MIC2103/04 Evaluation Board 75V, Synchronous Buck Controllers featuring Adaptive On-Time Control Hyper Speed Control™ Family General Description The Micrel MIC2103/04 are constant-frequency, synchronous buck controllers featuring a unique adaptive on-time control architecture. The MIC2103/04 operates over an input supply range of 4.5V to 75V and can be used to supply up to 15A of output current. The output voltage is adjustable down to 0.8V with a guaranteed accuracy of ±1%. The device operates with programmable switching frequency from 200kHz to 600kHz. The MIC2103 has Hyper Light Load® architecture, so it can operate in pulse skipping mode at light load. However, from medium load to heavy load, it operates in fixed frequency CCM mode. The MIC2104 has Hyper Speed Control architecture which operates in fixed frequency CCM mode under all load conditions. The basic parameters of the evaluation board are: 1. Input: 12V to 75V 2. Output: 0.8V to 5V at 10A (1) 3. 200kHz Switching Frequency (Adjustable 200kHz to 600kHz) Note: 1. Refer to temperature curves shown in Typical Characteristics section. Datasheets and support documentation can be found on Micrel’s web site at: www.micrel.com. Requirements The MIC2103 and MIC2104 evaluation board requires only a single power supply with at least 10A current capability. The MIC2103/04 has internal VDD LDO so no external linear regulator is required to power the internal biasing of the IC. In the applications with VIN < +5.5V, VDD should be tied to VIN to by-pass the internal linear regulator. The output load can either be a passive or an active load. Precautions The MIC2103/04 evaluation board does not have reverse polarity protection. Applying a negative voltage to the VIN and GND terminals may damage the device. The maximum VIN of the board is rated at 75V. Exceeding 75V on the VIN could damage the device. Getting Started 1. VIN Supply Connect a supply to the VIN and GND terminals, paying careful attention to the polarity and the supply range (12V < VIN < 75V). Monitor IIN with a current meter and input voltage at VIN and GND terminals with voltmeter. Do not apply power until step 4. 2. Connect Load and Monitor Output Connect a load to the VOUT and GND terminals. The load can be either a passive (resistive) or an active (as in an electronic load) type. A current meter may be placed between the VOUT terminal and load to monitor the output current. Ensure the output voltage is monitored at the VOUT terminal. 3. Enable Input The EN pin has an on board 100k pull-up resistor (R22) to VIN, which allows the output to be turned on when VDD exceeds its UVLO threshold. An EN connector is provided on the evaluation board for users to easily access the enable feature. Applying an external logic signal on the EN pin to pull it low or using a jumper to short the EN pin to GND will shut off the output of the MIC2103/04 evaluation board. 4. Turn on the Power Turn on the VIN supply and verify that the output voltage is regulated to 5.0V. Ordering Information Part Number Description MIC2103YML 10A EV MIC2103 Evaluation Board up to 5V Output MIC2104YML 10A EV MIC2104 Evaluation Board up to 5V Output Hyper Speed Control is a trademark of Micrel, 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 October 2012 M9999-100512 Micrel, Inc. MIC2103/04 10A Evaluation Board through the value of the resistor (R17). If the absolute value of the voltage drop on the bottom FET is greater than VCL, the V(ILIM) is lower than PGND and a short circuit event is triggered. A hiccup cycle to treat the short event is generated. The hiccup sequence, including the soft start, reduces the stress on the switching FETs and protects the load and supply for severe short conditions. Features Feedback Resistors The output voltage on the MIC2103/04 evaluation board, which is preset to 5.0V, is determined by the feedback divider: VOUT VREF 1 R BOTTOM R1 (Eq. 1) where VREF = 0.8V, and RBOTTOM is one of R4, R5, R6, R7, R8, R9, R10, R11 which corresponds to 0.9V, 1.0V, 1.2V, 1.5V, 1.8V, 2.5V, 3.3V, or 5V. Leaving the RBOTTOM open gives a 0.8V output voltage. All other voltages not listed above can be set by modifying RBOTTOM value according to: RBOTTOM R1 VREF VOUT VREF (Eq. 2) Figure 1. MIC2103/04 Current Limiting Circuit Note that the output voltage should not be set to exceed 5V due to the 6.3V voltage rating on the output capacitors. The short circuit current limit can be programmed by using the following formula. R17 Current Limit The MIC2103/04 uses the RDS(ON) and external resistor connected from ILIM pin to SW node to decide the current limit. In each switching cycle of the MIC2103/04 converter, the inductor current is sensed by monitoring the lowside MOSFET in the OFF period. The sensed voltage V(ILIM) is compared with the power ground (PGND) after a blanking time of 150ns. In this way the drop voltage over the resistor R17 (VCL) is compared with the drop over the bottom FET generating the short current limit. The small capacitor (C18) connected from ILIM pin to PGND filters the switching node ringing during the off time to allow a better short limit measurement. The time constant created by R17 and C18 should be much less than the minimum off time. The VCL drop allows programming of short limit October 2012 ( I CLIM PP 0.5) R DS (ON ) VCL (Eq. 3) I CL Where ICLIM = Desired Current limit ΔPP = Inductor current peak to peak RDS (ON) = On resistance of low-side power MOSFET VCL = Current limit threshold, the typical value is 14mV in EC table ICL = Current Limit source current, the typical value is 80µA in EC table. In case of a hard short, the short limit is folded down to allow an indefinite hard short on the output without any destructive effect. It is mandatory to make sure that the inductor current used to charge the output capacitance during soft start is under the folded short limit. Otherwise, the supply will go in hiccup mode and may not be finishing the soft start successfully. The MOSFET RDS(ON) varies 30% to 40% with temperature; therefore, it is recommended to add a 50% margin to ICL in the above equation to avoid false current limiting due to increased MOSFET junction temperature rise. It is also recommended to connect SW pin directly to the drain of the low-side MOSFET to accurately sense the MOSFETs RDS(ON). SW Node Test point J1 (VSW) is placed for monitoring the switching waveform, which is one of the most critical waveforms for the converter. 2 M9999-100512 Micrel, Inc. MIC2103/04 10A Evaluation Board Loop Gain Measurement The resistor, R14, is placed in series with the regulator feedback path. The control loop gain can be measured by connecting an impedance analyzer across the resistor and selecting the resistor value in between 20Ω to 50Ω. Switching Frequency 700 R19 = 100k, IOUT =10A 600 VIN = 48V VIN = 12V 500 SW FREQ (kHz) Setting the Switching Frequency The MIC2103/04 are adjustable-frequency, synchronous buck controllers featuring a unique adaptive on-time control architecture. The switching frequency can be adjusted between 200kHz and 600kHz by changing the resistor divider network consisting of R19 and R20. 400 VIN =75V 300 200 100 0 10.00 MIC2103/04 VDD VDD/PVDD C7 1µF AGND BST 100.00 1000.00 10000.00 R20 (k Ohm) Figure 3. Switching Frequency vs. R20 VIN VIN 2.2µF x3 C2, C3, C4 SW CS R19 . FREQ R20 FB PGND Figure 2. Switching Frequency Adjustment The following formula gives the estimated switching frequency: f SW _ ADJ f O R 20 R19 R 20 (Eq. 4) Where fO = Switching Frequency when R19 is 100k and R20 being open, fO is typically 600kHz at 12V input voltage. For more precise setting, it is recommended to use the following graph: October 2012 3 M9999-100512 Micrel, Inc. MIC2103/04 10A Evaluation Board MIC2103/04 0.8V to 5V/10A Evaluation Board Typical Characteristics 5.0V 3.3V 2.5V 1.8V 1.2V 0.8V EFFICIENCY (%) 80 70 60 50 40 30 100 80 20 1 2 3 4 5 6 7 8 60 50 40 30 1 2 EFFICIENCY (%) 3 4 5 6 7 8 50 40 30 fSW = 200kHz (CCM) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 OUTPUT CURRENT (A) October 2012 fSW = 200kHz (CCM) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Efficiency (VIN = 75V) vs. Output Current (MIC2103) 100 90 90 5.0V 3.3V 2.5V 1.8V 1.2V 0.8V 80 70 60 50 40 30 5.0V 3.3V 2.5V 1.8V 1.2V 0.8V 80 70 60 50 40 30 20 fSW = 200kHz (CCM) 10 0 0 30 OUTPUT CURRENT (A) 20 20 10 40 9 10 11 12 13 14 Efficiency (VIN = 48V) vs. Output Current (MIC2103) 100 EFFICIENCY (%) 5.0V 3.3V 2.5V 1.8V 1.2V 0.8V 60 50 OUTPUT CURRENT (A) 90 70 60 0 0 Efficiency (VIN = 38V) vs. Output Current (MIC2103) 80 70 10 0 9 10 11 12 13 14 5.0V 3.3V 2.5V 1.8V 1.2V 0.8V 80 fSW = 200kHz (CCM) OUTPUT CURRENT (A) 100 90 20 10 0 0 70 Efficiency (VIN = 24V) vs. Output Current (MIC2103) 100 20 fSW = 200kHz (CCM) 10 5.0V 3.3V 2.5V 1.8V 1.2V 0.8V 90 EFFICIENCY (%) 90 EFFICIENCY (%) 100 Efficiency (VIN = 18V) vs. Output Current (MIC2103) EFFICIENCY (%) Efficiency (VIN =12V) vs. Output Current (MIC2103) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 OUTPUT CURRENT (A) 4 fSW = 200kHz (CCM) 10 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 OUTPUT CURRENT (A) M9999-100512 Micrel, Inc. MIC2103/04 10A Evaluation Board MIC2103/04 0.8V to 5V/10A Evaluation Board Typical Characteristics (Continued) 100 70 60 90 50 40 30 70 60 40 30 fSW = 200kHz 0 1 2 3 4 5 6 7 8 0 1 2 4 5 6 7 8 0 50 40 30 5.0V 3.3V 2.5V 1.8V 1.2V 0.8V 70 60 50 30 5 6 7 8 1 2 3 30 4 5 6 7 8 fSW = 200kHz 0 9 10 11 12 13 14 1 2 VIN = 12V VOUT = 5.0V 80 ` 60 40 V IN = 48V V OUT = 5.0V 20 fSW = 200kHz DIE TEMPERATURE (°C) 120 DIE TEMPERATURE (°C) 120 100 3 4 5 6 7 8 Die Temperature* (VIN = 75V) vs. Output Current 100 80 60 40 VIN = 75V VOUT = 5.0V 20 fSW = 200kHz fSW = 200kHz 0 1 2 3 4 5 6 7 8 OUTPUT CURRENT (A) 9 10 0 9 10 11 12 13 14 OUTPUT CURRENT (A) 120 0 5.0V 3.3V 2.5V 1.8V 1.2V 0.8V 40 140 20 9 10 11 12 13 14 50 140 40 8 60 140 60 7 0 Die Temperature* (VIN = 48V) vs. Output Current Die Temperature* (VIN = 12V) vs. Output Current 80 6 70 OUTPUT CURRENT (A) OUTPUT CURRENT (A) 100 5 10 fSW = 200kHz 0 9 10 11 12 13 14 4 20 0 0 3 80 40 10 fSW = 200kHz 4 2 Efficiency (VIN = 75V) vs. Output Current (MIC2104) 100 20 20 3 1 OUTPUT CURRENT (A) EFFICIENCY (%) 60 EFFICIENCY (%) 70 2 fSW = 200kHz 90 80 5.0V 3.3V 2.5V 1.8V 1.2V 0.8V 1 30 9 10 11 12 13 14 90 80 EFFICIENCY (%) 3 Efficiency (VIN = 48V) vs. Output Current (MIC2104) 100 90 0 40 OUTPUT CURRENT (A) Efficiency (VIN = 38V) vs. Output Current (MIC2104) 10 50 0 OUTPUT CURRENT (A) 100 60 10 fsw = 200kHz 0 9 10 11 12 13 14 70 20 10 0 5.0V 3.3V 2.5V 1.8V 1.2V 0.8V 80 20 10 DIE TEMPERATURE (°C) 90 50 20 Efficiency (VIN = 24V) vs. Output Current (MIC2104) 100 5.0V 3.3V 2.5V 1.8V 1.2V 0.8V 80 EFFICIENCY (%) 80 EFFICIENCY (%) 100 5.0V 3.3V 2.5V 1.8V 1.2V 0.8V 90 Efficiency (VIN = 18V) vs. Output Current (MIC2104) EFFICIENCY (%) Efficiency (VIN =12V) vs. Output Current (MIC2104) 0 0 1 2 3 4 5 6 7 8 OUTPUT CURRENT (A) 9 10 0 1 2 3 4 5 6 7 8 9 10 OUTPUT CURRENT (A) Die Temperature* : The temperature measurement was taken at the hottest point on the MIC2103/04 case mounted on a 5 square inch 4 layer, 0.62”, FR-4 PCB with 2oz. finish copper weight per layer, see Thermal Measurement section. Actual results will depend upon the size of the PCB, ambient temperature and proximity to other heat emitting components. October 2012 5 M9999-100512 Micrel, Inc. MIC2103/04 10A Evaluation Board MIC2103/04 0.8V to 5V/10A Output Evaluation Board Schematic Figure 1. MIC2103/04 Evaluation Board for 0.8V to 5V/10A Output October 2012 6 M9999-100512 Micrel, Inc. MIC2103/04 10A Evaluation Board Bill of Materials 0.8V to 5V/10A Output Item C1 Part Number EEU-FC2A101 GRM32ER72A225K C2, C3, C4 C14 C3225X7R2A225K AVX C3225X5ROJ107M TDK AVX C1608X7R1H104K TDK AVX C1608X5R0J105K TDK C12 Murata AVX Murata TDK 3 100µF/6.3V Ceramic Capacitor, X5R, Size 1210 1 0.1µF/50V Ceramic Capacitor, X7R, Size 0603 2 1µF/6.3V Ceramic Capacitor, X7R, Size 0603 3 0.47µF/100V Ceramic Capacitor, X7R, Size 0805 1 0.1µF/100V Ceramic Capacitor, X7R, Size 0603 0.1µF/100V,X7S,0603 AVX C1608X7R2A102K TDK 1nF/100V Cermiac Capacitor, X7R, Size 0603 1 2.2nF/100V Cermiac Capacitor, X7R, Size 0603 1 Murata 06031C222KAT2A AVX C1608X7R2A222K TDK Sanyo(5) 470µF/6.3V, 7m-ohms, OSCON 6SEPC470M Sanyo 470µF/6.3V, 7m-ohms, OSCON C15 (OPEN) 6TPB470M Sanyo 470µF/6.3V, POSCAP C5 (OPEN) GRM32ER60J107ME20L Murata 100µF/6.3V Ceramic Capacitor, X7R, Size 1210 GCM1885C2A100JA16D Murata C13 C18 D1 6SEPC470MX 06031A100JAT2A BAT46W-TP L1 CDEP147NP-6R1MC-95 1 Murata 06031C102KAT2A GRM188R72A222KA01D 2.2µF/100V Ceramic Capacitor, X7R, Size 1210 Murata 06036C105KAT2A C1608X7S2A104K 1 Murata 06035C104KAT2A GRM188R72A104KA35D Qty (4) 12106D107MAT2A GRM188R72A102KA01D C11 TDK 100µF Aluminum Capacitor, 100V (3) Murata 08051C474KAT2A C10 Murata GRM32ER60J107ME20L GRM21BR72A474KA73 C9 (1) (2) AVX GRM188R70J105KA01D C7, C8, C17 Panasonic 12101C225KAT2A GRM188R71H104KA93D C6, C16 Manufacturer Description 10pF, 100V, 0603, NPO AVX MCC(6) Sumida (7) 1 1 100V Small Signal Schottky Diode, SOD123 1 6.1µH Inductor, 14.8A RMS Current 1 Notes: 1. Panasonic: www.panasonic.com. 2. Murata: www.murata.com. 3. TDK: www.tdk.com. 4. AVX: www.avx.com 5. Sanyo: www.sanyo.com. 6. MCC.: www.mccsemi.com. 7. Sumida: www.sumida.com. October 2012 7 M9999-100512 Micrel, Inc. MIC2103/04 10A Evaluation Board Bill of Materials 0.8V to 5V/10A Output (Continued) Item Part Number Q1 SIR878DP Q3 SIR882DP Manufacturer Description (8) Vishay Qty MOSFET, N-CH, Power SO-8 1 Vishay MOSFET, N-CH, Power SO-8 1 Q2, Q4 (OPEN) R1 CRCW060310K0FKEA Vishay Dale 10kΩ Resistor, Size 0603, 1% 1 R2, R23 CRCW08051R21FKEA Vishay Dale 1.21Ω Resistor, Size 0805, 5% 2 R3 CRCW060395K30FKEA Vishay Dale 95.3kΩ Resistor, Size 0603, 1% 1 R4 CRCW060380K6FKEA Vishay Dale 80.6kΩ Resistor, Size 0603, 1% 1 R5 CRCW060340K2FKEA Vishay Dale 40.2kΩ Resistor, Size 0603, 1% 1 R6 CRCW060320K0FKEA Vishay Dale 20kΩ Resistor, Size 0603, 1% 1 R7 CRCW060311K5FKEA Vishay Dale 11.5kΩ Resistor, Size 0603, 1% 1 R8 CRCW06038K06FKEA Vishay Dale 8.06kΩ Resistor, Size 0603, 1% 1 R9 CRCW06034K75FKEA Vishay Dale 4.75kΩ Resistor, Size 0603, 1% 1 R10 CRCW06033K24FKEA Vishay Dale 3.24kΩ Resistor, Size 0603, 1% 1 R11 CRCW06031K91FKEA Vishay Dale 1.91kΩ Resistor, Size 0603, 1% 1 R12 (OPEN) CRCW0603715R0FKEA Vishay Dale 715Ω Resistor, Size 0603, 1% R13 (OPEN) CRCW0603348R0FKEA Vishay Dale 348Ω Resistor, Size 0603, 1% R14, R15 CRCW06030000FKEA Vishay Dale 0Ω Resistor, Size 0603, 5% 2 R16 CRCW08052R0FKEA Vishay Dale 2Ω Resistor, Size 0805, 5% 1 R17 CRCW06032K21FKEA Vishay Dale 2.21kΩ Resistor, Size 0603, 1% 1 R18, R20 CRCW060349K9FKEA Vishay Dale 49.9kΩ Resistor, Size 0603, 1% 2 R19, R22 CRCW0603100K0FKEA Vishay Dale 100kΩ Resistor, Size 0603, 1% 2 R21 CRCW060349R9FKEA Vishay Dale 49.9Ω Resistor, Size 0603, 1% 1 MIC2103YML U1 MIC2104YML Micrel. Inc.(9) 75V Synchronous Buck DC-DC Controller 1 Notes: 8. Vishay: www.vishay.com. 9. Micrel, Inc.: www.micrel.com. October 2012 8 M9999-100512 Micrel, Inc. MIC2103/04 10A Evaluation Board Evaluation Board PCB Layout MIC2103/04 Evaluation Board Copper Layer 1 (Top) MIC2103/04 Evaluation Board Copper Layer 2 (Mid-Layer 1) October 2012 9 M9999-100512 Micrel, Inc. MIC2103/04 10A Evaluation Board Evaluation Board PCB Layout (Continued) MIC2103/04 Evaluation Board Copper Layer 3 (Mid-Layer 2) MIC2103/04 Evaluation Board Copper Layer 4 (Bottom) October 2012 10 M9999-100512 Micrel, Inc. MIC2103/04 10A Evaluation Board 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. October 2012 11 © 2012 Micrel, Incorporated. M9999-100512