MIC4575 Micrel MIC4575 200kHz Simple 1A Buck Voltage Regulator General Description Features The MIC4575 is a series of easy to use fixed and adjustable BiCMOS step-down (buck) switch-mode voltage regulators. The 200kHz MIC4575 duplicates the pinout and function of the 52kHz LM2575. The higher switching frequency may allow up to a 2:1 reduction in output filter inductor size. The MIC4575 is available in 3.3V, and 5V fixed output versions or a 1.23V to 20V adjustable output version. Both versions are capable of driving a 1A load with excellent line and load regulation. • Fixed 200kHz operation • 3.3V, 5V, and adjustable output versions • Voltage over specified line and load conditions: Fixed version: ±3% max. output voltage Adjustable version: ±2% max. feedback voltage • Guaranteed 1A switch current • Wide 4V to 24V input voltage range • Wide 1.23V to 20V output voltage range • Requires minimum external components • < 200µA typical shutdown mode • 75% efficiency (adjustable version > 75% typical) • Standard inductors and capacitors are 25% of typical LM2575 values. • Thermal shutdown • Overcurrent protection • 100% electrical thermal limit burn-in The feedback voltage is guaranteed to ±2% tolerance for adjustable versions, and the output voltage is guaranteed to ±3% for fixed versions, within specified voltages and load conditions. The oscillator frequency is guaranteed to ±10%. In shutdown mode, the regulator draws less than 200µA standby current. The regulator performs cycle-by-cycle current limiting and thermal shutdown for protection under fault conditions. This series of simple switch-mode regulators requires a minimum number of external components and can operate using a standard series of inductors. Frequency compensation is provided internally. The MIC4575 is available in TO-220 (T) and TO-263 (U) packages for the industrial temperature range. Applications • • • • • • • Simple high-efficiency step-down (buck) regulator Efficient preregulator for linear regulators On-card switching regulators Positive-to-negative converter (inverting buck-boost) Battery Charger Negative boost converter Step-down 6V to 3.3V for Intel Pentium™ and similar microprocessors Typical Applications L1 Shutdown Enable 5 8V to 24V SHDN 2 SW MIC4575-5.0BT FB VIN GND 1 C1 150µF 35V 5.0V/1A 68µH 4 D1 1N5819 3 C2 330µF 16V Fixed Regulator Shutdown Enable 5 6V to 24V 1 C1 22µF 35V SHDN SW MIC4575BU FB VIN 2 L1 68µH 4 GND 3 D1 3.6V/1A R2 2.37k 1% R1 1.24k 1% C3 3300pF C2 330µF 6.3V MBRS130LT3 Adjustable Regulator 4-106 April 1998• MIC4575 Micrel Ordering Information Part Number Voltage Temperature Range Package MIC4575-3.3BT 3.3V –40°C to +85°C 5-lead TO-220 MIC4575-5.0BT 5.0V –40°C to +85°C 5-lead TO-220 Adjustable –40°C to +85°C 5-lead TO-220 3.3V –40°C to +85°C 5-lead TO-263 5.0V –40°C to +85°C 5-lead TO-263 Adjustable –40°C to +85°C 5-lead TO-263 MIC4575BT MIC4575-3.3BU MIC4575-5.0BU MIC4575BU Pin Configuration TAB 5 4 3 2 1 SHDN FB GND SW VIN 5-Lead TO-220 (T) TAB 5 4 3 2 1 4 SHDN FB GND SW VIN 5-Lead TO-263 (U) Pin Description Pin Number Pin Name 1 VIN Supply Voltage (Input): Unregulated +4V to +40V supply voltage. 2 SW Switch (Output): Emitter of NPN output switch. Connect to external storage inductor and Shottky diode. 3, TAB GND 4 FB 5 SHDN April 1998• Pin Function Ground Feedback (Input): Output voltage feedback to regulator. Connect to output of supply for fixed versions. Connect to 1.23V tap of resistive divider for adjustable versions. Shutdown (Input): Logic low enables regulator. Logic high (> 2.4V) shuts down regulator. 4-107 MIC4575 Micrel Absolute Maximum Ratings Operating Ratings Supply Voltage (VIN) Note 1 ....................................... +40V Shutdown Voltage (VSHDN) .......................... –0.3V to +36V Output Switch (VSW) steady state ................................. –1V Storage Temperature (TS) ......................... –65°C to 150°C Supply Voltage (VIN) ................................................... +24V Junction Temperature ............................................. +150°C Package Thermal Resistance TO-220, TO-263 (θJA) ......................................... 65°C/W TO-220, TO-263 (θJA) ........................................... 2°C/W Electrical Characteristics VIN = 12V; ILOAD = 200mA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +85°C; unless noted. Parameter Condition Min Typ Max Units 1.217 1.230 1.243 V 1.193 1.180 1.230 1.267 1.280 V V MIC4575 [Adjustable] Feedback Voltage Feedback Voltage 8V ≤ VIN ≤ 24V, 0.2A ≤ ILOAD ≤ 1A Efficiency ILOAD = 1A, VOUT = 5V 77 Feedback Bias Current % 50 100 500 nA nA 3.234 3.3 3.366 V 3.168 3.135 3.3 3.432 3.465 V V MIC4575-3.3 Output Voltage Output Voltage 6V ≤ VIN ≤ 24V, 0.2A ≤ ILOAD ≤ 1A Efficiency ILOAD = 1A 72 % MIC4575-5.0 Output Voltage Output Voltage 8V ≤ VIN ≤ 24V, 0.2A ≤ ILOAD ≤ 1A Efficiency ILOAD = 1A 4.900 5.0 5.100 V 4.800 4.750 5.0 5.200 5.250 V V 77 % MIC4575 / -3.3 / -5.0 Oscillator Frequency 180 200 220 kHz 1 1.3 1.5 V V Saturation Voltage IOUT = 1A Maximum Duty Cycle (On) FB connected to 0V 90 95 Current Limit Peak Current, tON ≤ 3µs 1.7 1.3 2.2 3.0 3.2 A A Output Leakage Current VIN = 24V, FB connected to 0V Output = 0V Output = –1V 0 7.5 2 30 mA mA 5 10 mA 50 200 µA Quiescent Current Standby Quiescent Current SHDN = 5V (regulator off) SHDN Input Logic Level VOUT = 0V (regulator off) 2.2 2.4 VOUT = 3.3 or 5V (regulator on) SHDN Input Current SHDN = 5V (regulator off) SHDN = 0V (regulator on) –10 % 1.4 V V 1.2 1.0 0.8 V V 4 0.01 30 10 µA µA General Note: Devices are ESD protected, however, handling precautions are recommended. Note 1: The MIC4575 is not guaranteed to survive a short circuit to ground for input voltage above 24V. 4-108 April 1998• MIC4575 Micrel Block Diagrams +24V max. VIN Shutdown Enable SHDN CIN Internal Regulator Thermal Shutdown 200kHz Oscillator Current Limit Driver Comparator L1 SW VOUT 1A Switch D1 COUT 1.23V Bandgap Error Amp. R1 FB R2 MIC4575-x.x GND 4 Block Diagram with External Components Fixed Step-Down Regulator +24V max. VIN Shutdown Enable SHDN CIN Internal Regulator Thermal Shutdown 200kHz Oscillator VOUT Current Limit R1 Comparator Driver V REF R2 R1 + 1 R2 VOUT VREF 1 L1 SW VOUT 1A Switch D1 COUT Error Amp. 1.23V Bandgap R1 FB MIC4575 [Adjustable] GND Block Diagram with External Components Adjustable Step-Down Regulator April 1998• 4-109 R2 MIC4575 Micrel Functional Description A higher feedback voltage increases the error amplifier output voltage. A higher error amplifier voltage (comparator inverting input) causes the comparator to detect only the peaks of the sawtooth, reducing the duty cycle of the comparator output. A lower feedback voltage increases the duty cycle. Output Switching The MIC4575 is a variable duty cycle switch-mode regulator with an internal power switch. Refer to the block diagrams. Supply Voltage The MIC4575 operates from a +4V to +24V unregulated input. Highest efficiency operation is from a supply voltage around +15V. Enable/Shutdown The shutdown (SHDN) input is TTL compatible. Ground the input if unused. A logic-low enables the regulator. A logichigh shuts down the internal regulator which reduces the current to typically 50µA. When the internal switch is on, an increasing current flows from the supply VIN, through external storage inductor L1, to output capacitor COUT and the load. Energy is stored in the inductor as the current increases with time. When the internal switch is turned off, the collapse of the magnetic field in L1 forces current to flow through fast recovery diode D1, charging COUT. Feedback Fixed versions of the regulator have an internal resistive divider from the feedback (FB) pin. Connect FB directly to the output line. Output Capacitor External output capacitor COUT provides stabilization and reduces ripple. Return Paths Adjustable versions require an external resistive voltage divider from the output voltage to ground, connected from the 1.23V tap to FB. Duty Cycle Control A fixed-gain error amplifier compares the feedback signal with a 1.23V bandgap voltage reference. The resulting error amplifier output voltage is compared to a 200kHz sawtooth waveform to produce a voltage controlled variable duty cycle output. During the on portion of the cycle, the output capacitor and load currents return to the supply ground. During the off portion of the cycle, current is being supplied to the output capacitor and load by storage inductor L1, which means that D1 is part of the high-current return path. Applications Information The applications circuits that follow have been constructed and tested. Refer to Application Note 15 for additional information, including efficiency graphs and manufacturer’s addresses and telephone numbers for most circuits. L1 5 6V to 24V C1 150µF 35V 1 SHDN SW MIC4575-3.3BT VIN FB GND 3 C1 C2 D1 L1 L1 Nichicon Nichicon Motorola Sumida Bi For a mathematical approach to component selection and circuit design, refer to Application Note 14. L1 3.3V/1A 2 5 68µH 8V to 24V C2 330µF 16V 4 D1 1N5819 C1 150µF 35V UPL1V151MPH, ESR = 0.12Ω UPL1C331MPH, ESR = 0.12Ω 1N5819 RCH106-680K, DCR = 0.22Ω HM77-11003, DCR = 0.233Ω, Note 2 5 1 C1 68µF 63V SHDN SW FB VIN 2 L1 150µH 4 GND MBR160 3 C1 C2 D1 L1 Nichicon Nichicon Motorola Sumida MIC4575-5.0BT VIN FB GND Nichicon Nichicon Motorola Sumida Bi 2 5.0V/1A 68µH 4 D1 1N5819 C2 330µF 16V UPL1J151MPH, ESR = 0.12Ω UPL1C331MPH, ESR = 0.12Ω 1N5819 RCH106-680K, DCR = 0.22Ω HM77-11003, DCR = 0.233Ω, Note 2 Figure 2. 8V–24V to 5V/1A Buck Converter Through Hole MIC4575BT 16V to 24V SW 3 C1 C2 D1 L1 L2 Figure 1. 6V–24V to 3.3V/1A Buck Converter Through Hole 1 SHDN 12V/1A R2 13.0k 1% R1 1.50k 1% C2 330µF 16V UPL1J680MPH, ESR = 0.17Ω UPL1C331MPH, ESR = 0.12Ω MBR160 RCH110-151K, DCR = 0.23Ω Note 2: Surfacemount component. Figure 3. 16V–24V to 12V/1A Buck Converter, Through Hole 4-110 April 1998• MIC4575 Micrel 5 6V to 24V SHDN SW MIC4575BU 1 VIN FB C1 22µF 35V L1 2 4 GND C3 3300pF 5 6V to 24V C2 330µF 6.3V R1 1.50k 1% D1 3 L1 3.3V/1A R2 2.49k 1% 68µH 1 C1 150µF 35V SHDN SW MIC4575-3.3BU VIN FB GND 3.3V/1A 2 68µH 4 D1 MBRS130LT3 3 C2 470µF 16V MBRS130LT3 C1 C2 D1 L1 AVX AVX Motorola Coiltronics TPSE226M035R0300, ESR = 0.3Ω TPSE337M006R0100, ESR = 0.1Ω MBRS130LT3 CTX68-4P, DCR = 0.238Ω C1 C2 D1 L1 L1 Figure 4. 6V–24V to 3.3V/1A Buck Converter Low-Profile Surface Mount 5 8V to 24V SHDN SW MIC4575BU 1 FB VIN C1 22µF 35V L1 2 4 GND Figure 7. 6V–24V to 3.3V/1A Buck Converter Lower-Cost Surface Mount D1 L1 5 C3 3300pF C2 220µF 10V 8V to 24V AVX AVX Motorola Coiltronics TPSE226M035R0300, ESR = 0.3Ω TPSE227M010R0100, ESR = 0.1Ω MBRS130LT3 CTX68-4P, DCR = 0.238Ω 16V to 24V 1 C1 10µF 50V SHDN SW MIC4575BU FB VIN GND 3 C1 C2 D1 L1 2 L1 150µH 4 C3 3300pF 5 1 5 Sanyo Sanyo Motorola Coilcraft Bi 68µH 4 D1 MBRS130LT3 C2 470µF 16V 35CV150GX, ESR = 0.17Ω 16CV470GX, ESR = 0.17Ω MBRS130LT3 DO3316P-683, DCR = 0.16Ω HM77-11003, DCR = 0.233Ω SHDN SW FB VIN 3 4 2 L1 150µH 4 SS26 12V/1A R2 13.0k 1% R1 1.50k 1% C2 470µF 16V Nichicon UUX1H470MT1GS, ESR = 0.4Ω Sanyo 16CV470GX, ESR = 0.17Ω General Instruments SS26 Coiltcraft DO5022P-154, DCR = 0.218Ω Figure 9. 16V–24V to 12V/1A Buck Converter Lower-Cost Surface Mount VIN SW MIC4575-5.0BT SHDN FB GND 2 4 L1 10µH 3 C1 Nichicon UPL1V151MPH ESR = 0.13Ω C2 Nichicon UPL1C681MPH ESR = 0.065Ω D1 Motorola 1N5819 L1 Coiltronics PL52A-10-500 DCR = 0.045Ω D1 1N5819 C2 680µF 16V -5V/0.2A Figure 10. 8V–18V to –5V/0.2A Buck-Boost Converter Through Hole April 1998• 5V/1A 2 GND C1 C2 D1 L1 Figure 6. 16V–24V to 12V/1A Buck Converter Low-Profile Surface Mount C1 150µF 35V 1 C1 47µF 50V X2 Tokin C55YU1H106Z AVX TPSE686M020R0150, ESR = 0.15Ω General Instruments SS26 Coiltronics CTX150-4, DCR = 0.372Ω 8V to 18V MIC4575-5.0BU FB VIN GND MIC4575BU 16V to 24V C2 68µF 20V R1 1.50k 1% D1 SS26 SW Figure 8. 8V–24V to 5V/1A Buck Converter Lower-Cost Surface Mount 12V/1A R2 13.0k 1% SHDN 3 C1 C2 D1 L1 L1 Figure 5. 8V–24V to 5V/1A Buck Converter Low-Profile Surface Mount 5 1 C1 150µF 35V MBRS130LT3 C1 C2 D1 L1 35CV150GX, ESR = 0.17Ω 16CV470GX, ESR = 0.17Ω MBRS130LT3 DO3316P-683, DCR = 0.16Ω HM77-11003, DCR = 0.233Ω 5V/1A R2 3.01k 1% R1 1.00k 1% 68µH 3 Sanyo Sanyo Motorola Coilcraft Bi 4-111 MIC4575 Micrel 4.75V to 5.25V 1 5 C1 150µF 35V VIN 2 SW MIC4575BT SHDN FB GND C4 1000pF 4 L1 15µH R4 5.1K 3 R1 3.01k 1% R2 1.00K 1% C1 C2 D1 L1 Nichicon Nichicon Motorola Coiltronics C2 680µF 16V D1 R3 10K C3 0.01µF -5V/0.3A 1N5819 UPL1V151MPH, ESR = 0.12Ω UPL1C681MPH, ESR = 0.065Ω 1N5819 PL52A-15-500, DCR = 0.054Ω Figure 11. 5V to –5V/0.3A Buck-Boost Converter Through Hole 5 VIN 8V to 18V SHDN SW 2 4 4 1 MIC4575BU 1 FB VIN C1 22µF 35V GND AVX AVX AVX Motorola Coiltronics Coilcraft VOUT 5V/1A L1 3 1µH R2 3.01k 1% C4 220µF 10V R1 1.00K 1% 2 D1 MBRS130LT3 3 C1 C2 C4 D1 T1 L1 T1 68µH C3 3300pF 5mVP-P C2 220µF 10V TPSE226M035R0300, ESR = 0.3Ω TPSE227M010R0100, ESR = 0.1Ω TPSE227M010R0100, ESR = 0.1Ω MBRS130LT3 CTX68-4P, DCR = 0.238Ω DO1608C-102 Figure 12. Low Output-Noise Regulator (5mV Output Ripple ) 5 VIN 8V to 18V SHDN SW 2 2 T1 68µH R2 3.01k 1% R1 1.00K 1% MIC4575BU 1 C1 22µF 35V VIN FB 4 GND 3 +VOUT/+IOUT 5V/0.5A 1 D1 MBRS130LT3 C3 3300pF C2 220µF 10V 4 C5 220µF 10V C4 220µF 10V L1 D2 MBRS130LT3 3 +IOUT + IOUT C1 C2 C4 C5 D1 D2 T1 AVX AVX AVX AVX Motorola Motorola Coiltronics TPSE226M035R0300, ESR = 0.3Ω TPSE227M010R0100, ESR = 0.1Ω TPSE227M010R0100, ESR = 0.1Ω TPSE227M010R0100, ESR = 0.1Ω MBRS130LT3 MBRS130LT3 CTX68-4P, DCR = 0.238Ω DC -VOUT/-IOUT -5V/0.5A at VIN ≥15V Load Regulation≈±5% 1A +VOUT 0.5V VIN 0.5V DC 40% then IOUT +IOUT DC 40% then IOUT IOUT (1 DC) Figure 13. Split ±5V Supply 4-112 April 1998• MIC4575 Micrel Q1 2N4339 R3 3.3K 5 VIN 4V to 24V SHDN SW 68µH MIC4575BT 1 FB VIN C1 150µF 35V D1 1N5819 3 Nichicon Nichicon Motorola Coiltronics Micrel R1 200K 4 GND C1 C2 D1 L1 U2 U2 LM4041CIZ-1.2 VOUT (0-12V)/0.5A VOUT Min = 60mV R4 C2 330µF 330Ω 0.5W 16V L1 2 R2 15k UPL1V151MPH, ESR = 0.12Ω UPL1C331MPH, ESR = 0.12Ω 1N5819 PL52B-68-500, DCR = 0.095Ω LM4041CIZ-1.2 VIN min VOUT 0.9 VIN min VOUT 1.5V and 2.5V Figure 14. Adjustable (0V–12V) Output-Voltage Regulator U1 5 VIN 4V to 15V SHDN SW L1 68µH 2 VOUT 1V/1A 3 MIC4575BT 1 VIN FB 4 1 GND 2 U2 LM358 3 C1 150µF 35V D1 1N5819 C1 C2 D1 L1 U2 R1 R2 249Ω 1% 1.00k 1% 4 C2 330µF 16V R3 1k Nichicon UPL1V151MPH, ESR = 0.12Ω Nichicon UPL1C331MPH, ESR = 0.12Ω Motorola 1N5819 Coiltronics PL52B-68-500, DCR = 0.095Ω National LM358 Figure 15. Low Output-Voltage Regulator (1V) 5 VIN 9V to 24V SHDN Nichicon Nichicon Motorola Coiltronics National Siliconix KRL VIN min IOUT FB VIN 68µH 3 UPL1V151MPH, ESR = 0.12Ω UPL1C331MPH, ESR = 0.12Ω 1N5819 PL52B-68-500, DCR = 0.095Ω LM358 VN2222LL SP-1/2-A1-0R250J 2.5V R2 R1 D2 1N5819 R1 0.25Ω R2 200Ω 1% 4 GND VBATT 0.9 1.23V R5 L1 MIC4575BT 1 C1 150µF 35V C1 C2 D1 L1 U2 Q1 R1 SW 2 D1 1N5819 U2 LM358 Q1 VN2222LL R3 10K 3 1 2 C3 C4 1000pF 0.01µF R4 3k R5 1.00k 1% Figure 16. 1A Battery Charger (6–8 cells) April 1998• C2 330µF 16V 4-113 DZ1 1N5244 14V IOUT 1A 6-8 Cells VBATT MIC4575 Micrel D3 1N4148 5 VIN 8V to 24V SHDN MIC4575-BT FB VIN GND 1 C2 330µF 16V R2 100Ω 1% C4 1000pF MIC4575BT LM358 LM4041CIZ-1.2 UPL1V151MPH, ESR = 0.12Ω UPL1C331MPH, ESR = 0.12Ω 1N5819 1N5819 1N4148 PL52B-68-500, DCR = 0.095Ω SP-1-A1-0R100J VN2222LL VBATT / 0.9 1 2 U2A 1/2LM358 R3 10k VIN U2B 1/2 LM358 8 C3 5 7 0.01µF Q1 VN2222LL DZ1 1N5244 14V IOUT 0.1A to 1A 2-8 Cells VBATT VIN 3 R7 1k Micrel National Micrel Nichicon Nichicon Motorola Motorola Motorola Coiltronics KRL Siliconix VIN min D2 1N5819 R1 0.1Ω D1 1N5819 R6 3k 4 3 C1 150µF 35V U1 U2 U3 C1 C2 D1 D2 D3 L1 R1 Q1 SW L1 68µH 2 R5 10k VR1 10k U3 LM4041CIZ-1.2 6 4 R4 1.21k 1% 2.5V Figure 17. 0.1A–1A Variable-Current Battery Charger D3 1N4148 5 VIN 8V to 24V SHDN SW FB VIN GND 3 C1 150µF 35V D1 1N5819 R5 3k 4 R6 1k D2 1N5819 R1 0.1Ω 2 MIC4575-BT 1 L1 68µH C2 330µF 16V R2 100Ω 1% C4 1000pF IOUT 1A 2-8 Cells VBATT 3 1 2 U2A 1/2LM358 R3 10k C3 U1 U2 C1 C2 D1 D2 D3 L1 R1 Q1 Micrel National Nichicon Nichicon Motorola Motorola Motorola Coiltronics KRL Siliconix VIN min IOUT MIC4575BT LM358 UPL1V151MPH, ESR = 0.12Ω UPL1C331MPH, ESR = 0.12Ω 1N5819 1N5819 1N4148 PL52B-68-500, DCR = 0.095Ω SP-1-A1-0R100J VN2222LL VBATT / 0.9 1.23V R4 2.5V 0.01µF DZ1 1N5244 14V VIN 8 5 U2B 1/2 LM358 7 6 Q1 VN2222LL 4 R2 R1 R4 1.21k 1% Figure 18. 1A Battery Charger (2–8 Cells) 4-114 April 1998• MIC4575 Micrel U1 VIN 8V to 24V 1 VSW VIN MIC4575BT 5 C1 68µF 63V FB SD 68µH D1 MBR160 4 GND 3 C2 68µF 63V R1 30Ω C3 0.01µF R2 3.01k 1% +VSENSE R3 1.00k 1% C1 C2 C4 D1 L1 Nichicon Nichicon AVX Motorola Coiltronics VOUT 5V/1A 10 ft Wire 0.5 Ω +V L1 2 C4 220µF 10V –VSENSE R4 10Ω UPL1J680MPH, ESR = 0.17Ω UPL1J680MPH, ESR = 0.17Ω TPSE227M010R0100, ESR = 0.1 Ω MBRS160 PL52B-68-500, DCR = 0.095Ω –V Figure 19. Remote-Sensing Regulator 5 VIN 6V to 18V SHDN SW VIN FB GND C1 22µF 35V VOUT 12V/100mA T1 150µH 2 1 R2 13.0k 1% D3 1N4148 MIC4575BU 1 C2 68µF Q1 Si9435 2 4 C5 3300pF C3 68µF 20V 3 3 D1 MBRS130LT3 T1 R1 1.50K 1% 4 C1 C2 C3 C4 D1 D2 T1 Q1 AVX AVX AVX AVX Motorola Motorola Coiltronics Siliconix TPSE226M035R0300, ESR = 0.3Ω TPSE686M020R0150, ESR = 0.15Ω TPSE686M020R0150, ESR = 0.15Ω TPSE686M020R0150, ESR = 0.15Ω MBRS130LT3 MBRS130LT3 CTX150-4, DCR = 0.372Ω Si 9435, PMOS C4 68µF 20V R3 1k D2 –VOUT –12V/100mA (–11V to –12V) MBRS130LT3 Figure 20. 6V–18V to Split ±12V/100mA Supply L1 68µH U1 5 VIN 8V to 24V C1 150µF 35V SHDN SW D1 1N5819 MIC4575BU 1 VIN GND FB D2 1N5819 2 C2 330µF 16V C3 0.1µF 4 3 VIN C4 R3 R2 113k 1% 10k 1% R1 0.1Ω DZ1 1N5244 14V 0.01µF 8 8 7 U2B 1/2 LM358 U1 Micrel U2 National C1 Nichicon C2 Nichicon D1 Motorola D2 Motorola DZ1 Motorola L1 Bi R1 KRL MIC4575BT LM358 UPL1V151MPH, ESR = 0.12Ω UPL1C331MPH, ESR = 0.12Ω 1N5819 1N5819 1N5244 HM77-11003, DCR = 0.233Ω SP-1/2-A1-0R100J 6 R4 5 4 10k = IOUT = 1.23V R1 Figure 21. 1A Battery Charger April 1998• 4-115 VBATT + 2.5V 0.9 VIN min R2 R2 R3 IOUT 1A VBATT 2–8 Cells 4 MIC4575 Micrel U1 5 VIN 4V to 24V SHDN SW 2 FB 4 D1 1N5819 MIC4575BT 1 VOUT 0V–12V VOUTmin = 60mV L1 68µH VIN C1 150µF 35V GND 3 VIN 5 U2B 1/2LM358 C4 0.01µF 8 1 6 3 4 U1 U2 C1 C2 D1 L1 Micrel National Nichicon Nichicon Motorola Bi R3 R4 20k 1% 2k 1% R6 330Ω 0.5W R2 2k 1% U2A 2 7 C2 1000µF 16V R1 20k 1% C3 3300pF R6 220Ω 1/2LM358 R5 10K VIN min MIC4575BT LM358 UPL1V151MPH, ESR = 0.12Ω UPL1C102MPH, ESR = 0.047Ω 1N5819 HM77-11003, DCR = 0.233Ω = VOUT + 2.5V 0.9 VOUT max = 1.23V R1 R2 1 R1 = R3 and R2 = R4 Figure 22. Improved Adjustable Output-Voltage Regulator (0V–12V) D3 U1 5 VIN 8V to 24V C1 150µF 35V 1N4148 SHDN SW MIC4575BT 1 VIN GND 3 FB D1 1N5819 R5 3k 4 R6 1k 68µH U2A 1/2LM358 C4 1000pF C3 0.01µF C5 0.01µF 5 8 U2B 1/2 LM358 7 C2 330µF 16V R2 100Ω 1% 3 R3 10k 1 VIN IOUT 1A R1 0.1Ω L1 2 2 DZ1 1N5236 7.5V Q1 VN2222LL 4 R7 100k R8 100k U3 6 2 Bat A FLG A 7 IN U1 Micrel U2 National U3 Micrel C1 Nichicon C1 Nichicon D1 Motorola D2 Motorola DZ1 Motorala L1 Bi Q1 Siliconix R1 KRL MIC4575BT LM358 MIC2506BM UPL1V151MPH, ESR = 0.12Ω UPL1C331MPH, ESR = 0.12Ω 1N5819 1N5819 1N5236 HM77-11003, DCR = 0.233Ω VN2222LL SP-1/2-A1-0R100J R4 1.21k 1% Bat B FLG B 1 A/B 1 2 4 U4A 7404 8 OUT A 3 CTL A CTL B MIC2506 OUT B 5 R10 510k GND 6 R9 510k Bat B 4 Cells NiCad Bat A 4 Cells NiCad Figure 23. Switchable Battery-Pack Charger 4-116 April 1998• MIC4575 Micrel D3 U1 5 VIN 12V to 24V 1N4148 SHDN SW 2 MIC4575BT 1 VIN FB GND C1 150µF 35V D1 1N5819 R6 3k 4 R7 1k 3 68µH U2A 1/2LM358 C4 1000pF IOUT 1A D2 1N5819 R1 0.1Ω L1 VBATT 2 Li Cells C2 330µF 16V R2 100Ω 1% R5 1.0k 1% 3 1 U1 Micrel U2 National U3 National U4 National C1 Nichicon C1 Nichicon D1 Motorola D2 Motorola DZ1 Motorala L1 Bi R1 KRL Q1 Siliconix MIC4575BT LM358 LM3420 LM339 UPL1V151MPH, ESR = 0.12Ω UPL1C331MPH, ESR = 0.12Ω 1N5819 1N5819 1N5244 HM77-11003, DCR = 0.233Ω SP-1/2-A1-0R100J VN2222LL 8 IOUTEND IOUTEND Q1 VN2222LL 7 U2B 1/2 LM358 4 6 U3 3 VIN R8 10k R10 10k R9 10M R3 1.21k 1% C8 0.01µF Q2 2N2222 8 COMP IN LM3420 1 OUT GND 4 IOUT = 1.02A VIN min > = 2 C5 0.1µF 5 R2 R1 1.24V IOUT = R3 C3 0.01µF VIN VIN VBATT + 2.5V 0.9 C6 0.1µF 1.23V 3 R12 100k R4 13.0k 1% 4 7 1 END 60mA C7 0.01µF 6 12 R5 R2 – R4 R3 R1 LM339 Figure 24. Lithium-Ion Battery Charger with End-of-Charge Flag L1 68µH U1 5 VIN 9V to 18V SHDN R2 3.92k 1% MIC4575BU 1 VIN C1 22µF 35V U1 U2 C1 C2 C3 C4 D1 D2 L1 L2 SW GND 3 Micrel Micrel AVX AVX AVX Sprague Motorola Motorola Bi Coilcraft FB L2 1µH 6.0V U2 1 2 4 D1 MBRS130LT3 MIC4575BU MIC29150-5.0BU TPSE226M035R0300, ESR = 0.3Ω TPSE227M010R0100, ESR = 0.1Ω TPSE106M010R0200, ESR = 0.2Ω 293D226X0010C2W MBRS130LT3 MBRS130LT3 HM77-11003, DCR = 0.233Ω D016087C-102, DCR = 0.05Ω C2 220µF 10V VOUT = 1.23 C3 100µF 10V 1+ R2 R1 Figure 25. Low Output-Noise Regulator (<1mV) April 1998• 4-117 VIN 3 VOUT 5V/1A MIC29150 C3 3300pF R1 1.00k 1% VOUT GND 2 C4 22µF 10V