MIC49200 2A Low Voltage LDO with Dual Input Voltages General Description The MIC49200 is a high-bandwidth, low-dropout, 2A voltage regulator ideal for powering core voltages of lowpower microprocessors. The MIC49200 implements a dual supply configuration allowing for very low output impedance and very fast transient response. The MIC49200 requires a bias input supply and a main input supply, allowing for ultra-low input voltages on the main supply rail. The input supply operates from 1.4V to 6.5V and the bias supply requires between 3V and 6.5V for proper operation. The MIC49200 offers fixed output voltages from 0.9V to 1.8V and adjustable output voltages down to 0.9V. The MIC49200 requires a minimum of output capacitance for stability, working optimally with small ceramic capacitors. The MIC49200 is available in a 5-pin S-Pak. Its operating temperature range is –40°C to +125°C. Data sheets and support documentation can be found on Micrel’s web site at: www.micrel.com. Features • Input Voltage Range: VIN: 1.4V to 6.5V VBIAS: 3.0V to 6.5V • Stable with 1µF ceramic output capacitors • ±1% initial tolerance • Maximum dropout voltage (VIN–VOUT) of 500mV over temperature • Adjustable output voltage down to 0.9V • Ultra fast transient response (Up to 10MHz bandwidth) • Excellent line and load regulation specifications • Logic controlled shutdown option • Thermal shutdown and current limit protection • Junction temperature range: –40°C to 125°C Applications • • • • • • • Set-top box Graphics processors PC add-in cards Microprocessor core voltage supply Low voltage digital ICs High efficiency linear power supplies SMPS post regulators Typical Application Output Voltage (50mV/div) Load Transient VIN = 2.8V VOUT = 1.8V Output Current (1A/div) VBIAS = 4V Low Voltage, Fast Transient Response Regulator COUT = 1µF Time (40µs/div) Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com January 2006 M9999-011306 (408) 955-1690 Micrel, Inc. MIC49200 Ordering Information Part Number RoHS Compliant Output Current Voltage Junction Temperature Range Package MIC49200-1.0WR* 2A 1.0V –40°C to +125°C S-Pak-5 MIC49200-1.8WR* 2A 1.8V –40°C to +125°C S-Pak-5 MIC49200WR* 2A Adj –40°C to +125°C S-Pak-5 * RoHS compliant with ‘high-melting solder’ exemption. Pin Configuration 5-Pin S-Pak (R) Pin Description Pin Number S-Pak-5 Pin Name 1 EN Enable (Input): CMOS compatible input. Logic High = enable; Logic Low = shutdown. ADJ Adjustable regulator feedback input. Connect to resistor voltage divider. 2 VBIAS 3 GND Ground (TAB is connected to ground on S-Pak). 4 VIN Input voltage which supplies current to the output power device. 5 VOUT January 2006 Pin Function Input Bias voltage for powering all circuitry on the regulator with the exception of the output power device. Regulator Output. 2 M9999-011306 (408) 955-1690 Micrel, Inc. MIC49200 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VIN) ................................................ 8V Bias Supply Voltage (VBIAS) ..................................... 8V Enable Input Voltage (VEN)...................................... 8V Power Dissipation............................. Internally Limited ESD Rating(3) .........................................................3kV Supply voltage (VIN)....................................1.4V to 6.5V Bias Supply Voltage (VBIAS)...........................3V to 6.5V Enable Input Voltage (VEN)............................0V to 6.5V Junction Temperature ...................-40°C ≤ TJ ≤ +125°C Package Thermal Resistance S-Pak (θJA) ................................................. 2°C/W Electrical Characteristics(4) TA = 25°C with VBIAS = VOUT + 2.2V; VIN = VOUT + 1V; bold values indicate –40°C ≤ TJ ≤ +125°C(5), unless noted. Parameter Conditions Min Output Voltage Accuracy At 25°C Over temperature range (IOUT = 10mA) Typ Max Units -1 +1 % -2 +2 % Line Regulation VIN = VOUT + 1V to 6.5V 0.01 +0.1 %/V Load Regulation IL = 10mA to 2A 0.2 1 1.5 % % Dropout Voltage (VIN – VOUT) IL = 750mA 130 200 mV 300 mV 400 mV 500 mV 530 mV 625 mV -0.1 (Note 5) IL = 1.5A 280 400 IL = 2A Dropout Voltage (VBIAS – VOUT) (Note 5) IL = 750mA 1.3 IL = 1.5A 1.65 1.75 IL = 2A V 1.9 V 2.1 V 2.0 V 2.2 Ground Current (Note 6) IL = 0mA 15 IL = 2A 15 Ground Pin Current in Shutdown VEN ≤ 0.6V, (VBIAS + IINPUT) (Note 7) Current thru VBIAS IL = 0mA IL = 2A Current Limit Enable Input Threshold VOUT = 0V 2.5 Regulator enable 25 mA 30 mA 0.5 1 µA 2 µA 9 15 mA 25 mA 40 120 mA 3.5 5.3 A 6 A V 1.6 0.6 V 0.1 1 µA 0.9 0.909 V 0.918 V Regulator shutdown Enable Pin Input Current Independent of state V mA Reference Reference Voltage Adjustable version 0.891 0.882 January 2006 3 M9999-011306 (408) 955-1690 Micrel, Inc. MIC49200 Notes: 1. Exceeding the absolute maximum rating may damage the device. 2. The device is not guaranteed to function outside its operating range. 3. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF. 4. Specification for packaged product only. 5. For VOUT ≤ 1.1V, VBIAS dropout specification does not apply due to a minimum 3V VBIAS input. Dropout voltage is defined as the input-to-output differential at which the output voltage drops 2% below its nominal value measured at 1V differential for VIN and 2.2V differential for VBIAS. For outputs below 1.4V, dropout voltage is the input-to-output voltage differential with the minimum input voltage 1.4V. 6. IGND = IBIAS + (IIN – IOUT). At high loads, input current on VIN will be less then the output current, due to drive current being supplied by VBIAS. 7. Fixed output voltage versions only. January 2006 4 M9999-011306 (408) 955-1690 Micrel, Inc. MIC49200 Functional Diagram VBIAS VIN Ilimit VEN/ADJ Fixed Enable Bandgap Adj. R1 Fixed January 2006 5 VOUT R2 M9999-011306 (408) 955-1690 Micrel, Inc. MIC49200 Typical Characteristics Power Supply Rejection Ratio (Input Supply) 120 Power Supply Rejection Ratio (Bias Supply) 80 350 60 2A 80 100mA 60 300 250 40 200 VIN = VOUT + 1V = 1.5V V 20 VOUT = 4V BIAS COUT = 1µF 0 0.01 0.1 1 10 100 1,000 FREQUENCY (kHz) VIN = VOUT + 1V 20 VOUT = 1.5V VBIAS = 4V COUT = 1µF IOUT = 2A 0 0.01 0.1 1 10 100 1,000 FREQUENCY (kHz) Dropout Voltage (Bias Supply) Dropout Voltage vs. Temperature (Input Supply) 40 1.8 1.6 1.4 1.2 1 0.8 0.6 VIN = VOUT + 1V VOUT = 1.5V VBIAS = 5V COUT = 1µF 0.4 0.2 0 1.6 1.4 1200 1600 2000 OUTPUT CURRENT (mA) Dropout Characteristics (Input Supply) 10mA 550 500 IOUT = 2A 450 VIN = VOUT +1V 400 VOUT = 1.5V 350 VBIAS = 5V 300 COUT = 1µF 250 I = 1A 200 OUT 150 IOUT = 100mA 100 50 0 1.6 1.2 2A 1.0 1.0 0.8 0.8 0.6 0.6 0.4 0.4 VBIAS = 5V VOUT = 1.5V COUT = 1µF 0.2 0 0 1.80 1.75 1.70 1.65 1.60 1.55 1.50 1.45 1.40 1.35 1.30 1.25 1.20 1 2 3 4 5 INPUT VOLTAGE (V) 6 Output Voltage vs. Temperature TEMPERATURE (°C) January 2006 10mA 0 0 300 50 0 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 IOUT = 2A IOUT = 1A IOUT = 100mA VIN = VOUT +1V VOUT = 1.5V 0.2 VBIAS = 5V COUT = 1µF 0 Load Regulation 1.52 1.51 2A 1.50 1.49 1.48 VIN = VOUT + 1V VOUT = 1.5V COUT = 1µF 1 2 3 4 5 BIAS VOLTAGE (V) 6 Maximum Bias Current vs. Bias Voltage 1.47 1.46 300 200 200 150 150 VIN = VOUT + 1V VOUT = 1.5V IOUT = 2A COUT = 1µF VADJ = 0V 3.5 4.0 4.5 5.0 5.5 6.0 6.5 BIAS VOLTAGE (V) 6 VIN = VOUT + 1V VOUT = 1.5V VBIAS = 5V COUT = 1µF OUTPUT CURRENT (A) 250 0 3 1200 1600 2000 OUTPUT CURRENT (mA) Dropout Voltage vs. Temperature (Bias Supply) 250 50 VIN = VOUT + 1V VOUT = 1.5V VBIAS = 5V COUT = 1µF 100 TEMPERATURE (°C) Dropout Characteristics (Bias Supply) 0.2 100 VIN = VOUT + 1V VOUT = 1.5V VBIAS = 5V 150 TEMPERATURE (°C) 1.4 1.2 Dropout Voltage (Input Supply) 400 2A 100 450 100 50 0 Maximum Bias Current vs. Temperature IBIAS VIN = VOUT +1V VOUT = 1.5V VBIAS = 5V COUT = 1µF VADJ = 0V TEMPERATURE (°C) M9999-011306 (408) 955-1690 Micrel, Inc. 50 45 MIC49200 Bias Current vs. Temperature IOUT = 2A 40 35 30 V =V + 1V 25 VIN =OUT OUT 1.5V 20 VBIAS = 5V = 1µF C 15 OUT 10 5 0 50 IOUT = 1.5A 10 IOUT = 100mA 14 VIN = VOUT + 1V VOUT = 1.5V VBIAS = 5V COUT = 1µF 1200 1600 2000 OUTPUT CURRENT (A) Bias Current vs. Bias Voltage 12 2 VBIAS = VOUT + 2.1V 1 V OUT = 1.5V COUT = 1µF 0 1.5 2.5 3.5 4.5 5.5 INPUT VOLTAGE (V) 14 12 IOUT=0A 10 10 8 8 8 6 6 6 4 4 4 VIN = VOUT + 1V VOUT = 1.5V COUT = 1µF 0 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 BIAS VOLTAGE (V) 30 Bias Current vs. Bias Voltage VIN = VOUT + 1V 2 VOUT = 1.5V COUT = 1µF 0 3 3.5 4 4.5 5 5.5 6 BIAS VOLTAGE (V) 50 2 6.5 Bias Current vs. Bias Voltage 6.5 Bias Current vs. Bias Voltage IOUT = 100mA VIN = VOUT + 1V VOUT = 1.5V COUT = 1µF 0 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 BIAS VOLTAGE (V) 50 40 IOUT = 750mA 20 IOUT=0A 3 IOUT = 0A 2 Ground Current vs. Input Voltage 4 20 Ground Current vs. Bias Voltage 10 5 30 0 12 6 40 TEMPERATURE (°C) 14 Bias Current vs. Output Current 40 Bias Current vs. Bias Voltage IOUT = 2A IOUT = 1.5A 10 VIN = VOUT + 1V VOUT = 1.5V COUT = 1µF 30 30 20 20 10 VIN = VOUT + 1V VOUT = 1.5V COUT = 1µF 10 VIN = VOUT + 1V VOUT = 1.5V COUT = 1µF 0 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 BIAS VOLTAGE (V) 0 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 BIAS VOLTAGE (V) 0 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 BIAS VOLTAGE (V) Bias Current vs. Input Voltage Bias Current vs. Input Voltage Reference Voltage vs. Input Voltage 20 18 0.901 250 16 14 12 10 200 100mA 750mA 150 0mA 8 6 4 2 0 0 300 0.900 100 VOUT = 1.5V VBIAS = 5V COUT = 1µF 0.5 1.0 1.5 2.0 INPUT VOLTAGE (V) January 2006 2.5 VOUT = 1.5V = 5V V 50 CBIAS = 1µF OUT 0 0 2A 0.5 1.0 1.5 2.0 INPUT VOLTAGE (V) 7 2.5 0.899 1.5 VOUT = 1.5V VBIAS = 5V COUT = 1µF 2.5 3.5 4.5 5.5 INPUT VOLTAGE (V) 6.5 M9999-011306 (408) 955-1690 Micrel, Inc. 0.901 MIC49200 Reference Voltage vs. Bias Voltage 4.0 0.900 Short Circuit Current vs. Temperature 1.6 3.5 1.4 3.0 1.2 2.5 1.0 2.0 0.8 1.5 0.899 3 1.6 VIN = VOUT + 1V VOUT = 1.5V COUT = 1µF 3.5 4 4.5 5 5.5 6 BIAS VOLTAGE (V) 6.5 Enble Threshold vs. Temperature 1.4 ON 1.2 1.0 OFF 0.8 0.6 0.4 0.2 0 VIN = VOUT + 1V VOUT = 1V VBIAS = 5V COUT = 1µF TEMPERATURE (°C) January 2006 1.0 0.5 0 4.0 ON OFF 0.6 VIN = VOUT + 1V VOUT = 1V VBIAS = 5V COUT = 1µF 0.4 0.2 VIN = VOUT + 1V VOUT = 1V COUT = 1µF TEMPERATURE (°C) 0 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 BIAS VOLTAGE (V) Current Limit vs. Input Voltage Current Limit vs. Bias Voltage 4.0 3.5 3.5 3.0 3.0 2.5 2.5 2.0 2.0 1.5 1.5 1.0 1.0 VOUT = 1.5V VBIAS = 3.3V COUT = 1µF 0.5 0 1.5 Enable Threshold vs. Bias Voltage 2.5 3.5 4.5 5.5 INPUT VOLTAGE (V) 8 6.5 0.5 0 2 VIN = VOUT + 1V VOUT = 1.5V COUT = 1µF 3 4 5 BIAS VOLTAGE (V) 6 M9999-011306 (408) 955-1690 Micrel, Inc. MIC49200 Functional Characteristics Output Voltage (20mV/div) Line Transient (VBIAS) Output Voltage (20mV/div) Line Transient (VIN) VBIAS = 6V Bias Voltage (2V/div) VOUT = 1.5V VBIAS = 3.3V VBIAS = 4V VIN = 2.8V VOUT = 1.8V COUT = 1µF COUT = 1µF IOUT = 2A IOUT = 2A Time (100µs/div) Time (20µs/div) Enable Turn-On Load Transient Output Voltage (50mV/div) VIN = 3.3V Enable (2V/div) Input Voltage (2V/div) VIN = 5V VIN = 2.8V VBIAS = 4V Output Current (1A/div) Output Voltage (1V/div) VOUT = 1.8V VIN = VOUT + 1V VOUT = 1.8V VBIAS = 4V COUT = 1µF COUT = 1µF Time (40µs/div) Time (4µs/div) January 2006 9 M9999-011306 (408) 955-1690 Micrel, Inc. Applications Information The MIC49200 is an ultra-high performance, lowdropout linear regulator designed for high current applications requiring fast transient response. The MIC49200 utilizes two input supplies, significantly reducing dropout voltage, perfect for low-voltage, DCto-DC conversion. The MIC49200 requires a minimum of external components and obtains a bandwidth of up to 10MHz. As a µCap regulator, the output is tolerant of virtually any type of capacitor including ceramic type and tantalum type capacitors. The MIC49200 regulator is fully protected from damage due to fault conditions, offering linear current limiting and thermal shutdown. Bias Supply Voltage VBIAS, requiring relatively light current, provides power to the control portion of the MIC49200. VBIAS requires approximately 40mA for a 1.5A load current. Dropout conditions require higher currents. Most of the biasing current is used to supply the base current to the pass transistor. This allows the pass element to be driven into saturation thereby reducing the dropout to 400mV at a 2A load current. Bypassing on the bias pin is recommended to improve performance of the regulator during line and load transients. Small ceramic capacitors from VBIAS-to-ground help reduce high-frequency noise from being injected into the control circuitry from the bias rail and represent good design practice. Good bypass techniques typically include one larger capacitor such as 1µF ceramic and smaller valued capacitors such as 0.01µF or 0.001µF in parallel with that larger capacitor to decouple the bias supply. The VBIAS input voltage must be 2.1V above the output voltage with a minimum VBIAS input voltage of 3 volts. Input Supply Voltage VIN provides the high current to the collector of the pass transistor. The minimum input voltage is 1.4V, allowing conversion from low voltage supplies. Output Capacitor The MIC49200 requires a minimum of output capacitance to maintain stability. However, proper capacitor selection is important to ensure desired transient response. The MIC49200 is specifically designed to be stable with virtually any capacitance value and ESR. A 1µF ceramic chip capacitor should satisfy most applications. Output capacitance can be increased without bound. See “Typical Characteristic” subsection for examples of load transient response. January 2006 MIC49200 X7R dielectric ceramic capacitors are recommended because of their temperature performance. X7R-type capacitors change capacitance by 15% over their operating temperature range and are the most stable type of ceramic capacitors. Z5U and Y5V dielectric capacitors change value by as much as 50% and 60% respectively over their operating temperature ranges. To use a ceramic chip capacitor with Y5V dielectric, the value must be much higher than an X7R ceramic or a tantalum capacitor to ensure the same capacitance value over the operating temperature range. Tantalum capacitors have a very stable dielectric (10% over their operating temperature range) and can also be used with this device. Input Capacitor An input capacitor of 1µF or greater is recommended when the device is more than 4" away from the bulk supply capacitance, or when the supply is a battery. Small, surface-mount, ceramic chip capacitors can be used for the bypassing. The capacitor should be placed within 1" of the device for optimal performance. Larger values will help to improve ripple rejection by bypassing the input to the regulator, further improving the integrity of the output voltage. Thermal Design Linear regulators are simple to use. The most complicated design parameters to consider are thermal characteristics. Thermal design requires the following application-specific parameters: • Maximum ambient temperature (TA) • Output current (IOUT) • Output voltage (VOUT) • Input voltage (VIN) • Ground current (IGND) First, calculate the power dissipation of the regulator from these numbers and the device parameters from this datasheet. PD = VIN × IIN + VBIAS × IBIAS – VOUT × IOUT As the load increases, the input current will be less than the output current at high output currents. The bias current is a sum of base drive and ground current. Ground current is constant over load current. The heat sink thermal resistance is determined with this formula: θ SA = 10 TJ(MAX) − TA PD M9999-011306 (408) 955-1690 Micrel, Inc. The heat sink may be significantly reduced in applications where the maximum input voltage is known and large compared with the dropout voltage. Use a series input resistor to drop excessive voltage and distribute the heat between this resistor and the regulator. The low-dropout properties of the MIC49200 allow significant reductions in regulator power dissipation and the associated heat sink without compromising performance. When this technique is employed, a capacitor of at least 1µF is needed directly between the input and regulator ground. Refer to “Application Note 9” for further details and examples on thermal design and heat sink specification. Minimum Load Current The MIC49200, unlike most other high current regulators, does not require a minimum load to maintain output voltage regulation. January 2006 MIC49200 Adjustable Regulator Design The MIC49200 adjustable version allows programming the output voltage anywhere between 0.9V and 5V. Two resistors are used. The resistor value between VOUT and the adjust pin should not exceed 10kΩ. Larger values can cause instability. The resistor values are calculated by: ⎛R ⎞ VOUT = 0.9⎜⎜ 1 + 1⎟⎟ ⎝ R2 ⎠ Where VOUT is the desired output voltage. Enable The fixed output voltage versions of the MIC49200 feature an active high enable input (EN) that allows on-off control of the regulator. Supply currents reduce to “zero” when the device is in shutdown, with only microamperes of leakage current. The EN input has TTL/CMOS compatible thresholds for simple logic interfacing. EN may be directly tied to VIN and pulled up to the maximum supply voltage. 11 M9999-011306 (408) 955-1690 Micrel, Inc. MIC49200 Package Information 5-Pin S-Pak (R) 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. © 2005 Micrel, Inc. January 2006 12 M9999-011306 (408) 955-1690