MIC29/293/29/297 www.tvsat.com.pl Micrel MIC29/293/29/297 Series High-Current Low-Dropout Regulators General Description The MIC29/293/29/297 are high current, high accuracy, low-dropout voltage regulators. Using Micrel's proprietary Super ßeta PNP process with a PNP pass element, these regulators feature 3mV to 37mV (full load) dropout voltages and very low ground current. Designed for high current loads, these devices also find applications in lower current, extremely low dropout-critical systems, where their tiny dropout voltage and ground current values are important attributes. The MIC29/293/29/297 are fully protected against overcurrent faults, reversed input polarity, reversed lead insertion, overtemperature operation, and positive and negative transient voltage spikes. Five pin fixed voltage versions feature logic level ON/OFF control and an error flag which signals whenever the output falls out of regulation. Flagged states include low input voltage (dropout), output current limit, overtemperature shutdown, and extremely high voltage spikes on the input. On the MIC29xx and MIC29xx2, the ENABLE pin may be tied to V IN if it is not required for ON/OFF control. The MIC29/293/29 are available in 3- and -pin TO-22 and surface mount TO-263 packages. The MIC297 7.A regulators are available in 3- and -pin TO-247 packages. Features High Current Capability MIC29/29/292/293...A MIC293/293/2932/2933...3A MIC29/29/292/293...A MIC297/297/2972...7.A Low-Dropout Voltage... 3mV at Full Load Low Ground Current Accurate % Guaranteed Tolerance Extremely Fast Transient Response Reverse-battery and Load Dump Protection Zero-Current Shutdown Mode (-Pin versions) Error Flag Signals Output Out-of-Regulation (-Pin versions) Also Characterized For Smaller Loads With Industry- Leading Performance Specifications Fixed Voltage and Adjustable Versions Applications Battery Powered Equipment High-Efficiency Green Computer Systems Automotive Electronics High-Efficiency Linear Power Supplies High-Efficiency Post-Regulator For Switching Supply Pin Configuration 2 3 2 3 4 MIC29/293/ 29BT and MIC297BWT MIC29/292/293BT MIC293/2932/2933BT MIC29/292/293BT MIC297/2972BWT 2 3 MIC29/293BU 2 3 4 MIC29/292/293BU MIC293/2932/2933BU MIC29/292/293BU Pinout On all devices, the Tab is grounded. MIC29/293/29/297 Three Terminal Devices: Pin = Input, 2 = Ground, 3 = Output MIC29/293/29/297 Five Terminal Fixed Voltage Devices: Pin = Enable, 2 = Input, 3 = Ground, 4 = Output, = Flag MIC292/2932/292/2972 Adjustable with ON/OFF Control Pin = Enable, 2 = Input, 3 = Ground, 4 = Output, = Adjust MIC293/2933/293 Adjustable with Flag Pin = Flag, 2 = Input, 3 = Ground, 4 = Output, = Adjust Micrel, Inc. 849 Fortune Drive San Jose, CA 93 USA tel + (48) 944-8 fax + (48) 944-97 http://www.micrel.com March 2 MIC29/293/29/297
MIC29/293/29/297 Ordering Information Part Number Temp. Range* Volts Current Package MIC29-3.3BT 4 to +2 C 3.3.A TO-22 MIC29-4.2BT 4 to +2 C 4.2.A TO-22 MIC29-.BT 4 to +2 C..A TO-22 MIC29-2BT 4 to +2 C 2.A TO-22 MIC29-3.3BU 4 to +2 C 3.3.A TO-263 MIC29-.BU 4 to +2 C..A TO-263 MIC29-2BU 4 to +2 C 2.A TO-263 MIC29-3.3BT 4 to +2 C 3.3.A TO-22- MIC29-.BT 4 to +2 C..A TO-22- MIC29-2BT 4 to +2 C 2.A TO-22- MIC29-3.3BU 4 to +2 C 3.3.A TO-263- MIC29-.BU 4 to +2 C..A TO-263- MIC29-2BU 4 to +2 C 2.A TO-263- MIC292BT 4 to +2 C Adj.A TO-22- MIC292BU 4 to +2 C Adj.A TO-263- MIC293BT 4 to +2 C Adj.A TO-22- MIC293BU 4 to +2 C Adj.A TO-263- MIC293-3.3BT 4 to +2 C 3.3 3.A TO-22 MIC293-.BT 4 to +2 C. 3.A TO-22 MIC293-2BT 4 to +2 C 2 3.A TO-22 MIC293-3.3BU 4 to +2 C 3.3 3.A TO-263 MIC293-.BU 4 to +2 C. 3.A TO-263 MIC293-2BU 4 to +2 C 2 3.A TO-263 MIC293-3.3BT 4 to +2 C 3.3 3.A TO-22- MIC293-.BT 4 to +2 C. 3.A TO-22- MIC293-2BT 4 to +2 C 2 3.A TO-22- MIC293-3.3BU 4 to +2 C 3.3 3.A TO-263- MIC293-.BU 4 to +2 C. 3.A TO-263- MIC293-2BU 4 to +2 C 2 3.A TO-263- MIC2932BT 4 to +2 C Adj 3.A TO-22- MIC2932BU 4 to +2 C Adj 3.A TO-263- MIC2933BT 4 to +2 C Adj 3.A TO-22- MIC2933BU 4 to +2 C Adj 3.A TO-263- * Junction Temperature www.tvsat.com.pl Micrel Part Number Temp. Range* Volts Current Package MIC29-3.3BT 4 to +2 C 3.3.A TO-22 MIC29-.BT 4 to +2 C..A TO-22 MIC29-3.3BT 4 to +2 C 3.3.A TO-22- MIC29-.BT 4 to +2 C..A TO-22- MIC29-3.3BU 4 to +2 C 3.3.A TO-263- MIC29-.BU 4 to +2 C..A TO-263- MIC292BT 4 to +2 C Adj.A TO-22- MIC292BU 4 to +2 C Adj.A TO-263- MIC293BT 4 to +2 C Adj.A TO-22- MIC293BU 4 to +2 C Adj.A TO-263- MIC297-3.3BWT 4 to +2 C 3.3 7.A TO-247-3 MIC297-.BWT 4 to +2 C. 7.A TO-247-3 MIC297-3.3BWT 4 to +2 C 3.3 7.A TO-247- MIC297-.BWT 4 to +2 C. 7.A TO-247- MIC2972BWT 4 to +2 C Adj 7.A TO-247- MIC29xx versions are 3-terminal fixed voltage devices. MIC29xx are fixed voltage devices with ENABLE and ERROR flag. MIC29xx2 are adjustable regulators with ENABLE control. MIC29xx3 are adjustables with an ERROR flag. MIC29/293/29/297 2 March 2
MIC29/293/29/297 Absolute Maximum Ratings Power Dissipation... Internally Limited Lead Temperature (Soldering, seconds)... 26 C Storage Temperature Range... 6 C to + C Input Supply Voltage (Note )... 2V to +6V Electrical Characteristics Operating Ratings www.tvsat.com.pl Micrel Operating Junction Temperature... 4 C to +2 C Maximum Operating Input Voltage... 26V TO-22 θ JC... 2 C/W TO-263 θ JC... 2 C/W TO-247 θ JC.... C/W All measurements at T J = 2 C unless otherwise noted. Bold values are guaranteed across the operating temperature range. Adjustable versions are programmed to.v. Parameter Condition Min Typ Max Units Output Voltage I O = ma % ma I O I FL, (V OUT + V) V IN 26V (Note 2) 2 2 % Line Regulation I O = ma, (V OUT + V) V IN 26V.6. % Load Regulation V IN = V OUT + V, ma I OUT I FULL LOAD (Note 2, 6).2 % V O Output Voltage (Note 6) 2 ppm/ C T Temperature Coef. Dropout Voltage V OUT = %, (Note 3) MIC29 I O = ma 8 2 mv I O = 7mA 22 I O =.A 3 6 MIC293 I O = ma 8 7 I O =.A 2 I O = 3A 37 6 MIC29 I O = 2mA 2 2 I O = 2.A 2 I O = A 37 6 MIC297 I O = 2mA 8 2 I O = 4A 27 I O = 7.A 42 6 Ground Current MIC29 I O = 7mA, V IN = V OUT + V 8 2 ma I O =.A 22 MIC293 I O =.A, V IN = V OUT + V 3 ma I O = 3A 37 MIC29 I O = 2.A, V IN = V OUT + V ma I O = A 7 MIC297 I O = 4A, V IN = V OUT + V 3 7 ma I O = 7.A 2 I GNDDO Ground Pin V IN =.V less than specified V OUT. I OUT = ma Current at Dropout MIC29.9 ma MIC293.7 ma MIC29 2. ma MIC297 3. ma Current Limit MIC29 V OUT = V (Note 4) 2. 3. A MIC293 V OUT = V (Note 4) 4.. A MIC29 V OUT = V (Note 4) 7.. A MIC297 V OUT = V (Note 4) 9. A e n, Output Noise C L = µf 4 µv (rms) Voltage (Hz to khz) C L = 33µF 26 I L = ma Ground Current in Shutdown MIC29//2/3 only V EN =.4V 2 µa 3 µa March 2 3 MIC29/293/29/297
MIC29/293/29/297 Electrical Characteristics (Continued) Reference MIC29xx2/MIC29xx3 www.tvsat.com.pl Micrel Parameter Conditions Min Typical Max Units Reference Voltage.228.24.22 V.2.26 V max Reference Voltage (Note 8).23.277 V Adjust Pin 4 8 na Bias Current 2 Reference Voltage (Note 7) 2 ppm/ C Temperature Coefficient Adjust Pin Bias. na/ C Current Temperature Coefficient Flag Output (Error Comparator) MIC29xx/29xx3 Output Leakage V OH = 26V.. µa Current 2. Output Low Device set for V. V IN = 4.V 22 3 mv Voltage I OL = 2µA 4 Upper Threshold Device set for V (Note 9) 4 6 mv Voltage 2 Lower Threshold Device set for V (Note 9) 7 9 mv Voltage 4 Hysteresis Device set for V (Note 9) mv ENABLE Input MIC29xx/MIC29xx2 Input Logic Voltage Low (OFF).8 High (ON) 2.4 V Enable Pin V EN = 26V 6 µa Input Current 7 V EN =.8V µa 2 Regulator Output (Note ) µa Current in Shutdown MIC29/293/29/297 4 March 2
MIC29/293/29/297 Notes Note : Note 2: Note 3: Note 4: www.tvsat.com.pl Micrel Maximum positive supply voltage of 6V must be of limited duration (<msec) and duty cycle ( %). The maximum continuous supply voltage is 26V. Full Load current (I FL ) is defined as.a for the MIC29, 3A for the MIC293, A for the MIC29, and 7.A for the MIC297 families. Dropout voltage is defined as the input-to-output differential when the output voltage drops to 99% of its nominal value with V OUT + V applied to V IN V IN = V OUT (nominal) + V. For example, use V IN = 4.3V for a 3.3V regulator or use 6V for a V regulator. Employ pulse-testing procedures to minimize temperature rise. Note : Ground pin current is the regulator quiescent current. The total current drawn from the source is the sum of the load current plus the ground pin current. Note 6: Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range. Note 7: 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. Note 8: V REF V OUT (V IN V), 2.3V V IN 26V, ma < I L I FL, T J T J MAX. Note 9: 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 V, the Error output is guaranteed to go low when the output drops by 9 mv x V/.24 V = 384 mv. Thresholds remain constant as a percent of V OUT as V OUT is varied, with the dropout warning occurring at typically % below nominal, 7.7% guaranteed. Note : V EN.8V and V IN 26V, V OUT =. Note : 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. Block Diagram IN O.V. I LIMIT OUT FLAG.8V.24V Reference 28V R* EN ADJ Thermal Shutdown R2* GND Typical Applications * Feedback network in fixed versions only Adjustable version only V ± % MIC29-3.3 3.3V ± % @ A 47µF V IN V OUT R R2 V OUT =.24V [ + (R / R2)] Figure. Fixed output voltage. Figure 2. Adjustable output voltage configuration. For best results, the total series resistance should be small enough to pass the minimum regulator load current. March 2 MIC29/293/29/297
MIC29/293/29/297 Typical Characteristics MIC29x www.tvsat.com.pl Micrel DROPOUT VOLTAGE (mv) 4 4 3 3 2 2 MIC29x Dropout Voltage vs. Output Current.... OUTPUT CURRENT (A) DROPOUT VOLTAGE (V).8.7.6..4.3.2. MIC29x Dropout Voltage I LOAD =.A -6-3 3 6 9 2 OUTPUT VOLTAGE (V). 4. 3. 2.. MIC29-. Dropout Characteristics I OUT = ma I OUT =.A. 2 3 4 6 INPUT VOLTAGE (V) 2 2 MIC29x Ground Current vs. Output Current..4.8.2.6 OUTPUT CURRENT (A).2..8.6.4.2 MIC29x Ground Current vs. Supply Voltage V OUT = V I LOAD = ma. 2 4 6 8 SUPPLY VOLTAGE (V) 6 4 3 2 MIC29x Ground Current vs. Supply Voltage MIC292 I OUT =.A 2 4 6 8 SUPPLY VOLTAGE (V) 3 MIC29x Ground Current 2. MIC29x Ground Current 3 MIC29x Ground Current GROUND CURRENT (µa) 2 2 I LOAD = ma 2.... I LOAD = 2mA 2 2 I LOAD =.A -6-3 3 6 9 2. -6-3 3 6 9 2-6 -3 3 6 9 2 OUTPUT VOLTAGE (V) 3.4 3.38 3.36 3.34 3.32 3.3 3.28 3.26 3.24 3.22 MIC29-3.3 Output Voltage 3 DEVICES 3.2-6 -3 3 6 9 2 CURRENT (A) 3. 2. 2.... MIC29-3.3 Short Circuit Current V OUT = V. -6-3 3 6 9 2 GROUND CURRENT (µa).2..8.6.4.2. MIC29x Ground Current vs. Input Voltage R LOAD = Ω V OUT = V -.2-3 -2-2 3 INPUT VOLTAGE (V) MIC29/293/29/297 6 March 2
MIC29/293/29/297 www.tvsat.com.pl Micrel ENABLE CURRENT (µa) MIC29-xx/2 Enable Current vs. Temperaure 3 2 2 V EN = V V EN = 2V -6-3 3 6 9 2 OUTPUT (A) 4 2-2 2..... MIC29x Load Transient C OUT = µf I LOAD = ma -. - 2 2 OUTPUT (A) 2 - -2 2..... MIC29x Load Transient C OUT = µf I LOAD = ma -. - 2 2 ADJUST PIN CURRENT (na) MIC292/3 Adjust Pin Current 4 3 2 I LOAD = ma -6-3 3 6 9 2 INPUT (V) 3 2 - -2 8 6 MIC29x Line Transient C OUT = µf I LOAD = ma 4 -.2..2.4.6.8..2.4 INPUT (V) - 8 6 MIC29x Line Transient C OUT = µf I LOAD = ma 4 -.2..2.4.6.8..2.4 MIC29x Output Impedance vs. Frequency OUTPUT IMPEDANCE (Ω)... x x x 3 x 3 x 3 FREQUENCY (Hz) x 6 March 2 7 MIC29/293/29/297
MIC29/293/29/297 Typical Characteristics MIC293x www.tvsat.com.pl Micrel DROPOUT VOLTAGE (V).4.3.3.2.2... MIC293x Dropout Voltage vs. Output Current. 2 3 OUTPUT CURRENT (A) DROPOUT VOLTAGE (V).8.7.6..4.3.2. MIC293x Dropout Voltage I LOAD = 3A -6-3 3 6 9 2 OUTPUT VOLTAGE (V). 4. 3. 2.. MIC293-3.3 Dropout Characteristics I LOAD = ma I LOAD = 3A. 2 4 6 INPUT VOLTAGE (V) 4 3 2 MIC293x Ground Current vs. Output Current 2 3 OUTPUT CURRENT (A) 2.... MIC293x Ground Current vs. Supply Voltage FIXED 3.3V DEVICE R LOAD = Ω. 2 4 6 8 SUPPLY VOLTAGE (V) 2 7 2 MIC293x Ground Current vs. Supply Voltage FIXED 3.3V I OUT = 3A 2 4 6 8 SUPPLY VOLTAGE (V). MIC293x Ground Current 2. MIC293x Ground Current 6 MIC293x Ground Current.4.3.2. I OUT = ma... I OUT = 2mA 4 3 2 I OUT = 3A. -6-3 3 6 9 2. -6-3 3 6 9 2-6 -3 3 6 9 2 OUTPUT VOLTAGE (V) MIC293-3.3 Output Voltage 3.4 3.38 3.36 3.34 3.32 3.3 3.28 3.26 3.24 3 DEVICES 3.22 3.2-6 -3 3 6 9 2 CURRENT (A) 8 7 6 4 3 2 MIC293-. Short Circuit Current V OUT = V -6-3 3 6 9 2 2..... MIC293x Ground Current vs. Input Voltage R LOAD = Ω -. -3-2 - 2 3 INPUT VOLTAGE (V) MIC29/293/29/297 8 March 2
MIC29/293/29/297 www.tvsat.com.pl Micrel ENABLE CURRENT (µa) MIC293-x/2 Enable Current vs. Temperaure 3 2 2 V EN = V V EN = 2V -6-3 3 6 9 2 OUTPUT (A) 8 6 4 2-24 3 2 MIC293x Load Transient C OUT = µf I LOAD = ma - - 2 2 OUTPUT (A) - -4 3 2 MIC293x Load Transient C OUT = µf I LOAD = ma - - 2 2 ADJUST PIN CURRENT (na) MIC2932/3 Adjust Pin Current 4 3 2 I LOAD = ma -4 8.3-6 -3 3 6 9 2 INPUT (V) 4 2-2 6.3 4.3 MIC293x Line Transient C OUT = µf I LOAD = ma 2.3 -.2..2.4.6.8..2.4 INPUT (V) - - 8.3 6.3 4.3 MIC293x Line Transient C OUT = µf I LOAD = ma 2.3 -.2..2.4.6.8..2.4 MIC293x Output Impedance vs. Frequency OUTPUT IMPEDANCE (Ω)... x x x 3 x 3 x 3 FREQUENCY (Hz) x 6 March 2 9 MIC29/293/29/297
MIC29/293/29/297 Typical Characteristics MIC29x www.tvsat.com.pl Micrel DROPOUT VOLTAGE (V) 4 4 3 3 2 2 MIC29x Dropout Voltage vs. Output Current 2 3 4 OUTPUT CURRENT (A) DROPOUT VOLTAGE (V).8.7.6..4.3.2. MIC29x Dropout Voltage I LOAD = A -6-3 3 6 9 2 OUTPUT VOLTAGE (V). 4. 3. 2.. MIC29-3.3 Dropout Characteristics I LOAD = ma I LOAD = A. 2 4 6 INPUT VOLTAGE (V) 8 7 6 4 3 2 MIC29x Ground Current vs. Output Current 2 3 4 6 OUTPUT CURRENT (A) 3. 2. 2.... MIC29x Ground Current vs. Supply Voltage FIXED 3.3V VERSIONS R LOAD = Ω. 2 4 6 8 SUPPLY VOLTAGE (V) 2 7 2 MIC29x Ground Current vs. Supply Voltage FIXED 3.3V VERSION I LOAD = A 2 3 4 SUPPLY VOLTAGE (V). MIC29x Ground Current 4 MIC29x Ground Current MIC29x Ground Current.4.3.2. I OUT = ma 3 2 I OUT = ma 2 7 2 I OUT = A. -6-3 3 6 9 2-6 -3 3 6 9 2-6 -3 3 6 9 2 OUTPUT VOLTAGE (V) MIC29-3.3 Output Voltage 3.4 3.38 3.36 3.34 3.32 3.3 3.28 3.26 3.24 3 DEVICES 3.22 3.2-6 -3 3 6 9 2 CURRENT (A) 9 8 7 6 4 3 2 MIC29x-. Short Circuit Current V OUT = V -6-3 3 6 9 2 2. 2.... MIC29x Ground Current vs. Input Voltage. R LOAD = Ω -. -3-2 - 2 3 INPUT VOLTAGE (V) MIC29/293/29/297 March 2
MIC29/293/29/297 www.tvsat.com.pl Micrel ENABLE CURRENT (µa) MIC29-xx/2 Enable Current vs. Temperaure 3 2 2 V EN = V V EN = 2V -6-3 3 6 9 2 OUTPUT (A) MIC29x Load Transient C OUT = µf -6 4 3 2 I LOAD = ma - - 2 2 OUTPUT (A) - MIC29x Load Transient C OUT = µf -6 4 3 2 I LOAD = ma - - 2 2 ADJUST PIN CURRENT (na) MIC292/3 Adjust Pin Current 8 7 6 4 3 2 I LOAD = ma -6-3 3 6 9 2 INPUT (V) - - 8.2 6.2 4.2 MIC29x Line Transient C OUT = µf I LOAD = ma 2.2 -.2..2.4.6.8..2.4 INPUT (V) 2 - -2 8.2 6.2 4.2 MIC29x Line Transient C OUT = µf I LOAD = ma 2.2 -.2..2.4.6.8..2.4 MIC29x Output Impedance vs. Frequency OUTPUT IMPEDANCE (Ω)... x x x 3 x 3 x 3 FREQUENCY (Hz) x 6 March 2 MIC29/293/29/297
MIC29/293/29/297 Typical Characteristics MIC297x www.tvsat.com.pl Micrel DROPOUT VOLTAGE (mv) 4 4 3 3 2 2 MIC297x Dropout Voltage vs. Output Current 2 3 4 6 7 8 OUTPUT CURRENT (A) DROPOUT VOLTAGE (V)..9.8.7.6..4.3.2. MIC297x Dropout Voltage. -6-3 3 6 9 2 OUTPUT VOLTAGE (V). 4. 3. 2.. MIC297-3.3 Dropout Characteristics I LOAD = ma I LOAD = 7.A. 2 4 6 INPUT VOLTAGE (V) 2 8 6 4 2 MIC297x Ground Current vs. Output Current 2 3 4 6 7 8 OUTPUT CURRENT (A) 3. 3. 2. 2.... MIC297x Ground Current vs. Supply Voltage FIXED 3.3V VERSION I OUT = ma. 2 4 6 8 SUPPLY VOLTAGE (V) 7 2 7 2 MIC297x Ground Current vs. Supply Voltage FIXED 3.3V VERSION I LOAD = 7.A 2 4 6 8 SUPPLY VOLTAGE (V). MIC297x Ground Current 4 MIC297x Ground Current 2 MIC297x Ground Current.4.3.2. I OUT = ma 3 2 I OUT = 2mA I OUT = 7.A. -6-3 3 6 9 2-6 -3 3 6 9 2-6 -3 3 6 9 2 OUTPUT VOLTAGE (V) MIC297-3.3 Output Voltage 3.4 3.38 3.36 3.34 3.32 3.3 3.28 3.26 3.24 3 DEVICES 3.22 3.2-6 -3 3 6 9 2 CURRENT (A) 2 9 8 7 6 4 3 2 MIC297-. Short Circuit Current V OUT = V -6-3 3 6 9 2 3. 3. 2. 2..... MIC297x Ground Current vs. Input Voltage R LOAD = Ω -. -3-2 - 2 3 INPUT VOLTAGE (V) MIC29/293/29/297 2 March 2
MIC29/293/29/297 www.tvsat.com.pl Micrel ENABLE CURRENT (µa) MIC297-xx/2 Enable Current vs. Temperaure 3 2 2 V EN = V V EN = 2V -6-3 3 6 9 2 OUTPUT (A) -. 7.. 2.. MIC297x Load Transient C OUT = µf I LOAD = ma -2. - 2 2 OUTPUT (A) 3 2 - -2. 7.. 2.. MIC297x Load Transient C OUT = µf I LOAD = ma -2. - 2 2 ADJUST PIN CURRENT (na) MIC2972/3 Adjust Pin Current 8 7 6 4 3 2 I LOAD = ma -6-3 3 6 9 2 INPUT (V) - - 8.3 6.3 4.3 MIC297x Line Transient C OUT = µf I LOAD = ma 2.3 -.2..2.4.6.8..2.4 INPUT (V) 3 2 - -2 8.3 6.3 4.3 MIC297x Line Transient C OUT = µf I LOAD = ma 2.3 -.2..2.4.6.8..2.4 MIC297x Output Impedance vs. Frequency OUTPUT IMPEDANCE (Ω)... x x x 3 x 3 x 3 FREQUENCY (Hz) x 6 March 2 3 MIC29/293/29/297
MIC29/293/29/297 Applications Information The MIC29/293/29/297 are high performance low-dropout voltage regulators suitable for all moderate to high-current voltage regulator applications. Their 3mV to 4mV dropout voltage at full load make them especially valuable in battery powered systems and as high efficiency noise filters in post-regulator 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 V CE saturation voltage. A trade-off for the low dropout voltage is a varying base drive requirement. But Micrel s Super ßeta PNP process reduces this drive requirement to merely % of the load current. The MIC29 297 family of regulators 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 2 C maximum safe operating temperature. Transient protection allows device (and load) survival even when the input voltage spikes between 2V and +6V. When the input voltage exceeds about 3V to 4V, the overvoltage sensor temporarily disables the regulator. The output structure of these regulators allows voltages in excess of the desired output voltage to be applied without reverse current flow. MIC29xx and MIC29xx2 versions offer a logic level ON/OFF control: when disabled, the devices draw nearly zero current. An additional feature of this regulator family is a common pinout: a design s current requirement may change up or down yet use the same board layout, as all of these regulators have identical pinouts. V IN IN GND OUT V OUT Figure 3. Linear regulators require only two capacitors for operation. 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, T A Output Current, I OUT Output Voltage, V OUT Input Voltage, V IN www.tvsat.com.pl Micrel First, we calculate the power dissipation of the regulator from these numbers and the device parameters from this datasheet. ( ) P = I.V V D OUT IN OUT Where the ground current is approximated by % of I OUT. Then the heat sink thermal resistance is determined with this formula: TJ MAX TA θsa = θjc + θ P D ( ) Where T J MAX 2 C and θ CS is between and 2 C/W. 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.µf is needed directly between the input and regulator ground. Please refer to Application Note 9 and Application Hint 7 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. MIC29 297 regulators are stable with the following minimum capacitor values at full load: Device Full Load Capacitor MIC29... µf MIC293... µf MIC29... µf MIC297... 22µF 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.µf capacitor connected between Input and GND is recommended. This capacitor should have good characteristics to above 2kHz. Minimum Load Current The MIC29 297 regulators are specified between finite loads. If the output current is too small, leakage currents dominate and the output voltage rises. The following minimum load current swamps any expected leakage current across the operating temperature range: CS MIC29/293/29/297 4 March 2
MIC29/293/29/297 Device Minimum Load MIC29... ma MIC293... 7mA MIC29... ma MIC297... ma Adjustable Regulator Design V IN µf MIC292BT R R2 VOUT =.23V [ + (R / R2)] 22µF V OUT Figure 4. Adjustable Regulator with Resistors The adjustable regulator versions, MIC29xx2 and MIC29xx3, allow programming the output voltage anywhere between.2v and the 26V maximum operating rating of the family. www.tvsat.com.pl Micrel Two resistors are used. Resistors can be quite large, up to MΩ, because of the very high input impedance and low bias current of the sense comparator: The resistor values are calculated by: R R V OUT = 2.24 Where V O is the desired output voltage. Figure 4 shows component definition. Applications with widely varying load currents may scale the resistors to draw the minimum load current required for proper operation (see above). Error Flag MIC29xx and MIC29xx3 versions feature an Error Flag, which looks at the output voltage and signals an error condition when this voltage drops % below its expected value. The error flag is an open-collector output that pulls low under fault conditions. It may sink ma. 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. Enable Input MIC29xx and MIC29xx2 versions feature 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 3V. Enabling the regulator requires approximately 2µA of current. March 2 MIC29/293/29/297
MIC29/293/29/297 Package Information www.tvsat.com.pl Micrel.8 ±. (2.74 ±.3). D ±. (3.84 D ±.3).4 ±. (.4 ±.2).9 ±. (4.99 ±.3).76 ±. (4.47 ±.3) 7. ±. (.27 ±.3).88 ±. (2.78 ±.3).36 ±. (9.4 ±.3) 7 3.4 ±. (28.96 ±.2). ±.3 (.27 ±.8). ±. (2.4 ±.3).3 ±.3 (.76 ±.8).8 ±.8 (.46 ±.2). ±.2 (2.4 ±.) DIMENSIONS: INCH (MM) 3-Lead TO-22 (T).6 ±. 2 ±2.4±..±..76 ±.. ±..36±..6±.2 SEATING.4 +.4 PLANE.8. BSC. DIM. = INCH 8 MAX. ±.. ±.2 3-Lead TO-263 (U) MIC29/293/29/297 6 March 2
MIC29/293/29/297 www.tvsat.com.pl Micrel MOUNTING HOLE.2 (3.7) DIA TYP.62.64 (.748 6.26).8.2 (4.72.8) TYP.9.2 (4.826.334) TYP.86.88 (2.844 22.32).6.8 (4.64 4.72) Dimensions: inch (mm) 7 TYP.78.82 (9.82 2.828).2 (6.3) MAX.4.6 (.6.24).7.9 (.778 2.286)..3 (2.794 3.32).7.9 (.778 2.286).2.3 (.63.889).2 (.8) BSC 3-Lead TO-247 (WT) March 2 7 MIC29/293/29/297
MIC29/293/29/297 www.tvsat.com.pl Micrel.8 ±. (2.74 ±.3).4 ±. (.6 ±.38). D ±. (3.8 D ±.3).24 ±.7 (6.2 ±.43).77 ±.8 (4. ±.2). ±. (.27 ±.3).78 ±.8 (4.68 ±.46) SEATING PLANE. ±. (3.97 ±.2) 7 Typ..67 ±. (.7 ±.27).268 REF (6.8 REF).32 ±. (.8 ±.3).8 ±.8 (.46 ±.2).3 ±.3 (2.62±.33) Dimensions: inch (mm) -Lead TO-22 (T).6 ±. 2 ±2.4±..±..76 ±..6 ±..36±..6±.2 SEATING.4 +.4 PLANE.8.67±..32 ±.3 DIM. = INCH 8 MAX. ±.. ±.2 -Lead TO-263 (U) MIC29/293/29/297 8 March 2
MIC29/293/29/297 www.tvsat.com.pl Micrel MOUNTING HOLE.4.43 (3.6 3.63) DIA TYP.62.64 (.7 6.26).8.2 (4.7.8).8.28 (4.7.28).242 BSC (6. BSC).89.844 (2.8 2.44).7.26 (4.32.49) Dimensions: inch (mm).78.8 (9.8 2.32).4. (.2.4). BSC (2.4 BSC).8. (2.3 2.4).6.3 (.4.79) -Lead TO-247 (WT) March 2 9 MIC29/293/29/297
MIC29/293/29/297 www.tvsat.com.pl Micrel MICREL INC. 849 FORTUNE DRIVE SAN JOSE, CA 93 USA TEL + (48) 944-8 FAX + (48) 944-97 WEB 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. 2 Micrel Incorporated MIC29/293/29/297 2 March 2