ncp1578 ON Semiconductor, ncp1578 Datasheet
ncp1578
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ncp1578 Summary of contents
Page 1
... V/50 mA linear regulator. A pin is provided to enable or disable forced PWM mode of operation. An internal power good voltage monitor tracks the SMPS output. NCP1578 also features soft-start sequence, UVLO for linear regulator and switcher, overvoltage protection, overcurrent protection, and thermal shutdown. The IC is packaged in QFN20. ...
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... PGth + - VREF - 15% EN_LDO PGOOD PROGRAMMABLE DELAY AGND PG_DLY FOFF FPWM VBAT VCC SOFT START SS CONTROL EN_SW NCP1578 DETAILED BLOCK DIAGRAM THERMAL SHUTDOWN TSD OC FAULT INREGOUT CONTROL LOGIC SMPS PWM CONTROLLER OSC ADAPTIVE RAMP UVLO CONTROL Figure 1. Detailed Block Diagram http://onsemi.com ...
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... NCP1578 TYPICAL APPLICATION CIRCUITS FPWM 1 FPWM EN_LDO OCSET FOFF EN_SW EN_SW Figure 2. Single Supply VBAT Configuration Ext +5V FPWM 1 FPWM EN_LDO OCSET FOFF EN_SW EN_SW Figure 3. External 5 V and VIN Configuration http://onsemi.com VIN ( VOUT VOUT_GND PU PGND PGOOD PGDLY PGOOD SS COMP VIN (4 ...
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... VBST Positive supply of high-side gate driver of the SMPS. Connect boost capacitor between this pin and switching node SWN of the SMPS. 21 THPAD Copper pad on bottom of IC used for heatsinking. This pin should be connected to the ground plane under the IC. NCP1578 Description http://onsemi.com 4 ...
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... This device series contains ESD protection and exceeds the following tests: Human Body Model (HBM) ≤ 2.0 kV per JEDEC standard: JESD22–A114 for all pins. Machine Model (MM) ≤ 200 V per JEDEC standard: JESD22–A115 for all pins. 2. Latch–up Current Maximum Rating: ≤ 150 mA per JEDEC standard: JESD78. NCP1578 Symbol V LDO5 ...
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... TG Gate Driver Pull-Low Resistance BG Gate Driver Pull-High Resistance BG Gate Driver Pull-Low Resistance Soft-start Current PGDLY Delay Current PGDLY Threshold 3. Guaranteed by design, not tested in production. NCP1578 Symbol Test Conditions V Single Supply Configuration, See Figure 2 BAT Ext +5 V and V Configuration, See Figure LDO5 & ...
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... EN_SW Input Current FPWM Threshold High FPWM Threshold Low FPWM Input Current FOFF Threshold High FOFF Threshold Low FOFF Input Current 3. Guaranteed by design, not tested in production. NCP1578 Symbol Test Conditions OVPth With Respect to FB Voltage UVPth With Respect to FB Voltage VPG- With Respect to FB Voltage I_PGOOD = 5 ...
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... T , AMBIENT TEMPERATURE (°C) A Figure 6. V Feed Back Voltage vs. Ambient FB Temperature 44 43.5 43 42.5 42 41.5 41 -40 - AMBIENT TEMPERATURE (°C) A Figure 8. IOC Current vs Ambient Temperature NCP1578 5. 5.04 5.02 5. 4.98 4. -40 - AMBIENT TEMPERATURE (°C) A Figure 5. LDO5 Output Voltage vs. Ambient 320 310 300 ...
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... T , AMBIENT TEMPERATURE (°C) A Figure 12. Overcurrent Threshold vs. Ambient Temperature -14.5 -14.8 -15 -15.3 -15.5 -40 - AMBIENT TEMPERATURE (°C) A Figure 14. P Lower Threshold vs. GOOD Ambient Temperature NCP1578 1.25 1.24 1.23 1.22 1.21 1. -40 - AMBIENT TEMPERATURE (°C) A Figure 11. P GOOD 66 65 -40 - AMBIENT TEMPERATURE (°C) A Figure 13 ...
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... 25° With Power Saving Without Power Saving 50 0 OUTPUT CURRENT (A) o Figure 18. V Efficiency vs. Output Current o (Single Supply) Figure 20. Power Up Sequence NCP1578 3.350 3.325 3.300 3.275 3.250 20 25 0.5 1.5 Figure 17. V 100 ...
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... TYPICAL OPERATING CHARACTERISTICS Figure 22. Switcher Operation - CCM Mode Figure 24. Switcher Operation - Pulse SkippingMode (PSM) Figure 26. Load Transient - Load Step Up NCP1578 Figure 23. Switcher Operation - DCM Mode Figure 25. Switcher Operation - PSM Zoom-In Figure 27. Load Transient - Load Release http://onsemi.com 11 ...
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... TYPICAL OPERATING CHARACTERISTICS Figure 28. V OCP by Short Circuit to Ground out Figure 30. Undervoltage Protection NCP1578 Figure 29. V OCP by Steady I out Figure 31. Overvoltage Protection http://onsemi.com 12 Increases out ...
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... The NCP1578 includes power good voltage monitor, soft-start, over current protection, undervoltage protection, overvoltage protection, LDO5 UVLO and thermal shutdown. The NCP1578 allows for improved efficiency at light loads by allowing the synchronous MOSFET to turn off automatically making this device a ideal for battery operated systems ...
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... High 4. External + connecting to V and LDO5 pin. BAT 5. For this configuration recommended to pull EN_LDO to GND at any time. NCP1578 Cycling EN_SW or LDO5 can reset the undervoltage fault latch and restart the controller. Soft-Start The switcher V the device to prevent surge current from power supply and output voltage overshot during power up ...
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... LDO5 Ready SMPS Soft-Start EN_SW Should Be LDO5 Soft-Start Ready when LDO5 is LDO5 in Regulation High Enough to Maintain Logic Level Figure 33. Single V NCP1578 TIMING DIAGRAMS SMPS In PGOOD Delay PGOOD Goes Low Regulation and Goes High when LDO5 Goes UVLO Threshold Configuration (SMPS Disabled by EN_LDO) ...
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... EN_SW SMPS VOUT PGDLY PGOOD LDO5 > 4 Enable IC EN_SW Goes SMPS In High Regulation Figure 34. External 5 V (Connect to V NCP1578 TIMING DIAGRAMS (Continuous) PGOOD Delay PGOOD Goes Low Whenever and Goes High and LDO5) and V BAT http://onsemi.com 16 V Drop Rate Depends on ...
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... GENERAL APPLICATION INFORMATION of the error amplifier is used to provide pulse-width modulated (PWM) wave. Loop Compensation Since NCP1578 is a voltage mode PWM controller with LC output filter, type III compensation network is recommended to provide the good closed loop bandwidth (eq. 1) and phase boot with stability under any circumstances. The purpose of compensation is to obtain a stable close loop system with the highest possible bandwidth ...
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... The output capacitor's ESR will determine the output ripple voltage and the initial voltage drop after a high slew-rate transient. So, only specialized low-ESR NCP1578 the components of impedance network such that the control loop phase margin should be greater than 45°. Open Loop Error Amp Gain ...
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... For ON-resistance, in consideration of efficiency and power dissipation, it should be the lower the better. In general, for the buck converter, the R MOSFET is usually lower than that of high side MOSFET. NCP1578 It is because the switching on time of lower side MOSFET is longer than that of high side MOSFET especially at the high V ...
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... MOSFET's gates should be as shortest as possible. M1 NTMS7N03R2 Cbst M2 0.1uF Cvccp 1uF NTMS7N03R2 PGND 1 15 PGDLY PGOOD 3 13 NCP1578NMR2 COMP 5 11 Rcmp 2.7k Rfb1 Cfb Cvbat 100 10nF 1uF Cldo Rfb2a Rfb3 1.8k 5.6k 1uF http://onsemi ...
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... Rfb3 19 1 Rldo 20 1 Ren_ldo 21 1 Roc NCP1578 Part Description NCP1578 Buck Controller NTMS7N03R2 MOSFET N-Ch 7A, 30V, 23mW @ 4.5V MBRM120L Schottky Diode 1A, 20V, POWERMITE MBR0530T1 Schottky Diode 0.5A, V =0.375V @ 0.1A, SOD-123 F FDA1055-2R2M 2.2uH, 4.8mW max SP-CAP, 180uF, 6.3V, ESR=10mW SIZE-D Ceramic Capacitor 10uF/25V, 2512 Ceramic Capacitor 1uF/10V, 0805 Ceramic Capacitor 0 ...
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... G 0.50 BSC 0.020 BSC H 1.38 1.43 0.054 0.056 J 0.20 REF 0.008 REF K 0.00 0.05 0.000 0.002 L 0.35 0.45 0.014 0.018 M 2.00 BSC 0.079 BSC N 2.00 BSC 0.079 BSC P 1.38 1.43 0.054 0.056 R 0.60 0.80 0.024 0.031 ON Semiconductor Website: www.onsemi.com Order Literature: http://www.onsemi.com/orderlit For additional information, please contact your local Sales Representative NCP1578/D ...