MIC38150 HELDO® 1.5A High Efficiency Low Dropout Regulator General Description ® HELDO The MIC38150 is a 1.5A continuous output current step down converter. This is a follow on product in the new ® Features HELDO (High Efficiency Low Drop Out Regulators) family, that provide the benefits of an LDO. They are easy • Output current up to 1.5A to use, feature fast transient performance, high PSRR and • Input voltage range: 3.0V to 5.5V low noise while offering the efficiency of a switching • Adjustable output voltage down to 1.0V regulator. • Output noise less than 5mV As output voltages move lower, the output noise and • Ultra fast transient performance transient response of a switching regulator become an increasing challenge for designers. By combining a • Unique switcher plus LDO architecture switcher whose output is slaved to the input of a high • Fully integrated MOSFET switches performance LDO, high efficiency is achieved with a clean • Micro-power shutdown low noise output. The MIC38150 is designed to provide • Easy upgrade from LDO as power dissipation less than 5mV of peak-to-peak noise and over 70dB of becomes an issue PSRR at 1kHz. Furthermore, the architecture of the MIC38150 is optimized for fast load transients allowing the • Thermal shutdown and current limit protection ® output to maintain less than 30mV of output voltage • 4mm×6mm×0.9mm MLF package deviation even during ultra fast load steps. This makes the MIC38150 an ideal choice for low voltage ASICs and other Applications digital ICs. The MIC38150 features a fully integrated switching • Point-of-load applications regulator and LDO combination, operates with input • Networking, server, industrial power voltages from 3.0V to 5.5V input and offers adjustable • Wireless base-stations output voltages down to 1.0V. • Sensitive RF applications The MIC38150 is offered in the small 28-pin ® 4mm×6mm×0.9mm MLF package and can operate from –40°C to +125°C. Data sheets and support documentation can be found on Micrel’s web site at: www.micrel.com ___________________________________________________________________________________________________________ LOAD CURRENT (1A/div) OUTPUT VOLTAGE (50mV/div) Typical Application HELDO is a registered trademark of Micrel, Inc. MLF and MicroLeadFrame are registered trademark of Amkor Technologies Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com September 2009 M9999-091109-B Micrel, Inc. MIC38150 Ordering Information Output Current Part Number MIC38150HYHL 1.5A Voltage (1) Junction Temperature Range ADJ -40°C to +125°C Package ® PB-Free 28-Pin 4mm×6mm MLF Note: For additional voltage options, contact Micrel. Pin Configuration ® 28-Pin 4mm x 6mm MLF (ML) (Top View) Pin Description Pin Number Pin Name 1, 2, 3, 4, 5 SWO 6, 23, 24, 25, 26, 27, 28 SW 7, 22 ePAD Exposed heat-sink pad: Connect externally to PGND. 8 AVIN Analog Supply Voltage: Supply for the analog control circuitry. Requires bypass capacitor to ground. Nominal bypass capacitor is 1µF. 9 LPF Low Pass Filter: Attach external resistor from SW to increase hysteretic frequency. 10 AGND 11 FB Feedback: Input to the error amplifier. Connect to the external resistor divider network to set the output voltage. 12, 13 LDOOUT LDO Output: Output of voltage regulator. Place capacitor-to-ground to bypass the output voltage. Nominal bypass capacitor is 10µF. 14, 15 LDOIN 16, 17 PVIN 18 EN 19, 20, 21 PGND September 2009 Pin Name Switch (Output): This is the output of the PFM Switcher. Switch Node: Attach external resistor from LPF to increase hysteretic frequency. Analog Ground. LDO Input: Connect to SW output. Requires a bypass capacitor-to-ground. Nominal bypass capacitor is 10µF. Input Supply Voltage (Input): Requires bypass capacitor-to-ground. Nominal bypass capacitor is 10µF. Enable (Input): Logic low will shut down the device, reducing the quiescent current to less than 50µA. This pin can also be used as an under-voltage lockout function by connecting a resistor divider from EN pin-to-VIN and GND. It should be not left open. Power Ground. 2 M9999-091109-B Micrel, Inc. MIC38150 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VIN) .........................................................6V Output Switch Voltage (VSW) ...........................................6V Logic Input Voltage (VEN) ..................................-0.3V to VIN (3) Power Dissipation .................................. Internally Limited Storage Temperature (TS)................... -65°C ≤ TJ ≤ +150°C Lead Temperature (soldering, 10sec) ........................ 260°C (4) ESD Rating .............................................................. 1.5kV Supply voltage (VIN) ...................................... 3.0V to 5.5V Enable Input Voltage (VEN) ................................. 0V to VIN Junction Temperature Range .........–40°C ≤ TJ ≤ +125°C Package Thermal Resistance ® 4mm×6mm MLF (θJA) ..................................24°C/W Electrical Characteristics(5) TA = 25°C with VIN = VEN = 5V; IOUT = 10mA, VOUT = 1.8V. Bold values indicate –40°C ≤ TJ ≤ +125°C, unless noted. Parameter Conditions Min 3.0 Supply Voltage Range Under-Voltage Lockout Threshold Typ Turn-on UVLO Hysteresis Max Units 5.5 V 2.85 V 100 mV 1 mA Quiescent Current IOUT = 0A, Not switching, Open Loop Turn-on Time VOUT to 95% of nominal 200 500 µs Shutdown Current VEN = 0V 30 50 µA Feedback Voltage ±2.5% 1 1.025 V 0.975 Feedback Current Dropout Voltage (VIN – VOUT) 5 ILOAD = 1.5A; VOUT = 3V 0.85 1.75 nA 1.2 V Current Limit VFB = 0.9×VNOM Output Voltage Load Regulation VOUT = 1.8V, 10mA to 1.5A 0.1 3 1 % A Output Voltage Line Regulation VOUT = 1.8V, VIN from 3.0V to 5.5V 0.35 0.5 %/V Output Ripple ILOAD = 1.5A, COUTLDO = 20µF, COUTSW = 20µF LPF=25kΩ 2 mV Over-Temperature Shutdown 150 °C Over-Temperature Shutdown Hysteresis 15 °C (6) Enable Input Enable Input Threshold Regulator enable Enable Hysteresis 0.90 1 1.1 V 20 100 200 mV 0.03 1 µA Enable Input Current Notes: 1. Exceeding the absolute maximum rating may damage the device. 2. The device is not guaranteed to function outside its operating rating. 3. The maximum allowable power dissipation of any TA (ambient temperature) is PD(max) = (TJ(max) – TA) / θJA. Exceeding the maximum allowable power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. 4. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF. 5. Specification for packaged product only. 6. Enable pin should not be left open. September 2009 3 M9999-091109-B Micrel, Inc. MIC38150 Typical Characteristics VIN = 3.3V, VOUT = 1.8V, COUT = 10µF, RLPF = 25kΩ, IOUT = 100mA, unless noted 1.86 70 1.84 PSRR (dB) 60 50 40 30 20 1.80 1.78 1.76 1.74 0 1.72 1000 10000 FREQUENCY (Hz) 1.8 1.82 10 100 2.0 100000 VIN = 3.3V VOUT = 1.8V 0 1.0 0.6 0.4 0.3 0.6 0.9 1.2 LO AD CURRENT (A) 0 1.5 90 80 1.6 1.82 1.80 1.78 1.76 VIN = 3.3V IOUT = 10mA 1.2 1.0 0.8 0.6 0.4 VIN = 3.3V VOUT = 1.8V 0.2 -40 10 Dropout Voltage v s. Load Current 50 40 30 VIN = 5.0V VOUT = 3.3V RLPF = 25kΩ 10 60 110 160 T EMPERAT URE (°C) 0 210 0 0.3 0.6 0.9 1.2 LO AD CURRENT (A) 1.5 Current Lim it v s. Input Voltage Dropout Voltage v s. Temperature 0.9 5 60 20 0.0 20 40 60 80 100 120 T EM PERAT URE (°C) 2 3 4 INPUT VOLTAGE (V) 70 1.4 EFFICIENCY (%) O UTPUT VO LTAG E (V) 1.84 1 MIC38150 Efficiency 1.8 0 VOUT = 1.8V 0.2 2.0 -20 IOUT = 1.5A 0.8 1.86 -40 1.0 4.0 3.8 0.8 0.6 0.5 0.4 0.3 0.2 0.1 3.6 0.8 0.6 0.4 0.2 VOUT = 3.3V IOUT = 1.5A VOUT = 3.3V 0.0 CURRENT LIM IT (A) 0.7 DROPO UT VO LTAGE (V) DROPO UT VO LTAGE (V) 1.2 Therm al Shutdown 1.72 0.5 1 LOAD CURRENT (A) 1.5 3.4 3.2 3.0 2.8 2.6 VOUT= 1.8V COUT = 20µF RLPF = 25kΩ 2.4 2.2 0.0 0 2.0 -40 -20 0 20 40 60 80 100 120 T EM PERAT URE (°C) 3 3.5 4 4.5 5 INPUT VO LT AG E (V) 5.5 Operating Current vs. Input Voltage Enable Threshold 1.20 60 OPERATING CURRENT (mA) 1.15 ENABLE VOLTAGE (V) 1.4 1.88 1.74 IOUT = 10mA 1.6 0.0 Output Voltage v s. Temperature OUTPUT VO LTAGE (V) OUTPUT VOLTAGE (V) 1.88 80 O UTPUT VO LTAG E (V) 90 10 Output Voltage vs. Input Voltage Load Regulation MIC38150 PSRR 1.10 1.05 1.00 0.95 0.90 0.85 VOUT = 1.8V 0.80 50 40 30 20 VOUT = 1.8V COUT = 20µF 10 0 3 3.5 4 4.5 5 INPUT VOLTAGE (V) September 2009 5.5 3 3.5 4 4.5 5 INPUT VOLTAGE (V) 4 5.5 M9999-091109-B Micrel, Inc. MIC38150 Typical Characteristics VIN = 3.3V, VOUT = 1.8V, COUT = 10µF, RLPF = 25kΩ, IOUT = 100mA, unless noted Switch Frequency v s. RLPF Resistance (3.3V-1.0V) Switch Frequency v s. RLPF Resistance (3.3V-1.8V) 3 3 SW FREQUENCY (M Hz) SW FREQUENCY (MHz) 2.5 500mA 2 1.5 10mA 1 3 1.5A 0.5 0 2.5 1.5A SW FREQUENCY (MHz) 1A 2.5 500mA 2 1.5 10mA 1 1A 0.5 0 10 100 RLPF (kΩ) 1000 10 Switch Frequency vs. RLPF Resistance (5.0V-1.8V) 100 RLPF (kΩ) 1000 1.5A 1A 2 1.5 1 10mA 500mA 0.5 0 10 100 RLPF (kΩ) 1000 Switch Frequency v s. RLPF Resistance (5.0V-2.5V) 3 3 1.5A 1.5A 2.5 2.5 1A SW FREQUENCY (MHz) SW FREQUENCY (M Hz) Switch Frequency v s. RLPF Resistance (5.0V-1.0V) 2 1.5 10mA 500mA 1 0.5 0 500mA 2 1.5 10mA 1 1A 0.5 0 10 100 RLPF (kΩ) September 2009 1000 10 100 RLPF (kΩ) 5 1000 M9999-091109-B Micrel, Inc. MIC38150 Functional Characteristics LOAD CURRENT (1A/div) OUTPUT VOLTAGE (50mV/div) VIN = 3.3V, VOUT = 1.8V, COUT = 10µF, Inductor = 470nH; RLPF = 25kΩ, IOUT = 100mA, unless noted September 2009 6 M9999-091109-B Micrel, Inc. MIC38150 Block Diagram September 2009 7 M9999-091109-B Micrel, Inc. MIC38150 Adjustable Regulator Design Application Information Enable Input The MIC38150 features a TTL/CMOS compatible positive logic enable input for on/off control of the device. High enables the regulator while low disables the regulator. In shutdown the regulator consumes very little current (only a few microamperes of leakage). For simple applications the enable (EN) can be connected to VIN (IN). Input Capacitor PVIN provides power to the MOSFETs for the switch mode regulator section and the gate drivers. Due to the high switching speeds, a 10µF capacitor is recommended close to PVIN and the power ground (PGND) pin for bypassing. Analog VIN (AVIN) provides power to the analog supply circuitry. AVIN and PVIN must be tied together externally. Careful layout should be considered to ensure high frequency switching noise caused by PVIN is reduced before reaching AVIN. A 1µF capacitor as close to AVIN as possible is recommended. Adjustable Regulator with Resistors The adjustable MIC38150 output voltage can be programmed from 1V to 5.0V using a resistor divider from output to the FB pin. Resistors can be quite large, up to 100kΩ because of the very high input impedance and low bias current of the sense amplifier. For large value resistors (>50kΩ), R1 should be bypassed by a small capacitor (CFF = 0.1µF bypass capacitor) to avoid instability due to phase lag at the ADJ/SNS input. The output resistor divider values are calculated by: VOUT = 1V × ( Output Capacitor The MIC38150 requires an output capacitor for stable operation. As a µCap LDO, the MIC38150 can operate with ceramic output capacitors of 10µF or greater. Values of greater than 10µF improve transient response and noise reduction at high frequency. X7R/X5R dielectric-type ceramic capacitors are recommended because of their superior temperature performance. X7R-type capacitors change capacitance by 15% over their operating temperature range and are the most stable type of ceramic capacitors. Larger output capacitances can be achieved by placing tantalum or aluminum electrolytics in parallel with the ceramic capacitor. For example, a 100µF electrolytic in parallel with a 10µF ceramic can provide the transient and high frequency noise performance of a 100µF ceramic at a significantly lower cost. Specific undershoot/overshoot performance will depend on both the values and ESR/ESL of the capacitors. For less than 5mV noise performance at higher current loads, 20µF capacitors are recommended at LDOIN and LDOOUT. Efficiency Considerations Efficiency is defined as the amount of useful output power, divided by the amount of power supplied. Efficiency(%) = VOUT × IOUT × 100 VIN × IIN Maintaining high efficiency serves two purposes. It reduces power dissipation in the power supply, reducing the need for heat sinks and thermal design considerations and it reduces consumption of current for battery powered applications. Reduced current draw from a battery increases the devices operating time and is critical in hand held devices. There are two types of losses in switching converters; DC losses and switching losses. DC losses are simply 2 the power dissipation of I R. 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 2 Current . During the off cycle, the low side N-channel MOSFET conducts, also dissipating power. Device operating current also reduces efficiency. The product of the quiescent (operating) current and the supply voltage is another DC loss. 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, reducing the internal RDDSON. This improves efficiency by reducing DC losses in the device. As the inductors are reduced in size, the inductor losses are mainly caused by the DC resistance (DCR). Low Pass Filter Pin The MIC38150 features a Low Pass Filter (LPF) pin for adjusting the switcher frequency. By tuning the frequency, the user can further improve output ripple. Adjusting the frequency is accomplished by connecting a resistor between the LPF and SW pins. A small value resistor would increase the frequency while a larger value resistor decreases the frequency. Recommended RLPF value is 25kΩ. September 2009 R1 + 1) R2 8 M9999-091109-B Micrel, Inc. MIC38150 The DCR losses can be calculated as follows: 2 L_PD = IOUT × DCR Efficiency loss due to DCR is minimal at light loads and gains significance as the load is increased. September 2009 9 M9999-091109-B Micrel, Inc. MIC38150 input capacitors and IC pins. PCB Layout Guideline 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 MIC38150. IC • Place the IC close to the point of load (POL). • Use fat traces to route the input and output power lines. • The exposed pad (ePAD) on the bottom of the IC must be connected to the PGND pins of the IC. • Use several vias to connect the ePAD to the ground plane. • Signal and power grounds should be kept separate and connected at only one location. • Keep the switch node (SW) away from the feedback (FB) pin. Place the input capacitor next. • Place the input capacitors on the same side of the board and as close to the MIC38150 as possible. • Keep both the PVIN and PGND connections short. • Place several vias to the ground plane close to the input capacitor ground terminal, but not between the September 2009 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 used to limit the overvoltage spike seen on the input supply with power is suddenly applied. • The 1µF capacitor, which connects to the AVIN terminal, must be located right at the IC. The AVIN terminal is very noise sensitive and placement of the capacitor is very critical. Connections must be made with wide trace. Output Capacitor Input Capacitor • • 10 • Use a wide trace to connect the VSW output capacitor ground terminal to the PVIN input capacitor ground terminal. • The feedback trace should be separate from the power trace and connected as close as possible to the output capacitor. M9999-091109-B Micrel, Inc. MIC38150 Evaluation Board Schematics Bill of Materials Item C1, C3, C4, C14, C23 Part Number R2, R4 AVX LMK212BJ106KG-T Taiyo Yuden C2012X5R1A106K TDK GRM219R61A106KE44D Murata C2012X5R1A105K TDK 0805ZD105KAT2A AVX R3 10uF, 10V, X5R, 0805 Ceramic Capacitor 5 1uF, 10V, X5R, 0805 Ceramic Capacitor 1 (5) 8.06k, 1%, 1/10W, 0603 1 (5) 10k, 1%, 1/10W, 0603 2 (5) 24.9k, 1%, 1/10W, 0603 1 (1) CRCW06038061FRT1 Vishay U1 MIC38150-HYHL (4) (3) Murata CRCW06032492FRT1 Qty (2) (3) GRM219R61A105MA01D CRCW06031002KEYE3 Description (1) 0805ZD106MAT2A C2 R1 Manufacturer (4) Vishay Vishay (6) Micrel, Inc. ® HELDO 1.5A High Efficiency Low Dropout Regulator 1 Notes: 1. AVX: www.avx.com 2. Taiyo Yuden: www.t-yuden.com 3. TDK: www.tdk.com 4. Murata: www.murata.com 5. Vishay: www.vishay.com 6. Micrel, Inc.: www.micrel.com September 2009 11 M9999-091109-B Micrel, Inc. MIC38150 PCB Layout Top Layer Mid Layer 1 September 2009 12 M9999-091109-B Micrel, Inc. MIC38150 Mid Layer 2 Bottom Layer September 2009 13 M9999-091109-B Micrel, Inc. MIC38150 Package Information ® 28-Pin 4mm x 6mm MLF (ML) September 2009 14 M9999-091109-B Micrel, Inc. MIC38150 Recommended Landing 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 The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. 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. © 2009 Micrel, Incorporated. September 2009 15 M9999-091109-B