NCP1402 200 mA, PFM Step−Up Micropower Switching Regulator The NCP1402 series are monolithic micropower step−up DC to DC converter that are specially designed for powering portable equipment from one or two cell battery packs.These devices are designed to startup with a cell voltage of 0.8 V and operate down to less than 0.3 V. With only three external components, this series allow a simple means to implement highly efficient converters that are capable of up to 200 mA of output current at Vin = 2.0 V, VOUT = 3.0 V. Each device consists of an on−chip PFM (Pulse Frequency Modulation) oscillator, PFM controller, PFM comparator, soft−start, voltage reference, feedback resistors, driver, and power MOSFET switch with current limit protection. Additionally, a chip enable feature is provided to power down the converter for extended battery life. The NCP1402 device series are available in the Thin SOT−23−5 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. • • • • • • • • • • Extremely Low Startup Voltage of 0.8 V Operation Down to Less than 0.3 V High Efficiency 85% (Vin = 2.0 V, VOUT = 3.0 V, 70 mA) Low Operating Current of 30 A (VOUT = 1.9 V) Output Voltage Accuracy ± 2.5% Low Converter Ripple with Typical 30 mV Only Three External Components Are Required Chip Enable Power Down Capability for Extended Battery Life Micro Miniature Thin SOT−23−5 Packages Pb−Free Packages are Available 1 SOT23−5 (TSOP−5, SC59−5) SN SUFFIX CASE 483 PIN CONNECTIONS AND MARKING DIAGRAM CE 1 OUT 2 NC 3 5 LX 4 GND (Top View) xxx A Y W G = Marking = Assembly Location = Year = Work Week = Pb−Free Package (Note: Microdot may be in either location) ORDERING INFORMATION See detailed ordering and shipping information in the ordering information section on page 3 of this data sheet. Typical Applications • • • • • • • • 5 xxxAYW G G Features http://onsemi.com Cellular Telephones Pagers Personal Digital Assistants (PDA) Electronic Games Portable Audio (MP3) Camcorders Digital Cameras Handheld Instruments © Semiconductor Components Industries, LLC, 2006 March, 2006 − Rev. 7 1 Publication Order Number: NCP1402/D NCP1402 Vin VOUT CE LX 1 OUT NCP1402 2 NC 5 GND 3 4 Figure 1. Typical Step−Up Converter Application OUT 2 LX 5 VLX LIMITER DRIVER − + NC 3 PFM COMPARATOR POWER SWITCH PFM CONTROLLER VOLTAGE REFERENCE SOFT−START PFM OSCILLATOR GND 4 1 CE Figure 2. Representative Block Diagram PIN FUNCTION DESCRIPTIONS Pin # Symbol 1 CE 2 OUT 3 NC 4 GND 5 LX Pin Description Chip Enable pin (1) The chip is enabled if a voltage which is equal to or greater than 0.9 V is applied (2) The chip is disabled if a voltage which is less than 0.3 V is applied (3) The chip will be enabled if it is left floating Output voltage monitor pin, also the power supply pin of the device No internal connection to this pin Ground pin External inductor connection pin to power switch drain http://onsemi.com 2 NCP1402 ORDERING INFORMATION Device Output Voltage Device Marking Package NCP1402SN19T1 1.9 V DAU SOT23−5 NCP1402SN19T1G 1.9 V DAU SOT23−5 (Pb−Free) NCP1402SN27T1 2.7 V DAE SOT23−5 NCP1402SN27T1G 2.7 V DAE SOT23−5 (Pb−Free) NCP1402SN30T1 3.0 V DAF SOT23−5 NCP1402SN30T1G 3.0 V DAF SOT23−5 (Pb−Free) NCP1402SN33T1 3.3 V DAG SOT23−5 NCP1402SN33T1G 3.3 V DAG SOT23−5 (Pb−Free) NCP1402SN40T1 4.0 V DCR SOT23−5 NCP1402SN40T1G 4.0 V DCR SOT23−5 (Pb−Free) NCP1402SN50T1 5.0 V DAH SOT23−5 NCP1402SN50T1G 5.0 V DAH SOT23−5 (Pb−Free) Shipping † 3000 Units Per Reel †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. NOTE: The ordering information lists five standard output voltage device options. Additional device 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. ABSOLUTE MAXIMUM RATINGS Rating Symbol Value Unit VOUT 6.0 V Input/Output Pins LX (Pin 5) LX Peak Sink Current VLX ILX −0.3 to 6.0 400 V mA CE (Pin 1) Input Voltage Range Input Current Range VCE ICE −0.3 to 6.0 −150 to 150 V mA Thermal Resistance, Junction−to−Air RJA 250 °C/W TA −40 to +85 °C Operating Junction Temperature Range TJ −40 to +125 °C Storage Temperature Range Tstg −55 to +150 °C Power Supply Voltage (Pin 2) Operating Ambient Temperature Range (Note 2) Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. NOTES: 1. 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. 2. The maximum package power dissipation limit must not be exceeded. TJ(max) * TA PD + RJA 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 NCP1402 ELECTRICAL CHARACTERISTICS (For all values TA = 25°C, unless otherwise noted.) Characteristic Symbol Min Typ Max Unit Switch On Time (current limit not asserted) ton 3.6 5.5 7.6 s Switch Minimum Off Time toff 1.0 1.45 1.9 s Maximum Duty Cycle DMAX 70 78 85 % Minimum Startup Voltage (IO = 0 mA) Vstart − 0.8 0.95 V Vstart − −1.6 − mV/°C Vhold 0.3 − − V tSS 0.3 2.0 − ms Internal Switching N−Channel FET Drain Voltage VLX − − 6.0 LX Pin On−State Sink Current (VLX = 0.4 V) Device Suffix: 19T1 27T1 30T1 33T1 40T1 50T1 ILX OSCILLATOR Minimum Startup Voltage Temperature Coefficient (TA = −40°C to 85°C) Minimum Operation Hold Voltage (IO = 0 mA) Soft−Start Time (VOUT u 0.8 V) LX (PIN 5) V mA 110 130 130 130 130 130 145 180 190 200 210 215 − − − − − − VLXLIM 0.45 0.65 0.9 V ILKG − 0.5 1.0 A CE Input Voltage (VOUT = VSET x 0.96) High State, Device Enabled Low State, Device Disabled VCE(high) VCE(low) 0.9 − − − − 0.3 CE Input Current (Note 6) High State, Device Enabled (VOUT = VCE = 6.0 V) Low State, Device Disabled (VOUT = 6.0 V, VCE = 0 V) ICE(high) ICE(low) −0.5 −0.5 0 0.15 0.5 0.5 Voltage Limit Off−State Leakage Current (VLX = 6.0 V, TA = −40°C to 85°C) CE (PIN 1) V A TOTAL DEVICE Output Voltage Device Suffix: 19T1 27T1 30T1 33T1 40T1 50T1 VOUT V 1.853 2.632 2.925 3.218 3.900 4.875 1.9 2.7 3.0 3.3 4.0 5.0 1.948 2.768 3.075 3.383 4.100 5.125 VOUT Output Voltage Temperature Coefficient (TA = −40°C to +85°C) Device Suffix: 19T1 27T1 30T1 33T1 40T1 50T1 ppm/°C − − − − − − 150 150 150 150 150 150 − − − − − − Operating Current 2 (VOUT = VCE = VSET +0.5 V, Note 5) IDD2 − 13 15 A Off−State Current (VOUT = 5.0 V, VCE = 0 V, TA = −40°C to +85°C, Note 6) IOFF − 0.6 1.0 A Operating Current 1 (VOUT = VCE = VSET x 0.96) Device Suffix: 19T1 27T1 30T1 33T1 40T1 50T1 IDD1 A − − − − − − 5. VSET means setting of output voltage. 6. CE pin is integrated with an internal 10 M pullup resistor. http://onsemi.com 4 30 39 42 45 55 70 50 60 60 60 100 100 NCP1402 4.0 NCP1402SN19T1 L = 47 H TA = 25°C 2.0 VOUT, OUTPUT VOLTAGE (V) VOUT, OUTPUT VOLTAGE (V) 2.1 1.9 Vin = 1.5 V Vin = 0.9 V 1.8 Vin = 1.2 V 1.7 1.6 0 20 40 60 80 Vin = 2.5 V 3.0 Vin = 0.9 V 2.5 Vin = 1.2 V 2.0 0 20 40 60 80 100 120 140 160 180 200 IO, OUTPUT CURRENT (mA) Figure 3. NCP1402SN19T1 Output Voltage vs. Output Current Figure 4. NCP1402SN30T1 Output Voltage vs. Output Current 100 Vin = 4.0 V 80 Vin = 1.5 V Vin = 1.2 V 4.0 EFFICIENCY (%) 5.0 Vin = 2.0 V Vin = 3.0 V Vin = 0.9 V 3.0 NCP1402SN50T1 L = 47 H TA = 25°C 2.0 Vin = 1.5 V 60 Vin = 0.9 V Vin = 1.2 V 40 NCP1402SN19T1 L = 47 H TA = 25°C 20 1.0 0 0 20 40 60 80 100 120 140 160 180 200 0 20 40 60 80 100 120 140 160 180 200 IO, OUTPUT CURRENT (mA) IO, OUTPUT CURRENT (mA) Figure 5. NCP1402SN50T1 Output Voltage vs. Output Current Figure 6. NCP1402SN19T1 Efficiency vs. Output Current 100 100 Vin = 4.0 V Vin = 2.5 V 80 80 Vin = 2.0 V EFFICIENCY (%) EFFICIENCY (%) Vin = 2.0 V Vin = 1.5 V IO, OUTPUT CURRENT (mA) 6.0 VOUT, OUTPUT VOLTAGE (V) 3.5 1.5 100 120 140 160 180 200 NCP1402SN30T1 L = 47 H TA = 25°C 60 Vin = 0.9 V Vin = 1.2 V Vin = 1.5 V 40 NCP1402SN30T1 L = 47 H TA = 25°C 20 Vin = 3.0 V Vin = 1.2 V Vin = 2.0 V Vin = 0.9 V 40 NCP1402SN50T1 L = 47 H TA = 25°C 20 0 Vin = 1.5 V 60 0 0 20 40 60 80 100 120 140 160 180 200 0 20 40 60 80 100 120 140 160 180 200 IO, OUTPUT CURRENT (mA) IO, OUTPUT CURRENT (mA) Figure 7. NCP1402SN30T1 Efficiency vs. Output Current Figure 8. NCP1402SN50T1 Efficiency vs. Output Current http://onsemi.com 5 NCP1402 3.2 VOUT, OUTPUT VOLTAGE (V) VOUT, OUTPUT VOLTAGE (V) 2.1 2.0 1.9 1.8 1.7 NCP1402SN19T1 VOUT = 1.9 V x 0.96 Open−Loop Test 1.6 −50 −25 0 25 50 75 3.0 2.9 2.8 NCP1402SN30T1 VOUT = 3.0 V x 0.96 Open−Loop Test 2.7 −50 100 −25 25 50 75 100 TEMPERATURE (°C) Figure 9. NCP1402SN19T1 Output Voltage vs. Temperature Figure 10. NCP1402SN30T1 Output Voltage vs. Temperature 100 5.1 IDD1, OPERATING CURRENT 1 (mA) NCP1402SN50T1 VOUT = 5.0 V x 0.96 Open−Loop Test 5.0 4.9 4.8 4.7 −50 −25 0 25 50 75 80 60 40 20 0 −50 100 NCP1402SN19T1 VOUT = 1.9 V x 0.96 Open−Loop Test −25 TEMPERATURE (°C) 50 75 100 IDD1, OPERATING CURRENT 1 (mA) 100 NCP1402SN30T1 VOUT = 3.0 V x 0.96 Open−Loop Test 60 40 20 0 −50 25 Figure 12. NCP1402SN19T1 Operating Current 1 vs. Temperature 100 80 0 TEMPERATURE (°C) Figure 11. NCP1402SN50T1 Output Voltage vs. Temperature IDD1, OPERATING CURRENT 1 (mA) 0 TEMPERATURE (°C) 5.2 VOUT, OUTPUT VOLTAGE (V) 3.1 −25 0 25 50 75 80 60 40 20 0 −50 100 NCP1402SN50T1 VOUT = 5.0 V x 0.96 Open−Loop Test −25 0 25 50 75 TEMPERATURE (°C) TEMPERATURE (°C) Figure 13. NCP1402SN30T1 Operating Current 1 vs. Temperature Figure 14. NCP1402SN50T1 Operating Current 1 vs. Temperature http://onsemi.com 6 100 NCP1402 7.5 ton, SWITCH ON TIME (s) ton, SWITCH ON TIME (s) 7.5 7.0 6.5 6.0 NCP1402SN19T1 VOUT = 1.9 V x 0.96 Open−Loop Test 5.5 5.0 −50 −25 0 25 50 75 0 25 50 75 Figure 16. NCP1402SN30T1 Switch On Time vs. Temperature toff, MINIMUM SWITCH OFF TIME (s) NCP1402SN50T1 VOUT = 5.0 V x 0.96 Open−Loop Test −25 0 25 50 75 100 1.8 1.7 1.6 1.5 1.4 −50 NCP1402SN19T1 VOUT = 1.9 V x 0.96 Open−Loop Test −25 0 25 50 75 TEMPERATURE (°C) Figure 17. NCP1402SN50T1 Switch On Time vs. Temperature Figure 18. NCP1402SN19T1 Minimum Switch Off Time vs. Temperature 1.8 1.7 1.6 1.5 NCP1402SN30T1 VOUT = 3.0 V x 0.96 Open−Loop Test −25 0 25 50 75 100 100 1.8 1.7 1.6 1.5 NCP1402SN50T1 VOUT = 5.0 V x 0.96 Open−Loop Test 1.4 1.3 −50 −25 0 25 50 75 TEMPERATURE (°C) TEMPERATURE (°C) Figure 19. NCP1402SN30T1 Minimum Switch Off Time vs. Temperature Figure 20. NCP1402SN50T1 Minimum Switch Off Time vs. Temperature http://onsemi.com 7 100 1.9 TEMPERATURE (°C) toff, MINIMUM SWITCH OFF TIME (s) ton, SWITCH ON TIME (s) toff, MINIMUM SWITCH OFF TIME (s) −25 Figure 15. NCP1402SN19T1 Switch On Time vs. Temperature 5.5 1.3 −50 NCP1402SN30T1 VOUT = 3.0 V x 0.96 Open−Loop Test 5.5 TEMPERATURE (°C) 6.0 1.4 6.0 TEMPERATURE (°C) 6.5 4.5 −50 6.5 5.0 −50 100 7.0 5.0 7.0 100 NCP1402 100 DMAX, MAXIMUM DUTY CYCLE (%) DMAX, MAXIMUM DUTY CYCLE (%) 100 90 80 70 60 50 40 −50 NCP1402SN19T1 VOUT = 1.9 V x 0.96 Open−Loop Test −25 0 25 50 75 NCP1402SN30T1 VOUT = 3.0 V x 0.96 Open−Loop Test −25 0 25 50 75 Figure 22. NCP1402SN30T1 Maximum Duty Cycle vs. Temperature ILX, LX PIN ON−STATE CURRENT (mA) 60 NCP1402SN50T1 VOUT = 5.0 V x 0.96 Open−Loop Test −25 0 25 50 75 100 180 160 140 120 100 −50 NCP1402SN19T1 VOUT = 1.9 V x 0.96 VLX = 0.4 V Open−Loop Test −25 0 25 50 75 TEMPERATURE (°C) Figure 23. NCP1402SN50T1 Maximum Duty Cycle vs. Temperature Figure 24. NCP1402SN19T1 LX Pin On−State Current vs. Temperature 250 230 210 190 NCP1402SN30T1 VOUT = 3.0 V x 0.96 VLX = 0.4 V Open−Loop Test −25 0 25 50 75 100 100 300 275 250 225 200 175 −50 NCP1402SN50T1 VOUT = 5.0 V x 0.96 VLX = 0.4 V Open−Loop Test −25 0 25 50 75 TEMPERATURE (°C) TEMPERATURE (°C) Figure 25. NCP1402SN30T1 LX Pin On−State Current vs. Temperature Figure 26. NCP1402SN50T1 LX Pin On−State Current vs. Temperature http://onsemi.com 8 100 200 TEMPERATURE (°C) ILX, LX PIN ON−STATE CURRENT (mA) DMAX, MAXIMUM DUTY CYCLE (%) ILX, LX PIN ON−STATE CURRENT (mA) 50 Figure 21. NCP1402SN19T1 Maximum Duty Cycle vs. Temperature 70 150 −50 60 TEMPERATURE (°C) 80 170 70 TEMPERATURE (°C) 90 40 −50 80 40 −50 100 100 50 90 100 NCP1402 1.0 VLXLIM, VLX VOLTAGE LIMIT (V) VLXLIM, VLX VOLTAGE LIMIT (V) 1.0 0.8 0.6 0.4 0.2 NCP1402SN19T1 Open−Loop Test 0.0 −50 −25 0 25 50 75 0.4 0.2 NCP1402SN30T1 Open−Loop Test −25 0 25 50 75 100 TEMPERATURE (°C) TEMPERATURE (°C) Figure 27. NCP1402SN19T1 VLX Voltage Limit vs. Temperature Figure 28. NCP1402SN30T1 VLX Voltage Limit vs. Temperature RDS(on), SWITCH−ON RESISTANCE () 0.8 0.6 0.4 0.2 NCP1402SN50T1 Open−Loop Test 0.0 −50 −25 0 25 50 75 100 4.0 3.5 3.0 2.5 2.0 1.5 1.0 −50 NCP1402SN19T1 VOUT = 1.9 V x 0.96 VLX = 0.4 V Open−Loop Test −25 0 25 50 75 TEMPERATURE (°C) TEMPERATURE (°C) Figure 29. NCP1402SN50T1 VLX Voltage Limit vs. Temperature Figure 30. NCP1402SN19T1 Switch−on Resistance vs. Temperature 3.0 RDS(on), SWITCH−ON RESISTANCE () VLXLIM, VLX VOLTAGE LIMIT (V) 0.6 0.0 −50 100 1.0 RDS(on), SWITCH−ON RESISTANCE () 0.8 2.5 2.0 1.5 1.0 0.5 0.0 −50 NCP1402SN30T1 VOUT = 3.0 V x 0.96 VLX = 0.4 V Open−Loop Test −25 0 25 50 75 100 3.0 2.5 2.0 1.5 1.0 0.5 0.0 −50 NCP1402SN50T1 VOUT = 5.0 V x 0.96 VLX = 0.4 V Open−Loop Test −25 0 25 50 75 TEMPERATURE (°C) TEMPERATURE (°C) Figure 31. NCP1402SN30T1 Switch−on Resistance vs. Temperature Figure 32. NCP1402SN50T1 Switch−on Resistance vs. Temperature http://onsemi.com 9 100 100 Vstart 0.8 NCP1402SN19T1 L = 22 H COUT = 10 F IO = 0 mA 0.4 0.2 Vhold 0.0 −50 −25 0 25 50 75 100 NCP1402SN50T1 L = 22 H COUT = 10 F IO = 0 mA Vhold 0.2 0 −25 25 50 75 100 0.4 0.2 Vhold 0.0 −50 −25 0 25 50 75 100 2.0 1.5 Vstart 1.0 Vhold NCP1402SN19T1 L = 47 H COUT = 68 F TA = 25°C 0.5 0.0 0 10 20 30 40 50 60 70 80 90 100 TEMPERATURE (°C) IO, OUTPUT CURRENT (mA) Figure 35. NCP1402SN50T1 Startup/Hold Voltage vs. Temperature Figure 36. NCP1402SN19T1 Startup/Hold Voltage vs. Output Current 2.0 1.5 Vstart 1.0 Vhold NCP1402SN30T1 L = 47 H COUT = 68 F TA = 25°C 0.5 0.0 0 NCP1402SN30T1 L = 22 H COUT = 10 F IO = 0 mA 0.6 Figure 34. NCP1402SN30T1 Startup/Hold Voltage vs. Temperature 0.8 0.0 −50 0.8 Figure 33. NCP1402SN19T1 Startup/Hold Voltage vs. Temperature Vstart 0.4 Vstart TEMPERATURE (°C) 1.0 0.6 1.0 TEMPERATURE (°C) Vstart/Vhold, STARTUP/HOLD VOLTAGE (V) 0.6 Vstart/Vhold, STARTUP/HOLD VOLTAGE (V) 1.0 Vstart/Vhold, STARTUP/HOLD VOLTAGE (V) Vstart/Vhold, STARTUP/HOLD VOLTAGE (V) Vstart/Vhold, STARTUP/HOLD VOLTAGE (V) Vstart/Vhold, STARTUP/HOLD VOLTAGE (V) NCP1402 10 20 30 40 50 60 70 80 90 100 2.0 1.5 Vstart 1.0 0.5 NCP1402SN50T1 L = 47 H COUT = 68 F TA = 25°C Vhold 0.0 0 10 20 30 40 50 60 70 80 90 100 IO, OUTPUT CURRENT (mA) IO, OUTPUT CURRENT (mA) Figure 37. NCP1402SN30T1 Startup/Hold Voltage vs. Output Current Figure 38. NCP1402SN50T1 Startup/Hold Voltage vs. Output Current http://onsemi.com 10 NCP1402 5 s/div VOUT = 1.9 V, Vin = 1.2 V, IO = 30 mA, L = 47 H, COUT = 68 F 1. VLX, 1.0 V/div 2. VOUT, 20 mV/div, AC coupled 3. IL, 100 mA/div 5 s/div VOUT = 1.9 V, Vin = 1.2 V, IO = 70 mA, L = 47 H, COUT = 68 F 1. VLX, 1.0 V/div 2. VOUT, 20 mV/div, AC coupled 3. IL, 100 mA/div Figure 39. NCP1402SN19T1 Operating Waveforms (Medium Load) Figure 40. NCP1402SN19T1 Operating Waveforms (Heavy Load) 2 s/div VOUT = 3.0 V, Vin = 1.2 V, IO = 30 mA, L = 47 H, COUT = 68 F 1. VLX, 2.0 V/div 2. VOUT, 20 mV/div, AC coupled 3. IL, 100 mA/div 2 s/div VOUT = 3.0 V, Vin = 1.2 V, IO = 70 mA, L = 47 H, COUT = 68 F 1. VLX, 2.0 V/div 2. VOUT, 20 mV/div, AC coupled 3. IL, 100 mA/div Figure 41. NCP1402SN30T1 Operating Waveforms (Medium Load) Figure 42. NCP1402SN30T1 Operating Waveforms (Heavy Load) 2 s/div 2 s/div VOUT = 5.0 V, Vin = 1.5 V, IO = 30 mA, L = 47 H, COUT = 68 F 1. VLX, 2.0 V/div 2. VOUT, 20 mV/div, AC coupled 3. IL, 100 mA/div VOUT = 5.0 V, Vin = 1.5 V, IO = 60 mA, L = 47 H, COUT = 68 F 1. VLX, 2.0 V/div 2. VOUT, 20 mV/div, AC coupled 3. IL, 100 mA/div Figure 43. NCP1402SN50T1 Operating Waveforms (Medium Load) Figure 44. NCP1402SN50T1 Operating Waveforms (Heavy Load) http://onsemi.com 11 NCP1402 Vin = 1.2 V, L = 47 H, COUT = 68 F 1. VOUT = 1.9 V (AC coupled), 100 mV/div 2. IO = 0.1 mA to 80 mA Vin = 1.2 V, L = 47 H, COUT = 68 F 1. VOUT = 1.9 V (AC coupled), 100 mV/div 2. IO = 80 mA to 0.1 mA Figure 45. NCP1402SN19T1 Load Transient Response Figure 46. NCP1402SN19T1 Load Transient Response Vin = 1.5 V, L = 47 H, COUT = 68 F 1. VOUT = 3.0 V (AC coupled), 100 mV/div 2. IO = 0.1 mA to 80 mA Vin = 1.5 V, L = 47 H, COUT = 68 F 1. VOUT = 3.0 V (AC coupled), 100 mV/div 2. IO = 80 mA to 0.1 mA Figure 47. NCP1402SN30T1 Load Transient Response Figure 48. NCP1402SN30T1 Load Transient Response Vin = 2.4 V, L = 47 H, COUT = 68 F 1. VOUT = 5.0 V (AC coupled), 100 mV/div 2. IO = 0.1 mA to 80 mA Vin = 2.4 V, L = 47 H, COUT = 68 F 1. VOUT = 5.0 V (AC coupled), 100 mV/div 2. IO = 80 mA to 0.1 mA Figure 49. NCP1402SN50T1 Load Transient Response Figure 50. NCP1402SN50T1 Load Transient Response http://onsemi.com 12 NCP1402 100 NCP1402SN19T1 L = 47 H COUT = 68 F TA = 25°C 80 Vripple, RIPPLE VOLTAGE (mV) Vripple, RIPPLE VOLTAGE (mV) 100 60 40 Vin = 1.2 V Vin = 1.5 V 20 NCP1402SN30T1 L = 47 H COUT = 68 F TA = 25°C 80 Vin = 2.0 V 60 Vin = 0.9 V Vin = 1.2 V Vin = 1.5 V 40 Vin = 2.5 V 20 Vin = 0.9 V 0 0 0 20 40 60 80 100 120 140 160 180 200 0 60 80 100 120 140 160 180 200 IO, OUTPUT CURRENT (mA) Figure 51. NCP1402SN19T1 Ripple Voltage vs. Output Current Figure 52. NCP1402SN30T1 Ripple Voltage vs. Output Current 100 IDD1, OPERATING CURRENT 1 (mA) Vripple, RIPPLE VOLTAGE (mV) 40 IO, OUTPUT CURRENT (mA) 100 Vin = 4.0 V 80 Vin = 2.0 V Vin = 1.5 V 60 Vin = 3.0 V Vin = 1.2 V 40 NCP1402SN50T1 L = 47 H COUT = 68 F TA = 25°C 20 Vin = 0.9 V 0 80 85°C 25°C 60 −40°C 40 NCP1402SNXXT1 VOUT = VSET x 0.96 Open−loop Test 20 0 20 40 60 80 100 120 140 160 180 200 2 3 4 5 6 IO, OUTPUT CURRENT (mA) VOUT, OUTPUT VOLTAGE (V) Figure 53. NCP1402SN50T1 Ripple Voltage vs. Output Current Figure 54. NCP1402SNXXT1 Operating Current 1 vs. Output Voltage 300 −40°C 260 220 25°C 85°C 180 NCP1402SNXXT1 VOUT = VSET x 0.96 VLX = 0.4 V Open−loop Test 140 100 1 1 RDS(ON), SWITCH−ON RESISTANCE () 0 ILX, LX PIN ON−STATE CURRENT (mA) 20 2 3 4 6 5 3.5 NCP1402SNXXT1 VOUT = VSET x 0.96 VLX = 0.4 V Open−loop Test 3.0 2.5 85°C 2.0 25°C 1.5 −40°C 1.0 1 2 3 4 5 VOUT, OUTPUT VOLTAGE (V) VOUT, OUTPUT VOLTAGE (V) Figure 55. NCP1402SNXXT1 Pin On−state Current vs. Output Voltage Figure 56. NCP1402SNXXT1 Switch−On Resistance vs. Output Voltage http://onsemi.com 13 6 150 IO(max), MAX. OUTPUT CURRENT (mA) Iin(no load), NO LOAD INPUT CURRENT (A) NCP1402 NCP1402SNXXT1 L = 47 H IO = 0 mA TA = 25°C 5.0 V 125 100 3.3 V 75 3.0 V 50 2.7 V 25 1.9 V 0 0 1 2 3 4 5 6 400 3.3 V 5.0 V 3.0 V 300 2.7 V 200 1.9 V 100 NCP1402SNXXT1 L = 47 H TA = 25°C 0 1 0 2 3 4 Vin, INPUT VOLTAGE (V) Vin, INPUT VOLTAGE (V) Figure 57. NCP1402SNXXT1 No Load Input Current vs. Input Voltage Figure 58. NCP1402SNXXT1 Maximum Output Current vs. Input Voltage 5 DETAILED OPERATING DESCRIPTION Operation Soft−Start The NCP1402 series are monolithic power switching regulators optimized for applications where power drain must be minimized. These devices operate as variable frequency, voltage mode boost regulators and designed to operate in continuous conduction mode. Potential applications include low powered consumer products and battery powered portable products. The NCP1402 series are low noise variable frequency voltage−mode DC−DC converters, and consist of Soft−Start circuit, feedback resistor, reference voltage, oscillator, PFM comparator, PFM control circuit, current limit circuit and power switch. Due to the on−chip feedback resistor network, the system designer can get the regulated output voltage from 1.8 V to 5 V with a small number of external components. The operating current is typically 30 A (VOUT = 1.9 V), and can be further reduced to about 0.6 A when the chip is disabled (VCE < 0.3 V). The NCP1402 operation can be best understood by examining the block diagram in Figure 2. PFM comparator monitors the output voltage via the feedback resistor. When the feedback voltage is higher than the reference voltage, the power switch is turned off. As the feedback voltage is lower than reference voltage and the power switch has been off for at least a period of minimum off−time decided by PFM oscillator, the power switch is then cycled on for a period of on−time also decided by PFM oscillator, or until current limit signal is asserted. When the power switch is on, current ramps up in the inductor, storing energy in the magnetic field. When the power switch is off, the energy in the magnetic field is transferred to output filter capacitor and the load. The output filter capacitor stores the charge while the inductor current is high, then holds up the output voltage until next switching cycle. There is a Soft−Start circuit in NCP1402. When power is applied to the device, the Soft−Start circuit pumps up the output voltage to approximately 1.5 V at a fixed duty cycle, the level at which the converter can operate normally. What is more, the startup capability with heavy loads is also improved. Regulated Converter Voltage (VOUT) The VOUT is set by an internal feedback resistor network. This is trimmed to a selected voltage from 1.8 to 5.0 V range in 100 mV steps with an accuracy of $2.5%. Current Limit The NCP1402 series utilizes cycle−by−cycle current limiting as a means of protecting the output switch MOSFET from overstress and preventing the small value inductor from saturation. Current limiting is implemented by monitoring the output MOSFET current build−up during conduction, and upon sensing an overcurrent conduction immediately turning off the switch for the duration of the oscillator cycle. The voltage across the output MOSFET is monitored and compared against a reference by the VLX limiter. When the threshold is reached, a signal is sent to the PFM controller block to terminate the power switch conduction. The current limit threshold is typically set at 350 mA. Enable / Disable Operation The NCP1402 series offer IC shut−down mode by chip enable pin (CE pin) to reduce current consumption. An internal pullup resistor tied the CE pin to OUT pin by default i.e. user can float the pin CE for permanent “On”. When voltage at pin CE is equal or greater than 0.9 V, the chip will be enabled, which means the regulator 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 and 0.9 V to pin CE as this is the CE pin’s hyteresis voltage range. Clearly defined output states can only be obtained by applying voltage out of this range. http://onsemi.com 14 NCP1402 APPLICATIONS CIRCUIT INFORMATION L1 Vin C1 10 F CE D1 47 H 1 OUT NCP1402 2 NC LX 5 VOUT C2 68 F GND 3 4 Figure 59. Typical Application Circuit Step−up Converter Design Equations enough to maintain low ripple. Low inductance values supply higher output current, but also increase the ripple and reduce efficiency. Note that values below 27 H is not recommended due to NCP1402 switch limitations. Higher inductor values reduce ripple and improve efficiency, but also limit output current. The inductor should have small DCR, usually less than 1 to minimize loss. It is necessary to choose an inductor with saturation current greater than the peak current which the inductor will encounter in the application. NCP1402 step−up DC−DC converter designed to operate in continuous conduction mode can be defined by: Calculation Equation ǒV vM L Vin2 OUT IOmax Ǔ IPK (Vin * Vs)ton ) I min L Imin (ton ) toff)IO (Vin * VS)ton * 2L toff Q *NOTES: IPK − Imin − IO − IOmax − IL − Vin − VOUT − VF − VS − Q − Vripple − ESR − M − The diode is the main source of loss in DC−DC converters. The most importance parameters which affect their efficiency are the forward voltage drop, VF, 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 < 0.3 V Small reverse leakage current Fast reverse recovery time/ switching speed Rated current larger than peak inductor current, Irated > IPK Reverse voltage larger than output voltage, Vreverse > VOUT (Vin * Vs)ton (VOUT ) VF * Vin) toff Vripple Diode (IL * IO)toff [ Q ) (IL * IO)ESR COUT Peak inductor current Minimum inductor current Desired dc output current Desired maximum dc output current Average inductor current Nominal operating dc input voltage Desired dc output voltage Diode forward voltage Saturation voltage of the internal FET switch Charge stores in the COUT during charging up Output ripple voltage Equivalent series resistance of the output capacitor An empirical factor, when VOUT ≥ 3.0 V, M = 8 x 10−6, otherwise M = 5.3 x 10−6. Input Capacitor EXTERNAL COMPONENT SELECTION 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 value of 10 F should be suitable. Inductor The NCP1402 is designed to work well with a 47 H inductor in most applications. 47 H is a sufficiently low value to allow the use of a small surface mount coil, but large http://onsemi.com 15 NCP1402 Output Capacitor An evaluation board of NCP1402 has been made in the size of 23 mm x 20 mm only, as shown in Figures 60 and 61. Please contact your ON Semiconductor representative for availability. The evaluation board schematic diagram, the artwork and the silkscreen of the surface mount PCB are shown below: The output capacitor is used for sustaining the output voltage when the internal MOSFET is switched on and smoothing the ripple voltage. Low ESR capacitor should be used to reduce output ripple voltage. In general, a 47 uF to 68 uF low ESR (0.15 to 0.30 ) Tantalum capacitor should be appropriate. For applications where space is a critical factor, two parallel 22 uF low profile SMD ceramic capacitors can be used. 20 mm 23 mm Figure 60. NCP1402 PFM Step−Up DC−DC Converter Evaluation Board Silkscreen 20 mm 23 mm Figure 61. NCP1402 PFM Step−Up DC−DC Converter Evaluation Board Artwork (Component Side) http://onsemi.com 16 NCP1402 Components Supplier Supplier Part Number Inductor, L1 Parts Sumida Electric Co. Ltd. CD54−470L Schottky Diode, D1 ON Semiconductor Corp. MBR0520LT1 Description Phone Inductor 47 H / 0.72 A (852)−2880−6688 Schottky Power Rectifier (852)−2689−0088 (852)−2305−1168 (852)−2305−1168 Output Capacitor, C2 KEMET Electronics Corp. T494D686K010AS Low ESR Tantalum Capacitor 68 F / 10 V Input Capacitor, C1 KEMET Electronics Corp. T491C106K016AS Low Profile Tantalum Capacitor 10 F / 16 V PCB Layout Hints Grounding 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 Lx pin of U1 3. Trace from L1 to anode pin of D1 4. Trace from cathode pin of D1 to TP2 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 as shown in Figure 62, e.g.: C2 GND, C1 GND, and U1 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. Output Capacitor Power Signal Traces The output capacitor should be placed close to the output terminals to obtain better smoothing effect on the output ripple. Low resistance conducting paths should be used for the power carrying traces to reduce power loss so as to improve L1 TP1 Vin C1 10 F/16 V TP4 GND TP2 47 H + JP1 Enable On Off CE LX 1 OUT NCP1402 2 NC Vout D1 MBR0520LT1 + 5 GND 3 6 Figure 62. NCP1402 Evaluation Board Schematic Diagram http://onsemi.com 17 C2 68 F/10 V TP3 GND NCP1402 PACKAGE DIMENSIONS SOT23−5 (TSOP−5, SC59−5) SN SUFFIX CASE 483−02 ISSUE C 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. D S 5 4 1 2 3 B L G A MILLIMETERS INCHES DIM MIN MAX MIN MAX A 2.90 3.10 0.1142 0.1220 B 1.30 1.70 0.0512 0.0669 C 0.90 1.10 0.0354 0.0433 D 0.25 0.50 0.0098 0.0197 G 0.85 1.05 0.0335 0.0413 H 0.013 0.100 0.0005 0.0040 J 0.10 0.26 0.0040 0.0102 K 0.20 0.60 0.0079 0.0236 L 1.25 1.55 0.0493 0.0610 M 0_ 10 _ 0_ 10 _ S 2.50 3.00 0.0985 0.1181 J C 0.05 (0.002) H M K SOLDERING FOOTPRINT* 0.95 0.037 1.9 0.074 2.4 0.094 1.0 0.039 0.7 0.028 SCALE 10:1 mm Ǔ ǒinches *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. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights nor the rights of others. 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. 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