M9999-041811-A Micrel Inc. MIC23155 ⎡ ⎛ 1 − VOUT /VIN ⎞⎤ IPEAK = ⎢IOUT + VOUT ⎜⎜ ⎟⎟⎥ ⎝ 2 × f × L ⎠⎦ ⎣ As shown by the calculation above, the peak inductor current is inversely proportional to the switching frequency and the inductance. The lower the switching frequency or the inductance, the higher the peak current. As input voltage increases, the peak current also increases. The size of the inductor depends on the requirements of the application. Refer to the Typical Application Circuit and Bill of Materials for details. DC resistance (DCR) is also important. While DCR is inversely proportional to size, DCR can represent a significant efficiency loss. Refer to the Efficiency Considerations. The transition between Continuous Conduction Code (CCM) to HyperLight Load® mode is determined by the inductor ripple current and the load current. Application Information The MIC23155 is a high performance DC-DC step down regulator offering a small solution size. Supporting an output current up to 2A in a tiny 2.5mm x 2.5mm Thin MLF® package, the IC requires only four external components while meeting today’s miniature portable electronic device needs. Using the HyperLight Load® switching scheme, the MIC23155 is able to maintain high efficiency throughout the entire load range while providing ultra fast load transient response. The following sections provide additional device application information. Input Capacitor A 2.2µF ceramic capacitor or greater should be placed close to the VIN pin and PGND pin for bypassing. A Murata GRM188R60J475ME84D, size 0603, 4.7µF ceramic capacitor is recommended based upon performance, size and cost. A X5R or X7R temperature rating is recommended for the input capacitor. Output Capacitor The MIC23155 is designed for use with a 2.2µF or greater ceramic output capacitor. Increasing the output capacitance will lower output ripple and improve load transient response but could also increase solution size or cost. A low equivalent series resistance (ESR) ceramic output capacitor such as the Murata GRM188R60J475ME84D, size 0603, 4.7µF ceramic capacitor is recommended based upon performance, size and cost. Both the X7R or X5R temperature rating capacitors are recommended. Inductor Selection When selecting an inductor, it is important to consider the following factors: • Inductance • Rated current value • Size requirements • DC resistance (DCR) The diagram shows the signals for High Side switch Drive (HSD) for Ton control, the Inductor current, and the Low Side switch Drive (LSD) for TOFF control. In HLL mode, the inductor is charged with a fixed Ton pulse on the high side switch. After this, the low side switch is turned on and current falls at a rate VOUT/L. The controller remains in HLL mode while the inductor falling current is detected to cross approximately -50mA. When the LSD (or TOFF) time reaches its minimum and the inductor falling current is no longer able to reach the threshold, the part is in CCM mode. Once in CCM mode, the TOFF time will not vary. Therefore, it is important to note that if L is large enough, the HLL transition level will not be triggered. That inductor is: The MIC23155 is designed for use with a 0.47µH to 2.2µH inductor. For faster transient response, a 0.47µH inductor will yield the best result. For lower output ripple, a 2.2µH inductor is recommended. Maximum current ratings of the inductor are generally given in two methods; permissible DC current, and saturation current. Permissible DC current can be rated either for a 40°C temperature rise or a 10% to 20% loss in inductance. Ensure the inductor selected can handle the maximum operating current. When saturation current is specified, make sure that there is enough margin so that the peak current does not cause the inductor to saturate. Peak current can be calculated as follows: April 2011 LMAX = 12 VOUT ⋅135ns 2 ⋅ 50mA M9999-041811-A Micrel Inc. MIC23155 ⎡ ⎛ VOUT × IOUT Efficiency Loss = ⎢1 − ⎜⎜ ⎢⎣ ⎝ VOUT × IOUT + PDCR Efficiency Considerations Efficiency is defined as the amount of useful output power, divided by the amount of power supplied. ⎛V ×I Efficiency % = ⎜⎜ OUT OUT ⎝ VIN × IIN Efficiency loss due to DCR is minimal at light loads and gains significance as the load is increased. Inductor selection becomes a trade off between efficiency and size in this case. ⎞ ⎟⎟ × 100 ⎠ There are two types of losses in switching converters; DC losses and switching losses. DC losses are simply the power dissipation of I2R. Power is dissipated in the high side switch during the on cycle. Power loss is equal to the high side MOSFET RDSON multiplied by the switch current squared. During the off cycle, the low side Nchannel MOSFET conducts, also dissipating power. Device operating current also reduces efficiency. The product of the quiescent (operating) current and the supply voltage represents another DC loss. The current required driving the gates on and off at a constant 3MHz frequency and the switching transitions make up the switching losses. HyperLight Load® Mode The MIC23155 uses a minimum on and off time proprietary control loop (patented by Micrel). When the output voltage falls below the regulation threshold, the error comparator begins a switching cycle that turns the PMOS on and keeps it on for the duration of the minimum-on-time. This increases the output voltage. If the output voltage is over the regulation threshold, then the error comparator turns the PMOS off for a minimumoff-time until the output drops below the threshold. The NMOS acts as an ideal rectifier that conducts when the PMOS is off. Using a NMOS switch instead of a diode allows for lower voltage drop across the switching device when it is on. The asynchronous switching combination between the PMOS and the NMOS allows the control loop to work in discontinuous mode for light load operations. In discontinuous mode, the MIC23155 works in HyperLight Load® to regulate the output. As the output current increases, the off time decreases, thus provides more energy to the output. This switching scheme improves the efficiency of MIC23155 during light load currents by only switching when it is needed. As the load current increases, the MIC23155 goes into continuous conduction mode (CCM) and switches at a frequency centered at 3MHz. The equation to calculate the load when the MIC23155 goes into continuous conduction mode may be approximated by the following formula: Efficiency (VOUT = 1.8V) 100 90 EFFICIENCY (%) 80 70 VIN = 4.2V VIN =2.7V 60 VIN = 3.6V 50 VIN = 5V 40 30 20 10 COUT = 4.7µF 0 1 10 100 1000 ⎞⎤ ⎟⎥ × 100 ⎟ ⎠⎥⎦ 10000 OUTPUT CURRENT (mA) Figure 3. Efficiency Under Load ⎛ (V − VOUT ) × D ⎞ ⎟⎟ ILOAD > ⎜⎜ IN 2L × f ⎝ ⎠ As shown in the previous equation, the load at which the MIC23155 transitions from HyperLight Load® mode to PWM mode is a function of the input voltage (VIN), output voltage (VOUT), duty cycle (D), inductance (L) and frequency (f). As shown in Figure 4, as the Output Current increases, the switching frequency also increases until the MIC23155 goes from HyperLight Load® mode to PWM mode at approximately 180mA. The MIC23155 will switch at a relatively constant frequency around 3MHz once the output current is over 180mA. The figure above shows an efficiency curve. From no load to 100mA, efficiency losses are dominated by quiescent current losses, gate drive and transition losses. By using the HyperLight Load® mode, the MIC23155 is able to maintain high efficiency at low output currents. Over 100mA, efficiency loss is dominated by MOSFET RDSON and inductor losses. Higher input supply voltages will increase the gate-to-source threshold on the internal MOSFETs, thereby reducing the internal RDSON. This improves efficiency by reducing DC losses in the device. All but the inductor losses are inherent to the device. In which case, inductor selection becomes increasingly critical in efficiency calculations. As the inductors are reduced in size, the DC resistance (DCR) can become quite significant. The DCR losses can be calculated as follows: PDCR = IOUT2 x DCR From that, the loss in efficiency due to inductor resistance can be calculated as follows: April 2011 13 M9999-041811-A Micrel Inc. MIC23155 Switching Frequency vs. Output Current SWITCHING FREQUENCY (MHz) 5.0 4.5 4.0 L=0.47µH 3.5 3.0 2.5 L=1.0µH 2.0 1.5 1.0 0.5 0.0 0.1 1 10 100 1000 10000 OUTPUT CURRENT (mA) Figure 4. SW Frequency vs. Output Current April 2011 14 M9999-041811-A Micrel Inc. MIC23155 Typical Application Circuit (Fixed Output) Bill of Materials Item C1 C2 Part Number Manufacturer C1608X5R0J475K TDK GRM188R60J475KE19D Murata TDK GRM188R60J475KE84D Murata 1 Ceramic Capacitor, 4.7µF, 6.3V, X5R, Size 0603 1 C1608NPO0J471K TDK Ceramic Capacitor, 470pF, 6.3V, NPO, Size 0603 VLS3012ST-1R0N1R9 TDK 1µH, 2A, 60mΩ, L3.0mm x W3.0mm x H1.0mm LQH44PN1R0NJ0 Murata R3 CRCW06031002FKEA Vishay(3) U1 MIC23155-xYMT Micrel, Inc.(4) L1 Qty. (2) C1608X5R0J475K C3 Description (1) 1 1 1µH, 2.8A, 50mΩ, L4.0mm x W4.0mm x H1.2mm Resistor,10k, Size 0603 1 3MHz 2A Buck Regulator with HyperLight Load® Mode 1 Notes: 1. TDK: www.tdk.com 2. Murata: www.murata.com 3. Vishay: www.vishay.com 4. Micrel, Inc.: www.micrel.com April 2011 15 M9999-041811-A Micrel Inc. MIC23155 Typical Application Circuit (Adjustable Output) Bill of Materials Item C1 C2 Part Number C1608X5R0J475K Manufacturer TDK GRM188R60J475KE19D Murata(2) C1608X5R0J475K TDK GRM188R60J475KE84D Murata C1608NPO0J471K TDK VLS3010ST-1R0N1R9 TDK C3 L1 LQH44PN1R0NJ0 Description Qty. (1) 1 Ceramic Capacitor, 4.7µF, 6.3V, X5R, Size 0603 1 Ceramic Capacitor, 470pF, 6.3V, NPO, Size 0603 1 1µH, 2A, 60mΩ, L3.0mm x W3.0mm x H1.0mm (2) Murata 1µH, 2.8A, 50mΩ, L4.0mm x W4.0mm x H1.2mm 1 R1 CRCW06033013FKEA Vishay(3) Resistor,301k, Size 0603 1 R2 CRCW06031583FKEA Vishay Resistor,158k, Size 0603 1 R3 CRCW06031002FKEA Vishay U1 MIC23155YMT Resistor,10k, Size 0603 (4) Micrel, Inc. 1 ® 3MHz 2A Buck Regulator with HyperLight Load Mode 1 Notes: 1. TDK: www.tdk.com 2. Murata: www.murata.com 3. Vishay: www.vishay.com 4. Micrel, Inc.: www.micrel.com April 2011 16 M9999-041811-A Micrel Inc. MIC23155 PCB Layout Recommendations Top Layer Bottom Layer April 2011 17 M9999-041811-A Micrel Inc. MIC23155 Package Information 10-Pin 2.5mm x 2.5mm Thin MLF April 2011 18 ® M9999-041811-A Micrel Inc. MIC23155 Recommended Land Pattern 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. April 2011 19 M9999-041811-A