MIC5205 Micrel MIC5205 150mA Low-Noise LDO Regulator General Description Features The MIC5205 is an efficient linear voltage regulator with ultralow-noise output, very low dropout voltage (typically 17mV at light loads and 165mV at 150mA), and very low ground current (600µA at 100mA output). The MIC5205 offers better than 1% initial accuracy. • • • • • • • • • • • Designed especially for hand-held, battery-powered devices, the MIC5205 includes a CMOS or TTL compatible enable/ shutdown control input. When shutdown, power consumption drops nearly to zero. Regulator ground current increases only slightly in dropout, further prolonging battery life. Key MIC5205 features include a reference bypass pin to improve its already excellent low-noise performance, reversed-battery protection, current limiting, and overtemperature shutdown. The MIC5205 is available in fixed and adjustable output voltage versions in a small SOT-23-5 package. Ultra-low-noise output High output voltage accuracy Guaranteed 150mA output Low quiescent current Low dropout voltage Extremely tight load and line regulation Very low temperature coefficient Current and thermal limiting Reverse-battery protection “Zero” off-mode current Logic-controlled electronic enable Applications • • • • • • • For low-dropout regulators that are stable with ceramic output capacitors, see the µCap MIC5245/6/7 family. Cellular telephones Laptop, notebook, and palmtop computers Battery-powered equipment PCMCIA VCC and VPP regulation/switching Consumer/personal electronics SMPS post-regulator/dc-to-dc modules High-efficiency linear power supplies Ordering Information Part Number Marking Voltage Accuracy Junction Temp. Range* Package MIC5205BM5 MIC5205-2.5BM5 LBAA Adj 1% –40°C to +125°C SOT-23-5 LB25 2.5V 1% –40°C to +125°C SOT-23-5 MIC5205-2.7BM5 LB27 2.7V 1% –40°C to +125°C SOT-23-5 MIC5205-2.8BM5 LB28 2.8V 1% –40°C to +125°C SOT-23-5 MIC5205-2.85BM5 LB2J 2.85V 1% –40°C to +125°C SOT-23-5 MIC5205-2.9BM5 LB29 2.9V 1% –40°C to +125°C SOT-23-5 MIC5205-3.0BM5 LB30 3.0V 1% –40°C to +125°C SOT-23-5 MIC5205-3.3BM5 LB33 3.3V 1% –40°C to +125°C SOT-23-5 MIC5205-3.6BM5 LB36 3.6V 1% –40°C to +125°C SOT-23-5 MIC5205-3.8BM5 LB38 3.8V 1% –40°C to +125°C SOT-23-5 MIC5205-4.0BM5 LB40 4.0V 1% –40°C to +125°C SOT-23-5 MIC5205-5.0BM5 LB50 5.0V 1% –40°C to +125°C SOT-23-5 Other voltages available. Contact Micrel for details. Typical Application VIN MIC5205-x.xBM5 1 5 2 3 Enable Shutdown EN EN (pin 3) may be connected directly to IN (pin 1). 4 VOUT COUT = 2.2µF tantalum Low-Noise Operation: CBYP CBYP = 470pF, COUT ≥ 2.2µF Basic Operation: CBYP = not used, COUT ≥ 1µF Ultra-Low-Noise Regulator Application Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com June 2000 1 MIC5205 MIC5205 Micrel Pin Configuration EN GND IN 3 2 EN GND IN 1 3 LBxx 2 1 Part Identification LBAA 4 5 4 5 BYP OUT ADJ OUT MIC5205-x.xBM5 Fixed Voltages MIC5205BM5 Adjustable Voltage Pin Description MIC5205-x.x (fixed) MIC5205 (adjustable) Pin Name Pin Function 1 1 IN Supply Input 2 2 GND 3 3 EN Enable/Shutdown (Input): CMOS compatible input. Logic high = enable, logic low or open = shutdown. BYP Reference Bypass: Connect external 470pF capacitor to GND to reduce output noise. May be left open. 4 ADJ Adjust (Input): Adjustable regulator feedback input. Connect to resistor voltage divider. 5 OUT Regulator Output 4 5 Ground Absolute Maximum Ratings (Note 1) Operating Ratings (Note 2) Supply Input Voltage (VIN) ............................ –20V to +20V Enable Input Voltage (VEN) ........................... –20V to +20V Power Dissipation (PD) ............... Internally Limited, Note 3 Lead Temperature (soldering, 5 sec.) ....................... 260°C Junction Temperature (TJ) ....................... –40°C to +125°C Storage Temperature (TS) ....................... –65°C to +150°C Input Voltage (VIN) ....................................... +2.5V to +16V Enable Input Voltage (VEN) .................................. 0V to VIN Junction Temperature (TJ) ....................... –40°C to +125°C Thermal Resistance, SOT-23-5 (θJA) ....................... Note 3 MIC5205 2 June 2000 MIC5205 Micrel Electrical Characteristics VIN = VOUT + 1V; IL = 100µA; CL = 1.0µF; VEN ≥ 2.0V; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted. Symbol Parameter Conditions Min Typical VO Output Voltage Accuracy variation from specified VOUT ∆VO/∆T Output Voltage Temperature Coefficient Note 4 ∆VO/VO Line Regulation VIN = VOUT + 1V to 16V 0.004 0.012 0.05 %/V %/V ∆VO/VO Load Regulation IL = 0.1mA to 150mA, Note 5 0.02 0.2 0.5 % % VIN – VO Dropout Voltage, Note 6 IL = 100µA 10 IL = 50mA 110 IL = 100mA 140 IL = 150mA 165 50 70 150 230 250 300 275 350 mV mV mV mV mV mV mV mV –1 –2 Max Units 1 2 % % 40 ppm/°C IGND Quiescent Current VEN ≤ 0.4V (shutdown) VEN ≤ 0.18V (shutdown) 0.01 1 5 µA µA IGND Ground Pin Current, Note 7 VEN ≥ 2.0V, IL = 100µA 80 IL = 50mA 350 IL = 100mA 600 IL = 150mA 1300 125 150 600 800 1000 1500 1900 2500 µA µA µA µA µA µA µA µA PSRR Ripple Rejection frequency = 100Hz, IL = 100µA 75 dB ILIMIT Current Limit VOUT = 0V 320 ∆VO/∆PD Thermal Regulation Note 8 0.05 %/W eno Output Noise IL = 50mA, CL = 2.2µF, 470pF from BYP to GND 260 nV/ Hz 500 mA ENABLE Input VIL Enable Input Logic-Low Voltage regulator shutdown VIH Enable Input Logic-High Voltage regulator enabled IIL Enable Input Current VIL ≤ 0.4V VIL ≤ 0.18V VIH ≥ 2.0V VIH ≥ 2.0V IIH 0.4 0.18 2.0 V 0.01 2 V V 5 –1 –2 20 25 µA µA µA µA 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: The maximum allowable power dissipation at 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. The θJA of the MIC5205xxBM5 (all versions) is 220°C/W mounted on a PC board (see “Thermal Considerations” section for further details). Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range. Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load range from 0.1mA to 150mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification. 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. Ground pin current is the regulator quiescent current plus pass transistor base current. The total current drawn from the supply is the sum of the load current plus the ground pin current. Thermal regulation is defined as the change in output voltage at a time “t” after a change in power dissipation is applied, excluding load or line regulation effects. Specifications are for a 150mA load pulse at VIN = 16V for t = 10ms. Note 4: Note 5: Note 6: Note 7: Note 8: June 2000 3 MIC5205 MIC5205 Micrel Typical Characteristics PSRR (dB) -20 -80 -20 PSRR (dB) PSRR (dB) 0 VIN = 6V VOUT = 5V -40 -60 -80 -40 -60 -80 IOUT = 10mA COUT = 1µF Power Supply Rejection Ratio VIN = 6V VOUT = 5V -40 -60 -80 IOUT = 100mA COUT = 1µF -100 1E+1 1k 1E+4 10k 1E+5 1M 1E+7 10M 10 1E+2 100k 1E+6 100 1E+3 FREQUENCY (Hz) MIC5205 IOUT = 100mA 20 COUT = 1µF 10 0 0.1 0.2 0.3 VOLTAGE DROP (V) 0.4 100 90 80 1mA 70 60 IOUT = 100mA 50 40 10mA 30 20 10 0 COUT = 2.2µF CBYP = 0.01µF 0 0.1 0.2 0.3 VOLTAGE DROP (V) 0.4 Turn-On Time vs. Bypass Capacitance 10000 -60 -20 10mA VIN = 6V VOUT = 5V -40 0 30 Power Supply Rejection Ratio 1000 100 IOUT = 10mA COUT = 2.2µF CBYP = 0.01µF -100 1E+1 1k 1E+4 10k 1E+5 1M 1E+7 10M 10 1E+2 100k 1E+6 100 1E+3 FREQUENCY (Hz) PSRR (dB) PSRR (dB) -20 IOUT = 1mA COUT = 2.2µF CBYP = 0.01µF -80 -100 1E+1 1k 1E+4 10k 1E+5 1M 1E+7 10M 10 1E+2 100k 1E+6 100 1E+3 FREQUENCY (Hz) 0 -60 -20 PSRR (dB) PSRR (dB) -20 VIN = 6V VOUT = 5V -40 0 VIN = 6V VOUT = 5V 1mA 40 Power Supply Ripple Rejection vs. Voltage Drop -100 1E+1 1k 1E+4 10k 1E+5 1M 1E+7 10M 10 1E+2 100k 1E+6 100 1E+3 FREQUENCY (Hz) Power Supply Rejection Ratio 50 0 Power Supply Rejection Ratio -80 IOUT = 1mA COUT = 1µF -100 1E+1 1k 1E+4 10k 1E+5 1M 1E+7 10M 10 1E+2 100k 1E+6 100 1E+3 FREQUENCY (Hz) 0 IOUT = 100µA COUT = 2.2µF CBYP = 0.01µF -100 1E+1 1k 1E+4 10k 1E+5 1M 1E+7 10M 10 1E+2 100k 1E+6 100 1E+3 FREQUENCY (Hz) Power Supply Rejection Ratio -20 -60 -80 IOUT = 100µA COUT = 1µF -100 1E+1 1k 1E+4 10k 1E+5 1M 1E+7 10M 10 1E+2 100k 1E+6 100 1E+3 FREQUENCY (Hz) 0 -40 RIPPLE REJECTION (dB) -60 VIN = 6V VOUT = 5V TIME (µs) -40 Power Supply Ripple Rejection vs. Voltage Drop 60 RIPPLE REJECTION (dB) VIN = 6V VOUT = 5V -20 PSRR (dB) 0 Power Supply Rejection Ratio 10 10 Power Supply Rejection Ratio 100 1000 CAPACITANCE (pF) 10000 Dropout Voltage vs. Output Current 320 VIN = 6V VOUT = 5V -40 -60 IOUT = 100mA COUT = 2.2µF CBYP = 0.01µF -80 -100 1E+1 1k 1E+4 10k 1E+5 1M 1E+7 10M 10 1E+2 100k 1E+6 100 1E+3 FREQUENCY (Hz) 4 DROPOUT VOLTAGE (mV) 0 Power Supply Rejection Ratio 280 +125°C 240 200 +25°C 160 120 –40°C 80 40 0 0 40 80 120 160 OUTPUT CURRENT (mA) June 2000 MIC5205 Micrel Typical Characteristics Noise Performance Noise Performance 10 Noise Performance 10 10 10mA, COUT = 1µF 0.001 0.01 0.001 VOUT = 5V 0.0001 1E+1 10 1E+2 1k 1E+4 100 1E+3 10k 1E+5 100k 1E+6 1M 1E+7 10M FREQUENCY (Hz) Noise Performance 10mA 0.1 VOUT = 5V COUT = 22µF 1mA 0.001 tantalum CBYP = 10nF 0.0001 1k 1E+4 1E+1 10 1E+2 1M 1E+7 10k 1E+5 100k 1E+6 10M 100 1E+3 FREQUENCY (Hz) Noise Performance 10 1 10mA 100mA 0.1 0.01 0.001 100mA 0.01 Noise Performance NOISE (µV/√Hz) NOISE (µV/√Hz) 100mA 1mA VOUT = 5V COUT = 10µF 0.001 electrolytic 10mA CBYP = 100pF 0.0001 1k 1E+4 1E+1 10 1E+2 1M 1E+7 10k 1E+5 100k 1E+6 10M 100 1E+3 FREQUENCY (Hz) June 2000 1mA 10 0.1 0.01 VOUT = 5V COUT = 10µF electrolytic 0.0001 1k 1E+4 1E+1 10 1E+2 1M 1E+7 10k 1E+5 100k 1E+6 10M 100 1E+3 FREQUENCY (Hz) 10 1 10mA 0.1 NOISE (µV/√Hz) 0.01 1mA COUT = 1µF CBYP = 10nF 1 100mA VOUT = 5V COUT = 10µF electrolytic CBYP = 1nF 1mA 0.0001 1k 1E+4 1E+1 10 1E+2 1M 1E+7 10k 1E+5 100k 1E+6 10M 100 1E+3 FREQUENCY (Hz) 5 1 NOISE (µV/√Hz) 0.1 1 NOISE (µV/√Hz) NOISE (µV/√Hz) 1 100mA 0.1 0.01 0.001 1mA VOUT = 5V COUT = 10µF electrolytic CBYP = 10nF 10mA 0.0001 1E+1 10 1E+2 100 1E+3 1k 1E+4 10M 10k 1E+5 100k 1E+6 1M 1E+7 FREQUENCY (Hz) MIC5205 MIC5205 Micrel Block Diagrams VIN OUT IN VOUT COUT BYP CBYP (optional) Bandgap Ref. V REF EN Current Limit Thermal Shutdown MIC5205-x.xBM5 GND Ultra-Low-Noise Fixed Regulator VIN OUT IN VOUT COUT ADJ R1 R2 Bandgap Ref. V REF CBYP (optional) EN VOUT = VREF (1 + R2/R1) Current Limit Thermal Shutdown MIC5205BM5 GND Ultra-Low-Noise Adjustable Regulator MIC5205 6 June 2000 MIC5205 Micrel Thermal Considerations The MIC5205 is designed to provide 150mA of continuous current in a very small package. Maximum power dissipation can be calculated based on the output current and the voltage drop across the part. To determine the maximum power dissipation of the package, use the junction-to-ambient thermal resistance of the device and the following basic equation: Applications Information Enable/Shutdown Forcing EN (enable/shutdown) high (> 2V) enables the regulator. EN is compatible with CMOS logic gates. If the enable/shutdown feature is not required, connect EN (pin 3) to IN (supply input, pin 1). See Figure 1. Input Capacitor A 1µF capacitor should be placed from IN to GND if there is more than 10 inches of wire between the input and the ac filter capacitor or if a battery is used as the input. Reference Bypass Capacitor PD(max) = θ JA TJ(max) is the maximum junction temperature of the die, 125°C, and TA is the ambient operating temperature. θJA is layout dependent; Table 1 shows examples of junction-toambient thermal resistance for the MIC5205. BYP (reference bypass) is connected to the internal voltage reference. A 470pF capacitor (CBYP) connected from BYP to GND quiets this reference, providing a significant reduction in output noise. CBYP reduces the regulator phase margin; when using CBYP, output capacitors of 2.2µF or greater are generally required to maintain stability. The start-up speed of the MIC5205 is inversely proportional to the size of the reference bypass capacitor. Applications requiring a slow ramp-up of output voltage should consider larger values of CBYP. Likewise, if rapid turn-on is necessary, consider omitting CBYP. If output noise is not a major concern, omit CBYP and leave BYP open. Package SOT-23-5 (M5) θJA Recommended θJA 1" Square Minimum Footprint Copper Clad 220°C/W θJC 170°C/W 130°C/W Table 1. SOT-23-5 Thermal Resistance The actual power dissipation of the regulator circuit can be determined using the equation: PD = (VIN – VOUT) IOUT + VIN IGND Substituting PD(max) for PD and solving for the operating conditions that are critical to the application will give the maximum operating conditions for the regulator circuit. For example, when operating the MIC5205-3.3BM5 at room temperature with a minimum footprint layout, the maximum input voltage for a set output current can be determined as follows: Output Capacitor An output capacitor is required between OUT and GND to prevent oscillation. The minimum size of the output capacitor is dependent upon whether a reference bypass capacitor is used. 1.0µF minimum is recommended when CBYP is not used (see Figure 2). 2.2µF minimum is recommended when CBYP is 470pF (see Figure 1). Larger values improve the regulator’s transient response. The output capacitor value may be increased without limit. PD(max) = (125°C – 25°C) 220°C/W PD(max) = 455mW The junction-to-ambient thermal resistance for the minimum footprint is 220°C/W, from Table 1. The maximum power dissipation must not be exceeded for proper operation. Using the output voltage of 3.3V and an output current of 150mA, the maximum input voltage can be determined. From the Electrical Characteristics table, the maximum ground current for 150mA output current is 2500µA or 2.5mA. 455mW = (VIN – 3.3V) 150mA + VIN ·2.5mA The output capacitor should have an ESR (effective series resistance) of about 5Ω or less and a resonant frequency above 1MHz. Ultra-low-ESR capacitors can cause a low amplitude oscillation on the output and/or underdamped transient response. Most tantalum or aluminum electrolytic capacitors are adequate; film types will work, but are more expensive. Since many aluminum electrolytics have electrolytes that freeze at about –30°C, solid tantalums are recommended for operation below –25°C. At lower values of output current, less output capacitance is required for output stability. The capacitor can be reduced to 0.47µF for current below 10mA or 0.33µF for currents below 1mA. No-Load Stability 455mW = VIN ·150mA – 495mW + VIN ·2.5mA 950mW = VIN ·152.5mA VIN(max) = 6.23V Therefore, a 3.3V application at 150mA of output current can accept a maximum input voltage of 6.2V in a SOT-23-5 package. For a full discussion of heat sinking and thermal effects on voltage regulators, refer to the Regulator Thermals section of Micrel’s Designing with Low-Dropout Voltage Regulators handbook. The MIC5205 will remain stable and in regulation with no load (other than the internal voltage divider) unlike many other voltage regulators. This is especially important in CMOS RAM keep-alive applications. June 2000 (TJ(max) – TA ) 7 MIC5205 MIC5205 Micrel Fixed Regulator Applications VIN MIC5205-x.xBM5 1 5 2 3 R2 VOUT = 1.242V × + 1 R1 VOUT This equation is correct due to the configuration of the bandgap reference. The bandgap voltage is relative to the output, as seen in the block diagram. Traditional regulators normally have the reference voltage relative to ground and have a different VOUT equation. 2.2µF 4 470pF Figure 1. Ultra-Low-Noise Fixed Voltage Application Resistor values are not critical because ADJ (adjust) has a high input impedance, but for best results use resistors of 470kΩ or less. A capacitor from ADJ to ground provides greatly improved noise performance. Figure 1 includes a 470pF capacitor for low-noise operation and shows EN (pin 3) connected to IN (pin 1) for an application where enable/shutdown is not required. COUT = 2.2µF minimum. VIN VIN MIC5205-x.xBM5 VOUT 1 5 2 3 Enable Shutdown 1 R1 3 1.0µF VOUT 5 2 2.2µF 4 4 470pF EN R2 Figure 3. Ultra-Low-Noise Adjustable Voltage Application Figure 2. Low-Noise Fixed Voltage Application Figure 2 is an example of a low-noise configuration where CBYP is not required. COUT = 1µF minimum. Adjustable Regulator Applications Figure 3 includes the optional 470pF noise bypass capacitor from ADJ to GND to reduce output noise. Dual-Supply Operation When used in dual supply systems where the regulator load is returned to a negative supply, the output voltage must be diode clamped to ground. The MIC5205BM5 can be adjusted to a specific output voltage by using two external resistors (Figure 3). The resistors set the output voltage based on the following equation: MIC5205 MIC5205BM5 8 June 2000 MIC5205 Micrel Package Information 1.90 (0.075) REF 0.95 (0.037) REF 1.75 (0.069) 1.50 (0.059) 3.00 (0.118) 2.60 (0.102) DIMENSIONS: MM (INCH) 3.02 (0.119) 2.80 (0.110) 0.50 (0.020) 0.35 (0.014) 1.30 (0.051) 0.90 (0.035) 0.20 (0.008) 0.09 (0.004) 10° 0° 0.15 (0.006) 0.00 (0.000) 0.60 (0.024) 0.10 (0.004) SOT-23-5 (M5) June 2000 9 MIC5205 MIC5205 MIC5205 Micrel 10 June 2000 MIC5205 June 2000 Micrel 11 MIC5205 MIC5205 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. © 2000 Micrel Incorporated MIC5205 12 June 2000