MIC49500 5A Dual Supply, Low Voltage, High Bandwidth LDO General Description Features The MIC49500 is an ultra-high-bandwidth, lowdropout, 5.0A voltage regulator ideal for powering core voltages of low-voltage microprocessors. The MIC49500 implements a dual supply configuration allowing for very low output impedance and very fast transient response. • Input voltage range: – VIN: 1.4V to 6V – VBIAS: 3.0V to 6V • Stable with 10µF ceramic output capacitor • +1.0% initial output tolerance • Maximum dropout (VIN – VOUT) is 500mV over temperature • Adjustable output voltage down to 0.7V • Ultra Fast Transient Response (Up to 10MHz bandwidth) • Excellent line and load regulation specifications • Logic controlled shutdown option • Thermal shutdown and current limit protection • Thin 7-pin S-Pak package • TO-263 7-pin package • –40°C to +125°C operating junction temperature range The MIC49500 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 6V and the bias supply requires between 3V and 6V for proper operation. The MIC49500 can regulate to an output voltage as low as 0.7V, making it an ideal product for low-voltage to low-voltage conversion. The MIC49500 requires a minimum of output capacitance for stability, working optimally with any type of capacitor, including small ceramic capacitors. Available in fixed output voltages from 0.9V to 1.8V and adjustable output voltages down to 0.7V, the MIC49500 comes in both 7-pin S-Pak and TO-263 packages. The MIC49500 is rated to the full operating temperature range of -40°C to 125°C junction temperature. Applications • • • • ASIC Core Voltage Regulator PLD/FPGA Core Power Supply Linear Point-of-Load Conversion High Speed Post-Regulator Typical Application OUT IN R1 VBIAS = 3.1V CBIAS = 1µF Ceramic BIAS ADJ R2 GND Load Transient VOUT = 1.0V Output Voltage (50mV/div) MIC49500WR CIN = 1µF Ceramic Low Voltage, Fast Transient Response Regulator VOUT = 1.8V VIN = 2.8V COUT = 10µF Ceramic VBIAS = 3.9V COUT = CBIAS = 10µF 5A Output Current (2A/div) VIN = 2.0V 0A Time (10µs/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 November 2005 M9999-110805 (408) 955-1690 Micrel, Inc. MIC49500 Block Diagram VBIAS VIN Ilimit EN Enable ADJ Bandgap SNS / ADJ FIX (SNS) VOUT ADJ FIX GND November 2005 2 M9999-110805 (408) 955-1690 Micrel, Inc. MIC49500 Ordering Information Part Number* Voltage Junction Temperature Range Package Lead Finish* MIC49500-0.9WR 0.9V –40°C to +125°C S-Pak-7 RoHS Compliant MIC49500-1.2WR 1.2V –40°C to +125°C S-Pak-7 RoHS Compliant MIC49500WR ADJ –40°C to +125°C S-Pak-7 RoHS Compliant MIC49500-0.9WU 0.9V –40°C to +125°C TO-263 RoHS Compliant MIC49500-1.2WU 1.2V –40°C to +125°C TO-263 RoHS Compliant MIC49500WU ADJ –40°C to +125°C TO-263 RoHS Compliant Other Voltage available. Contact Micrel for details. * RoHS compliant with ‘high-melting solder’ exemption. Pin Configuration 7 6 5 4 3 2 1 VSNS/ADJ NC VOUT GND VIN VBIAS EN 7 6 5 4 3 2 1 MIC49500WR (S-Pak-7) VSNS/ADJ NC VOUT GND VIN VBIAS EN MIC49500WU (TO263-7) Pin Description Pin Number S-Pak-7 Pin Name (Fixed) Pin Name (Adj) 1 EN EN 2 VBIAS VBIAS 3 VIN VIN Input Voltage: Main Power Input Supply. Supplies main current to output device. 4 GND GND Ground: Package TAB is connected to Ground. 5 VOUT VOUT Output Voltage: Regulator Output. 6 NC 7 VSNS - 7 - ADJ November 2005 Pin Function Enable: TTL/CMOS compatible input. Logic high = enable, logic low or open = shutdown. Bias Supply: Bias supply input for powering all internal circuitry of the device, except the main current path. No Connect Remote Voltage Sense: Connect direct the load to improve regulation. Connect direct to pin 6 if not used. Adjust Input. Connect external resistor divider to program output voltage. 3 M9999-110805 (408) 955-1690 Micrel, Inc. MIC49500 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VIN) ............................................. 6.5V Bias Supply Voltage (VBIAS) .................................. 6.5V Enable Input Voltage (VEN)................................... 6.5V Power Dissipation............................. Internally Limited ESD Rating(3) .........................................................3kV Supply voltage (VIN).......................................1.4V to 6V Bias Supply Voltage (VBIAS)..............................3V to 6V Enable Input Voltage (VEN)........................... 0V to VBIAS Junction Temperature Range........-40°C ≤ TJ ≤ +125°C Package Thermal Resistance S-Pak (θJC) ................................................. 2°C/W TO-263 (θJC) ............................................... 2°C/W Electrical Characteristics(4) VIN = VOUT + 1.0V; VBIAS = VOUT + 2.1V; COUT = 10µF; IOUT = 10mA; TJ = 25°C, bold values indicate –40°C to +125°C, unless noted. Parameter Output Voltage Accuracy Conditions Min o At 25 C, fixed voltage options Over temperature range Output Voltage Line Regulation VIN = VOUT + 1V to 6V Output Voltage Load Regulation IL = 10mA to 5A VIN – VO; Dropout Voltage VBIAS – VO; Dropout Voltage Typ Max Units -1 +1 % -2 +2 % -0.1 +0.1 %/V 0.2 1.0 % IL = 2.5A 145 300 mV IL = 5.0A 290 500 mV IL = 2.5A 1.5 2.0 V 2.1 IL = 5.0A 1.7 VOUT = 1.2V; IL = 0mA 55 VOUT = 1.2V; IL = 5.0A 55 90 mA Ground Pin Current in Shutdown VIL < 0.6V 0.1 5 µA Current thru VBIAS IL = 0mA 30 50 mA IL = 5.0A 70 120 mA 9.5 A Ground Pin Current Current Limit VOUT = 0V 5.5 7.5 Regulator enable 1.6 1.2 V mA Enable Input Enable Input Threshold Regulator shutdown Enable Hysteresis 20 Enable Pin Input Current Turn-on Time COUT = 10µF; Note 5 V 1.15 0.6 V 50 150 mV 0.1 5 µA 10 45 µs 0.7 0.707 V 0.714 V Reference Voltage (Adjustable Output Only) VREF TA = 25°C 0.693 -40°C < TA < 125°C 0.686 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, 1.5k in series with 100pF. 4. Specification for packaged product only. 5. Turn-on time is measured from 10% of the positive edge of the enable signal to 90% of the rising edge of the output voltage of the regulator. November 2005 4 M9999-110805 (408) 955-1690 Micrel, Inc. MIC49500 Typical Characteristics Ground Current vs. Load Current 60 1.6 55 1.4 50 1.2 45 1.0 40 0.8 35 25 0 0 60 50 60 30 10 0 0 1 2 3 4 OUTPUT CURRENT (A) 800 1A 40 2.5A 0 1.8 5A 5 Ground Current vs. Temperature 0 100µA VIN = VOUT + 1V VOUT = 3V COUT = 10µF 20 40 60 80 TEMPERATURE (°C) Output Voltage vs. Temperature 250 720 200 20 40 60 80 TEMPERATURE (°C) 1.0 VIN = VOUT + 1V VOUT = 1.5V VBIAS = 3.3V COUT = 10µF 0.4 0.2 0 0 Room Cold 1.5 0.8 1 2 3 4 OUTPUT CURRENT (A) November 2005 Hot 0.5 5 0 0 Dropout Voltage vs. Output Current 150 VIN = VOUT + 1V VOUT = 1.5V VBIAS = 3.3V COUT = 10µF IOUT = 100µA 2.5 1.0 VIN = VOUT = 1V VOUT = 1.5V COUT = 10µF 20 40 60 80 TEMPERATURE (°C) 1.30 350 1.6 0.6 1.40 740 2.0 Output Voltage vs. Temperature 1.35 100 0.5 1 1.5 2 2.5 ENABLE VOLTAGE (V) 5 3 VIN = VOUT + 1V VOUT = 1.5V VBIAS = 3.3V COUT = 10µF 50 0 0 Enable Threshold 1.2 5 1.50 300 620 1.4 2 3 4 BIAS VOLTAGE (V) 1.60 780 760 600 1 1.45 640 V BIAS Dropout Voltage vs. Output Current 0 0 1.55 660 VIN = 4V VOUT = 3V COUT = 10µF 20 40 60 80 TEMPERATURE (°C) VIN = VOUT + 1V VOUT = 1.5V COUT = CIN = 10µF 0.2 1.65 1A 680 500mA 0.4 1.70 5A 700 100µA 20 0 5 50 0 1 2 3 4 INPUT VOLTAGE (V) 10 Bias Current vs. Temperature 60 10 VOUT = 1.5V VBIAS = 3.3V COUT = 10µF 20 VIN = VOUT + 1V VOUT = 1.8V VBIAS = 3.3V COUT = CBIAS = 10µF 20 5A 0.6 30 500mA 40 30 1.0 0.8 40 50 2.5A 1.2 5A 2.5A 70 50mA 1.4 2.5A 0.2 Bias Current vs. Output Current 80 50mA 0.4 20 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 LOAD CURRENT (A) Output Voltage vs. Bias Voltage 1.6 0.6 VIN = VOUT + 1V VOUT = 1.2V VEN = VIN VBIAS = 3.3V COUT = 10µF 30 Output Voltage vs. Input Voltage 10 9 8 7 6 5 4 3 2 1 0 2.5 1 2 3 4 OUTPUT CURRENT (I) 5 Current Limit vs. Input Voltage VIN = 2.5V VOUT = 0V VBIAS = 3.3V COUT = 10µF 3 3.5 4 4.5 5 INPUT VOLTAGE (V) 5.5 M9999-110805 (408) 955-1690 Micrel, Inc. MIC49500 Typical Characteristics 10 Output Noise Spectral Density 1 0.1 VIN = 3.8V VOUT = 2.8V COUT = 10µF IOUT = 10mA 0.01 0.01 0.1 1 10 100 1,000 10,000 FREQUENCY (kHz) November 2005 6 M9999-110805 (408) 955-1690 Micrel, Inc. MIC49500 Functional Characteristics Load Transient Output Voltage (50mV/div) Enable Voltage (1V/div) Enable Turn-On VOUT = 1.8V VIN = 2.8V Output Current (2A/div) Output Voltage (500mV/div) 5A VOUT = 1.8V VIN = VBIAS = 5V IOUT = 10mA COUT = CBIAS = 10µF 0A Time (2µs/div) Time (10µs/div) Line Transient (VIN) Line Transient (VBIAS) Bias Voltage (1V/div) Input Voltage (1V/div) VBIAS = 3.9V COUT = CBIAS = 10µF 5V 4V 5V 4V VOUT = 1.5V VOUT = 1.5V VIN = 2.5V VBIAS = 3.6V IOUT = 1A IOUT = 1A Time (100µs/div) Time (100µs/div) November 2005 COUT = 10µF Output Voltage (20mV/div) Output Voltage (10mV/div) COUT = 10µF 7 M9999-110805 (408) 955-1690 Micrel, Inc. MIC49500 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. Applications Information The MIC49500 is an ultra-high performance, low dropout linear regulator designed for high current applications requiring fast transient response. The MIC49500 utilizes two input supplies, significantly reducing dropout voltage, perfect for low-voltage, DCto-DC conversion. The MIC49500 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 and tantalum. The MIC49500 regulator is fully protected from damage due to fault conditions, offering constant current limiting and thermal shutdown. Input Capacitor An input capacitor of 1µF or greater is recommended when the device is more than 4 inches 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. Bias Supply Voltage VBIAS, requiring relatively light current, provides power to the control portion of the MIC49500. VBIAS requires approximately 70mA for 5A load current. 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, reducing the dropout to 290mV at a 5A 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 are 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 3.0V. 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) 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. First, calculate the power dissipation of the regulator from these numbers and the device parameters from this datasheet. Output Capacitor The MIC49500 requires a minimum of output capacitance to maintain stability. However, proper capacitor selection is important to ensure desired transient response. The MIC49500 is specifically designed to be stable with a wide range of capacitance values and ESR. A 10µF ceramic chip capacitor should satisfy most applications. Output capacitance can be increased without bound. See typical characteristics for examples of load transient response. The input current will be less than the output current as the output load increases. The bias current is a sum of base drive and ground current. Ground current is constant over load current. Then the heat sink thermal resistance is determined with this formula: November 2005 PD = VIN × IIN + VBIAS × IBIAS – VOUT × IOUT SA 8 = ⎛ TJ(MAX) ± TA ⎝PD JC CS) M9999-110805 (408) 955-1690 Micrel, Inc. MIC49500 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 MIC49500 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. Adjustable Regulator Design The MIC49500 adjustable version allows programming the output voltage anywhere between 0.7Vand 6V. 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: R1 = R2 × 0.7 ±1 Where VOUT is the desired output voltage. Enable The fixed output voltage versions of the MIC49500 feature an active high enable input (EN) that allows on-off control of the regulator. Current drain reduces to “zero” when the device is 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. Minimum Load Current The MIC49500, unlike most other high current regulators, does not require a minimum load to maintain output voltage regulation. Power Sequencing There is no power sequencing requirement for VIN and VBIAS, giving more flexibility to the user. November 2005 VOUT 9 M9999-110805 (408) 955-1690 Micrel, Inc. MIC49500 Package Information 7-Pin SPAK (R) 7-Pin TO-263 (U) November 2005 10 M9999-110805 (408) 955-1690 Micrel, Inc. MIC49500 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. November 2005 11 M9999-110805 (408) 955-1690