MIC29311 Micrel MIC29311 3A Fast-Response LDO Regulator for USB Preliminary Information General Description Features The MIC29311 is a 3A, fast response, low-dropout (LDO) voltage regulator. Using Micrel’s proprietary Super βeta PNP™ process, the MIC29311 offers exceptional dropout (600mV at 3A) and low ground current (60mA at 3A). Fast transient response allows it to recover quickly from large load changes while maintaining a steady output. The device can be sent into a “zero-current” off mode when the TTL compatible enable is brought low. Designed specifically for Universal Serial Bus (USB) applications, the MIC29311 works with USB power switches to provide an economical solution for self-powered hubs. The 5.1V output voltage is optimized to work with lower-cost high on-resistance USB power switches (300mΩ) to provide a minimum of 4.75V at 500mA to downstream ports. Used with MIC2527 quad USB power switches, the MIC29311 can power up to 6 downstream ports. Features of the MIC29311 include thermal shutdown, current limit, reversed-battery and reversed-lead insertion protection. An overvoltage clamp is available to maintain a safe output when the input voltage exceeds 8V. An error flag is also available to indicate of the output falls out of regulation, or when an overcurrent condition occurs. The MIC29311 is available in a 5-pin TO-220 or TO-263 package with a fixed 5.1V output voltage. For other high current, low-dropout voltage regulators, please see the MIC29150/300/500/750 and the MIC29310, MIC29510, MIC29710. • • • • • • • • • • Fast transient response 3A output current over full temperature range 600mV dropout voltage at full load Low ground current 3% total accuracy “Zero” off-mode current Thermal Shutdown Current Limiting Reversed battery protection Fixed 5.1V Output Applications • • • • Self-powered USB hubs USB power switching High-efficiency linear power supplies High-efficiency switching supply post-regulator Typical Application Ferrite Bead MIC29311-5.1 LDO Regulator AC Line 5.8V @ 3A 6.3Vac 3A 47µF VBUS D+ MIC5207-3.3 100mA max. LDO Regulator IN OUT D– GND 10k IN EN V+ GND D+ FLAG GND 0.01µF 33µF D– GND ON/OFF Downstream USB Port 1 4.75V min 500mA max. VBUS OVERCURRENT D+ 33µF 4.7 µF Upstream USB Port Bold lines indicate 0.1" wide, 1-oz. copper high-current traces. VBUS 5.1V 33µF 3.3V USB Controller 1.0 µF OUT 0.01µF D– GND Downstream USB Port 2 4.75V min 500mA max. D+ D– GND 10k VBUS D+ 0.01µF 33µF D– GND Downstream USB Port 6 4.75V min 500mA max. Simple USB Stand-Alone 6-Port Self-Powered Hub Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com December 1998 1 MIC29311 MIC29311 Micrel Ordering Information Part Number Voltage Temperature Range Package MIC29311-5.1BT 5.1V 0°C to +125°C TO-220-5 MIC29311-5.1BU 5.1V 0°C to +125°C TO-263-5 Pin Configuration ERR OUT GND IN EN 5 4 3 2 1 TAB TAB 5 4 3 2 1 TO-220-5 (T) ERR OUT GND IN EN TO-263-5 (U) Pin Description Pin Number Pin Name 1 EN Enable (Input): Logic-level high enable/logic-level low shutdown control. 2 IN Unregulated Input: +16V maximum supply. 3, TAB GND Ground: Ground pin and TAB are internally connected. 4 OUT Regulator Output 5 ERR Error Flag (Output): Open-collector (active-low) output. Active low indicates overcurrent or undervoltage output conditions. MIC29311 Pin Function 2 December 1998 MIC29311 Micrel Absolute Maximum Ratings (Note 1) Operating Ratings (Note 2) Input Voltage (VIN) ........................................ –20V to +12V Enable Voltage (VEN) .................................... –20V to +12V Error Output Voltage (VERR) ............................. 0V to +12V Lead Temperature (soldering, 5 sec.) ....................... 260°C ESD Rating, Note 3 Input Voltage (VIN) ........................................................ +8V Maximum Power Dissipation (PD(max))..................... Note 4 Junction Temperature (TJ) ........................... 0°C to +125°C Package Thermal Resistance TO-220-5 (θJA) .................................................... 55°C/W TO-220-5 (θJC) ...................................................... 2°C/W TO-263-5 (θJC) ...................................................... 2°C/W Electrical Characteristics TA = 25°C, bold values indicate 0°C ≤ TJ ≤ +125°C; unless noted. Parameter Condition Max Units Output Tolerange 10mA ≤ IOUT < 3A, (VOUT + 1V) ≤ VIN ≤ 8V +3 % Line Regulation IOUT = 10mA, (VOUT + 1V) ≤ VIN ≤ 8V 0.06 0.5 % Load Regulation VIN = VOUT + 1V, 10mA ≤ IOUT 3A 0.2 1 % Output Voltage Temperature Coefficient Note 5 20 100 ppm/°C Dropout Voltage, Note 6 IOUT = 100mA 80 200 mV IOUT = 750mA 220 mV IOUT = 1.5A 330 mV IOUT = 3A 600 1000 mV VIN = 6.1V, IOUT = 750mA 5 20 mA VIN = 6.1V, IOUT = 1.5A 15 VIN = 6.1V, IOUT = 3A 60 150 mA Dropout Ground Current VIN = 4.6V, IOUT = 10mA 2 3 mA Current Limit VIN = 3V, VOUT = 0V Ground Current, Note 7 Min –3 3.0 Minimum Load Current Typ mA 3.8 7 A 10 mA CLOAD = 10µF 400 µV(rms) CLOAD = 33µF 260 µV(rms) Output Leakage Current VIN = 6.1V, VERR = 8V 0.1 1 2 µA µA Output Low Voltage VIN = 4.1V, IERR = 250µA 220 300 400 mV mV Output Noise Voltage Error Flag Output December 1998 3 MIC29311 MIC29311 Parameter Micrel Condition Min Typ Max Units 0.8 V Enable Input Logic Low Voltage regulator shutdown Logic High Voltage regulator enabled Enable Input Current VEN = VIN 2.4 V 15 VEN = 0.8V Regulator Output Current VIN = ≤8V, VEN ≤ 0.8V (shutdown), VOUT = 0V, Note 8 Note 1. Exceeding the absolute maximum rating may damage the device. Note 2. The device is not guaranteed to function outside its operating rating. Note 3. Devices are ESD sensitive. Handling precautions recommended. 10 30 75 µA µA 2 4 µA µA 20 µA Note 4. PD(max) = (TJ(max) – TA) ÷ θJA, where θJA depends upon the printed curcuit board layout. See “Applications Information.” Note 5. Output voltage temperature coefficient is defined as the ∆VOUT(worst case) ÷ (TJ(max) – TJ(min)) where TJ(max) is +125°C and TJ(min) is 0°C. Note 6. VDO = VIN – VOUT when VOUT decreases to 99% of its nominal output voltage with VIN = VOUT + 1V. Note 7. IGND is the quiescent current. IIN = IGND + IOUT. Note 8. VEN ≤ 0.8V and VIN ≤ 8V, VOUT = 0. MIC29311 4 December 1998 MIC29311 Micrel Typical Characteristics Dropout Voltage vs. Output Current MIC2931x Dropout Voltage vs. Temperature 0.4 0.3 0.2 0.1 1 2 OUTPUT CURRENT (A) 0.8 0.6 ILOAD = 3A 0.4 0.2 0 3 0 Ground Current vs. Input Voltage 1.0 0.5 2 4 6 8 INPUT VOLTAGE (V) 150 100 50 0 10 0 IOUT = 750mA 2 1 10 Ground Current vs. Output Current OUTPUT VOLTAGE (V) 40 30 20 10 December 1998 10 3 6 VOUT = 3.3V 0.5 0.0 RLOAD = 100Ω -0.5 -20 IOUT = 1.5A 30 60 90 120 TEMPERATURE (°C) 5.08 5.06 5.04 5.02 5.00 0 20 80 IOUT = 3A 60 40 20 0 150 0 Output Voltage vs. Temperature 30 60 90 120 TEMPERATURE (°C) 150 Short Circuit Current vs. Temperature 6 5.16 5.14 5.12 5.10 -10 0 10 INPUT VOLTAGE (V) 100 5 5.20 5.18 50 1 2 OUTPUT CURRENT (A) 2 4 INPUT VOLTAGE (V) Ground Current vs. Temperature 15 0 0 150 60 0 1 1.0 5 CURRENT (A) 4 30 60 90 120 TEMPERATURE (°C) ILOAD = 3A 2 1.5 GROUND CURRENT (mA) GROUND CURRENT (mA) GROUND CURRENT (mA) 5 0 2 4 6 8 INPUT VOLTAGE (V) 20 0 3 Ground Current vs. Temperature 6 0 Awaiting Further Characterization Data 2.0 IOUT = 3A Ground Current vs. Temperature 3 ILOAD = 10mA 4 Ground Current vs. Input Voltage GROUND CURRENT (mA) GROUND CURRENT (mA) GROUND CURRENT (mA) 1.5 0 5 0 0 150 200 IOUT = 10mA GROUND CURRENT (mA) 30 60 90 120 TEMPERATURE (°C) 6 Ground Current vs. Input Voltage 2.0 0.0 OUTPUT VOLTAGE (V) 0.5 0.0 0 7 1.0 DROPOUT VOLTAGE (mV) DROPOUT VOLTAGE (V) 0.6 Dropout Characteristics Awaiting Further Characterization Data 4 3 VOUT = 0V 2 1 30 60 90 120 TEMPERATURE (°C) 5 150 0 0 30 60 90 120 TEMPERATURE (°C) 150 MIC29311 MIC29311 Micrel Enable Current vs. Temperaure 10 VEN = 2V 10 5 0 30 60 90 120 TEMPERATURE (°C) 0.01 0.001 150 10x100 0 0.1 1x106 15 100x103 VEN = 5V 20 1 10x103 25 1x103 30 100x100 35 OUTPUT IMPEDANCE (Ω) ENABLE CURRENT (µA) 40 Output Impedance vs. Frequency FREQUENCY (Hz) VOUT 5.1V nominal MIC29311-5.1 EN VIN = VOUT + 1V 1µF OUT 10k IN OUTPUT VOLTAGE Load Transient Response (See Test Circuit Schematic) ERR GND 330µF AVX TPSE337M006R0100 tantalum 4 +20mV 5.1V –20mV 1ms/division Error Output LOAD CURRENT IOUT switching between 200mA and 3A Load Transcient Response Test Circuit 3A 200mA 0mA Line Transient Response with 3A Load, 100µF Output Capacitance INPUT VOLTAGE INPUT VOLTAGE Line Transient Response with 3A Load, 10µF Output Capacitance 8.0V 6.0V 8.0V 6.0V +20mV 200µs/division IOUT = 3A COUT =10µF OUTPUT VOLTAGE OUTPUT VOLTAGE 200µs/division 5.1V –20mV MIC29311 6 +20mV IOUT = 3A COUT = 100µF 5.1V –20mV December 1998 MIC29311 Micrel Functional Diagram IN OUT O.V. ILIMIT 1.180V FLAG Reference 18V 1.240V R1* EN Thermal Shutdown R2* GND December 1998 7 MIC29311 MIC29311 Micrel The heat sink may be significantly reduced in applications where the minimum input voltage is known and is 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 Micrel Super ßeta PNP regulators allow very 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. Please refer to Application Note 9 for further details and examples on thermal design and heat sink specification. Capacitor Requirements For stability and minimum output noise, a capacitor on the regulator output is necessary. The value of this capacitor is dependent upon the output current; lower currents allow smaller capacitors. The MIC29311 regulator is stable with a minimum capacitor value of 10µF at full load. This capacitor need not be an expensive low ESR type: aluminum electrolytics are adequate. In fact, extremely low ESR capacitors may contribute to instability. Tantalum capacitors are recommended for systems where fast load transient response is important. Where the regulator is powered from a source with a high AC impedance, a 0.1µF capacitor connected between Input and GND is recommended. This capacitor should have good characteristics to above 250kHz. When the regulator is located more than 3 inches from the ac bulk supply capacitors, a 1µF or greater input capacitor is recommended. Minimum Load Current The MIC29311 regulator is specified between finite loads. If the output current is too small, leakage currents dominate and the output voltage rises. A 10mA minimum load current is necessary for proper regulation. Enable Input The MIC29311 version features an enable (EN) input that allows on-off control of the device. Special design allows “zero” current drain when the device is disabled—only microamperes of leakage current flows. The EN input has TTL/ CMOS compatible thresholds for simple interfacing with logic, or may be directly tied to VIN. Enabling the regulator requires approximately 20µA of current into the EN pin. Error Flag The MIC29311 features an error flag which looks at the output voltage and signals an error condition when this voltage drops 5% below its expected value. The error flag is an opencollector output that pulls low under fault conditions. It may sink 10mA. Low output voltage signifies a number of possible problems, including an overcurrent fault (the device is in current limit) and low input voltage. The flag output is inoperative during overtemperature shutdown conditions. USB Applications The main application of the MIC29311 is to control power distribution in a self-powered Universal Serial Bus hub. For self-powered hubs, the MIC29311 provides 5.1V ±3% to downstream ports from an unregulated supply voltage (see Applications Information The MIC29311 is a high-performance low-dropout voltage regulator suitable for all moderate to high-current voltage regulator applications. The 600mV dropout voltage at full load makes it especially valuable in battery-powered systems and as high-efficiency noise filters in “post-regulator” applications. Its unique output voltage makes the MIC39311 ideal for Universal Serical Bus (USB) power switching applications. Unlike older NPN-pass transistor designs, where the minimum dropout voltage is limited by the base-emitter voltage drop and collector-emitter saturation voltage, dropout performance of the PNP output of these devices is limited merely by the low VCE saturation voltage. A trade-off for the low dropout voltage is a varying base drive requirement. But Micrel’s Super βeta PNP™ process reduces this drive requirement to merely 1% to 5% of the load current. The MIC29311 regulator is fully protected from damage due to fault conditions. Current limiting is provided. This limiting is linear; output current under overload conditions is constant. Thermal shutdown disables the device when the die temperature exceeds the maximum safe operating temperature. Transient protection allows device (and load) survival even when the input voltage spikes above and below nominal. The output structure of these regulators allows voltages in excess of the desired output voltage to be applied without reverse current flow. The MIC29311 version offers a logic level on-off control: when disabled, the device draws nearly zero current. MIC29311-5.1 VIN IN Enable Shutdown EN OUT VOUT FLG GND Flag Figure 1. Input and Output Capacitors 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 First, calculate the power dissipation of the regulator from these numbers and the device parameters from this datasheet. ( PD = IOUT 1.02VIN − VOUT ) Where the ground current is approximated by 2% of IOUT. Then the heat sink thermal resistance is determined by: θSA = TJ(max) − TA PD − θ JC + θCS Where TJ (max) ≤ 125°C and θCS is between 0 and 2°C/W. MIC29311 8 December 1998 MIC29311 Micrel ment for self-powered USB hubs. The output voltage is a function of the minimum output voltage of the power supply, the PCB trace resistance and the on-resistance of the switch. Table 1 shows the maximum allowable on-resistance for a 5.1V power supply in a self-powered hub, assuming 30mV of voltage drop due to PCB trace resistance. The 5.1V of the MIC29311 and the 300mΩ on-resistance of each MIC2527 switch provides an economical solution to power management of self-powered hubs. “Typical Application”). USB requires that the downstream voltage supplied to peripherals from a self-powered hub is between 4.75V and 5.25V. The MIC29311 provides regulation with this requirement. The enable pin input controls ganged power for up to seven downstream ports, each drawing up to 500mA. The device has an output current limiting circuit that linearly decreases the output voltage as the output current exceeds 3A. When the part is out of regulation by 5%, the error flag goes low and signals a fault condition to the microcontroller, allowing the system to be disabled. This provides the overcurrent protection that is required by USB. In Figure 2, the MIC29311 provides power to the MIC2527 quad power switches. The MIC2527 provides power switching to four independently controlled downstream ports. Two MIC2527s can be used to provide a 6-port, self-powered hub in conjunction with the MIC29311. The 5.1V output of the MIC29311 is optimized to ensure that under maximum load condition, the output voltage of each channel of the MIC2527 remains above 4.75V. This is the minimum voltage require- Nominal Supply Minimum Maximum Maximum Voltage Tolerance Voltage Voltage RON 1% 5.05V 5.15V 540mΩ 2% 5V 5.2V 440mΩ 5.10V 3% 4.95V 5.25V 340mΩ 4% 4.9V 5.3V — 5% 4.85V 5.36V — Table 1. Max. Allowable On-Resistance For further information concerning USB power management, refer to Application Note 17 and Application Hint 30. MIC29311-5.1 LDO Regulator 5.7V IN EN Ferrite Bead 5.1V ±3% OUT ERR GND VBUS 10k 47k 3.3V USB Controller MIC5207-3.3 LDO Regulator 4.7 µF IN V+ ON/OFF OVERCURRENT OUT 1µF GND ENA GND 0.01µF IN FLGA ENB IN OUTA FLGB OUTB OUTC FLGC OUTD END GND GND FLGD D+ 33µF* MIC2527 ENC D+ D– 4.75V min. at 500mA D– GND 0.1 µF Downstream USB Port 1 500mA max. VBUS D+ 33µF* 0.01µF D– GND Downstream USB Port 2 500mA max. VBUS Bold lines indicate 0.1" wide, 1-oz. copper high-current traces. D+ 33µF* 0.01µF D– GND * 33µF, 16V tantalum or 100µF, 10V electrolytic per port Downstream USB Port 3 500mA max. VBUS D+ 33µF* 0.01µF D– GND Downstream USB Port 4 500mA max. Figure 2. 4-Port Self-Powered Hub December 1998 9 MIC29311 MIC29311 Micrel Package Information 0.150 D ±0.005 (3.81 D ±0.13) 0.177 ±0.008 (4.50 ±0.20) 0.400 ±0.015 (10.16 ±0.38) 0.050 ±0.005 (1.27 ±0.13) 0.108 ±0.005 (2.74 ±0.13) 0.241 ±0.017 (6.12 ±0.43) 0.578 ±0.018 (14.68 ±0.46) SEATING PLANE 7° Typ. 0.550 ±0.010 (13.97 ±0.25) 0.067 ±0.005 (1.70 ±0.127) 0.032 ±0.005 (0.81 ±0.13) 0.268 REF (6.81 REF) 0.018 ±0.008 (0.46 ±0.20) 0.103 ±0.013 (2.62±0.33) Dimensions: inch (mm) TO-220-5 (T) 0.176 ±0.005 0.405±0.005 0.065 ±0.010 20°±2° 0.060 ±0.005 0.050±0.005 0.360±0.005 0.600±0.025 SEATING PLANE 0.004 +0.004 –0.008 0.067±0.005 0.032 ±0.003 8° MAX 0.100 ±0.01 0.015 ±0.002 DIM. = INCH TO-263-5 (U) MIC29311 10 December 1998 MIC29311 December 1998 Micrel 11 MIC29311 MIC29311 Micrel MICREL INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 TEL + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB USA http://www.micrel.com This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc. © 1998 Micrel Incorporated MIC29311 12 December 1998