PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 3-A, WIDE-INPUT ADJUSTABLE SWITCHING REGULATOR FEATURES APPLICATIONS • • • • • • • • • • • 3-A Output Current Wide-Input Voltage (7 V to 36 V) / (15 V to 36 V) Wide-Output Voltage Adjust (2.5 V to 12.6 V) / (11.85 V to 22 V) High Efficiency (Up to 96%) On/Off Inhibit Under-Voltage Lockout Output Current Limit Overtemperature Shutdown Operating Temperature: -40°C to 85°C Surface Mount Package Available • • General-Purpose, Industrial Controls, HVAC Systems Test and Measurement, Medical Instrumentation AC/DC Adaptors, Vehicles, Marine, and Avionics DESCRIPTION The PTN78060 is a series of high-efficiency, step-down integrated switching regulators (ISR), that represent the third generation in the evolution of the popular (PT)78ST200, 78ST300, (PT)78HT200, and 78HT300 series of products. In new designs, the PTN78060 series may also be considered in place of the PT6200, PT6210, and PT6300 series of single in-line pin (SIP) products. In all cases, the PTN78060 has either similar or improved electrical performance characteristics. The caseless, double-sided package has excellent thermal characteristics, and is compatible with TI's roadmap for RoHS and lead-free compliance. Operating from a wide-input voltage range, the PTN78060 provides high-efficiency, step-down voltage conversion for loads of up to 3 A. The output voltage can be set to any value over a wide adjustment range using a single external resistor. The PTN78060W may be set to any value within the range, 2.5 V to 12.6 V, and the PTN78060H from 11.85 V to 22 V. The output voltage of the PTN78060W can be as little as 2 V lower than the input, allowing operation down to 7 V, with an output voltage of 5 V. The output voltage of the PTN78060H can be as little as 3 V lower than the input, allowing operation down to 15 V, with an output voltage of 12 V. The PTN78060 has undervoltage lockout, an integral on/off inhibit, and includes an output current limit and overtemperature protection. It is well suited to a wide variety of general-purpose applications that operate off 12-V, 24-V, or 28-V DC power. STANDARD APPLICATION VI 7 1 PTN78060 (Top View) 2 6 Inhibit 3 CI* Ceramic (Required) GND 4 VO VO Sense 5 RSET# 1%, 0.05 W (Required) CO* 100 mF (Required) L O A D GND *See the Application Information section for capacitor recommendations. The minimum input capacitance is 2.2 mF for PTN78060W, and 14.1 mF (3 x 4.7 mF) for PTN78060H. #RSET is required to adjust the output voltage. See the Application Information section for Values. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2004–2005, Texas Instruments Incorporated PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. ORDERING INFORMATION PTN78060 (Basic Model) Output Voltage 2.5 V - 12.6 V Part Number Description Package Designator PTN78060WAH Horizontal T/H EUW-7 Horizontal SMD EUY-7 Horizontal T/H EUW-7 Horizontal SMD EUY-7 PTN78060WAS (1) (2) PTN78060WAZ (3) (2) PTN78060HAH 11.85 V - 22 V (1) (2) (3) PTN78060HAS (1) (2) PTN78060HAZ (3) (2) Standard option specifies Sn/Pb pin solder ball material. Add a T suffix for tape and reel option on SMD packages. Pb-free option specifies Sn/Ag pin solder ball material. ABSOLUTE MAXIMUM RATINGS (1) over operating free-air temperature range unless otherwise noted all voltages with respect to GND UNIT TA Operating free-air temperature Over VI range Solder reflow temperature Surface temperature of module body or pins Tstg Storage temperature VI Input surge voltage, 10 ms maximum V(Inhibit) Inhibit (pin 3) input voltage PO Output power (1) –40°C to 85°C Horizontal SMD (suffix AS) 235°C Horizontal SMD (suffix AZ) 260°C –40°C to 125°C 38 V –0.3 V to 5 V VO≥ 15 V 45 W Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. RECOMMENDED OPERATING CONDITIONS VI Input voltage TA Operating free-air temperature MIN MAX PTN78060W 7 36 PTN78060H 15 36 –40 85 UNIT V °C PACKAGE SPECIFICATIONS PTN78060x (Suffix AH, AS, and AZ) Weight 3.9 grams Flammability Meets UL 94 V-O Mechanical shock Per Mil-STD-883D, Method 2002.3, 1 ms, 1/2 sine, mounted Mechanical vibration Mil-STD-883D, Method 2007.2, 20-2000 Hz (1) 2 Qualification limit. 500 Gs (1) Horizontal T/H (suffix AH) 20 Gs (1) Horizontal SMD (suffix AS and AZ) 20 Gs (1) PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 ELECTRICAL CHARACTERISTICS operating at 25°C free-air temperature, VI = 20 V, VO = 5 V, IO = IO (max), CI = 2.2 µF, CO = 100 µF (unless otherwise noted) PARAMETER PTN78060W TEST CONDITIONS MIN TYP IO Output current TA = 85°C, natural convection airflow VI Input voltage range Over IO range Set-point voltage tolerance TA = 25°C Temperature variation –40°C to +85°C Line regulation Over VI range ±10 Load regulation Over IO range ±10 Total output voltage variation Includes set point, line, load –40 < TA < 85°C VO VO (adj) MAX 0 7 (1) 36 UNIT 3 A (2) V ±2% (3) ±0.5% mV mV ±3% Output voltage adjust range (3) VI < 12 V 2.5 VI – 2 12 V ≤ VI ≤ 15.1 V 2.5 VI – 2.5 15.1 V < VI ≤ 25 V 2.5 12.6 VI > 25 V 0.1 × VI 12.6 V VI = 24 V, IO = 3 A η Efficiency RSET = 732 Ω, VO = 12 V 94% RSET = 21 kΩ, VO = 5 V 86% RSET = 78.7 kΩ, VO = 3.3 V IO (LIM) Output voltage ripple 20-MHz bandwidth Current limit threshold ∆VO = –50 mV 82% 1% VO V(PP) 5.5 A 1-A/µs load step from 50% to 100% IOmax Transient response Recovery time 100 VO over/undershoot 5 Input high voltage (VIH) Inhibit control (pin 3) Input low voltage (VIL) 1 Input standby current Pin 3 connected to GND FS Switching frequency Over VI and IO ranges CI External input capacitance Ceramic or nonceramic CO External output capacitance MTBF (1) (2) (3) (4) (5) (6) (7) Calculated reliability 0.3 440 2.2 (5) 100 (6) 550 V mA 17 mA 660 kHz µF 200 Nonceramic Per Telcordia SR-332, 50% stress, TA = 40°C, ground benign (4) –0.25 Ceramic Equivalent series resistance (nonceramic) Open –0.1 Input low current (IIL) II(stby) µs %VO µF 2,000 17 (7) 8.9 mΩ 106 Hr For output voltages less than 10 V, the minimum input voltage is 7 V or (VO + 2) V, whichever is greater. For output voltages of 10 V and higher, the minimum input voltage is (VO + 2.5) V. See the Application Information section for further guidance. For output voltages less than 3.6 V, the maximum input voltage is 10 × VO . See the Application Information section for further guidance. The set-point voltage tolerance is affected by the tolerance and stability of RSET. The stated limit is unconditionally met if RSET has a tolerance of 1% with 100 ppm/°C or better temperature stability. This control pin has an internal pullup, and if left open-circuit, the module operates when input power is applied. The open-circuit voltage is typically 1.5 V. A small, low-leakage (< 100 nA) MOSFET is recommended for control. An external pull-up resistor should not be used. See the Application Information for further guidance. An external 2.2-µF ceramic capacitor is required across the input (VI and GND) for proper operation. Locate the capacitor close to the module. 100 µF of output capacitance is required for proper operation. See the Application Information section for further guidance. This is the typical ESR for all the electrolytic (nonceramic) capacitance. Use 17 mΩ as the minimum when using max-ESR values to calculate. 3 PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 ELECTRICAL CHARACTERISTICS operating at 25°C free-air temperature, VI = 24 V, VO = 12 V, IO = IO (max), CI = 3 × 4.7 µF, CO = 100 µF (unless otherwise noted) PARAMETER IO Output current PTN78060H TEST CONDITIONS MIN TA = 85°C, natural convection airflow VO VO (adj) η 3 (1) VO = 15 V 0 3 (1) 2 (1) 0 15 (2) Input voltage range Over IO range Set-point voltage tolerance TA = 25°C 36 Temperature variation –40°C to +85°C Line regulation Over VI range ±10 Load regulation Over IO range ±10 Total output voltage variation Includes set point, line, load –40 < TA < 85°C UNIT A V ±2% (3) ±0.5% Output voltage adjust range VI < 19 V 11.85 VI – 3 11.85 VI – 4 VI≥ 26 V 11.85 95% Current limit threshold ∆VO = –50 mV V 22 VI = 24 V, RSET = 15 kΩ, VO = 15 V IO = 2 A, VI = 32 V, RSET = 95.3 Ω, VO = 22 V, 20-MHz bandwidth mV (3) 19 V ≤ VI ≤ 25 V 93% Output voltage ripple mV ±3% VI = 24 V, RSET = 383 k Ω, VO = 12 V Efficiency IO (LIM) MAX 0 VO = 22 V VI TYP VO = 12 V 96% 1.2% VO V(PP) 5.5 A 1-A/µs load step from 50% to 100% IOmax Transient response Recovery time 100 VO over/undershoot 5 Input high voltage (VIH) Inhibit control (pin 3) Input low voltage (VIL) 1 Input standby current Pin 3 connected to GND FS Switching frequency Over VI and IO ranges CI External input capacitance Ceramic or nonceramic External output capacitance Nonceramic Equivalent series resistance (nonceramic) MTBF (1) (2) (3) (4) (5) (6) (7) 4 Calculated reliability Per Telcordia SR-332, 50% stress, TA = 40°C, ground benign (4) 0.3 –0.25 440 14.1 550 mA 660 (5) kHz µF 0 200 100 (6) 2,000 10 (7) 8.9 V mA 17 Ceramic CO Open –0.1 Input low current (IIL) II(stby) µs %VO µF mΩ 106 Hr The maximum output current is 3 amps or a maximum output power of 45 W, whichever is less. See the Application Information section for further guidance. For output voltages less than 19 V, the minimum input voltage is 15 V or (VO + 3) V, whichever is greater. For output voltages of 19 V and higher, the minimum input voltage is (VO + 4) V. See the Application Information for further guidance. The set-point voltage tolerance is affected by the tolerance and stability of RSET. The stated limit is unconditionally met if RSET has a tolerance of 1% with 100 ppm/°C or better temperature stability. This control pin has an internal pullup, and if left open-circuit, the module operates when input power is applied. The open-circuit voltage is typically 1.5 V. A small, low-leakage (< 100 nA) MOSFET is recommended for control. See the Application Information section for further guidance. Three external 4.7-µF ceramic capacitors are required across the input (VI and GND) for proper operation. Locate the capacitor close to the module. 100 µF of output capacitance is required for proper operation. See the Application Information section for further guidance. This is the typical ESR for all the electrolytic (nonceramic) capacitance. Use 17 mΩ as the minimum when using max-ESR values to calculate. PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 PIN ASSIGNMENT 1 7 PTN78060 (Top View) 2 6 3 4 5 TERMINAL FUNCTIONS TERMINAL NAME NO. GND 1, 7 VI Inhibit 2 3 I/O DESCRIPTION This is the common ground connection for the VI and VO power connections. It is also the 0-VDC reference for the Inhibit and VO Adjust control inputs. I The positive input voltage power node to the module, which is referenced to common GND. I The Inhibit pin is an open-collector/drain active-low input that is referenced to GND. Applying a low-level ground signal to this input disables the module's output and turns off the output voltage. When the Inhibit control is active, the input current drawn by the regulator is significantly reduced. If the Inhibit pin is left open-circuit, the module produces an output whenever a valid input source is applied. VO Adjust 4 I A 1% resistor must be connected between this pin and GND (pin 7) to set the output voltage. If left open-circuit, the output voltage is set to a default value. The temperature stability of the resistor should be 100 ppm/°C (or better). The standard resistor value for a number of common output voltages is provided in the application information. VO Sense 5 I The sense input allows the regulation circuit to compensate for voltage drop between the module and the load. For optimum voltage accuracy, VO Sense should be connected to VO. If the sense feature is not used, this pin may be left disconnected. VO 6 O The regulated positive power output with respect to the GND node. 5 PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 TYPICAL CHARACTERISTICS (7-V INPUT) (1) (2) EFFICIENCY vs OUTPUT CURRENT OUTPUT VOLTAGE RIPPLE vs OUTPUT CURRENT 100 VO = 5 V 80 VO = 3.3 V 70 VO = 2.5 V 60 50 0 0.5 1 1.5 2 2.5 40 VO = 3.3 V 30 VO = 2.5 V VO = 5 V 20 10 0 3 2 PD − Power Dissipation − W V O − Output Voltage Ripple − mV PP 50 90 Efficiency − % POWER DISSIPATION vs OUTPUT CURRENT 1.6 VO = 2.5 V 1.2 VO = 3.3 V 0.8 VO = 5 V 0.4 0 0 0.5 1 1.5 2 2.5 IO − Output Current − A IO − Output Current − A Figure 1. Figure 2. 3 0 0.5 1 1.5 2 2.5 3 IO − Output Current − A Figure 3. TEMPERATURE DERATING vs OUTPUT CURRENT TEMPERATURE DERATING vs OUTPUT CURRENT 90 90 200 LFM 80 70 Ambient Temperature − C Ambient Temperature − C 80 100 LFM 60 Nat conv 50 40 VO = 3.3 V 30 0.5 1 1.5 2 2.5 IO − Output Current − A Figure 4. 6 Nat conv 50 40 VO = 5 V 20 0 (2) 100 LFM 60 30 20 (1) 200 LFM 70 3 0 0.5 1 1.5 2 2.5 IO − Output Current − A 3 Figure 5. The electrical characteristic data has been developed from actual products tested at 25° C. This data is considered typical for the converter. Applies to Figure 1, Figure 2, and Figure 3. The temperature derating curves represent the conditions at which internal components are at or below the manufacturer's maximum operating temperatures. Derating limits apply to modules soldered directly to a 100 mm x 100 mm, double-sided PCB with 2 oz. copper. Applies to Figure 4 and Figure 5. PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 TYPICAL CHARACTERISTICS (15-V INPUT) (1) (2) EFFICIENCY vs OUTPUT CURRENT OUTPUT VOLTAGE RIPPLE vs OUTPUT CURRENT 100 80 VO = 12 V VO = 9 V 70 VO = 5 V VO = 3.3 V 60 VO = 2.5 V VO = 5 V 0 0.5 1 1.5 2 2.5 VO = 12 V 60 VO = 3.3 V 40 20 3 1 VO = 12 V 0.5 0.5 1 1.5 2 2.5 3 0 0.5 1 1.5 2 2.5 Figure 6. Figure 7. Figure 8. TEMPERATURE DERATING vs OUTPUT CURRENT TEMPERATURE DERATING vs OUTPUT CURRENT TEMPERATURE DERATING vs OUTPUT CURRENT 90 200 LFM 80 70 100 LFM 60 Nat conv 50 40 VO = 3.3 V 80 70 100 LFM 60 Nat conv 50 40 VO = 5 V 30 20 1 1.5 2 2.5 IO − Output Current − A Figure 9. 3 200 LFM 70 100 LFM Nat conv 60 50 40 VO = 12 V 30 20 0.5 3 IO − Output Current − A 90 Ambient Temperature − C Ambient Temperature − C VO = 9 V IO − Output Current − A 80 (2) 1.5 0 0 200 LFM 0 VO = 3.3 V IO − Output Current − A 90 30 2 VO = 2.5 V 0 50 VO = 9 V 80 Ambient Temperature − C Efficiency − % 90 2.5 PD − Power Dissipation − W V O − Output Voltage Ripple − mV PP 100 (1) POWER DISSIPATION vs OUTPUT CURRENT 20 0 0.5 1 1.5 2 2.5 IO − Output Current − A Figure 10. 3 0 0.5 1 1.5 2 2.5 IO − Output Current − A 3 Figure 11. The electrical characteristic data has been developed from actual products tested at 25° C. This data is considered typical for the converter. Applies to Figure 6, Figure 7, and Figure 8. The temperature derating curves represent the conditions at which internal components are at or below the manufacturer's maximum operating temperatures. Derating limits apply to modules soldered directly to a 100 mm x 100 mm, double-sided PCB with 2 oz. copper. Applies to Figure 9 through Figure 11. 7 PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 TYPICAL CHARACTERISTICS (24-V INPUT) (1) (2) EFFICIENCY vs OUTPUT CURRENT VO = 5 V VO = 3.3 V 60 VO = 2.5 V 50 40 0 0.5 1 1.5 2 2.5 2.5 160 140 VO = 12 V 120 100 80 VO = 3.3 V 60 VO = 5 V VO = 2.5 V 40 VO = 15 V VO = 12 V 2 VO = 5 V 1.5 VO = 3.3 V 1 VO = 2.5 V 0.5 20 0 3 0 0.5 1 IO - Output Current - A 1.5 2 2.5 0 3 0 1 1.5 2 2.5 Figure 13. Figure 14. TEMPERATURE DERATING vs OUTPUT CURRENT TEMPERATURE DERATING vs OUTPUT CURRENT TEMPERATURE DERATING vs OUTPUT CURRENT 90 Ambient Temperature - °C Air Flow 70 100 LFM 60 Nat conv 50 40 VO = 3.3 V 30 90 200 LFM 200 LFM 80 70 100 LFM 60 Air Flow 50 Nat conv 40 30 80 200 LFM 70 100 LFM 60 Air Flow 40 30 VO = 12 V 20 20 3 Nat conv 50 VO = 5 V 0.5 1 1.5 2 2.5 IO - Output Current - A 3 IO - Output Current - A Figure 12. 80 20 0 0.5 IO - Output Current - A 90 Ambient Temperature - °C PD - Power Dissipation - W 80 3 VO = 15 V 180 Ambient Temperature - °C Efficiency - % 90 70 POWER DISSIPATION vs OUTPUT CURRENT 200 VO = 15 V VO = 12 V VO - Output Voltage Ripple - mVPP 100 OUTPUT VOLTAGE RIPPLE vs OUTPUT CURRENT 0 0.5 1 1.5 2 2.5 IO - Output Current - A Figure 15. 3 Figure 16. 0 0.5 1 1.5 2 2.5 IO - Output Current - A 3 Figure 17. TEMPERATURE DERATING vs OUTPUT CURRENT Ambient Temperature - °C 90 80 200 LFM 70 Air Flow 100 LFM 60 Nat conv 50 40 30 VO = 15 V 20 0 0.5 1 1.5 2 2.5 IO - Output Current - A 3 Figure 18. (1) (2) 8 The electrical characteristic data has been developed from actual products tested at 25° C. This data is considered typical for the converter. Applies to Figure 12, Figure 13, and Figure 14. The temperature derating curves represent the conditions at which internal components are at or below the manufacturer's maximum operating temperatures. Derating limits apply to modules soldered directly to a 100 mm x 100 mm, double-sided PCB with 2 oz. copper. Applies to Figure 15 through Figure 18. PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 TYPICAL CHARACTERISTICS (32-V INPUT) (1) (2) EFFICIENCY vs OUTPUT CURRENT OUTPUT VOLTAGE RIPPLE vs OUTPUT CURRENT 300 VO = 22 V 90 Efficiency - % 80 VO = 15 V 70 VO = 12 V 60 VO = 5 V 50 VO = 3.3 V 0 0.5 1 1.5 2 2.5 3 VO = 22 V 250 VO = 15 V 200 150 VO = 12 V 100 VO = 5 V 50 VO = 3.3 V 0.5 1 1.5 2 VO = 5 V 1 VO = 3.3 V 0.5 0 3 0.5 1 1.5 2 2.5 3 IO - Output Current - A Figure 19. Figure 20. Figure 21. TEMPERATURE DERATING vs OUTPUT CURRENT TEMPERATURE DERATING vs OUTPUT CURRENT TEMPERATURE DERATING vs OUTPUT CURRENT 90 90 200 LFM 200 LFM Air Flow 200 LFM Air Flow 100 LFM 70 60 100 LFM 50 Nat conv 40 VO = 3.3 V 30 20 200 LFM 80 Air Flow 200 LFM Air Flow 100 LFM Ambient Temperature - °C 80 Ambient Temperature - °C Ambient Temperature - °C 2.5 VO = 12 V 1.5 IO - Output Current - A 90 70 60 100 LFM 50 Nat conv 40 VO = 5 V 30 20 0 0.5 1 1.5 2 2.5 3 80 Air Flow 200 LFM Air Flow 100 LFM 70 60 100 LFM 50 Nat conv 40 VO = 12 V 30 20 0 0.5 1 1.5 2 2.5 3 0 0.5 1 1.5 2 2.5 IO - Output Current - A IO - Output Current - A IO - Output Current - A Figure 22. Figure 23. Figure 24. TEMPERATURE DERATING vs OUTPUT CURRENT 90 80 Ambient Temperature - °C Ambient Temperature - °C 3 TEMPERATURE DERATING vs OUTPUT CURRENT 90 Air 200 Flow LFM 200 LFM 70 100 LFM Air Flow 60 Nat conv 100 LFM 50 Nat conv 40 VO = 15 V 30 20 80 Air Flow 0.5 1 1.5 2 2.5 IO - Output Current - A Figure 25. 3 200 LFM 70 100 LFM 60 Nat conv 50 40 VO = 22 V 30 20 0 (2) VO = 15 V 2 0 0 VO = 22 V 2.5 0 3 IO - Output Current - A (1) PD - Power Dissipation - W VO - Output Voltage Ripple - mVPP 100 40 POWER DISSIPATION vs OUTPUT CURRENT 0 0.5 1 1.5 2 IO - Output Current - A Figure 26. The electrical characteristic data has been developed from actual products tested at 25° C. This data is considered typical for the converter. Applies to Figure 19, Figure 20, and Figure 21. The temperature derating curves represent the conditions at which internal components are at or below the manufacturer's maximum operating temperatures. Derating limits apply to modules soldered directly to a 100 mm x 100 mm, double-sided PCB with 2 oz. copper. Applies to Figure 22 through Figure 26. 9 PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 APPLICATION INFORMATION Adjusting the Output Voltage of the PTN78060 Wide-Output Adjust Power Modules General A resistor must be connected between the VO Adjust control (pin 4) and GND (pin 1) to set the output voltage. The adjustment range is from 2.5 V to 12.6 V for PTN78060W. The adjustment range is from 11.85 V to 22 V for PTN78060H. If pin 4 is left open, the output voltage defaults to the lowest value. Table 2 gives the standard resistor value for a number of common voltages, and with the actual output voltage that the value produces. For other output voltages, the resistor value can either be calculated using Equation 1 and the constants for the applicable product in Table 1. Alternatilvey, RSET can be simply selected from the range of values given in Table 3 and Table 4. Figure 27 shows the placement of the required resistor. RSET = 54.9 kW ´ 1.25 V VO - Vmin - RP (1) Table 1. RSET Formula Constants PRODUCT VMIN RP PTN780x0W 2.5 V 6.49 kΩ PTN780x0H 11.824 V 6.65 kΩ Input Voltage Considerations The PTN78060 is a step-down switching regulator. In order that the output remains in regulation, the input voltage must exceed the output by a minimum differential voltage. Another consideration is the pulse width modulation (PWM) range of the regulator's internal control circuit. For stable operation, its operating duty cycle should not be lower than some minimum percentage. This defines the maximum advisable ratio between the regulator input and output voltage magnitudes. For satisfactory performance, the operating input voltage range of the PTN78060x must adhere to the following requirements. 1. For PTN78060W output voltages lower than 10 V, the minimum input voltage is (VO+ 2 V ) or 7 V, whichever is higher. 2. For PTN78060W output voltages equal to 10 V and higher, the minimum input voltage is (VO+ 2.5 V ). 3. The maximum input voltage for PTN78060W is (10 × VO ) or 36 V, whichever is less. 4. For PTN78060H output voltages lower than 19 V, the minimum input voltage is (VO + 3 V) or 15 V, whichever is higher. 5. For PTN78060H output voltages equal to 19 V and higher, the minimum input voltage is (VO+ 4 V ) . As an example, Table 2 gives the operating input voltage range for the common output bus voltages. In addition, the Electrical Characteristics table defines the available output voltage adjust range for various input voltages. Table 2. Standard Values of Rset for Common Output Voltages PRODUCT PTN780x0W PTN780x0H 10 VO (Required) RSET (Standard Value) VO (Actual) Operating VI Range 2.5 V Open 2.5 V 7 V to 25 V 3.3 V 78.7 kΩ 3.306 V 7 V to 33 V 5V 21 kΩ 4.996 V 7 V to 36 V 12 V 732 Ω 12.002 V 14.5 V to 36 V 12 V 383 kΩ 12.000 V 15 V to 36 V 15 V 15 kΩ 14.994 V 18 V to 36 V 18 V 4.42 kΩ 18.023 V 21 V to 36 V 22 V 95.3 21.998 V 26 V to 36 V PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 5 Sense VI 2 VI PTN78060W VO 6 VO Inhibit GND GND Adjust 3 4 1 7 CI 2.2 mF Ceramic + C O 100 mF RSET 0.05 W 1% Inhibit GND GND (1) A 0.05-W rated resistor may be used. The tolerance should be 1%, with a temperature stability of 100 ppm/°C (or better). Place the resistor as close to the regulator as possible. Connect the resistor directly between pins 4 and 7 using dedicated PCB traces. (2) Never connect capacitors from VO Adjust to either GND or VO. Any capacitance added to the VO Adjust pin affects the stability of the regulator. Figure 27. PTN78060W VO Adjust Resistor Placement Table 3. PTN78060W Output Voltage Set-Point Resistor Values VO RSET VO RSET VO RSET VO RSET 2.50 V Open 3.7 V 50.7 kΩ 6.1 V 12.6 kΩ 9.0 V 4.07 kΩ 2.55 V 1.37 MΩ 3.8 V 46.3 kΩ 6.2 V 12.1 kΩ 9.2 V 3.75 kΩ 2.60 V 680 kΩ 3.9 V 42.5 kΩ 6.3 V 11.6 kΩ 9.4 V 3.46 kΩ 2.65 V 451 kΩ 4.0 V 39.3 kΩ 6.4 V 11.1 kΩ 9.6 V 3.18 kΩ 2.70 V 337 kΩ 4.1 V 36.4 kΩ 6.5 V 10.7 kΩ 9.8 V 2.91 kΩ 2.75 V 268 kΩ 4.2 V 33.9 kΩ 6.6 V 10.2 kΩ 10.0 V 2.66 kΩ 2.80 V 222 kΩ 4.3 V 31.6 kΩ 6.7 V 9.85 kΩ 10.2 V 2.42 kΩ 2.85 V 190 kΩ 4.4 V 29.6 kΩ 6.8 V 9.47 kΩ 10.4 V 2.20 kΩ 2.90 V 165 kΩ 4.5 V 27.8 kΩ 6.9 V 9.11 kΩ 10.6 V 1.98 kΩ 2.95 V 146 kΩ 4.6 V 26.2 kΩ 7.0 V 8.76 kΩ 10.8 V 1.78 kΩ 3.00 V 131 kΩ 4.7 V 24.7 kΩ 7.1 V 8.43 kΩ 11.0 V 1.58 kΩ 3.05 V 118 kΩ 4.8 V 23.3 kΩ 7.2 V 8.11 kΩ 11.2 V 1.40 kΩ 3.10 V 108 kΩ 4.9 V 22.1 kΩ 7.3 V 7.81 kΩ 11.4 V 1.22 kΩ 3.15 V 99.1 kΩ 5.0 V 21.0 kΩ 7.4 V 7.52 kΩ 11.6 V 1.05 kΩ 3.20 V 91.5 kΩ 5.1 V 19.9 kΩ 7.5 V 7.24 kΩ 11.8 V 889 Ω 3.25 V 85.0 kΩ 5.2 V 18.9 kΩ 7.6 V 6.97 kΩ 12.0 V 734 Ω 3.30 V 79.3 kΩ 5.3 V 18.0 kΩ 7.7 V 6.71 kΩ 12.2 V 585 Ω 3.35 V 74.2 kΩ 5.4 V 17.2 kΩ 7.8 V 6.46 kΩ 12.4 V 442 Ω 3.40 V 69.8 kΩ 5.5 V 16.4 kΩ 7.9 V 6.22 kΩ 12.6 V 305 Ω 3.45 V 65.7 kΩ 5.6 V 15.6 kΩ 8.0 V 5.99 kΩ 3.50 V 62.1 kΩ 5.7 V 15.0 kΩ 8.2 V 5.55 kΩ 3.55 V 58.9 kΩ 5.8 V 14.3 kΩ 8.4 V 5.14 kΩ 3.60 V 55.9 kΩ 5.9 V 13.7 kΩ 8.6 V 4.76 kΩ 3.65 V 53.2 kΩ 6.0 V 13.1 kΩ 8.8 V 4.40 kΩ 11 PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 5 Sense VI 2 VI PTN78060H VO VO 6 Inhibit GND GND Adjust 3 4 1 7 C1 4.7 mF Ceramic C3 4.7 mF Ceramic C2 4.7 mF Ceramic RSET 0.05 W 1% + C4 100 mF GND GND (1) A 0.05-W rated resistor may be used. The tolerance should be 1%, with a temperature stability of 100 ppm/° C (or better). Place the resistor as close to the regulator as possible. Connect the resistor directly between pins 4 and 7 using dedicated PCB traces. (2) Never connect capacitors from VO Adjust to either GND or VO. Any capacitance added to the VO Adjust pin affects the stability of the regulator. Figure 28. PTN78060H VO Adjust Resistor Placement Table 4. PTN78060H Output Voltage Set-Point Resistor Values 12 VO RSET VO RSET VO RSET 11.85 V 2633 kΩ 13.50 V 34.3 kΩ 17.20 V 6.12 kΩ 11.90 V 896 kΩ 13.65 V 30.9 kΩ 17.40 V 5.66 kΩ 11.95 V 538 kΩ 13.80 V 28.1 kΩ 17.60 V 5.23 kΩ 12.00 V 451 kΩ 13.95 V 25.6 kΩ 17.80 V 4.83 kΩ 12.10 V 242 kΩ 14.10 V 23.5 kΩ 18.00 V 4.46 kΩ 12.15 V 204 kΩ 14.25 V 21.6 kΩ 18.20 V 4.11 kΩ 12.20 V 176 kΩ 14.40 V 19.9 kΩ 18.40 V 3.79 kΩ 12.25 V 154 kΩ 14.55 V 18.5 kΩ 18.60 V 3.48 kΩ 12.30 V 138 kΩ 14.70 V 17.2 kΩ 18.80 V 3.19 kΩ 12.35 V 124 kΩ 14.85 V 16.0 kΩ 19.00 V 2.91 kΩ 12.40 V 113 kΩ 15.00 V 14.9 kΩ 19.20 V 2.65 kΩ 12.45 V 103 kΩ 15.15 V 13.9 kΩ 19.40 V 2.41 kΩ 12.50 V 94.9 kΩ 15.30 V 13.1 kΩ 19.60 V 2.18 kΩ 12.55 V 87.9 kΩ 15.45 V 12.3 kΩ 19.80 V 1.95 kΩ 12.60 V 81.8 kΩ 15.60 V 11.5 kΩ 20.00 V 1.74 kΩ 12.65 V 76.4 kΩ 15.75 V 10.8 kΩ 20.20 V 1.54 kΩ 12.70 V 71.7 kΩ 15.90 V 10.2 kΩ 20.40 V 1.35 kΩ 12.75 V 67.5 kΩ 16.05 V 9.59 kΩ 20.60 V 1.17 kΩ 12.80 V 63.7 kΩ 16.20 V 9.03 kΩ 20.80 V 995 Ω 12.85 V 60.2 kΩ 16.35 V 8.51 kΩ 21.00 V 829 kΩ 12.90 V 57.1 kΩ 16.50 V 8.03 kΩ 21.20 V 669 Ω 12.95 V 54.3 kΩ 16.65 V 7.57 kΩ 21.40 V 516 Ω 13.00 V 51.7 kΩ 16.80 V 7.14 kΩ 21.80 V 229 Ω 13.05 V 49.3 kΩ 17.10 V 6.36 kΩ 22.00 V 94 Ω PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 CAPACITOR RECOMMENDATIONS for the PTN78060 WIDE-OUTPUT ADJUST POWER MODULES PTN78060W Input Capacitor PTN78060W has a minimum requirement for input capacitance of 2.2 µF of ceramic capacitance. The dielectric may have either an X5R or X7R temperature characteristic. Ceramic capacitors should be located within 0.5 inch (1,27 cm) of the regulator's input pins. Electrolytic capacitors can be used at the input, but only in addition to the required ceramic capacitance. The minimum ripple current rating for any nonceramic capacitance must be at least 500 mA rms for VO ≤ 5.5 V. For VO > 5.5 V, the minimum ripple current rating is 750 mA rms. The ripple current rating of electrolytic capacitors is a major consideration when they are used at the input. This ripple current requirement can be reduced by placing more ceramic capacitors at the input, in addition to the minimum required 2.2 µF. Tantalum capacitors are not recommended for use at the input bus, as none were found to meet the minimum voltage rating of 2 × (maximum dc voltage + ac ripple). The 2× rating is standard practice for regular tantalum capacitors to ensure reliability. Polymer-tantalum capacitors are more reliable, and are available with a maximum rating of typically 20 V. These can be used with input voltages up to 16 V. PTN78060H Input Capacitor PTN78060H has a minimum requirement for input capacitance of 14.1 µF (3 × 4.7 µF) of ceramic capacitance. The dielectric may have either an X5R or X7R temperature characteristic. Ceramic capacitors should be located within 0.5 inch (1,27 cm) of the regulator's inpt pins. Electrolytic capacitors can be used at the input, but only in addition to the required ceramic capacitance. The minimum ripple current rating for any nonceramic capacitance must be at least 400 mA rms. The ripple current rating of electrolytic capacitors is a major consideration when they are used at the input. This ripple current requirement can be reduced by placing more ceramic capacitors at the input, in addition to the minimum required 14.1 µF. Tantalum capacitors are not recommended for use at the input bus, as none were found to meet the minimum voltage rating of 2 × (maximum dc voltage + ac ripple). The 2× rating is standard practice for regular tantalum capacitors to ensure reliability. Polymer-tantalum capacitors are more reliable, and are available with a maximum rating of typically 20 V. These can be used with input voltages up to 16 V. Output Capacitor The minimum capacitance required to ensure stability is a 100-µF capacitor. Either ceramic or electrolytic-type capacitors can be used. The minimum ripple current rating for the nonceramic capacitance must be at least 150 mA rms. The stability of the module and voltage tolerances are compromised if the capacitor is not placed near the output bus pins. A high-quality, computer-grade electrolytic capacitor should be adequate. A ceramic capacitor can be also be located within 0.5 inch (1,27 cm) of the output pin. For applications with load transients (sudden changes in load current), the regulator response improves with additional capacitance. Additional electrolytic capacitors should be located close to the load circuit. These capacitors provide decoupling over the frequency range, 2 kHz to 150 kHz. Aluminum electrolytic capacitors are suitable for ambient temperatures above 0° C. For operation below 0° C, tantalum or Os-Con type capacitors are recommended. When using one or more nonceramic capacitors, the calculated equivalent ESR should be no lower than 10 mΩ (17 mΩ using the manufacturer's maximum ESR for a single capacitor). A list of capacitors and vendors are identified in Table 5 and Table 6, the recommended capacitor tables. Ceramic Capacitors Above 150 kHz, the performance of aluminum electrolytic capacitors becomes less effective. To further reduce the reflected input ripple current, or improve the output transient response, multilayer ceramic capacitors must be added. Ceramic capacitors have low ESR, and their resonant frequency is higher than the bandwidth of the regulator. When placed at the output, their combined ESR is not critical as long as the total value of ceramic capacitance does not exceed 200 µF. 13 PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 Tantalum Capacitors Tantalum-type capacitors may be used at the output, and are recommended for applications where the ambient operating temperature can be less than 0°C. The AVX TPS, Sprague 593D/594/595, and Kemet T495/T510/T520 capacitors series are suggested over many other tantalum types due to their rated surge, power dissipation, and ripple current capability. As a caution, many general-purpose tantalum capacitors have considerably higher ESR, reduced power dissipation, and lower ripple current capability. These capacitors are also less reliable as they have lower power dissipation and surge current ratings. Tantalum capacitors that do not have a stated ESR or surge current rating are not recommended for power applications. When specifying Os-Con and polymer tantalum capacitors for the output, the minimum ESR limit is encountered well before the maximum capacitance value is reached. Capacitor Table The capacitor tables, Table 5 and Table 6, identify the characteristics of capacitors from a number of vendors with acceptable ESR and ripple current (rms) ratings. The recommended number of capacitors required at both the input and output buses is identified for each capacitor type. This is not an extensive capacitor list. Capacitors from other vendors are available with comparable specifications. Those listed are for guidance. The rms rating and ESR (at 100 kHz) are critical parameters necessary to ensure both optimum regulator performance and long capacitor life. Designing for Load Transients The transient response of the dc/dc converter has been characterized using a load transient with a di/dt of 1 A/µs. The typical voltage deviation for this load transient is given in the data sheet specification table using the required value of output capacitance. As the di/dt of a transient is increased, the response of a converter's regulation circuit ultimately depends on its output capacitor decoupling network. This is an inherent limitation of any dc/dc converter once the speed of the transient exceeds its bandwidth capability. If the target application specifies a higher di/dt or lower voltage deviation, the requirement can only be met with additional output capacitor decoupling. In these cases, special attention must be paid to the type, value, and ESR of the capacitors selected. If the transient performance requirements exceed those specified in the data sheet, the selection of output capacitors becomes more important. Review the minimum ESR in the characteristic data sheet for details on the capacitance maximum. Table 5. Recommended Input/Output Capacitors (PTN78060W) CAPACITOR CHARACTERISTICS QUANTITY WORKING VOLTAGE (V) VALUE (µF) EQUIVALENT SERIES RESISTANCE (ESR) (Ω) 85° C MAXIMUM RIPPLE CURRENT (IRMS) (mA) Panasonic FC( Radial) 50 180 0.119 850 10 × 16 FK (SMD) 50 330 0.12 900 12.50 × 13.5 United Chemi-Con PXA (SMD) 16 180 0.016 4360 8 × 12 LXZ 50 120 0.16 620 10 × 12,5 1 (1) MVY(SMD) 50 100 0.300 500 10 × 10 1 Nichicon UWG (SMD) 50 100 0.300 500 10 × 10 1 F550 (Tantalum) 10 100 0.055 2000 7,7 × 4,3 N/R HD 50 120 0.072 979 10 × 12,5 1 Sanyo Os-Con SVP (SMD) 20 100 0.024 2500 8 × 12 2890 10 × 5 CAPACITOR VENDOR/ COMPONENT SERIES SP (1) (2) (3) 14 16 100 0.032 PHYSICAL SIZE (mm) INPUT OUTPUT BUS BUS 1 1 1 VENDOR NUMBER 1 EEUFC1H181 (1) 1 EEVFK1H331Q (1) ≤1 PXA16VC180MF60 (VO < 14 V) 1 LXZ50VB121M10X12LL (VI < 32 V) 1 MVY50VC101M10X10TP (VO ≤ 5.5 V) 1 UWG1H101MNR1GS (2) ≤ 3 (3) 1 F551A107MN (VO ≤ 5 V) UHD1H151MHR 1 (1) ≤2 20SVP100M (VI ≤ 16 V) 1 (1) ≤2 16SP100M (VI ≤ 14 V) The voltage rating of the input capacitor must be selected for the desired operating input voltage range of the regulator. To operate the regulator at a higher input voltage, select a capacitor with the next higher voltage rating. Not recommended (N/R). The voltage rating does not meet the minimum operating limits in most applications. The maximum voltage rating of the capacitor must be selected for the desired set-point voltage (VO ). To operate at a higher output voltage select a capacitor with a higher voltage rating. PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 Table 5. Recommended Input/Output Capacitors (PTN78060W) (continued) CAPACITOR CHARACTERISTICS QUANTITY WORKING VOLTAGE (V) VALUE (µF) EQUIVALENT SERIES RESISTANCE (ESR) (Ω) 85° C MAXIMUM RIPPLE CURRENT (IRMS) (mA) 20 100 0.085 1543 20 100 0.200 > 817 Murata X5R Ceramic 6.3 100 0.002 >1000 3225 N/R (2) ≤2 GRM32ER60J107M (VO ≤ 5.5 V) TDK X5R Ceramic 6.3 100 0.002 >1000 3225 N/R (2) ≤2 C3225X5R0J107MT (VO ≤ 5.5 V) Murata X5R Ceramic 16 47 0.002 >1000 3225 1 ≤4 GRM32ER61C476M (Vo ~ VI ≤ 13.5 V) Kemet X5R Ceramic 6.3 47 0.002 >1000 3225 N/R (2) ≤4 C1210C476K9PAC (VO ≤ 5.5 V) TDK X5R Ceramic 6.3 47 0.002 >1000 3225 N/R (2) ≤4 C3225X5R0J476MT (VO ≤ 5.5 V) Murata X5R Ceramic 6.3 47 0.002 >1000 3225 N/R (2) ≤4 GRM42-2X5R476M6.3 (VO ≤ 5.5 V) TDK X7R Ceramic 25 2.2 0.002 >1000 3225 ≥1 (4) 1 C3225X7R1E225KT/MT (VO ≤ 20 V) Murata X7R Ceramic 25 2.2 0.002 >1000 3225 ≥1 (4) 1 GRM32RR71E225K (VO ≤ 20 V) Kemet X7R Ceramic 25 2.2 0.002 >1000 3225 ≥1 (5) 1 C1210C225K3RAC (VO ≤ 20 V) AVX X7R Ceramic 25 2.2 0.002 >1000 3225 ≥1 (5) 1 C12103C225KAT2A (VO ≤ 20 V) Kemet X7R Ceramic 50 1.0 0.002 >1000 3225 ≥2 (6) 1 C1210C105K5RAC Murata X7R Ceramic 50 4.7 0.002 >1000 3225 ≥1 1 GRM32ER71H475KA88L TDK X7R Ceramic 50 2.2 0.002 >1000 3225 ≥1 1 C3225X7R1H225KT Murata X7R Ceramic 50 1.0 0.002 >1000 3225 ≥2 (6) 1 GRM32RR71H105KA01L TDK X7R Ceramic 50 1.0 0.002 >1000 3225 ≥2 (6) 1 C3225X7R1H105KT Kemet Radial Through-hole 50 1.0 0.002 >1000 5,08 × 7,62 × 9,14 H ≥2 (6) 1 C330C105K5R5CA Murata Radial Through-hole 50 2.2 0.004 >1000 10 H × 10 W ×4D 1 RPER71H2R2KK6F03 CAPACITOR VENDOR/ COMPONENT SERIES AVX Tantalum TPS (SMD) (4) (5) (6) VENDOR NUMBER PHYSICAL SIZE (mm) INPUT OUTPUT BUS BUS 7,3 L × 4,3 W × 4,1 H N/R (2) ≤3 TPSV107M020R0085 (VO ≤ 10 V) N/R (2) ≤3 TPSE107M020R0200 (VO ≤ 10 V) (1) ≥1 The maximum rating of the ceramic capacitor limits the regulator's operating input voltage to 20 V. Select an alternative ceramic component to operate at a higher input voltage. The maximum rating of the ceramic capacitor limits the regulator's operating input voltage to 20 V. Select an alternative ceramic component to operate at a higher input voltage. A total capacitance of 2 µF is an acceptable replacement value for a single 2.2-µF ceramic capacitor 15 PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 Table 6. Recommended Input/Output Capacitors (PTN78060H) CAPACITOR CHARACTERISTICS QUANTITY WORKING VOLTAGE (V) VALUE (µF) EQUIVALENT SERIES RESISTANCE (ESR) (Ω) 85° C MAXIMUM RIPPLE CURRENT (IRMS) (mA) Panasonic FC( Radial) 50 100 0.162 615 10 × 12.5 FK (SMD) 50 150 0.18 670 10 × 10,2 United Chemi-Con PXA (SMD) 16 180 0.016 4360 8 × 12 LXZ 50 120 0.160 620 10 × 12,5 MVY(SMD) 50 100 0.300 500 10 × 10 Nichicon UWG (SMD) 50 100 0.300 500 HD 50 120 0.072 Sanyo Os-Con SVP (SMD) 20 100 SP 20 120 CAPACITOR VENDOR/ COMPONENT SERIES PHYSICAL SIZE (mm) INPUT OUTPUT BUS BUS VENDOR NUMBER ≥1 EEUFC1H101 ≥1 EEVFK1H151P ≤1 PXA16VC180MF60 (VO < 14 V) 1 (1) ≥1 LXZ50VB121M10X12LL 1 ≥1 MVY50VC101M10X10TP 10 × 10 1 ≥1 UWG1H101MNR1GS 979 10 × 12,5 1 ≥1 UHD1H151MHR 0.024 2500 8 × 12 1 (1) ≤2 20SVP100M (VI ~VO≤ 16 V) 0.024 3110 8 × 10,5 1 (1) ≤2 20SP120M (VI~VO ≤ 16 V) 1 1 (1) N/R (2) TDK X7R Ceramic 25 2.2 0.002 >1000 3225 ≥6 (3) Murata X7R Ceramic 25 2.2 0.002 >1000 3225 ≥6 (3) 1 GRM32RR71E225K (VI~VO ≤ 20 V) Kemet X7R Ceramic 25 2.2 0.002 >1000 3225 ≥6 (3) 1 C1210C225K3RAC (VI~VO ≤ 20 V) AVX X7R Ceramic 25 2.2 0.002 >1000 3225 ≥6 (3) 1 C12103C225KAT2A (VI~VO ≤ 20 V) Murata X7R Ceramic 50 4.7 0.002 >1000 3225 1 GRM32ER71H475KA88L TDK X7R Ceramic 50 3.3 0.002 >1000 3225 ≥4 (4) 1 CKG45NX7R1H335M Murata Radial Through-hole 50 3.3 0.003 >1000 12,5 H × 12,5 W × 4 ≥4 (5) 1 RPER71H3R3KK6F03 Kemet Radial Through-hole 50 4.7 0.003 >1000 5,08 × 7,62 × 9,14 1 C350C475K5R5CA (1) (2) (3) (4) (5) ≥3 ≥3 1 C3225X7R1E225KT/MT (VI~VO ≤ 20 V) The voltage rating of the input capacitor must be selected for the desired operating input voltage range of the regulator. To operate the regulator at a higher input voltage, select a capacitor with the next higher voltage rating. Not recommended (N/R). The voltage rating does not meet the minimum operating limits in most applications. The maximum rating of the ceramic capacitor limits the regulator's operating input voltage to 20 V. Select an alternative ceramic component to operate at a higher input voltage. A total capacitance of 13.2 µF is an acceptable replacement value for 3 × 4.7 µF ceramic capacitors A total capacitance of 2 µF is an acceptable replacement value for a single 2.2-µF ceramic capacitor Power-Up Characteristics When configured per the standard application, the PTN78060 power module produces a regulated output voltage following the application of a valid input source voltage. During power up, internal soft-start circuitry slows the rate that the output voltage rises, thereby limiting the amount of in-rush current that can be drawn from the input source. The soft-start circuitry introduces a short time delay (typically 5 ms – 10 ms) into the power-up characteristic. This is from the point that a valid input source is recognized. Figure 29 shows the power-up waveforms when operating from a 12-V input and with the output voltage adjusted to 5 V. The waveforms were measured with a 2.8-A resistive load. 16 PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 VI (5 V/div) VO (2 V/div) II (2 A/div) t - Time = 5 ms/div Figure 29. Power-Up Waveforms Undervoltage Lockout The undervoltage lockout (UVLO) circuit prevents the module from attempting to power up until the input voltage is above the UVLO threshold. This is to prevent the modulte from drawing excessive current from the input source at power up. Below the UVLO threshold, the module is held off. Current Limit Protection The module is protected against load faults with a continuous current limit characteristic. Under a load-fault condition, the output current increases to the current limit threshold. Attempting to draw current that exceeds the current limit threshold causes the module to progressively reduce its output voltage. Current is continuously supplied to the fault until the fault is removed. Once it is removed, the output voltage promptly recovers. When limiting output current, the regulator experiences higher power dissipation, which increases its temperature. If the temperature increase is excessive, the module overtemperature protection begins to periodically turn the output voltage off. Overtemperature Protection A thermal shutdown mechanism protects the module's internal circuitry against excessively high temperatures. A rise in temperature may be the result of a drop in airflow, a high ambient temperature, or a sustained current limit condition. If the internal temperature rises excessively, the module turns itself off, reducing the output voltage to zero. The module excercises a soft-start power up when the sensed temperature has decreased by about 10° C below the trip point. NOTE: Overtemperature protection is a last resort mechanism to prevent damage to the module. It should not be relied on as permanent protection against thermal stress. Always operate the module within its temperature derated limits, for the worst-case operating conditions of output current, ambient temperature, and airflow. Operating the module above these limits, albeit below the thermal shutdown temperature, reduces the long-term reliability of the module. Output Voltage Sense An external voltage sense improves the load regulation performance of the module by enabling it to compensate for any IR-voltage drop between the module and the load circuit. This voltage drop is caused by the flow of current through the resistance in the printed-circuit board connections. 17 PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 To use the output voltage sense feature, simply connect the VO Sense input (pin 5) to VO, close to the device that draws the most supply current. If an external voltage sense is not desired, the VO Sense input may be left open circuit. An internal resistor (15 Ω or less), connected between this input and VO, ensures that the output remains in regulation. With VO Sense connected, the difference between the voltage measure directly between the VO and GND, and that measured from VO Sense to GND, represents the amount of IR-voltage drop being compensated by the regulator. This should be limited to a maximum of 0.3 V. Note: The external voltage sense is not designed to compensate for the forward drop of nonlinear or frequency-dependent components that may be placed in series with the regulator's output. Examples include OR-ing diodes, filter inductors, ferrite beads, and fuses. When these components are enclosed by the external sense connection, they are effectively placed inside the regulation control loop. This can adversely affect the stability of the module. Output On/Off Inhibit The inhibit feature can be used wherever there is a requirement for the output voltage to be turned off. The power module functions normally when the Inhibit control (pin 3) is left open-circuit, providing a regulated output whenever a valid source voltage is connected to VI with respect to GND. Figure 30 shows the the circuit used to demonstrate the inhibit function. Note the discrete transistor (Q1). Turning Q1 on applies a low voltage to the Inhibit control pin and turns the module off. The output voltage decays as the load circuit discharges the capacitance. The current drawn at the input is reduced to typically 17 mA. If Q1 is then turned off, the module executes a soft-start power up. A regulated output voltage is produced within 20 ms. Figure 31 shows the typical rise in the output voltage, following the turn off of Q1. The turn off of Q1 corresponds to the fall in the waveform, Q1 Vgs. The waveforms were measured with a 2.8-A resistive load. 5 Sense VI = 12 V 2 PTN78060 VI VO VO = 5 V 6 Inhibit GND GND Adjust 3 CI 2.2 mF Ceramic Inhibit Q1 BSS138 1 7 4 RSET 21 kW 0.05 W 1% + CO 100 mF GND GND Figure 30. On/Off Inhibit Control Circuit 18 L O A D PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 VO (2 V/div) II (1 A/div) Q1 VGS (10 V/div) t - Time = 5 ms/div Figure 31. Power-Up Response From Inhibit Control Optional Input/Output Filters Power modules include internal input and output ceramic capacitors in all of their designs. However, some applications require much lower levels of either input reflected or output ripple/noise. This application describes various filters and design techniques found to be successful in reducing both input and output ripple/noise. Input/Output Capacitors The easiest way to reduce output ripple and noise is to add one or more 1-µF ceramic capacitors, such as C4 shown in Figure 32. Ceramic capacitors should be placed close to the output power terminals. A single 1-µF capacitor reduces the output ripple/noise by 10% to 30% for modules with a rated output current of less than 3 A. (Note: C3 is recommended to improve the regulators transient response, and does not reduce output ripple and noise.) Switching regulators draw current from the input line in pulses at their operating frequency. The amount of reflected (input) ripple/noise generated is directly proportional to the equivalent source impedance of the power source including the impedance of any input lines. The addition of C1, minimum 1-µF ceramic capacitor, near the input power pins, reduces reflected conducted ripple/noise by up to 20%. 5 Sense VI 2 VI PTN78060W Inhibit 3 C1 1 mF 50 V Ceramic C2* 2.2 mF 50 V Ceramic (Required) GND 1 VO VO 6 Adjust 7 4 + RSET # C3 100 mF (Required) C4 1 mF Ceramic GND GND * See specifications for required value and type. For PTN78060H, C2 is equal to 3 x 4.7 mF. Application Information section for suggested value and type. # See Figure 32. Adding High-Frequency Bypass Capacitors To The Input and Output 19 PTN78060W, PTN78060H www.ti.com SLTS229A – NOVEMBER 2004 – REVISED APRIL 2005 π Filters If a further reduction in ripple/noise level is required for an application, higher order filters must be used. A π (pi) filter, employing a ferrite bead (Fair-Rite part number 2673000701 or equivalent) in series with the input or output terminals of the regulator reduces the ripple/noise by at least 20 db (see Figure 33 and Figure 34). In order for the inductor to be effective ceramic capacitors are also required. (Note: see Capacitor Recommendations for additional information on vendors and component suggestions.) These inductors plus ceramic capacitors form an excellent filter because of the rejection at the switching frequency (650 kHz - 1 MHz). The placement of this filter is critical. It must be located as close as possible to the input or output pins to be effective. The ferrite bead is small (12,5 mm × 3 mm), easy to use, low cost, and has low dc resistance. Fair-Rite also manufactures a surface-mount bead (part number 2773021447). It is rated to 5 A, and can be used on the output bus. As an alternative, suitably rated 1-µH to 5-µH wound inductors can be used in place of the ferrite inductor bead. 5 Sense VI L1 1 - 5 mH 2 VI PTN78060W Inhibit GND GND 3 1 7 C1 1 mF 50 V Ceramic C2* 2.2 mF 50 V Ceramic (Required) VO L2 1 - 5 mH 6 Adjust 4 RSET # C3 100 mF (Optional) C4 1 mF Ceramic GND C5 † GND * See specifications for required value and type. For PTN78060H, C2 is equal to 3 x 4.7 mF. # See Application Information section for suggested value and type. † Recommended whenever IO is greater than 2 A. Figure 33. Adding π Filters (IO ≤ 3 A) 45 40 Attenuation − dB 35 1 MHz 30 25 20 600 kHz 15 10 0 0.5 1 1.5 2 Load Current − A 2.5 3 Figure 34. π-Filter Attenuation vs. Load Current 20 VO PACKAGE OPTION ADDENDUM www.ti.com 18-Jul-2006 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty PTN78060HAH ACTIVE DIP MOD ULE EUW 7 36 Pb-Free (RoHS) Call TI N / A for Pkg Type PTN78060HAS ACTIVE DIP MOD ULE EUY 7 36 TBD Call TI Level-1-235C-UNLIM PTN78060HAST ACTIVE DIP MOD ULE EUY 7 250 TBD Call TI Level-1-235C-UNLIM PTN78060HAZ ACTIVE DIP MOD ULE EUY 7 36 Pb-Free (RoHS) Call TI Level-3-260C-168 HR PTN78060HAZT ACTIVE DIP MOD ULE EUY 7 250 Pb-Free (RoHS) Call TI Level-3-260C-168 HR PTN78060WAD ACTIVE DIP MOD ULE EUW 7 36 Pb-Free (RoHS) Call TI N / A for Pkg Type PTN78060WAH ACTIVE DIP MOD ULE EUW 7 36 Pb-Free (RoHS) Call TI N / A for Pkg Type PTN78060WAS ACTIVE DIP MOD ULE EUY 7 36 TBD Call TI Level-1-235C-UNLIM PTN78060WAST ACTIVE DIP MOD ULE EUY 7 250 TBD Call TI Level-1-235C-UNLIM PTN78060WAZ ACTIVE DIP MOD ULE EUY 7 36 Pb-Free (RoHS) Call TI Level-3-260C-168 HR PTN78060WAZT ACTIVE DIP MOD ULE EUY 7 250 Pb-Free (RoHS) Call TI Level-3-260C-168 HR Lead/Ball Finish MSL Peak Temp (3) (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI Addendum-Page 1 PACKAGE OPTION ADDENDUM www.ti.com 18-Jul-2006 to Customer on an annual basis. Addendum-Page 2