Features. Enable Shutdown 2. LAx. Regulator Circuit

Transcription

1 MIC53 MIC53 Teeny SC-7 µcap Low-Dropout Regulator Final Information General Description The MIC53 is a µcap 8mA linear voltage regulator in the Teeny SC-7 package. Featuring half the footprint of the standard SOT-3 package, this Teeny SC-7 regulator has very low dropout voltage (typically mv at light loads and 3mV at 8mA) and very low ground current (5µA at ma output). It also offers better than 3% initial accuracy and includes a logic-compatible enable input. The µcap regulator design is optimized to work with lowvalue, low-cost ceramic capacitors. The outputs typically require only.47µf of output capacitance for stability. Designed especially for hand-held, battery-powered devices, the MIC53 can be controlled by a CMOS or TTL compatible logic signal. When disabled, power consumption drops nearly to zero. If on-off control is not required, the enable pin may be tied to the input for 3-terminal operation. The ground current of the MIC53 increases only slightly in dropout, further prolonging battery life. Key MIC53 features include current limiting, overtemperature shutdown, and protection against reversed battery. The MIC53 is available in.5v,.6v,.7v,.8v, 3.V, 3.3V, 3.6V, and 5.V fixed voltages. Other voltages are available; contact for details. Ordering Information Features Teeny SC-7 package Wide selection of output voltages Guaranteed 8mA output Low quiescent current Low dropout voltage Tight load and line regulation Low temperature coefficient Current and thermal limiting Reversed input polarity protection Zero off-mode current Logic-controlled shutdown Stability with low ESR ceramic capacitors Applications Cellular telephones Laptop, notebook, and palmtop computers Battery-powered equipment Bar code scanners SMPS post-regulator/dc-to-dc modules High-efficiency linear power supplies Typical Applications Part Number Marking Voltage Junction Temp. Range Package Standard Pb-Free Standard Pb-Free MIC53-.5BC5 MIC53-.5YC5 LAM LAM.5V 4 C to +5 C SC-7-5 MIC53-.6BC5 MIC53-.6YC5 LAQ LAQ.6V 4 C to +5 C SC-7-5 MIC53-.7BC5 MIC53-.7YC5 LAL LAL.7V 4 C to +5 C SC-7-5 MIC53-.8BC5 MIC53-.8YC5 LAJ LAJ.8V 4 C to +5 C SC-7-5 MIC53-3.BC5 MIC53-3.YC5 LAG LAG 3.V 4 C to +5 C SC-7-5 MIC53-3.3BC5 MIC53-3.3YC5 LAE LAE 3.3V 4 C to +5 C SC-7-5 MIC53-3.6BC5 MIC53-3.6YC5 LAD LAD 3.6V 4 C to +5 C SC-7-5 MIC53-5.BC5 MIC53-5.YC5 LAB LAB 5.V 4 C to +5 C SC-7-5 Other voltages available. Contact for details. Enable Shutdown 5 LAx 3 4 V OUT.47µF Regulator Circuit Teeny is a trademark of, Inc., Inc. 849 Fortune Drive San Jose, CA 953 USA tel + (48) fax + (48) August 4 MIC53

2 MIC53 Pin Configuration GND 3 NC LAx EN 4 5 OUT IN SC-7-5 (C5) Pin Description Pin Number Pin Name Pin Function EN Enable (Input): TTL/CMOS compatible control input. Logic high = enabled; logic low or open = shutdown. NC Not internally connected. 3 GND Ground 4 OUT Regulator Output 5 IN Supply Input Absolute Maximum Ratings (Note ) Input Supply Voltage (V IN )... V to +V Enable Input Voltage (V EN )... V to +V Power Dissipation (P D )... Internally Limited Storage Temperature Range (T S )... 6 C to +5 C Lead Temperature (Soldering, 5 sec.)... 6 C ESD, Note 3 Operating Ratings (Note ) Input Voltage (V IN )....5V to 6V Enable Input Voltage (V EN )... V to V IN Junction Temperature Range... 4 C to +5 C Thermal Resistance (θ JA )... Note 4 MIC53 August 4

3 MIC53 Electrical Characteristics V IN = V OUT + V; ; C L =.47µF; V EN.V; T J = 5 C, bold values indicate 4 C T J +5 C; unless noted. Symbol Parameter Conditions Min Typ Max Units V O Output Voltage Accuracy 3 3 % 4 4 % V O / T Output Voltage Temp. Coefficient Note 5 5 ppm/ C V O /V O Line Regulation V IN = V OUT + V to 6V.8.3 %.5 % V O /V O Load Regulation I L =.ma to 8mA, Note %.5 % V IN V O Dropout Voltage, Note 7 I L = µa mv I L = ma 35 mv I L = 5mA 5 mv I L = 8mA 8 6 mv I Q Quiescent Current V EN.4V (shutdown). µa I GND Ground Pin Current, Note 8 I L = µa, V EN.V (active) 8 µa I L = ma, V EN.V (active) 5 75 µa I L = 5mA, V EN.V (active) 85 µa I L = 8mA, V EN.V (active) 8 3 µa I GNDDO Ground Pin Current in Dropout V IN = V OUT(nominal).5V, Note 8 3 µa I LIMIT Current Limit V OUT = V 8 5 ma V O/ P D Thermal Regulation Note 9.5 %/W Enable Input V IL Enable Input Voltage Level Logic Low (off).6 V V IH Logic High (on). V I IL Enable Input Current V IL.6V. µa I IH V IH.V 8 5 µa Note. Note. Note 3. Note 4. Note 5. Note 6. Note 7. Note 8. Note 9. Exceeding the absolute maximum rating may damage the device. The device is not guaranteed to function outside its operating rating. Devices are ESD sensitive. Handling precautions recommended. The maximum allowable power dissipation is a function of the maximum junction temperature, T J(max), the junction-to-ambient thermal resistance, θ JA, and the ambient temperature, T A. The maximum allowable power dissipation at any ambient temperature is calculated using: P D(max) = (T J(max) T A ) θ JA. Exceeding the maximum allowable power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. θ JA of the SC-7-5 is 45 C/W, mounted on a PC board. 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. 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 % below its nominal value measured at V 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 an 8mA load pulse at V IN = 6V for t = ms. August 4 3 MIC53

4 MIC53 Typical Characteristics DROPOUT VOLTAGE (mv) Dropout Voltage vs. Output Current C IN = µf DROPOUT VOLTAGE (mv) 4 3 Dropout Voltage C IN = µf I L = 8mA I L = µa OUTPUT VOLTAGE (V) 4 3 Dropout Characteristics I L = µa I L = 8mA C IN = µf.. OUTPUT CURRENT (ma) SUPPLY VOLTAGE (V) GROUND CURRENT (µa) 5 5 Ground Current vs. Output Current V IN = V OUT + V OUTPUT CURRENT (ma) GROUND CURRENT (ma) Ground Current vs. Supply Voltage I L = 5mA I L = µa V OUT = 3.3V SUPPLY VOLTAGE (V) GROUND CURRENT (ma) Ground Current C IN = µf I L = 8mA I L = 5mA I L = µa OUTPUT VOLTAGE (V) Output Voltage vs. Output Current C IN = µf. 5 5 OUTPUT CURRENT (ma) SHORT CIRCUIT CURRENT (ma) Short Circuit Current vs. Input Voltage C IN = µf INPUT VOLTAGE (V) OUTPUT (mv) LOAD (ma) Thermal Regulation (3.3V Version) OUTPUT VOLTAGE (V) Output Voltage C IN = µf DEVICES HI / AVG / LO.8.6 CURVES APPLICABLE AT µa AND 5mA OUTPUT CURRENT (ma) Short Circuit Current C IN = µf MIN. SUPPLY VOLTAGE (V) Minimum Supply Voltage V OUT = 3.3V C IN = µf MIC53 4 August 4

5 MIC53 OUTPUT (mv) OUTPUT (ma) Load Transient V IN = V OUT OUTPUT (mv) OUTPUT (ma) Load Transient V IN = V OUT OUTPUT (V) Line Transient OUTPUT (V) - 8 Line Transient C L = µf INPUT (V) INPUT (V) Ripple Voltage vs. Frequency Ripple Voltage vs. Frequency Ripple Voltage vs. Frequency RIPPLE VOLTAGE (db) I L = µa V IN = V OUT + RIPPLE VOLTAGE (db) V IN = V OUT + RIPPLE VOLTAGE (db) I L = 5mA V IN = V OUT + x x x 3 x 3 x 3 FREQUENCY (Hz) x 6 x x x 3 x 3 x 3 FREQUENCY (Hz) x 6 x x x 3 x 3 x 3 FREQUENCY (Hz) x 6 August 4 5 MIC53

6 MIC53 OUTPUT IMPEDANCE (Ω). Output Impedance I L = µa OUTPUT (V) ENABLE (V) Enable Characteristics (3.3V Version) I L = µa OUTPUT (V) ENABLE (V) Enable Characteristics (3.3V Version) I L = µa. x x x x 3 x 3 x 3 FREQUENCY (Hz) x TIME (µs) ENABLE VOLTAGE (mv) Enable Voltage V OFF C IN = µf V ON ENABLE CURRENT (µa) 4 3 Enable Current V EN = V C IN = µf V EN = 5V MIC53 6 August 4

7 MIC53 Applications Information Input Capacitor A.µF capacitor should be placed from IN to GND if there is more than inches of wire between the input and the ac filter capacitor or when a battery is used as the input. Output Capacitor Typical PNP-based regulators require an output capacitor to prevent oscillation. The MIC53 is ultrastable, requiring only.47µf of output capacitance for stability. The regulator is stable with all types of capacitors, including the tiny, low-esr ceramic chip capacitors. The output capacitor value can be increased without limit to improve transient response. No-Load Stability The MIC53 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. Enable Input The MIC53 features nearly zero off-mode current. When EN (enable input) is held below.6v, all internal circuitry is powered off. Pulling EN high (over.v) re-enables the device and allows operation. When EN is held low, the regulator typically draws only na of current. While the logic threshold is TTL/CMOS compatible, EN may be pulled as high as V, independent of V IN. Thermal Behavior The MIC53 is designed to provide 8mA of continuous current in a very small profile 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: TJ(max) TA PD(max) = θja T J(max) is the maximum junction temperature of the die, 5 C, and T A is the maximum ambient temperature. θ JA is the junction-to-ambient thermal resistance ambient of the regulator. The θ JA of the MIC53 is 45 C/W. The actual power dissipation of the regulator circuit can be determined using one simple equation. P D = (V IN V OUT ) I OUT + V IN I GND Substituting P D(max), determined above, for P D and solving for the operating conditions that are critical to the application will give the maximum operating conditions for the regulator circuit. For example, if we are operating the MIC53-3.BC5 at room temperature, with a minimum footprint layout, we can determine the maximum input voltage for a set output current. 5 5 PD(max) = 45 C / W PD(max) = mw To prevent the device from entering thermal shutdown, maximum power dissipation cannot be exceeded. Using the output voltage of 3.V, and an output current of 8mA, we can determine the maximum input voltage. Ground current, maximum of 3mA for 8mA of output current, can be taken from the Electrical Characteristics section of the data sheet. mw = (V IN 3.V) 8mA + V IN 3mA mw = (8mA V IN + 3mA V IN ) 4mW 46mW = 83mA V IN V IN = 5.57V max. Therefore, a 3.V application at 8mA of output current can accept a maximum input voltage of 5.6V in an SC-7-5 package. For a full discussion of heat sinking and thermal effects on voltage regulators, refer to Regulator Thermals section of s Designing with Low-Dropout Voltage Regulators handbook. Fixed Voltage Regulator The MIC53 is ideal for general-purpose voltage regulation in any handheld device. Applications that are tight for space can easily use the Teeny SC-7 regulator which occupies half the space of a SOT-3-5 regulator. The MIC53 offers a smaller system solution, only requiring a small multilayer ceramic capacitor for stability. MIC53-x.x V OUT 3.V IN OUT 3.6V Li-Ion EN GND Cell.47µF Figure. Single-Cell Regulator August 4 7 MIC53

8 MIC53 Package Information.65 (.56) BSC.35 (.53).5 (.45).4 (.94).8 (.7). (.87).8 (.7). (.39).8 (.3). (.43).8 (.3) DIMENSIONS: MM (INCH).8 (.7). (.4).3 (.).5 (.6). (.4). (.) SC-7-5 (C5).3 (.). (.4) MICREL, INC. 849 FORTUNE DRIVE SAN JOSE, CA 953 USA TEL + (48) FAX + (48) 474- WEB This information is believed to be accurate and reliable, however no responsibility is assumed by 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, Inc. 4, Incorporated MIC53 8 August 4