MIIC5271

MIIC5271 MICREL | Alldatasheet

Document overview

• Manufacturer or author: Apple User
• PDF pages: 10

Technical content

Features

• Stable with ceramic or tantalum capacitor
• Positive and negative enable thresholds
• Low dropout voltage: 500mV @ 100mA
• Low ground current: 35µA @ load = 100µA
• Tight initial accuracy: ±2%
• Tight load and line regulation
• Thermal shutdown
• Current limiting
• IttyBitty SOT-23-5 packaging
• Zero-current off-mode

Applications

• GaAsFET bias
• Portable cameras and video recorders
• PDAs
• Battery-powered equipment
• Post-regulation of DC-DC converters IttyBitty is a registered trademark of Micrel, Inc. Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com

Ordering Information

Voltage* Junction Temp. Range Package MIC5271BM5 L9AA Adj. –40°C to +125°C SOT-23-5 MIC5271-3.0BM5 L930 –3.0V –40°C to +125°C SOT-23-5 MIC5271-5.0BM5 L950 –5.0V –40°C to +125°C SOT-23-5 * For other voltage options, please contact Micrel Marketing. MIC5271BM5 GND EN –OUT –IN 1µF 10µF –5.0V –6.0V VIN V OUT ADJ Regulator With Adjustable Output -11 -13 -15 ENABLE VOLTAGE (V) SUPPLY VOLTAGE (V) Enable Input Regulator On Regulator On Regulator Off

–IN –OUT ADJ L9AA GND MIC5271BM5 Adjustable Output Voltage Pin Description Pin Number Pin Name Pin Function (Adj.) EN Enable Input. TTL logic compatible enable input. Logic High = ON, Logic Low or open = OFF. GND Ground. ADJ Adjustable (Input): Adjustable feedback output connects to resistor voltage divider. –OUT Negative Regulator Output. –IN Negative Supply Input.

Absolute Maximum Ratings (Note 1) ESD Rating, Note 3 Operating Ratings (Note 2) Electrical Characteristics (Note 5) VIN = VOUT – 1.0V; COUT = 4.7µF, IOUT = 100µA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted. Symbol Parameter Condition Min Typ Max Units VOUT Output Voltage Accuracy Variation from nominal VOUT ∆VOUT/∆T Output Voltage Temperature Note 6 100 ppm/°C Coefficient ∆VOUT/VOUT Line Regulation VIN = VOUT – 1V to –16V 0.04 0.15 %/V 0.2 ∆VOUT/VOUT Load Regulation IOUT = 100µA to 100mA, Note 7 0.4 1.8 2.0 VIN – VOUT Dropout Voltage, Note 8 IOUT = 100µA mV IOUT = 50mA 360 500 mV IOUT = 100mA 500 700 mV 900 IGND Ground Current, Note 9 IOUT = 100µA 100 µA IOUT = 50mA 0.9 mA IOUT = 100mA 2.0 3.0 mA IGND_SD Ground current in shutdown VEN = ±0.6V –1.0 0.1 +1.0 µA PSRR Ripple Rejection f = 120Hz dB ILIMIT Current Limit VOUT = 0V 235 350 mA Enable Input TON Turn-on Time Time to VOUT = 90% nom. µs VEN Input Low voltage Regulator OFF ±0.6 V Input High Voltage Regulator ON ±2.0 V IEN Enable Input Current VEN = ± 0.6V and –2.0V 0.1 µA VEN = +2.0V 5.6 10.0 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. Note 4. The maximum allowable power dissipation is a function of the maximum junction temperature, TJ(max), the junction-to-ambient thermal resistance, θJA, and the ambient temperature, TA. The maximum allowable power dissipation at any ambient temperature is calculated using: PD(max) = (TJ(max) – TA) / θJA, where θJA is 235°C/W. Exceeding the maximum allowable power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. See the “Thermal Considerations” section for details. Note 5. Specification for packaged product only. Note 6. Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range. Note 7. Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load range from 100µA to 100mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification. Note 8. 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. Note 9. 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.

-0.5 -1.5 -2.5 -3.5 OUTPUT VOLTAGE (V) SUPPLY VOLTAGE (V) Dropout Characteristics

0 Load

-100mA Load -3.26 -3.265 -3.27 -3.275 -3.28 -3.285 -3.29 -3.295 -3.3 -3.305 -20 -40 -60 -80 -100 OUTPUT VOLTAGE (V) OUTPUT CURRENT (mA) Output Voltage vs. Output Current -3.2 -3.22 -3.24 -3.26 -3.28 -3.3 -3.32 -3.34 -3.36 -3.38 -3.4 -40 -20 20 40 60 80 100 120 OUTPUT VOLTAGE (V) TEMPERATURE (°C) Output Voltage vs. Temperature -0.5 -1.5 -2.5 -20 -40 -60 -80 -100 GROUND CURRENT (mA) OUTPUT CURRENT (mA) Ground Current vs. Output Current 5VIN -10 -20 -30 -40 -50 -60 -70 -80 -90 GROUND CURRENT (µA) SUPPLY VOLTAGE (V) Ground Current Characteristics 0µA Load -100µA Load -1mA Load -0.5 -1.5 -2.5 GROUND CURRENT (mA) SUPPLY VOLTAGE (V) Ground Current Characteristics -100mA Load -50mA Load -10mA Load -10 -15 -20 -25 -30 -40 -20 20 40 60 80 100 120 GROUND CURRENT (µA) TEMPERATURE (°C) Ground Current vs. Temperature 0A Load -1mA Load -0.5 -1.5 -2.5 -3.5 -40 -20 20 40 60 80 100 120 GROUND CURRENT (µA) TEMPERATURE (°C) Ground Current vs. Temperature -50A Load -100mA Load 0.2 0.4 0.6 0.8 1.2 1.4 1.6 -10 -13 -16 ENABLE THRESHOLD (V) SUPPLY VOLTAGE (V) Positive Enable Threshold vs. Supply Voltage Enable Off Enable On -0.2 -0.4 -0.6 -0.8 -1.2 -1.4 -1.6 -10 -13 -16 ENABLE THRESHOLD (V) SUPPLY VOLTAGE (V) Negative Enable Threshold vs. Supply Voltage Enable Off Enable On -100 -200 -300 -400 -500 -600 -20 -40 -60 -80 -100 DROPOUT VOLTAGE (mV) OUTPUT CURRENT (mA) Dropout vs. Output Current -50 -100 -150 -200 -250 -300 -350 -400 -40 -20 20 40 60 80 100 120 DROPOUT VOLTAGE (mV) TEMPERATURE (°C) Dropout vs. Temperature 0A Load -10mA Load

Typical Characteristics (continued) -100 -200 -300 -400 -500 -600 -700 -40 -20 20 40 60 80 100 120 DROPOUT VOLTAGE (mV) TEMPERATURE (°C) Dropout vs. Temperature -50mA Load -100mA Load

Functional Characteristics Load Transient TIME (2ms/div.) -100mA COUT = 1µF Ceramic VIN = 5V VOUT = 3V -10mA Output Current (50mA/div.) VOUT (10mV/div.) Load Transient TIME (2ms/div.) -100mA COUT = 1µF Ceramic VIN = 5V VOUT = 3V -10mA Output Current (50mA/div.) VOUT (10mV/div.)

MIC5271-x.x

The MIC5271 is a general-purpose negative regulator that can be used in any system that requires a clean negative voltage from a negative output. This includes post regulating of DC-DC converters (transformer based or charge pump based voltage converters). These negative voltages typically require a negative low dropout voltage regulator to provide a clean output from typically noisy lines. Input Capacitor A 1µF input capacitor should be placed from IN to GND if there is more than 2 inches of wire or trace between the input and the AC filter capacitor, or if a battery is used as the input. Output Capacitor The MIC5271 requires an output capacitor for stable opera- tion. A minimum of 1µF of output capacitance is required. The output capacitor can be increased without limitation to im- prove transient response. The output does not require ESR to maintain stability, therefore a ceramic capacitor can be used. High-ESR capacitors may cause instability. Capacitors with an ESR of 3Ω or greater at 100kHz may cause a high frequency oscillation. Low-ESR tantalums are recommended due to the tight ca- pacitance tolerance over temperature. Ceramic chip capacitors have a much greater dependence on temperature, depending upon the dielectric. The X7R is recommended for ceramic capacitors because the dielectric will change capacitance value by approximately 15% over temperature. The Z5U dielectric can change capacitance value by as much 50% over temperature, and the Y5V dielectric can change capacitance value by as much as 60% over temperature. To use a ceramic chip capacitor with the Y5V dielectric, the value must be much higher than a tanta- lum to ensure the same minimum capacitor value over temperature. No-Load Stability The MIC5271 does not require a load for stability. Enable Input The MIC5271 comes with an enable pin that allows the regulator to be disabled. Forcing the enable pin higher than the negative threshold and lower than the positive threshold disables the regulator and sends it into a “zero” off-mode current state. In this state, current consumed by the regulator goes nearly to zero. The MIC5271 will be in the on mode when the voltage applied to the enable pin is either greater than the positive threshold or less than the negative threshold. -11 -13 -15 ENABLE VOLTAGE (V) SUPPLY VOLTAGE (V) Enable Input Regulator On Regulator On Regulator Off Thermal Considerations Absolute values will be used for thermal calculations to clarify the meaning of power dissipation and voltage drops across the part. Proper thermal design for the MIC5271-5.0BM5 can be accomplished with some basic design criteria and some simple equations. The following information must be known to implement your regulator design: VIN = input voltage VOUT = output voltage IOUT = output current TA = ambient operating temperature IGND = ground current Maximum power dissipation can be determined by knowing the ambient temperature, TA, the maximum junction tem- perature, 125°C, and the thermal resistance, junction to ambient. The thermal resistance for this part, assuming a minimum footprint board layout, is 235°C/W. The maximum power dissipation at an ambient temperature of 25°C can be determined with the following equation: P T T D(max) J(max) A JA θ P 125 C 25 C

235 C/W

D(max) = P 425mW D(max) = The actual power dissipation of the regulator circuit can be determined using one simple equation. PD = (VIN – VOUT)IOUT + VIN × IGND Substituting PD(max), determined above, for PD and solving for the operating conditions that are critical to the application will give the maximum operating conditions for the regulator circuit. The maximum power dissipation number cannot be exceeded for proper operation of the device. The maximum input voltage can be determined using the output voltage of 5.0V and an output current of 100mA. Ground current, of 1mA for 100mA of output current, can be taken from the “Electrical Characteristics ” section of the data sheet. 425mW V 5.0V 100mA V 1mA IN IN 425mW 100mA V 1mA V 500mW IN IN ) − 925mW 101mA VIN V 9.16Vmax IN = Therefore, a –5.0V application at 100mA of output current can accept a maximum input voltage of –9.16V in a SOT-23-5 package. For a full discussion of heat sinking and thermal effects on voltage regulators, refer to Regulator Thermals section of Micrel’s “Designing with Low Dropout Voltage Regulators” handbook.

Figure 1. Adjustable Voltage Application

Package Information

0.20 (0.008) 0.09 (0.004) 0.60 (0.024) 0.10 (0.004) 3.02 (0.119) 2.80 (0.110) 10° 3.00 (0.118) 2.60 (0.102) 1.75 (0.069) 1.50 (0.059) 0.95 (0.037) REF 1.30 (0.051) 0.90 (0.035) 0.15 (0.006) 0.00 (0.000) DIMENSIONS: MM (INCH) 0.50 (0.020) 0.35 (0.014) 1.90 (0.075) REF SOT-23-5 (M5) MICREL, INC.

1849 FORTUNE DRIVE

SAN JOSE, CA 95131 USA TEL + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB http://www.micrel.com The information furnished by Micrel in this datasheet 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 at Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2003 Micrel, Incorporated.