NCP1450ASN19T1G

NCP1450A PWM Step−up DC−DC Controller The NCP1450A series are PWM step−up DC−DC switching controller that are specially designed for powering portable equipment from one or two cells battery packs. The NCP1450A series have a driver pin, EXT pin, for connecting to an external transistor. Large output currents can be obtained by connecting a low ON−resistance external power transistor to the EXT pin. The device will automatically skip switching cycles under light load condition to maintain high efficiency at light loads. With only six external components, this series allows a simple means to implement highly efficient converter for large output current applications. Each device consists of an on−chip Pulse Width Modulation (PWM) oscillator, PWM controller, phase−compensated error amplifier, soft−start, voltage reference, and driver for driving external power transistor. Additionally, a chip enable feature is provided to power down the converter for extended battery life. The NCP1450A device series are available in the TSOP−5 package with five standard regulated output voltages. Additional voltages that range from 1.8 V to 5.0 V in 100 mV steps can be manufactured. Features http://onsemi.com 5 1 TSOP−5 SN SUFFIX CASE 483 MARKING DIAGRAM AND PIN CONNECTIONS CE OUT NC 1 xxxAYWG G 2 3 (Top View) xxx =Specific Device Marking A = Assembly Location Y = Year W = Work Week G = Pb−Free Package (Note: Microdot may be in either location) 5 EXT • High Efficiency 86% at IO = 200 mA, VIN = 2.0 V, VOUT = 3.0 V • • • • • • • • • • • • • • 88% at IO = 400 mA, VIN = 3.0 V, VOUT = 5.0 V Low Startup Voltage of 0.9 V typical at IO = 1.0 mA Operation Down to 0.6 V Five Standard Voltages: 1.9 V, 2.7 V, 3.0 V, 3.3 V, 5.0 V with High Accuracy ± 2.5% Low Conversion Ripple High Output Current up to 1000 mA (3.0 V version at VIN = 2.0 V, L = 10 mH, COUT = 220 mF) Fixed Frequency Pulse Width Modulation (PWM) at 180 kHz Chip Enable Pin with On−chip 150 nA Pullup Current Source Low Profile and Micro Miniature TSOP−5 Package Pb−Free Packages are Available 4 GND ORDERING INFORMATION See detailed ordering and shipping information in the ordering information section on page 3 of this data sheet. Typical Applications Personal Digital Assistant (PDA) Electronic Games Portable Audio (MP3) Digital Still Cameras Handheld Instruments © Semiconductor Components Industries, LLC, 2005 1 December, 2005 − Rev. 7 Publication Order Number: NCP1450A/D NCP1450A VIN CE 1 OUT 2 NC 3 EXT 5 VOUT NCP1450A GND 4 Figure 1. Typical Step−up Converter Application OUT 2 NC 3 + − Error Amplifier PWM Controller Driver EXT 5 Phase Compensation Voltage Reference 180 kHz Oscillator Soft−Start GND 4 1 CE Figure 2. Representative Block Diagram PIN FUNCTION DESCRIPTION Pin # 1 Symbol CE Pin Description Chip Enable Pin (1) The chip is enabled if a voltage equal to or greater than 0.9 V is applied. (2) The chip is disabled if a voltage less than 0.3 V is applied. (3) The chip is enabled if this pin is left floating. Output voltage monitor pin and also the power supply pin for the device. No internal connection to this pin. Ground pin. ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁ Á 2 3 4 5 OUT NC GND EXT External transistor drive pin. http://onsemi.com 2 NCP1450A ORDERING INFORMATION (Note 1) Device NCP1450ASN19T1 NCP1450ASN19T1G NCP1450ASN27T1G NCP1450ASN27T1 NCP1450ASN30T1 NCP1450ASN30T1G NCP1450ASN33T1 NCP1450ASN33T1G NCP1450ASN50T1 NCP1450ASN50T1G 5.0 V DBD 3.3 V DBC 3.0 V 180 KHz DBA 2.7 V DAZ 1.9 V DAY Output Voltage Switching Frequency Marking Package TSOP−5 TSOP−5 (Pb−Free) TSOP−5 TSOP−5 (Pb−Free) TSOP−5 TSOP−5 (Pb−Free) TSOP−5 TSOP−5 (Pb−Free) TSOP−5 TSOP−5 (Pb−Free) 3000 Units on 7 Inch Reel Shipping† †For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D. 1. The ordering information lists five standard output voltage device options. Additional devices with output voltage ranging from 1.8 V to 5.0 V in 100 mV increments can be manufactured. Contact your ON Semiconductor representative for availability. MAXIMUM RATINGS Rating Power Supply Voltage (Pin 2) Input/Output Pins EXT (Pin 5) EXT Sink/Source Current CE (Pin 1) Input Voltage Range Input Current Range Symbol VOUT VEXT IEXT VCE ICE Value 6.0 Unit V ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á ÁÁÁÁ Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á Á Á Á Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁ Á Á Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á ÁÁÁÁ Á Á Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á ÁÁÁÁÁ Á Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á −0.3 to 6.0 −150 to 150 −0.3 to 6.0 −150 to 150 500 250 V mA V mA Power Dissipation and Thermal Characteristics Maximum Power Dissipation @ TA = 25°C Thermal Resistance Junction−to−Air Operating Ambient Temperature Range PD RqJA TA TJ mW °C/W °C °C °C −40 to +85 Operating Junction Temperature Range Storage Temperature Range −40 to +150 −55 to +150 Tstg Maximum ratings are those values beyond which device damage can occur. Maximum ratings applied to the device are individual stress limit values (not normal operating conditions) and are not valid simultaneously. If these limits are exceeded, device functional operation is not implied, damage may occur and reliability may be affected. 2. This device series contains ESD protection and exceeds the following tests: Human Body Model (HBM) $2.0 kV per JEDEC standard: JESD22−A114. Machine Model (MM) $200 V per JEDEC standard: JESD22−A115. 3. Latchup Current Maximum Rating: $150 mA per JEDEC standard: JESD78. 4. Moisture Sensitivity Level (MSL): 1 per IPC/JEDEC standard: J−STD−020A. http://onsemi.com 3 NCP1450A ELECTRICAL CHARACTERISTICS (For all values TA = 25°C, unless otherwise noted.) Characteristic OSCILLATOR Frequency (VOUT = VSET 0.96, Note 5) fOSC Df DMAX Vstart DVstart Vhold tSS 144 − 70 − − − − 180 0.11 80 0.8 −1.6 0.6 100 216 − 90 0.9 − 0.7 250 kHz %/°C % V mV/°C V ms Frequency Temperature Coefficient (TA = −40°C to 85°C) Maximum PWM Duty Cycle (VOUT = VSET Minimum Startup Voltage (IO = 0 mA) Minimum Startup Voltage Temperature Coefficient (TA = −40°C to 85°C) Minimum Operation Hold Voltage (IO = 0 mA) Soft−Start Time (VOUT = VSET, Note 6) CE (PIN 1) CE Input Voltage (VOUT = VSET High State, Device Enabled Low State, Device Disabled 0.96) VCE(high) VCE(low) ICE(high) ICE(low) 0.9 − −0.5 0 − − 0 0.15 − 0.3 mA 0.5 0.5 V 0.96) Symbol Min Typ Max Unit CE Input Current (Note 6) High State, Device Enabled (VOUT = VCE = 5.0 V) Low State, Device Disabled (VOUT = 5.0 V, VCE = 0 V) EXT (PIN 5) EXT “H” Output Current (VEXT = VOUT −0.4 V) Device Suffix: 19T1 27T1 30T1 33T1 50T1 EXT “L” Output Current(VEXT = 0.4 V) Device Suffix: 19T1 27T1 30T1 33T1 50T1 TOTAL DEVICE Output Voltage Device Suffix: 19T1 27T1 30T1 33T1 50T1 Output Voltage Temperature Coefficient (TA = −40 to +85°C) Operating Current (VOUT = VCE = VSET Device Suffix: 19T1 27T1 30T1 33T1 50T1 0.96, Note 5) IEXTH − − − − − IEXTL 20.0 30.0 30.0 30.0 35.0 38.3 48.0 50.8 52.0 58.2 − − − − − −25.0 −35.0 −37.7 −40.0 −53.7 −20.0 −30.0 −30.0 −30.0 −35.0 mA mA VOUT 1.853 2.633 2.925 3.218 4.875 DVOUT IDD − − − − − ISTB IOFF − − 55 93 98 103 136 15 0.6 90 140 150 160 220 20 1.5 − 1.9 2.7 3.0 3.3 5.0 150 1.948 2.768 3.075 3.383 5.125 − V ppm/°C mA Standby Current (VOUT = VCE = VSET +0.5 V) Off−State Current (VOUT = 5.0 V, VCE = 0 V, TA = −40 to +85°C, Note 7) 5. VSET means setting of output voltage. 6. This parameter is guaranteed by design. 7. CE pin is integrated with an internal 150 nA pullup current source. mA mA http://onsemi.com 4 NCP1450A 2.1 VOUT, OUTPUT VOLTAGE (V) VOUT, OUTPUT VOLTAGE (V) 3.2 2.0 3.1 VIN = 2.5 V 3.0 VIN = 0.9 V 2.9 NCP1450ASN30T1 L = 10 mH Q = NTGS3446T1 COUT = 220 mF TA = 25°C 0 200 400 VIN = 1.2 V VIN = 1.5 V VIN = 2.0 V 1.9 VIN = 0.9 V 1.8 NCP1450ASN19T1 L = 10 mH Q = NTGS3446T1 COUT = 220 mF TA = 25°C 0 200 400 600 800 1000 VIN = 1.2 V VIN = 1.5 V 1.7 2.8 1.6 IO, OUTPUT CURRENT (mA) 2.7 600 800 1000 IO, OUTPUT CURRENT (mA) Figure 3. NCP1450ASN19T1 Output Voltage vs. Output Current Figure 4. NCP1450ASN30T1 Output Voltage vs. Output Current 5.2 VOUT, OUTPUT VOLTAGE (V) VIN = 4.5 V EFFICIENCY (%) VIN = 1.2 V 5.0 VIN = 1.5 V 4.9 VIN = 0.9 V 4.8 NCP1450ASN50T1 L = 10 mH Q = NTGS3446T1 COUT = 220 mF TA = 25°C 400 600 800 1000 VIN = 2.5 V VIN = 3.0 V VIN = 2.0 V VIN = 4.0 V 100 VIN = 1.5 V 80 VIN = 1.2 V 60 VIN = 0.9 V 40 NCP1450ASN19T1 L = 10 mH Q = NTGS3446T1 COUT = 220 mF TA = 25°C 0.1 1 10 100 1000 5.1 20 4.7 0 200 IO, OUTPUT CURRENT (mA) 0 0.01 IO, OUTPUT CURRENT (mA) Figure 5. NCP1450ASN50T1 Output Voltage vs. Output Current Figure 6. NCP1450ASN19T1 Efficiency vs. Output Current 100 VIN = 2.0 V 80 EFFICIENCY (%) VIN = 1.5 V EFFICIENCY (%) VIN = 2.5 V 100 VIN = 4.0 V VIN = 3.0 V 80 VIN = 2.5 V VIN = 2.0 V 60 VIN = 4.5 V VIN = 1.2 V VIN = 0.9 V 40 NCP1450ASN50T1 L = 10 mH Q = NTGS3446T1 COUT = 220 mF TA = 25°C 0.1 1 10 100 1000 VIN = 1.5 V 60 40 NCP1450ASN30T1 L = 10 mH Q = NTGS3446T1 COUT = 220 mF TA = 25°C 10 100 1000 20 VIN = 1.2 V VIN = 0.9 V 20 0 0.01 0.1 1 0 0.01 IO, OUTPUT CURRENT (mA) IO, OUTPUT CURRENT (mA) Figure 7. NCP1450ASN30T1 Efficiency vs. Output Current Figure 8. NCP1450ASN50T1 Efficiency vs. Output Current http://onsemi.com 5 NCP1450A 2.1 VOUT, OUTPUT VOLTAGE (V) VOUT, OUTPUT VOLTAGE (V) 3.2 2.0 3.1 1.9 3.0 1.8 NCP1450ASN19T1 L = 22 mH IO = 0 mA VIN = 1.2 V −25 0 25 50 75 100 2.9 NCP1450ASN30T1 L = 22 mH IO = 0 mA VIN = 1.2 V −25 0 25 50 75 100 1.7 2.8 1.6 −50 2.7 −50 TEMPERATURE (°C) TEMPERATURE (°C) Figure 9. NCP1450ASN19T1 Output Voltage vs. Temperature Figure 10. NCP1450ASN30T1 Output Voltage vs. Temperature 5.2 IDD, OPERATING CURRENT (mA) VOUT, OUTPUT VOLTAGE (V) 100 5.1 80 5.0 60 4.9 NCP1450ASN50T1 L = 22 mH IO = 0 mA VIN = 1.2 V −25 0 25 50 75 100 40 NCP1450ASN19T1 VOUT = 1.9 V x 0.96 Open−Loop Test −25 0 25 50 75 100 4.8 20 4.7 −50 0 −50 TEMPERATURE (°C) TEMPERATURE (°C) Figure 11. NCP1450ASN50T1 Output Voltage vs. Temperature Figure 12. NCP1450ASN19T1 Operating Current vs. Temperature 140 IDD, OPERATING CURRENT (mA) IDD, OPERATING CURRENT (mA) 200 120 180 100 160 80 NCP1450ASN30T1 VOUT = 3.0 V x 0.96 Open−Loop Test −25 0 25 50 75 100 140 NCP1450ASN50T1 VOUT = 5.0 V x 0.96 Open−Loop Test −25 0 25 50 75 100 60 120 40 −50 100 −50 TEMPERATURE (°C) TEMPERATURE (°C) Figure 13. NCP1450ASN30T1 Operating Current vs. Temperature Figure 14. NCP1450ASN50T1 Operating Current vs. Temperature http://onsemi.com 6 NCP1450A 25 ISTD, STANDBY CURRENT (mA) ISTD, STANDBY CURRENT (mA) 25 20 20 15 15 10 NCP1450ASN19T1 VOUT = 1.9 V + 0.5 V Open−Loop Test −25 0 25 50 75 100 10 NCP1450ASN30T1 VOUT = 3.0 V + 0.5 V Open−Loop Test −25 0 25 50 75 100 5 5 0 −50 0 −50 TEMPERATURE (°C) TEMPERATURE (°C) Figure 15. NCP1450ASN19T1 Standby Current vs. Temperature Figure 16. NCP1450ASN30T1 Standby Current vs. Temperature 25 IOFF, OFF−STATE CURRENT (mA) ISTD, STANDBY CURRENT (mA) 1.0 NCP1450ASN19T1 VOUT = 5.0 V VCE = 0 V Open−Loop Test 20 0.8 15 0.6 10 NCP1450ASN50T1 VOUT = 5.0 V + 0.5 V Open−Loop Test −25 0 25 50 75 100 0.4 5 0.2 0 −50 0.0 −50 −25 0 25 50 75 100 TEMPERATURE (°C) TEMPERATURE (°C) Figure 17. NCP1450ASN50T1 Standby Current vs. Temperature 1.0 IOFF, OFF−STATE CURRENT (mA) IOFF, OFF−STATE CURRENT (mA) NCP1450ASN30T1 VOUT = 5.0 V VCE = 0 V Open−Loop Test 1.2 Figure 18. NCP1450ASN19T1 Off−State Current vs. Temperature 0.8 1.0 NCP1450ASN50T1 VOUT = 5.0 V VCE = 0 V Open−Loop Test 0.6 0.8 0.4 0.6 0.2 0.4 0.0 −50 −25 0 25 50 75 100 0.2 −50 −25 0 25 50 75 100 TEMPERATURE (°C) TEMPERATURE (°C) Figure 19. NCP1450ASN30T1 Off−State Current vs. Temperature Figure 20. NCP1450ASN50T1 Off−State Current vs. Temperature http://onsemi.com 7 NCP1450A fOSC, OSCILLATOR FREQUENCY (kHz) fOSC, OSCILLATOR FREQUENCY (kHz) 300 250 200 150 100 50 0 −50 NCP1450ASN19T1 VOUT = 1.9 V x 0.96 Open−Loop Test −25 0 25 50 75 100 300 250 200 150 100 50 0 −50 NCP1450ASN30T1 VOUT = 3.0 V x 0.96 Open−Loop Test −25 0 25 50 75 100 TEMPERATURE (°C) TEMPERATURE (°C) Figure 21. NCP1450ASN19T1 Oscillator Frequency vs. Temperature Figure 22. NCP1450ASN30T1 Oscillator Frequency vs. Temperature fOSC, OSCILLATOR FREQUENCY (kHz) 300 250 200 150 100 50 0 −50 NCP1450ASN50T1 VOUT = 5.0 V x 0.96 Open−Loop Test −25 0 25 50 75 100 DMAX, MAXIMUM DUTY CYCLE (%) 100 90 80 70 60 50 40 −50 NCP1450ASN19T1 VOUT = 1.9 V x 0.96 Open−Loop Test −25 0 25 50 75 100 TEMPERATURE (°C) TEMPERATURE (°C) Figure 23. NCP1450ASN50T1 Oscillator Frequency vs. Temperature 100 DMAX, MAXIMUM DUTY CYCLE (%) 90 80 70 60 50 40 −50 NCP1450ASN30T1 VOUT = 3.0 V x 0.96 Open−Loop Test −25 0 25 50 75 100 DMAX, MAXIMUM DUTY CYCLE (%) 100 90 80 70 60 50 Figure 24. NCP1450ASN19T1 Maximum Duty Cycle vs. Temperature NCP1450ASN50T1 VOUT = 5.0 V x 0.96 Open−Loop Test −25 0 25 50 75 100 40 −50 TEMPERATURE (°C) TEMPERATURE (°C) Figure 25. NCP1450ASN30T1 Maximum Duty Cycle vs. Temperature Figure 26. NCP1450ASN50T1 Maximum Duty Cycle vs. Temperature http://onsemi.com 8 NCP1450A IEXTH, EXT “H” OUTPUT CURRENT (mA) 0 IEXTH, EXT “H” OUTPUT CURRENT (mA) −20 −10 −30 −20 −40 −30 NCP1450ASN19T1 VOUT = 1.9 V x 0.96 VEXT = VOUT − 0.4 V Open−Loop Test −25 0 25 50 75 100 −50 NCP1450ASN30T1 VOUT = 3.0 V x 0.96 VEXT = VOUT − 0.4 V Open−Loop Test −25 0 25 50 75 100 −40 −60 −50 −50 −70 −50 TEMPERATURE (°C) TEMPERATURE (°C) Figure 27. NCP1450ASN19T1 EXT “H” Output Current vs. Temperature Figure 28. NCP1450ASN30T1 EXT “H” Output Current vs. Temperature IEXTH, EXT “H” OUTPUT CURRENT (mA) IEXTL, EXT “L” OUTPUT CURRENT (mA) −40 50 −50 40 −60 30 −70 NCP1450ASN50T1 VOUT = 5.0 V x 0.96 VEXT = VOUT − 0.4 V Open−Loop Test −25 0 25 50 75 100 20 NCP1450ASN19T1 VOUT = 1.9 V x 0.96 VEXT = 0.4 V Open−Loop Test −25 0 25 50 75 100 −80 10 −90 −50 0 −50 TEMPERATURE (°C) TEMPERATURE (°C) Figure 29. NCP1450ASN50T1 EXT “H” Output Current vs. Temperature 80 90 Figure 30. NCP1450ASN19T1 EXT “L” Output Current vs. Temperature IEXTL, EXT “L” OUTPUT CURRENT (mA) 70 IEXTL, EXT “L” OUTPUT CURRENT (mA) 80 60 70 50 NCP1450ASN30T1 VOUT = 3.0 V x 0.96 VEXT = 0.4 V Open−Loop Test −25 0 25 50 75 100 60 NCP1450ASN50T1 VOUT = 5.0 V x 0.96 VEXT = 0.4 V Open−Loop Test −25 0 25 50 75 100 40 50 40 −50 30 −50 TEMPERATURE (°C) TEMPERATURE (°C) Figure 31. NCP1450ASN30T1 EXT “L” Output Current vs. Temperature Figure 32. NCP1450ASN50T1 EXT “L” Output Current vs. Temperature http://onsemi.com 9 NCP1450A 25 25 REXTH, EXT “H” ON−RESISTANCE (W) 20 REXTH, EXT “H” ON−RESISTANCE (W) 20 15 15 10 NCP1450ASN19T1 VOUT = 1.9 V x 0.96 VEXT = VOUT − 0.4 V Open−Loop Test −25 0 25 50 75 100 10 NCP1450ASN30T1 VOUT = 3.0 V x 0.96 VEXT = VOUT − 0.4 V Open−Loop Test −25 0 25 50 75 100 5 5 0 −50 0 −50 TEMPERATURE (°C) TEMPERATURE (°C) Figure 33. NCP1450ASN19T1 EXT “H” ON−Resistance vs. Temperature Figure 34. NCP1450ASN30T1 EXT “H” ON−Resistance vs. Temperature REXTH, EXT “H” ON−RESISTANCE (W) 20 NCP1450ASN50T1 VOUT = 5.0 V x 0.96 VEXT = VOUT − 0.4 V Open−Loop Test REXTL, EXT “L” ON−RESISTANCE (W) 25 25 NCP1450ASN19T1 VOUT = 1.9 V x 0.96 VEXT = 0.4 V Open−Loop Test 20 15 15 10 10 5 5 0 −50 −25 0 25 50 75 100 0 −50 −25 0 25 50 75 100 TEMPERATURE (°C) TEMPERATURE (°C) Figure 35. NCP1450ASN50T1 EXT “H” ON−Resistance vs. Temperature 25 NCP1450ASN30T1 VOUT = 3.0 V x 0.96 VEXT = 0.4 V Open−Loop Test 25 Figure 36. NCP1450ASN19T1 EXT “L” ON−Resistance vs. Temperature REXTL, EXT “L” ON−RESISTANCE (W) REXTL, EXT “L” ON−RESISTANCE (W) 20 20 NCP1450ASN50T1 VOUT = 5.0 V x 0.96 VEXT = 0.4 V Open−Loop Test 15 15 10 10 5 5 0 −50 −25 0 25 50 75 100 0 −50 −25 0 25 50 75 100 TEMPERATURE (°C) TEMPERATURE (°C) Figure 37. NCP1450ASN30T1 EXT “L” ON−Resistance vs. Temperature Figure 38. NCP1450ASN50T1 EXT “L” ON−Resistance vs. Temperature http://onsemi.com 10 NCP1450A Vstart/Vhold, STARTUP/HOLD VOLTAGE (V) 1.0 Vstart/Vhold, STARTUP/HOLD VOLTAGE (V) 1.0 0.8 Vstart 0.6 NCP1450ASN19T1 L = 22 mH COUT = 0.1 mF IO = 0 mA 0.8 NCP1450ASN30T1 L = 22 mH COUT = 0.1 mF IO = 0 mA Vstart 0.6 0.4 0.4 Vhold Vhold 0.2 0.2 0.0 −50 −25 0 25 50 75 100 0.0 −50 −25 0 25 50 75 100 TEMPERATURE (°C) TEMPERATURE (°C) Figure 39. NCP1450ASN19T1 Startup/Hold Voltage vs. Temperature Figure 40. NCP1450ASN30T1 Startup/Hold Voltage vs. Temperature Vstart/Vhold, STARTUP/HOLD VOLTAGE (V) 1.0 VRIPPLE, RIPPLE VOLTAGE (mV) 200 180 160 140 120 100 80 60 40 20 0 25 50 75 100 0 200 400 600 800 1000 IO, OUTPUT CURRENT (mA) NCP1450ASN19T1 L = 10 mH Q = NTGS3446T1 COUT = 220 mF TA = 25°C VIN = 0.9 V 0.8 Vstart VIN = 1.5 V VIN = 1.2 V 0.6 0.4 NCP1450ASN50T1 L = 22 mH COUT = 0.1 mF IO = 0 mA −25 0 Vhold 0.2 0.0 −50 TEMPERATURE (°C) Figure 41. NCP1450ASN50T1 Startup/Hold Voltage vs. Temperature 200 VRIPPLE, RIPPLE VOLTAGE (mV) VRIPPLE, RIPPLE VOLTAGE (mV) 180 160 140 120 100 80 60 40 20 0 0 200 400 600 800 1000 IO, OUTPUT CURRENT (mA) VIN = 2.0 V VIN = 2.5 V NCP1450ASN30T1 L = 10 mH Q = NTGS3446T1 COUT = 220 mF TA = 25°C VIN = 0.9 V VIN = 1.5 V 200 180 160 140 120 100 80 60 40 20 0 0 Figure 42. NCP1450ASN19T1 Ripple Voltage vs. Output Current VIN = 2.0 V VIN = 0.9 V VIN = 1.2 V VIN = 1.5 V VIN = 2.5 V VIN = 1.2 V NCP1450ASN50T1 L = 10 mH Q = NTGS3446T1 COUT = 220 mF TA = 25°C VIN = 3.0 V VIN = 4.5 V VIN = 4.0 V 200 400 600 800 1000 IO, OUTPUT CURRENT (mA) Figure 43. NCP1450ASN30T1 Ripple Voltage vs. Output Current Figure 44. NCP1450ASN50T1 Ripple Voltage vs. Output Current http://onsemi.com 11 NCP1450A Vstart/Vhold, STARTUP/HOLD VOLTAGE (V) 2.0 Vstart NCP1450ASN19T1 L = 10 mH Q = NTGS3446T1 COUT = 220 mF TA = 25°C Vstart/Vhold, STARTUP/HOLD VOLTAGE (V) 2.0 1.6 1.6 NCP1450ASN19T1 L = 10 mH Q = MMJT9410 COUT = 220 mF TA = 25°C Vstart 1.2 1.2 0.8 Vhold 0.4 0.8 Vhold 0.4 0.0 0 20 40 60 80 100 IO, OUTPUT CURRENT (mA) 0.0 0 20 40 60 80 100 IO, OUTPUT CURRENT (mA) Figure 45. NCP1450ASN19T1 Startup/Hold Voltage vs. Output Current (Using MOSFET) Figure 46. NCP1450ASN19T1 Startup/Hold Voltage vs. Output Current (Using BJT) Vstart/Vhold, STARTUP/HOLD VOLTAGE (V) 2.0 Vstart NCP1450ASN30T1 L = 10 mH Q = NTGS3446T1 COUT = 220 mF TA = 25°C Vhold 0.4 Vstart/Vhold, STARTUP/HOLD VOLTAGE (V) 2.0 Vstart 1.6 1.6 1.2 1.2 Vhold 0.8 NCP1450ASN30T1 L = 10 mH Q = MMJT9410 COUT = 220 mF TA = 25°C 0 20 40 60 80 100 0.8 0.4 0.0 0 20 40 60 80 100 IO, OUTPUT CURRENT (mA) 0.0 IO, OUTPUT CURRENT (mA) Figure 47. NCP1450ASN30T1 Startup/Hold Voltage vs. Output Current (Using MOSFET) Figure 48. NCP1450ASN30T1 Startup/Hold Voltage vs. Output Current (Using BJT) Vstart/Vhold, STARTUP/HOLD VOLTAGE (V) 1.6 Vstart Vstart/Vhold, STARTUP/HOLD VOLTAGE (V) 2.0 2.0 Vstart 1.6 1.2 Vhold 1.2 Vhold 0.8 NCP1450ASN50T1 L = 10 mH Q = MMJT9410 COUT = 220 mF TA = 25°C 0 20 40 60 80 100 0.8 0.4 NCP1450ASN50T1 L = 10 mH Q = NTGS3446T1 COUT = 220 mF TA = 25°C 0 20 40 60 80 100 0.4 0.0 IO, OUTPUT CURRENT (mA) 0.0 IO, OUTPUT CURRENT (mA) Figure 49. NCP1450ASN50T1 Startup/Hold Voltage vs. Output Current (Using MOSFET) Figure 50. NCP1450ASN50T1 Startup/Hold Voltage vs. Output Current (Using BJT) http://onsemi.com 12 NCP1450A 2 ms/div VOUT = 1.9 V, VIN = 1.2 V, IO = 20 mA, L = 10 mH, COUT = 220 mF 1. VL, 1.0 V/div 2. IL, 500 mA/div 3. VOUT, 50 mV/div, AC coupled 2 ms/div VOUT = 1.9 V, VIN = 1.2 V, IO = 500 mA, L = 10 mH, COUT = 220 mF 1. VL, 1.0 V/div 2. IL, 500 mA/div 3. VOUT, 50 mV/div, AC coupled Figure 51. NCP1450ASN19T1 Operating Waveforms (Medium Load) Figure 52. NCP1450ASN19T1 Operating Waveforms (Heavy Load) 2 ms/div VOUT = 3.0 V, VIN = 1.8 V, IO = 20 mA, L = 10 mH, COUT = 220 mF 1. VL, 2.0 V/div 2. IL, 500 mA/div 3. VOUT, 50 mV/div, AC coupled 2 ms/div VOUT = 3.0 V, VIN = 1.8 V, IO = 500 mA, L = 10 mH, COUT = 220 mF 1. VL, 2.0 V/div 2. IL, 500 mA/div 3. VOUT, 50 mV/div, AC coupled Figure 53. NCP1450ASN30T1 Operating Waveforms (Medium Load) Figure 54. NCP1450ASN30T1 Operating Waveforms (Heavy Load) 2 ms/div VOUT = 5.0 V, VIN = 3.0 V, IO = 20 mA, L = 10 mH, COUT = 220 mF 1. VL, 2.0 V/div 2. IL, 500 mA/div 3. VOUT, 50 mV/div, AC coupled 2 ms/div VOUT = 5.0 V, VIN = 3.0 V, IO = 500 mA, L = 10 mH, COUT = 220 mF 1. VL, 2.0 V/div 2. IL, 500 mA/div 3. VOUT, 50 mV/div, AC coupled Figure 55. NCP1450ASN50T1 Operating Waveforms (Medium Load) http://onsemi.com 13 Figure 56. NCP1450ASN50T1 Operating Waveforms (Heavy Load) NCP1450A VIN = 1.5 V, L = 4.7 mH, COUT = 220 mF 1. VOUT, 1.9 V (AC coupled), 200 mV/div 2. IO, 1.0 mA to 100 mA VIN = 1.5 V, L = 4.7 mH, COUT = 220 mF 1. VOUT, 1.9 V (AC coupled), 200 mV/div 2. IO, 100 mA to 1.0 mA Figure 57. NCP1450ASN19T1 Load Transient Response Figure 58. NCP1450ASN19T1 Load Transient Response VIN = 2.0 V, L = 4.7 mH, COUT = 220 mF 1. VOUT, 3.0 V (AC coupled), 200 mV/div 2. IO, 1.0 mA to 100 mA VIN = 2.0 V, L = 4.7 mH, COUT = 220 mF 1. VOUT, 3.0 V (AC coupled), 200 mV/div 2. IO, 100 mA to 1.0 mA Figure 59. NCP1450ASN30T1 Load Transient Response Figure 60. NCP1450ASN30T1 Load Transient Response VIN = 3.0 V, L = 4.7 mH, COUT = 220 mF 1. VOUT, 5.0 V (AC coupled), 200 mV/div 2. IO, 1.0 mA to 100 mA VIN = 3.0 V, L = 4.7 mH, COUT = 220 mF 1. VOUT, 5.0 V (AC coupled), 200 mV/div 2. IO, 100 mA to 1.0 mA Figure 61. NCP1450ASN50T1 Load Transient Response Figure 62. NCP1450ASN50T1 Load Transient Response http://onsemi.com 14 NCP1450A 2.1 VOUT, OUTPUT VOLTAGE (V) VOUT, OUTPUT VOLTAGE (V) 3.2 2.0 VIN = 1.5 V 3.1 VIN = 2.0 V VIN = 2.5 V 1.9 NCP1450ASN19T1 L = 10 mH Q = MMJT9410 Rb = 560 W Cb = 0.003 mF COUT = 220 mF TA = 25°C 600 800 1000 3.0 VIN = 1.5 V 2.9 VIN = 0.9 V 2.8 VIN = 1.2 V NCP1450ASN30T1 L = 10 mH Q = MMJT9410 Rb = 560 W Cb = 0.003 mF COUT = 220 mF TA = 25°C 600 800 1000 1.8 VIN = 0.9 V VIN = 1.2 V 1.7 1.6 0 200 400 IO, OUTPUT CURRENT (mA) 2.7 0 200 400 IO, OUTPUT CURRENT (mA) Figure 63. NCP1450ASN19T1 Output Voltage vs. Output Current (Ext. BJT) Figure 64. NCP1450ASN30T1 Output Voltage vs. Output Current (Ext. BJT) 5.2 VOUT, OUTPUT VOLTAGE (V) VIN = 4.5 V 5.1 VIN = 1.5 V 5.0 VIN = 2.5 V VIN = 4.0 V VIN = 3.0 V EFFICIENCY (%) 100 VIN = 1.5 V VIN = 1.2 V 60 NCP1450ASN19T1 L = 10 mH Q = MMJT9410 Rb = 560 W Cb = 0.003 mF COUT = 220 mF TA = 25°C 10 100 1000 80 4.9 VIN = 2.0 V VIN = 1.2 V 4.8 VIN = 0.9 V 4.7 0 200 400 NCP1450ASN50T1 L = 10 mH Q = MMJT9410 Rb = 560 W Cb = 0.003 mF COUT = 220 mF TA = 25°C 600 800 1000 40 20 VIN = 0.9 V 0 0.01 0.1 1 IO, OUTPUT CURRENT (mA) IO, OUTPUT CURRENT (mA) Figure 65. NCP1450ASN50T1 Output Voltage vs. Output Current (Ext. BJT) 100 VIN = 2.5 V VIN = 2.0 V VIN = 1.5 V VIN = 1.2 V VIN = 0.9 V 100 Figure 66. NCP1450ASN19T1 Efficiency vs. Output Current (Ext. BJT) 80 EFFICIENCY (%) 60 EFFICIENCY (%) VIN = 4.0 V VIN = 3.0 V 80 VIN = 2.5 V VIN = 2.0 V VIN = 0.9 V 60 VIN = 4.5 V VIN = 1.5 V VIN = 1.2 V NCP1450ASN50T1 L = 10 mH Q = MMJT9410 Rb = 560 W Cb = 0.003 mF COUT = 220 mF TA = 25°C 40 20 NCP1450ASN30T1 L = 10 mH Q = MMJT9410 Rb = 560 W Cb = 0.003 mF COUT = 220 mF TA = 25°C 0.1 1 10 100 1000 40 20 0 0.01 0 0.01 0.1 1 10 100 1000 IO, OUTPUT CURRENT (mA) IO, OUTPUT CURRENT (mA) Figure 67. NCP1450ASN30T1 Efficiency vs. Output Current (Ext. BJT) Figure 68. NCP1450ASN50T1 Efficiency vs. Output Current (Ext. BJT) http://onsemi.com 15 NCP1450A IIN, NO LOAD INPUT CURRENT (mA) 10 NCP1450ASNXXT1 L = 10 mH Q = NTGS3446T1 COUT = 220 mF TA = 25°C IIN, NO LOAD INPUT CURRENT (mA) 100 F C 10 E B 1 D 0.1 A. VOUT = 1.9 V, Rb = 1 kW B. VOUT = 3.0 V, Rb = 1 kW C. VOUT = 5.0 V, Rb = 1 kW D. VOUT = 1.9 V, Rb = 560 W E. VOUT = 3.0 V, Rb = 560 W F. VOUT = 5.0 V, Rb = 560 W NCP1450ASNXXT1 L = 10 mH Q = MMJT9410 COUT = 220 mF TA = 25°C 1 VOUT = 5.0 V 0.1 A VOUT = 3.0 V VOUT = 1.9 V 0.01 1 2 3 VIN, INPUT VOLTAGE (V) 4 5 0.01 0 1 2 3 4 5 VIN, INPUT VOLTAGE (V) Figure 69. NCP1450ASNXXT1 No Load Input Current vs. Input Voltage (Using MOSFET) Figure 70. NCP1450ASNXXT1 No Load Input Current vs. Input Voltage (Using BJT) Components Supplier Parts Inductor: L1, L2 Supplier Sumida Electric Co. Ltd. ON Semiconductor ON Semiconductor ON Semiconductor Part Number CD54−100MC MBRM110L Description Inductor 10 mH/1.44 A Phone (852) 2880−6688 (852) 2689−0088 (852) 2689−0088 (852) 2689−0088 (852) 2305−1168 (852) 2305−1168 ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á ÁÁÁÁÁÁ Á Á Á Á Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á Schottky Diode: D1, D2 MOSFET: Q1 BJT: Q2 Schottky Power Rectifier NTGS3446T1 MMJT9410 Power MOSFET N−Channel Bipolar Power Transistor Output Capacitor: C1, C3 Input Capacitor: C2, C4 KEMET Electronics Corp. KEMET Electronics Corp. T494D227K006AS T491C106K016AS Low ESR Tantalum Capacitor 220 mF/6.0 V Low Profile Tantalum Capacitor 10 mF/16 V http://onsemi.com 16 NCP1450A DETAILED OPERATING DESCRIPTION Operation Soft Start The NCP1450A series are monolithic power switching controllers optimized for battery powered portable products where large output current is required. The NCP1450A series are low noise fixed frequency voltage−mode PWM DC−DC controllers, and consist of startup circuit, feedback resistor divider, reference voltage, oscillator, loop compensation network, PWM control circuit, and low ON resistance driver. Due to the on−chip feedback resistor and loop compensation network, the system designer can get the regulated output voltage from 1.8 V to 5.0 V with 0.1 V stepwise with a small number of external components. The quiescent current is typically 93 mA (VOUT = 2.7 V, fOSC = 180 kHz), and can be further reduced to about 1.5 mA when the chip is disabled (VCE t 0.3 V). The NCP1450A operation can be best understood by referring to the block diagram in Figure 2. The error amplifier monitors the output voltage via the feedback resistor divider by comparing the feedback voltage with the reference voltage. When the feedback voltage is lower than the reference voltage, the error amplifier output will decrease. The error amplifier output is then compared with the oscillator ramp voltage at the PWM controller. When the ramp voltage is higher than the error amplifier output, the high−side driver is turned on and the low−side driver is turned off which will then switch on the external transistor; and vice versa. As the error amplifier output decreases, the high−side driver turn−on time increases and duty cycle increases. When the feedback voltage is higher than the reference voltage, the error amplifier output increases and the duty cycle decreases. When the external power switch is on, the current ramps up in the inductor, storing energy in the magnetic field. When the external power switch is off, the energy stored in the magnetic field is transferred to the output filter capacitor and the load. The output filter capacitor stores the charge while the inductor current is higher than the output current, then sustains the output voltage until the next switching cycle. As the load current is decreased, the switch transistor turns on for a shorter duty cycle. Under the light load condition, the controller will skip switching cycles to reduce power consumption, so that high efficiency is maintained at light loads. There is a soft start circuit in NCP1450A. When power is applied to the device, the soft start circuit first pumps up the output voltage to approximately 1.5 V at a fixed duty cycle. This is the voltage level at which the controller can operate normally. In addition to that, the startup capability with heavy loads is also improved. Oscillator The oscillator frequency is internally set to 180 kHz at an accuracy of "20% and with low temperature coefficient of 0.11%/°C. Regulated Converter Voltage (VOUT) The VOUT is set by an integrated feedback resistor network. This is trimmed to a selected voltage from 1.8 V to 5.0 V range in 100 mV steps with an accuracy of "2.5%. Compensation The device is designed to operate in continuous conduction mode. An internal compensation circuit was designed to guarantee stability over the full input/output voltage and full output load range. Enable/Disable Operation The NCP1450A series offer IC shutdown mode by chip enable pin (CE pin) to reduce current consumption. When voltage at pin CE is equal or greater than 0.9 V, the chip will be enabled, which means the controller is in normal operation. When voltage at pin CE is less than 0.3 V, the chip is disabled, which means IC is shutdown. Important: DO NOT apply a voltage between 0.3 V to 0.9 V to pin CE as this is the CE pin’s hysteresis voltage range. Clearly defined output states can only be obtained by applying voltage out of this range. http://onsemi.com 17 NCP1450A APPLICATION CIRCUIT INFORMATION Step−up Converter Design Equations The NCP1450A PWM step−up DC−DC controller is designed to operate in continuous conduction mode and can be defined by the following equations. External components values can be calculated from these equations, however, the optimized value should obtained through experimental results. Calculation D Equation V ) VD * VIN v OUT VOUT ) VD * VS IO (1 * D) Calculate the maximum inductance value which can generate the desired current output and the preferred delta inductor current to average inductor current ratio: Lv (3.3 V ) 0.3 V * 2.4 V)(1 * 0.364)2 + 13.5 mH 180000 Hz 1 A 0.2 Determine the average inductor current and peak inductor current: 1 IL + + 1.57 A 1 * 0.364 IPK + 1.57A (1 ) 0.2) + 1.73A 2 Á Á Á Á Á Á Á Á Á Á Á Á ÁÁÁÁÁ Á Á Á Á Á Á Á Á Á Á Á Á Á ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á Á Á Á Á Á Á Á Á Á ÁÁÁÁÁ Á Á Á Á Á Á Á Á Á Á Á Á Á ÁÁÁÁÁ ÁÁÁÁÁ Á Á Á Á Á Á Á Á Á Á Á Á ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á Á Á Á Á Á Á Á Á Á ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á Á Á Á Á Á Á Á Á Á ÁÁÁÁÁ Á Á Á Á Á Á Á Á Á Á Á Á Á ÁÁÁÁÁ ÁÁÁÁÁ Á Á Á Á Á Á Á Á Á Á Á Á ÁÁÁÁÁ Á IL L (VOUT ) VD * VIN)(1 * D)2 f IO DIR IL (1 ) DIR) 2 IPK DQ ( IL * IO)(1 * D) f VPP DQ [ ) ( IL * IO) ESR COUT NOTES: D − On−time duty cycle IL − Average inductor current IPK − Peak inductor current DIR − Delta inductor current to average inductor current ratio IO − Desired dc output current VIN − Nominal operating dc input voltage VOUT − Desired dc output voltage VD − Diode forward voltage VS − Saturation voltage of the external transistor switch − Charge stores in the COUT during charging up DQ ESR − Equivalent series resistance of the output capacitor Therefore, a 12 mH inductor with saturation current larger than 1.73 A can be selected as the initial trial. Calculate the delta charge stored in the output capacitor during the charging up period in each switching cycle: DQ + (1.57A * 1A)(1 * 0.364) + 2.01 mC 18000Hz Determine the output capacitance value for the desired output ripple voltage: Assume the ESR of the output capacitor is 0.15 W, COUT u 2.01mC 100mV * (1.57A * 1A) 0.15W + 138.6 mF Therefore, a Tantalum capacitor with value of 150 mF to 220 mF and ESR of 0.15 W can be used as the output capacitor. However, according to experimental result, 220 mF output capacitor gives better overall operational stability and smaller ripple voltage. External Component Selection Inductor Selection Design Example It is supposed that a step−up DC−DC controller with 3.3 V output delivering a maximum 1000 mA output current with 100 mV output ripple voltage powering from a 2.4 V input is to be designed. Design parameters: VIN = 2.4 V VOUT = 3.3 V IO = 1.0 A Vpp = 100 mV f = 180 kHZ DIR = 0.2 (typical for small output ripple voltage) Assume the diode forward voltage and the transistor saturation voltage are both 0.3 V. Determine the maximum steady state duty cycle at VIN = 2.4 V: D+ 3.3 V ) 0.3 V * 2.4 V + 0.364 3.3 V ) 0.3 V * 0.3 V The NCP1450A is designed to work well with a 6.8 to 12 mH inductors in most applications 10 mH is a sufficiently low value to allow the use of a small surface mount coil, but large enough to maintain low ripple. Lower inductance values supply higher output current, but also increase the ripple and reduce efficiency. Higher inductor values reduce ripple and improve efficiency, but also limit output current. The inductor should have small DCR, usually less than 1 W, to minimize loss. It is necessary to choose an inductor with a saturation current greater than the peak current which the inductor will encounter in the application. http://onsemi.com 18 NCP1450A Diode The diode is the largest source of loss in DC−DC converters. The most importance parameters which affect their efficiency are the forward voltage drop, VD , and the reverse recovery time, trr. The forward voltage drop creates a loss just by having a voltage across the device while a current flowing through it. The reverse recovery time generates a loss when the diode is reverse biased, and the current appears to actually flow backwards through the diode due to the minority carriers being swept from the P−N junction. A Schottky diode with the following characteristics is recommended: Small forward voltage, VF t 0.3 V Small reverse leakage current Fast reverse recovery time/switching speed Rated current larger than peak inductor current, Irated u IPK Reverse voltage larger than output voltage, Vreverse u VOUT Input Capacitor more efficient switch than a BJT transistor. However, the MOSFET requires a higher voltage to turn on as compared with BJT transistors. An enhancement N−channel MOSFET can be selected by the following guidelines: 1. Low ON−resistance, RDS(on), typically < 0.1 W. 2. Low gate threshold voltage, VGS(th), must be < VOUT, typically < 1.5 V, it is especially important for the low VOUT device, like VOUT = 1.9 V. 3. Rated continuous drain current, ID, should be larger than the peak inductor current, i.e. ID > IPK. 4. Gate capacitance should be 1200 pF or less. For bipolar NPN transistor, medium power transistor with continuous collector current typically 1 A to 5 A and VCE(sat) < 0.2 V should be employed. The driving capability is determined by the DC current gain, HFE, of the transistor and the base resistor, Rb; and the controller’s EXT pin must be able to supply the necessary driving current. Rb can be calculated by the following equation: V 0.7 0.4 Rb + OUT * * | IEXTH| Ib I Ib + PK HFE The input capacitor can stabilize the input voltage and minimize peak current ripple from the source. The value of the capacitor depends on the impedance of the input source used. Small Equivalent Series Resistance (ESR) Tantalum or ceramic capacitor with a value of 10 mF should be suitable. Output Capacitor The output capacitor is used for sustaining the output voltage when the external MOSFET or bipolar transistor is switched on and smoothing the ripple voltage. Low ESR capacitor should be used to reduce output ripple voltage. In general, a 100 mF to 220 mF low ESR (0.10 W to 0.30 W) Tantalum capacitor should be appropriate. External Switch Transistor Since the pulse current flows through the transistor, the exact Rb value should be finely tuned by the experiment. Generally, a small Rb value can increase the output current capability, but the efficiency will decrease due to more energy is used to drive the transistor. Moreover, a speed−up capacitor, Cb, should be connected in parallel with Rb to reduce switching loss and improve efficiency. Cb can be calculated by the equation below: Cb v 2p Rb 1 fOSC 0.7 An enhancement N−channel MOSFET or a bipolar NPN transistor can be used as the external switch transistor. For enhancement N−channel MOSFET, since enhancement MOSFET is a voltage driven device, it is a External Component Reference Data Device NCP1450ASN19T1 NCP1450ASN30T1 NCP1450ASN50T1 NCP1450ASN19T1 NCP1450ASN30T1 NCP1450ASN50T1 VOUT 1.9 V 3.0 V 5.0 V 1.9 V 3.0 V 5.0 V Inductor Model CD54 CD54 CD54 CD54 CD54 CD54 It is due to the variation in the characteristics of the transistor used. The calculated value should be used as the initial test value and the optimized value should be obtained by the experiment. Inductor Value 12 mH 10 mH 10 mH 12 mH 10 mH 10 mH External Transistor NTGS3446T1 NTGS3446T1 NTGS3446T1 MMJT9410 MMJT9410 MMJT9410 Diode MBRM110L MBRM110L MBRM110L MBRM110L MBRM110L MBRM110L Output Capacitor 220 mF 220 mF 220 mF 220 mF 220 mF 220 mF http://onsemi.com 19 NCP1450A An evaluation board of NCP1450A has been made in the small size of 89 mm x 51 mm. The artwork and the silk screen of the surface−mount evaluation board PCB are shown in Figures 71 and 72. Please contact your ON Semiconductor representative for availability. The evaluation board schematic diagrams are shown in Figures 73 and 74. 51 mm 89 mm Figure 71. NCP1450A PWM Step−up DC−DC Controller Evaluation Board Silkscreen 51 mm 89 mm Figure 72. NCP1450A PWM Step−up DC−DC Controller Evaluation Board Artwork (Component Side) http://onsemi.com 20 NCP1450A L1 10 mH TP1 VIN ON CE OFF JP1 NTGS3446T1 C2 10 mF CE 1 OUT 2 C3 NC 0.1 mF 3 EXT 5 IC1 GND 4 TP4 GND Q1 C1 220 mF D1 MBRM110L TP3 VOUT TP2 GND Figure 73. NCP1450A Evaluation Board Schematic Diagram 1 (Step−up DC−DC Converter Using External MOSFET Switch) L2 10 mH TP5 VIN JP2 D2 MBRM110L TP7 VOUT CE 1 OUT 2 C6 0.1 mF NC 3 EXT 5 IC2 GND 4 Cb 3000 pF TP8 GND Rb 560 TP6 GND Figure 74. NCP1450A Evaluation Board Schematic Diagram 2 (Step−up DC−DC Converter Using External Bipolar Transistor Switch) PCB Layout Hints Grounding Output Capacitor One point grounding should be used for the output power return ground, the input power return ground, and the device switch ground to reduce noise. In Figure 73, e.g.: C2 GND, C1 GND, and IC1 GND are connected at one point in the evaluation board. The input ground and output ground traces must be thick enough for current to flow through and for reducing ground bounce. Power Signal Traces NCP1450A C5 10 mF ON CE OFF NCP1450A Q2 MMJT9410 C4 220 mF The output capacitor should be placed close to the output terminals to obtain better smoothing effect on the output ripple. Switching Noise Decoupling Capacitor A 0.1 mF ceramic capacitor should be placed close to the OUT pin and GND pin of the NCP1450A to filter the switching spikes in the output voltage monitored by the OUT pin. Low resistance conducting paths should be used for the power carrying traces to reduce power loss so as to improve efficiency (short and thick traces for connecting the inductor L can also reduce stray inductance), e.g.: short and thick traces listed below are used in the evaluation board: 1. Trace from TP1 to L1 2. Trace from L1 to anode pin of D1 3. Trace from cathode pin of D1 to TP3 http://onsemi.com 21 NCP1450A PACKAGE DIMENSIONS TSOP−5 SN SUFFIX CASE 483−02 ISSUE E NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: MILLIMETER. 3. MAXIMUM LEAD THICKNESS INCLUDES LEAD FINISH THICKNESS. MINIMUM LEAD THICKNESS IS THE MINIMUM THICKNESS OF BASE MATERIAL. 4. A AND B DIMENSIONS DO NOT INCLUDE MOLD FLASH, PROTRUSIONS, OR GATE BURRS. MILLIMETERS MIN MAX 2.90 3.10 1.30 1.70 0.90 1.10 0.25 0.50 0.85 1.05 0.013 0.100 0.10 0.26 0.20 0.60 1.25 1.55 0_ 10 _ 2.50 3.00 INCHES MIN MAX 0.1142 0.1220 0.0512 0.0669 0.0354 0.0433 0.0098 0.0197 0.0335 0.0413 0.0005 0.0040 0.0040 0.0102 0.0079 0.0236 0.0493 0.0610 0_ 10 _ 0.0985 0.1181 D 5 1 2 4 3 S B L G A J C 0.05 (0.002) H K M DIM A B C D G H J K L M S SOLDERING FOOTPRINT* 1.9 0.074 0.95 0.037 2.4 0.094 1.0 0.039 0.7 0.028 SCALE 10:1 mm inches *For additional information on our Pb−Free strategy and soldering details, please download the ON Semiconductor Soldering and Mounting Techniques Reference Manual, SOLDERRM/D. ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice to any products herein. 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SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner. PUBLICATION ORDERING INFORMATION LITERATURE FULFILLMENT: Literature Distribution Center for ON Semiconductor P.O. Box 61312, Phoenix, Arizona 85082−1312 USA Phone: 480−829−7710 or 800−344−3860 Toll Free USA/Canada Fax: 480−829−7709 or 800−344−3867 Toll Free USA/Canada Email: orderlit@onsemi.com N. American Technical Support: 800−282−9855 Toll Free USA/Canada Japan: ON Semiconductor, Japan Customer Focus Center 2−9−1 Kamimeguro, Meguro−ku, Tokyo, Japan 153−0051 Phone: 81−3−5773−3850 ON Semiconductor Website: http://onsemi.com Order Literature: http://www.onsemi.com/litorder For additional information, please contact your local Sales Representative. http://onsemi.com 22 NCP1450A/D