MIC33153

MIC33153 MICREL | Alldatasheet

Document overview

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Technical content

Features

• Internal inductor − Simplifies design to two external capacitors
• Input voltage: 2.7V to 5.5V
• Output voltage: fixed or adjustable (0.62V to 3.6V)
• Up to 1.2 A output current
• Up to 93% peak efficiency
• 85% typical efficiency at 1mA
• Power Good (PG) output
• Programmable soft start
• 22µA typical quiescent current
• 4MHz PWM operation in continuous mode
• Ultra-fast transient response
• Low ripple output voltage − 35mVpp ripple in HyperLight Load™ mode − 7mV output voltage ripple in full PWM mode
• 0.01µA shutdown current
• Thermal shutdown and current limit protection
• 14-pin 3.0 x 3.5 x 1.1mm MLF ® package
• –40° C to +125°C junction temperature range

Applications

• Solid State Drives (SSD)
• Mobile handsets
• Portable media/MP3 players
• Portable navigation devices (GPS)
• WiFi/WiMax/WiBro modules
• Wireless LAN cards
• Portable applications Typical Application Fixed Output Voltage Adjustable Output Voltage September 2010 M9999-092910-A

Micrel Inc. MIC33153 September 2010 2 M9999-092910-A

Ordering Information

Part Number1 Marking Code Nominal Output Voltage Junction Temperature Range Package2 MIC33153-4YHJ −4 33153 1.2V –40°C to +125°C 14-pin 3.0 x 3.5 x 1.1mm MLF® MIC33153YHJ MIC 33153 Adjustable –40°C to +125°C 14-pin 3.0 x 3.5 x 1.1mm MLF® Notes: 1. Other options available (1V - 3.3V). Contact Micrel Marketing for details. 2. MLF is GREEN RoHS compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free. Pin Configuration 14- Pin 3.0mm x 3.5mm MLF® (HJ) Fixed Output Voltage (Top View) 14- Pin 3.0mm x 3.5mm MLF® (HJ) Adjustable Output Voltage (Top View) Pin Description Pin Number (Fixed) Pin Number (Adjustable) Pin Name Pin Function 1 1 SS Soft Start: Place a capacitor from this pin to ground to program the soft start time. Do not leave floating, 100pF minimum CSS is required. 2 2 AGND Analog Ground: Connect to central ground point where all high current paths meet (CIN, COUT, PGND) for best operation. 3 3 VIN Input Voltage: Connect a capacitor to ground to decouple the noise. 4 4 PGND Power Ground. 5,6,7 5,6,7 OUT Output Voltage: The output of the regulator. Connect to SNS pin. For adjustable option, connect to feedback resistor network. 8,9,10 8,9,10 SW Switch: Internal power MOSFET output switches before Inductor 11 11 EN Enable: Logic high enables operation of the regulator. Logic low will shut down the device. Do not leave floating. 12 12 SNS Sense: Connect to VOUT as close to output capacitor as possible to sense output voltage. 13 13 PG Power Good: Open drain output for the Power Good (PG) indicator. Use a pull up resistor from this pin to a voltage source to detect a power good condition. 14 − NC Not Internally Connected. − 14 FB Feedback: Connect a resistor divider from the output to ground to set the output voltage.

Micrel Inc. MIC33153 September 2010 3 M9999-092910-A Absolute Maximum Ratings(1) Storage Temperature Range ..…………… −65°C to +150°C Operating Ratings(2) Enable Input Voltage (VEN) .. ……………………….0V to V IN Junction Temperature Range (TJ).. …. −40°C ≤ TJ ≤ +125°C Thermal Resistance Electrical Characteristics(4) TA = 25°C; VIN = VEN = 3.6V; COUT = 4.7µF unless otherwise specified. Bold values indicate –40°C ≤ TJ ≤ +125°C, unless noted. Parameter Condition Min. Typ. Max. Units Supply Voltage Range 2.7 5.5 V Under-Voltage Lockout Threshold (Turn-On) 2.45 2.55 2.65 V Under-Voltage Lockout Hysteresis 75 mV Quiescent Current IOUT = 0mA , SNS > 1.2 * VOUT Nominal 22 45 µA Shutdown Current VEN = 0V; VIN = 5.5V 0.01 5 µA Feedback Regulation Voltage ILOAD = 20mA 0.6045 0.62 0.6355 V Current Limit SNS = 0.9*VOUTNOM 2.2 3.3 A 1mA < ILOAD < 1A, VIN = 3.6V if VOUTNOM < 2.5V 0.8 Output Voltage Load Regulation 1mA < ILOAD < 1A, VIN = 5.0V if VOUTNOM ≥ 2.5V 0.85 %/A PWM Switch ON-Resistance ISW = 100mA PMOS ISW = −100mA NMOS 0.2 0.19 Ω Maximum Switching Frequency IOUT = 300mA 4 MHz Soft Start Time VOUT = 90%, CSS = 470pF 320 µs Soft Start Current VSS = 0V 2.7 µA PG Threshold (Rising) 86 92 96 % PG Threshold Hysteresis 7 % PG Delay Time Rising 68 µs Enable Threshold Turn-On 0.5 0.9 1.2 V Enable Input Current 0.1 2 µA Over-Temperature Shutdown 160 °C 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.

Micrel Inc. MIC33153 September 2010 4 M9999-092910-A Typical Characteristics Efficiency (VOUT = 3.3V) 100 1 10 100 1000 10000 OUTPUT CURRENT (mA ) EFFICIENCY (%) COUT = 4.7µF VIN = 4.2V VIN = 5.0V VIN = 5.5V Efficiency (VOUT = 2.5V) 100 1 10 100 1000 10000 OUTPUT CURRENT (mA ) EFFICIENCY (%) COUT = 4.7µF VIN = 3.6V VIN = 4.2V VIN = 5.5V Efficiency (VOUT = 1.8V) 100 1 10 100 1000 10000 OUTPUT CURRENT (mA ) EFFICIENCY (%) COUT = 4.7µF VIN = 3.0V VIN = 3.6V VIN = 4.2V Efficiency (VOUT = 1.5V) 100 1 10 100 1000 10000 OUTPUT CURRENT (mA ) EFFICIENCY (%) COUT = 4.7µF VIN = 3.0V VIN = 3.6V VIN = 4.2V Efficiency (VOUT = 1.2V) 100 1 10 100 1000 10000 OUTPUT CURRENT (mA ) EFFICIENCY (%) COUT = 4.7µF VIN = 3.0V VIN = 3.6V VIN = 4.2V Efficiency (VOUT = 1.0V) 100 1 10 100 1000 10000 OUTPUT CURRENT (mA ) EFFICIENCY (%) COUT = 4.7µF VIN = 3.0V VIN = 3.6V VIN = 4.2V Current Limit vs. Input Voltage 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 INPUT VOLTAGE (V) CURRENT LIMIT (A) Quiescent Current vs. Input Voltage INPUT VOLTAGE (V) QUIESCENT CURRENT (µA) No Switching SNS > 1.2 * VOUTNOM COUT = 4.7µF T = 125°C T = 20°C T = - 45°C Shutdown Current vs. Input Voltage INPUT VOLTAGE (V) SHUTDOWN CURRENT (nA) Line Regulation (Light Load) 1.700 1.720 1.740 1.760 1.780 1.800 1.820 1.840 1.860 1.880 1.900 2 . 533 . 544 . 555 . 5 INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) VOUTNOM = 1.8V COUT = 4.7µF IOUT = 160mA IOUT = 40mA IOUT = 1mA Line Regulation (Heavy Load) 1.700 1.720 1.740 1.760 1.780 1.800 1.820 1.840 1.860 1.880 1.900 2.5 3 3.5 4 4.5 5 5.5 INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) VOUTNOM = 1.8V COUT = 4.7µF IOUT = 500mA IOUT = 300mA IOUT = 1000mA Load Regulation 1.100 1.150 1.200 1.250 1.300 0 200 400 600 800 1000 1200 OUTPUT CURRENT (mA) OUTPUT VOLTAGE (V) VOUTNOM = 1.2V COUT = 4.7µF VIN = 4.2V VIN = 3.6V VIN = 3.0V

Micrel Inc. MIC33153 September 2010 5 M9999-092910-A Typical Characteristics Feedback Voltage vs. Temperature 0.59 0.60 0.61 0.62 0.63 0.64 0.65 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) FB VOLTAGE (V) VIN = 3.6V UVLO Threshold vs. Temperature 2.46 2.47 2.48 2.49 2.50 2.51 2.52 2.53 2.54 2.55 2.56 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) UVLO THRESHOLD (V) ON OFF Enable Threshold vs. Temperature 0.2 0.4 0.6 0.8 1.2 1.4 1.6 1.8 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (%) VEN THRESHOLD (V) VOUT = 3.6V Turn ON Turn OFF Enable Voltage vs. Input Voltage 0.2 0.4 0.6 0.8 1.2 1.4 1.6 1.8 INPUT VOLTAGE (V) ENABLE VOLTAGE (V) COUT = 4.7µF IOUT = 150mA Enable ON Enable OFF VOUT Rise Time vs. CSS 100 1000 10000 100000 1000000 100 1000 10000 100000 1000000 CSS (pF) RISE TIME (µs) SW Frequency vs. Temperature 0.5 1.5 2.5 3.5 4.5 5.5 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) SW FREQUENCY (MHz)VIN = 3.6V COUT = 4.7µF Load = 400mA Switching Frequency vs. Output Current 0.5 1.5 2.5 3.5 4.5 0.1 1 10 100 1000 10000 OUTPUT CURRENT (mA) SW FREQUENCY (MHz) VIN = 3.6V VIN = 4.2V

Micrel Inc. MIC33153 September 2010 6 M9999-092910-A Functional Characteristics

Micrel Inc. MIC33153 September 2010 7 M9999-092910-A Functional Characteristics (Continued)

Micrel Inc. MIC33153 September 2010 8 M9999-092910-A Functional Characteristics (Continued)

Micrel Inc. MIC33153 September 2010 10 M9999-092910-A 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 so 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. 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. MIC33153 features ex ternal soft start circuitry via the soft start (SS) pin that reduces in rush current and prevents the output voltage from overshooting at start up. Do not leave the EN pin floating. 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. 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. 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. 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. Power Good PG The Power Good (PG) pin is an open drain output which indicates logic high when the output voltage is typically above 92% of its steady state voltage. When the output voltage is below 86%, the PG pin indicates logic low. A pull up resistor of more than 10k Ω should be connected from PG to V OUT. SS The soft start (SS) pin is used to control the output voltage ramp up time. The approximate equation for the ramp time in milliseconds is: T(ms) = 270x10 3 x ln (10) x CSS where: T is the time in milliseconds and C SS is the external soft start capacitance (in Farads). For example, for a C SS = 470pF, T rise ~ 0.3ms or 300µs. See the Typical Characterist ics curve for a graphical guide. The minimum recommended value for C SS is 100pF. FB The feedback (FB) pin is provided for the adjustable voltage option (no internal connection for fixed options). This is the control input for programming 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 programmed between 0.65V and 3.6V using the following equation: ⎛ + × =R2 R11 V VREFOUT where: R1 is the top resistor, R2 is the bottom resistor. Example feedback resistor values: VOUT R1 R2 1.2V 274k 294k 1.5V 316k 221k 1.8V 301k 158k 2.5V 324k 107k 3.3V 309k 71.5k

Micrel Inc. MIC33153 September 2010 12 M9999-092910-A 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 R DSON. 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: P DCR = IOUT 2 x DCR From that, the loss in efficiency due to inductor resistance can be calculated as follows: 100P I V I V1 LossEfficiency DCROUTOUT OUTOUT × + × ×− = 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. The effect of MOSFET voltage drops and DCR losses in conjunction with the maximum duty cycle combine to limit maximum output voltage for a given input voltage. The following graph shows this relationship based on the typical resistive losses in the MIC33153: VOUTMAX vs. VIN 0.5 1.5 2.5 3.5 4.5 2.5 3 3.5 4 4.5 5 5.5 INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1.2A 800mA 400mA 100mA HyperLight Load™ Mode MIC33153 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 t he regulation threshold, then the error comparator turns the PMOS off for a minimum off time until the output drops below the threshold. The NMOS acts as an ideal rect ifier 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 MIC33153 works in pulse frequency modulation (PFM) 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 MIC33153 during light load currents by only switching when it is needed. As the load current increases, the MIC33153 goes into continuous conduction mode (CCM) and switches at a frequency centered at 4MHz. The equation to calculate the load when the MIC33153 goes into continuous conduction mode may be approximated by the following formula: × −> f 2L D ) V (VI OUTIN LOAD As shown in the above equation, the load at which MIC33153 transitions from HyperLight Load™ mode to PWM mode is a function of the input voltage (VIN), output voltage (V OUT), duty cycle (D), inductance (L) and frequency (f). For example, if V IN = 3.6V, V OUT=1.8V, D=0.5, f=4MHz and the internal inductance of MIC33153 is 0.47μH, then the device will enter HyperLight Load™ mode or PWM mode at approximately 200mA.

Micrel Inc. MIC33153 September 2010 13 M9999-092910-A As can be seen in the diagram, total thermal resistance RθJA = RθJC + RθCA. Hence this can also be written: Power Dissipation Considerations As with all power devices, the ultimate current rating of the output is limited by the thermal properties of the package and the PCB it is mounted on. There is a simple, Ohm’s law type of relationship between thermal resistance, power dissipation and temperature which is analogous to an electrical circuit: ( ) AMBJADISS J T RθP T +×= Since effectively all of the power loss in the converter is dissipated within the MIC33153 package, P DISS can be calculated thus: 1)η 1( P POUTDISS − × = Where: η = Efficiency taken from efficiency curves RθJC and RθJA are found in the operating ratings section of the datasheet. From this simple circuit, one can calculate V X if one knows ISOURCE, VZ and the resistor values, R XY and R YZ using the equation: Example: A MIC33153 is intended to drive a 1A load at 1.8V and is placed on a printed circuit board which has a ground plane area of at least 25mm square. The voltage source is a Li-ion battery with a lower operating threshold of 3V and the ambient temperature of the assembly can be up to 50 ºC. () Z YZ XYSOURCEX V R RI V + + ×= Thermal circuits can be considered using these same rules and can be drawn similarly replacing current sources with power dissipation (in Watts), resistance with thermal resistance (in ºC/W) and voltage sources with temperature (in ºC): Summary of variables: IOUT = 1A VOUT = 1.8V VIN = 3V to 4.2V TAMB = 50ºC RθJA = 55ºC/W from Datasheet η @ 1A = 80% (worst case with V IN=4.2V from the Typical Characteristics Efficiency vs. Load graphs) 1)0.80 The worst case switch and inductor resistance will increase at higher temperatures, so a margin of 20% can be added to account for this: Now replacing the variables in the equation for V X, one can find the junction temperature (T J) from power dissipation, ambient temperature and the known thermal resistance of the PCB (RθCA) and the package (RθJC): PDISS = 0.45 x 1.2 = .54W () AMBCAJCDISS J T RθRθP T + + × = Therefore: TJ = 0.54W x (55 ºC/W) + 50ºC TJ = 79.7ºC This is well below the maximum 125ºC.

Micrel Inc. MIC33153 September 2010 14 M9999-092910-A Typical Application Circuit (Fixed Output) Bill of Materials Item Part Number Manufacturer Description Qty. C1608X5R0J475K TDK (1) C1, C2 GRM188R60J475KE19D Murata (2) Ceramic Capacitor, 4.7µF, 6.3V, X5R, Size 0603 2 C3 C1608NPO0J471K TDK(1) Ceramic Capacitor, 470pF, 6.3V, NPO, Size 0603 1 R3, R4 CRCW06031002FKEA Vishay(3) Resistor, 10k, Size 0603 2 U1 MIC33153-xYHJ Micrel, Inc.(4) 4MHz 1.2A Buck Regulator with HyperLight Load™ Mode and Fixed Output Voltage 1 Notes: 1. TDK: www.tdk.com. 2. Murata: www.murata.com. 3. Vishay: www.vishay.com.

Micrel Inc. MIC33153 September 2010 15 M9999-092910-A Typical Application Circuit (Adjustable Output) Bill of Materials Item Part Number Manufacturer Description Qty. C1608X5R0J475K TDK (1) C1, C2 GRM188R60J475KE19D Murata (2) Ceramic Capacitor, 4.7µF, 6.3V, X5R, Size 0603 2 C3 C1608NPO0J471K TDK(1) Ceramic Capacitor, 470pF, 6.3V, NPO, Size 0603 1 C4 − − Not Fitted (NF) 0 R1 CRCW06033013FKEA Vishay(3) Resistor, 301k, Size 0603 1 R2 CRCW06031583FKEA Vishay(3) Resistor, 158k, Size 0603 1 R3, R4 CRCW06031002FKEA Vishay(3) Resistor, 10k, Size 0603 2 U1 MIC33153-YHJ Micrel, Inc.(4) 4MHz 1.2A Buck Regulator with HyperLight Load™ Mode and Adjustable Output Voltage 1 1. TDK: www.tdk.com. 2. Murata : www.murata.com. 3. Vishay: www.vishay.com.

Micrel Inc. MIC33153 September 2010 16 M9999-092910-A PCB Layout Recommendations Top Layer Bottom Layer

Micrel Inc. MIC33153 September 2010 17 M9999-092910-A

Package Information

14-Pin 3.0mm x 3.5mm MLF® (HJ) 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 reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical impla 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. can nt © 2010 Micrel, Incorporated.