MIC2920A/29201/29202/29204

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1 MIC292A/292/2922/2924 MIC292A/292/2922/2924 4mA Low-Dropout Voltage Regulator General Description The MIC292A family are bulletproof, efficient voltage regulators with very low dropout voltage (typically 4mV at light loads and 7mV at 25mA), and very low quiescent current (4µA typical). The quiescent current of the MIC292A increases only slightly in dropout, prolonging battery life. Key MIC292A features include protection against reversed battery, fold-back current limiting, and automotive load dump protection (6V positive transient). The MIC292 is available in several configurations. The MIC292A-x.x devices are three pin fixed voltage regulators available in.v, 4.85V, 5V, and 2V outputs. The MIC292 is a fixed regulator offering a logic compatible ON/OFF (shutdown) input and an error flag output. This flag may also be used as a power-on reset signal. A logic-compatible shutdown input is provided on the adjustable MIC2922 which allows the regulator to be switched on and off. The MIC pin SOIC adjustable regulator includes both shutdown and error flag pins and may be pin-strapped for 5V output or programmed from.24v to 26V using two external resistors. Features High output voltage accuracy Guaranteed 4mA output Low quiescent current Low dropout voltage Extremely tight load and line regulation Very low temperature coefficient Current and thermal limiting Input withstands 2V reverse battery and 6V positive transients Error flag warns of output dropout Logic-controlled electronic shutdown Output programmable from.24v to 26V (MIC2922/MIC2924) Available in TO-22-, TO-22-5, and surface-mount TO-26-5, SOT-22, and SO-8 packages. Applications Battery-powered equipment Cellular telephones Laptop, notebook, and palmtop computers PCMCIA V CC and V PP regulation/switching Bar code scanners Automotive electronics SMPS post-regulators Voltage reference High-efficiency linear power supplies Pin Configuration TAB TAB TAB OUTP UT 8 INPUT S E N S E 2 7 NC SHUTDOWN 6 NC GROUND 4 5 E R R O R 2 MIC292-.BM (SOIC-8) OUTP UT 8 INPUT S E N S E 2 7 A D JUST INPUT OUTPUT GROUND MIC292A-x.xBS (SOT-22) SHUTDOWN 6 5V TAP TAB GROUND 4 5 E R R O R MIC2924BM (SOIC-8) 5-Lead Package Pinouts MIC292 MIC2922 ) Error Adjust 2) Input Shutdown ) Ground Ground 4) Output Input 5) Shutdown Output MIC292/2922BU (TO-26-5) 2 IN OUT GND MIC292A-xxBT (TO-22) MIC292/2922BT (TO-22-5) Tab is Ground on SOT-22, TO-22, and TO-26 packages. 28 Fortune Drive San Jose, CA 95 USA tel + (48) fax + (48) February 25 M

2 MIC292A/292/2922/2924 Ordering Information Part Number Voltage Junction Temp. Range Package Standard Pb-Free MIC292A-.BS MIC292A-.WS*.V -4 C to +25 C SOT-22 MIC292A-.BT MIC292A-.WT*.V -4 C to +25 C TO-22- MIC292A-4.8BS MIC292A-4.8WS* 4.85V -4 C to +25 C SOT-22 MIC292A-4.8BT MIC292A-4.8WT* 4.85V -4 C to +25 C TO-22- MIC292A-5.BS MIC292A-5.WS* 5.V -4 C to +25 C SOT-22 MIC292A-5.BT MIC292A-5.WT* 5.V -4 C to +25 C TO-22- MIC292A-2BS MIC292A-2WS* 2V -4 C to +25 C SOT-22 MIC292A-2BT MIC292A-2WT* 2V -4 C to +25 C TO-22- MIC292-.BM MIC292-.YM.V -4 C to +25 C SO-8 MIC292-.BT MIC292-.WT*.V -4 C to +25 C TO-22-5 MIC292-.BU MIC292-.WU*.V -4 C to +25 C TO-26-5 MIC BT MIC WT* 4.85V -4 C to +25 C TO-22-5 MIC BU MIC WU* 4.85V -4 C to +25 C TO-26-5 MIC292-5.BT MIC292-5.WT* 5.V -4 C to +25 C TO-22-5 MIC292-5.BU MIC292-5.WU* 5.V -4 C to +25 C TO-26-5 MIC292-2BT MIC292-2WT* 2V -4 C to +25 C TO-22-5 MIC292-2BU MIC292-2WU* 2V -4 C to +25 C TO-26-5 MIC2922BT MIC2922WT* Adj -4 C to +25 C TO-22-5 MIC2922BU MIC2922WU* Adj -4 C to +25 C TO-26-5 MIC2924BM MIC2924YM 5V and Adj -4 C to +25 C SO-8 MIC2924BN MIC2924YN 5V and Adj -4 C to +25 C 8-pin PDIP * Pb-Free RoHS compliant with high-melting solder exemption. M February 25

3 MIC292A/292/2922/2924 Absolute Maximum Ratings Operating Ratings Input Supply Voltage... 2V to +6V Adjust Input Voltage (Notes 9 and )....5V to +26V Power Dissipation... Internally Limited, Note Operating Junction Temperature Range... 4 C to +25 C Lead Temperature (Soldering, 5 seconds)...26 C Storage Temperature Range C to +5 C If Military/Aerospace specified devices are required, contact your local Micrel representative/distributor for availability and specifications. Operating Input Supply Voltage...2V to 26V Adjust Input Voltage (Notes 9 and )....5V to +26V Shutdown Input Voltage....V to +V Error Comparator Output Voltage....V to +VOperating Junction Temperature Range... 4 C to +25 C Thermal Characteristics: SOT 22 θ JC... 5 C/W TO-22 θ JC... C/W TO-26 θ JC... C/W 8-Pin SOIC θ JA...Note Across the full operating temperature, the minimum input voltage range for full output current is 4.V to 26V. Output will remain in-regulation at lower output voltages and low current loads down to an input of 2V at 25 C. Electrical Characteristics Limits in standard typeface are for T J = 25 C and limits in boldface apply over the full operating temperature range. Unless otherwise specified, V IN = V OUT + V, = ma, C L = µf. Adjustable versions are set for an ouptu of 5V. The MIC2922 V SHUTDOWN.7V. The eight pin MIC2924 is configured with the Adjust pin tied to the 5V Tap, the Output is tied to Output Sense (V OUT = 5V), and V SHUTDOWN.7V. Symbol Parameter Conditions Min Typ Max Units V O Output Voltage Accuracy Variation from factory trimmed V OUT - -2 ma 4mA, across temp. range MIC292A-2 and only ma 4mA, across temp. range -4 4 V O Output Voltage (Note 2) 2 ppm/ C T Temperature Coef. V OUT > V only 8 5 V O Line Regulation V IN = V OUT + V to 26V.. % V O.4 V O V O Load Regulation IL = to 25mA (Note ).4.6. % V IN - V O I GND I GNDDO Dropout Voltage (Note 4) Ground Pin Current (Note 5) Ground Pin Current at Dropout (Note 5) = ma = ma = 25mA = 4mA = ma = ma = 25mA IMIT Current Limit V OUT = V (Note 6) V OUT > V only V OUT > V only = 4mA V IN =.5V less than designed V OUT (V OUT =.V) I O = ma % mv µa ma 8 4 µa V O Thermal Regulation (Note 7).5.2 %/W P D e n Output Noise Voltage (Hz to khz) IL = ma CL = µf CL = µf 4 26 ma µv RMS February 25 M

4 MIC292A/292/2922/2924 Parameter Conditions Min Typ Max Units MIC2922, MIC2924 Reference Voltage MIC Reference Voltage MIC2922 (Note 8) V Reference Voltage MIC Reference Voltage MIC2924 (Note 8) V Adjust Pin Bia Current Reference Voltage Temperature Coefficient Adjust Pin Bias Current Temperature Coefficient Error Comparator Output Leakage Current Output Low Voltage Upper Threshold Voltage Lower Threshold Voltage (Note 7) 2 ppm/ C MIC292, MIC2924 V V na. na/ C V OH = 26V.. 2. V IN = 4.5V I OL = 25µA (Note 9) µa mv 6 mv (Note 9) Hysteresis (Note 9) 5 mv Shutdown Input Input Logic Voltage Shutdown Pin Input Current Regulator Output Current in Shutdown MIC292, MIC2922, MIC2924. Low (ON).7 High (OFF) 2. V SHUTDOWN = 2.4V 5 V SHUTDOWN = 26V (Note ) 2 mv V µa µa µa M February 25

5 MIC292A/292/2922/2924 Notes: General: Note : Note 2: Note : Note 4: Note 5: Note 6: Note 7: Note 8: Note 9: Note : Note : Note 2: Devices are ESD protected; however, handling precautions are recommended. Absolute maximum ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating the device outside of its rated operating conditions. 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 (MAX) = (T J(MAX) T A ) / θ Exceeding the maximum allowable power JA. dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. The junction to ambient thermal resistance of the MIC2924BM is 6 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 mv below its nominal value measured at V differential. At low values of programmed output voltage, the minimum input supply voltage of 4.V over temperature must be taken into account. The MIC292A operates down to 2V of input at reduced output current at 25 C. Ground pin current is the regulator quiescent current. The total current drawn from the supply is the sum of the load current plus the ground pin current. The MIC292A features fold-back current limiting. The short circuit (V OUT = V) current limit is less than the maximum current with normal output voltage. 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 2mA load pulse at V IN = 2V (a 4W pulse) for T = ms. V REF V OUT (V IN V), 4.V V IN 26V, ma < 4 ma, T J T J MAX. Comparator thresholds are expressed in terms of a voltage differential at the Adjust terminal below the nominal reference voltage measured at 6V input. To express these thresholds in terms of output voltage change, multiply by the error amplifier gain = V OUT /V REF = (R + R2)/R2. For example, at a programmed output voltage of 5V, the Error output is guaranteed to go low when the output drops by 95 mv x 5V/.25 V = 84 mv. Thresholds remain constant as a percent of VOUT as VOUT is varied, with the dropout warning occurring at typically 5% below nominal, 7.7% guaranteed. V SHUTDOWN 2V, V IN 26V,V OUT =, with Adjust pin tied to 5V Tap or to the R, R2 junction (see Figure ) with R 5. 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. Maximum positive supply voltage of 6V must be of limited duration (< ms) and duty cycle ( %). The maximum continuous supply voltage is 26V. Schematic Diagram IN A D J U S T Q5A Q9 Q5B Q25 R8 2 Q26 Q24 OUT Q6 Q Q R 8 C 2 pf Q4 Q5 R 2.6 Q2 Q7 Q8 Q6 Q7 Q4 R7 2 S E N S E R27 V TAP R28 Q42 Q4 R R 2 R2 5 Q4 R 5 R5 8 Q R6 4 R4 Q2 R8.4 R Q R 5 Q2 R2 R Q8 C2 4 pf R4 5 Q9 Q2 Q29 Q28 Q22 R5 R6 R7 Ω Q2 R2 8 Ω 5 E R R O R Q7 Q6 R22 5 Q Q R24 5 R2 6 SHDN Q8 Q4 R26 6 R DENOTES CONNECTION ON MIC292A-xx AND MIC292-xx V E R S I O N S O N LY Q9 GND February 25 5 M

6 MIC292A/292/2922/2924 Typical Characteristics 5 Dropout Voltage vs. Output C urrent 7 Dropout Voltage vs. Temperature 6 Dropout C haracteris tics DROPOUT VOLTAGE (mv) 4 2 DROPOUT VOLTAGE (mv) OAD = 4mA OUTPUT VOLTAGE (V) OAD = ma OAD = 4mA 2 4 OUTPUT CURRENT (ma) INPUT VOLTAGE (V) 2 vs. Output C urrent 2 vs. S upply V oltage vs. S upply V oltage GROUND CURRENT (ma) GROUND CURRENT (µa) 5 5 V OUT = 5V I OUT = ma GROUND CURRENT (ma) V OUT = 5V I OUT = 4mA. 4 OUTPUT CURRENT (ma) SUPPLY VOLTAGE (V) INPUT VOLTAGE (V).2 vs. Temperature vs. Temperature 25 vs. Temperature GROUND CURRENT (ma).5..5 I OUT = ma GROUND CURRENT (ma) 2 OAD = ma GROUND CURRENT (ma) OAD = 4mA OUTPUT VOLTAGE (V) Fixed.V Output Voltage vs. Temperature CURRENT (ma) S hort C ircuit and Maximum C urrent vs. Temperature V OUT = V NOMINAL.5V S AMP LE S (HI/AV G /LO) V OUT =.V V OUT = V GROUND CURRENT (µa) vs. S upply V oltage R LOAD = Ω INPUT VOLTAGE (V) M February 25

7 MIC292A/292/2922/2924 ENABLE CURRENT (µa) MIC 292/2 S hutdown C urrent vs. Temperaure 25 V E N = 5V 75 5 V E N = 2V OUTPUT (mv) OUTPUT (ma) L oad T rans ient 2 C OUT = µf ma TIME (ms) OUTPUT (mv) OUTPUT (ma) L oad T rans ient C 5 OUT = µf ma TIME (ms) ADJUST PIN CURRENT (na) MIC 2922 A djus t P in C urrent vs. Temperature OAD = ma OUTPUT (mv) INPUT (V) L ine T rans ient C OUT = µf = ma TIME (ms) OUTPUT (mv) INPUT (V) L ine T rans ient C OUT = µf = ma TIME (ms) Output Impedance vs. Frequency OUTPUT IMPEDANCE (Ω). OAD = ma. k k k M FREQUENCY (Hz) x x x x x x x 6 REJECTION (db) R ipple R ejection C L = µf = ma ma - E+ E+2 E+ k E+4 k E+5 k E+6 M FREQUENCY (Hz) February 25 7 M

8 MIC292A/292/2922/2924 Applications Information External Capacitors A µf (or greater) capacitor is required between the MIC292A output and ground to prevent oscillations due to instability. Most types of tantalum or aluminum electrolytics will be adequate; film types will work, but are costly and therefore not recommended. Many aluminum electrolytics have electrolytes that freeze at about C, so solid tantalums are recommended for operation below 25 C. The important parameters of the capacitor are an effective series resistance of about 5Ω or less and a resonant frequency above 5kHz. The value of this capacitor may be increased without limit. At lower values of output current, less output capacitance is required for output stability. The capacitor can be reduced to 2.2µF for current below ma or µf for currents below ma. Adjusting the MIC2922/2924 to voltages below 5V runs the error amplifier at lower gains so that more output capacitance is needed. For the worst-case situation of a 5mA load at.2v output (Output shorted to Adjust) a 47µF (or greater) capacitor should be used. The MIC292A/292 will remain in regulation with a minimum load of ma. When setting the output voltage of the MIC2922/2924 versions with external resistors, the current through these resistors may be included as a portion of the minimum load. A.µF capacitor should be placed from the MIC292A input to ground if there is more than inches of wire between the input and the AC filter capacitor or if a battery is used as the input. Error Detection Comparator Output (MIC292/MIC2924) A logic low output will be produced by the comparator whenever the MIC292/2924 output falls out of regulation by more than approximately 5%. This figure is the comparator s built-in offset of about 75mV divided by the.25v reference voltage. (Refer to the block diagram on Page ). This trip level remains 5% below normal regardless of the programmed output voltage of the MIC292/2924. For example, the error flag trip level is typically 4.75V for a 5V output or.4v for a 2V output. The out of regulation condition may be due either to low input voltage, extremely high input voltage, current limiting, or thermal limiting. Figure is a timing diagram depicting the ERROR signal and the regulated output voltage as the MIC292/2924 input is ramped up and down. The ERROR signal becomes valid (low) at about.v input. It goes high at about 5V input (the input voltage at which V OUT = 4.75). Since the MIC292/2924 s dropout voltage is load-dependent (see curve in Typical Performance Characteristics), the input voltage trip point (about 5V) will vary with the load current. The output voltage trip point (approximately 4.75V) does not vary with load. The error comparator has an NPN open-collector output which requires an external pull-up resistor. Depending on system requirements, this resistor may be returned to the 5V output or some other supply voltage. In determining a value for this resistor, note that while the output is rated to sink 25µA, this sink current adds to battery drain in a low battery condition. Suggested values range from k to MΩ. The resistor is not required if this output is unused. Programming the Output Voltage (MIC2922/2924) The MIC2922/2924 may be programmed for any output voltage between its.25v reference and its 26V maximum rating, using an external pair of resistors, as shown in Figure. The complete equation for the output voltage is V OUT = V REF { + R /R 2 } I FB R where V REF is the nominal.25 reference voltage and I FB is the Adjust pin bias current, nominally 2nA. The minimum recommended load current of µa forces an upper limit of.2mω on the value of R 2, if the regulator must work with no load (a condition often found in CMOS in standby), I FB will produce a 2% typical error in V OUT which may be eliminated at room temperature by trimming R. For better accuracy, choosing R 2 = k reduces this error to.7% while increasing the resistor program current to 2µA. Since the MIC2922/2924 typically draws µa at no load with SHUTDOWN open-circuited, this is a negligible addition. The MIC2924 may be pin-strapped for 5V using the internal voltage divider by tying Pin (output) to Pin 2 (sense) and Pin 7 (Adjust) to Pin 6 (V Tap). Configuring the MIC292-.BM For the MIC292-.BM, the output (Pin ) and sense pin (pin 2), must be connected to ensure proper operation. They are not connected internally. Reducing Output Noise In reference applications it may be advantageous to reduce the AC noise present at the output. One method is to reduce the regulator bandwidth by increasing the size of the output capacitor. This is relatively inefficient, as increasing the capaci- OUTPUT VOLTAGE E R R O R INPUT VOLTAGE 4.75V NOT * VALID.V * SEE APPLICATIONS INFORMATION Figure. ERROR Output Timing 5V NOT * VALID M February 25

9 MIC292A/292/2922/2924 tor from µf to 22µF only decreases the noise from 4µV to 6µV RMS for a khz bandwidth at 5V output. Noise can be reduced fourfold by a bypass capacitor across R, since it reduces the high frequency gain from 4 to unity. Pick C BYPASS = 2 πr 2 Hz or about.µf. When doing this, the output capacitor must be increased to µf to maintain stability. These changes reduce the output noise from 4µV to µv rms for a khz bandwidth at 5V output. With the bypass capacitor added, noise no longer scales with output voltage so that improvements are more dramatic at higher output voltages. Automotive Applications The MIC292A is ideally suited for automotive applications for a variety of reasons. It will operate over a wide range of input voltages with very low dropout voltages (4mV at light loads), and very low quiescent currents (µa typical). These features are necessary for use in battery powered systems, such as automobiles. It is a bulletproof device with the ability to survive both reverse battery (negative transients up to 2V below ground), and load dump (positive transients up to 6V) conditions. A wide operating temperature range with low temperature coefficients is yet another reason to use these versatile regulators in automotive designs. Typical Applications V IN +V IN +VIN VOUT V OUT = 5V E R R O R OUTPUT 5 E R R O R 8 VIN VOUT VOUT.2 26V GND + µf ON SHUTDOWN INPUT O F F SHUTDOWN GND ADJUST 4 7.2V R pf µf R V OUT = V R E F x ( + ) R 2 V R E F R 2 NOTE: PINS 2 AND 6 ARE LEFT OPEN Figure 2. MIC292A-5. Fixed +5V Regulator Figure. MIC2922/2924 Adjustable Regulator. Pinout is for MIC V +V IN E R R O R OUTPUT 8 +VIN 5 E R R O R VOUT SHUTDOWN INPUT SD O F F GND ADJUST ON 4 7 *VOUT = VIN SHUTDOWN INPUT LOW = ON HIGH = OFF HIGH = 5V OUT SHUT- DOWN 8 +V IN VOUT GND ADJUST pf 22 % % 8 % + V CC OUT µf * Minimum Input-Output Voltage ranges from 4mV to 4mV, depending on load current LOW =.V OUT 2N2222 PIN LOW= ENABLE OUTPUT. Q ON =.V, Q OFF = 5.V. Figure 4. MIC2924 Wide Input Voltage Range Current Limiter Figure 5. MIC2922/ V or.v Selectable Regulator with Shutdown. Pinout is for MIC2924. February 25 9 M

10 MIC292A/292/2922/2924 Package Information 8-Pin SOIC (M).5 (.24) 2.9 (.4) C L C L.7 (.46). (.) 7.49 (.295) 6.7 (.264) 2.4 (.95) 2.2 (.87) 4.7 (.85) 4.5 (.77).4 (.4).85 (.) DIMENSIONS: MM (INCH). (.4).2 (.8) 6.7 (.264) 6. (.248).7 (.67) 6.52 (.6) MAX.8 (.5).25 (.).84 (.).64 (.25).9 (.6) MIN SOT-22 (S) M February 25

11 MIC292A/292/2922/2924 -Lead TO-22 (T) 5-Lead TO-22 (T) February 25 M

12 MIC292A/292/2922/2924 θ4 θ θ2 θ θ θ θ2 θ θ4 θ 5-Lead TO-26 (U) MICREL INC. 28 FORTUNE DRIVE SAN JOSE, CA 95 USA TEL + (48) FAX + (48) 474- WEB This 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. 998 Micrel Incorporated M February 25

MIC2920A/29201/29202/29204

MIC2920A/29201/29202/29204 MIC292A/292/2922/2924 MIC292A/292/2922/2924 4mA Low-Dropout Voltage Regulator General Description The MIC292A family are bulletproof efficient voltage regulators with very low drop out voltage (typically