PTV12020LAH

PTV12020W/L www.ti.com SLTS231C – NOVEMBER 2004 – REVISED FEBRUARY 2007 16-A, 12-V INPUT NONISOLATED WIDE-OUTPUT ADJUST SIP MODULE Check for Samples: PTV12020W/L FEATURES APPLICATIONS • • • • • • 1 2 • • • • • • • • • • • Up to 16-A Output Current 12-V Input Voltage Wide-Output Voltage Adjust (1.2 V to 5.5 V)/(0.8 V to 1.8 V) Efficiencies up to 93% On/Off Inhibit Output Voltage Sense Prebias Start Up Undervoltage Lockout Auto-Track™ Sequencing Output Overcurrent Protection (Nonlatching, Auto-Reset) Overtemperature Protection Operating Temperature: –40°C to 85°C Safety Agency Approvals: UL/IEC/CSA-22.2 60950-1 POLA™ Alliance Compatible Multivoltage Digital Systems High-End Computing Networking DESCRIPTION The PTV12020 series of nonisolated power modules are part of a new class of complete dc/dc switching regulator modules from Texas Instruments. These regulators combine high performance with double-sided, surface mount construction to give designers the flexibility to power the most complex multiprocessor digital systems using off-the-shelf catalog parts. The PTV12020 series is produced in a 12-pin, single in-line pin (SIP) package. The SIP footprint minimizes board space, and offers an alternate package option for space conscious applications. Operating from a 12-V input bus, the series provides step-down conversion to a wide range of output voltages, at up to 16 A of output current. The output voltage of the W-suffix parts can be set to any value over the range of 1.2 V to 5.5 V. The L-suffix parts have an adjustment range of 0.8 V to 1.8 V. The output voltage is set using a single external resistor. This series includes Auto-Track™. Auto-Track™ simplifies the task of supply-voltage sequencing in a power system by enabling the output voltage of multiple modules to accurately track each other, or any external voltage, during power up and power down. Other operating features include an on/off inhibit, and the ability to start up into an existing output voltage or prebias. For improved load regulation, an output voltage sense is provided. A nonlatching overcurrent trip and overtemperature shutdown protects against load faults. Target applications include complex multivoltage, multiprocessor systems that incorporate the industry's highspeed DSPs, microprocessors, and bus drivers. For start-up into a non-prebiased output, review page 13 in the Application Information section. For start-up into a prebiased output, review page 17 in the Application Information section. 1 2 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. POLA, Auto-Track, TMS320 are trademarks of Texas Instruments. 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 © 2004–2007, Texas Instruments Incorporated PTV12020W/L SLTS231C – NOVEMBER 2004 – REVISED FEBRUARY 2007 www.ti.com This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. STANDARD APPLICATION VOSense Track 9 Track VI 5, 6 VI 7 Sense PTV12020x VO VO 3, 4 Inhibit GND GND VOAdj 12 10, 11 1, 2 8 C1* 560 mF (Required) Inhibit C2* 22 mF Ceramic (Required) RSET# 1% 0.05 W (Required) GND * See the #R SET is C3* 330 mF (Optional) L O A D GND Application Information section for capacitor recommendations. required to adjust the output voltage higher than its lowest value. See the Application Information section for values. ORDERING INFORMATION PTV12020 (Basic Model) (1) Output Voltage Part Number DESCRIPTION Package (1) 1.2 V – 5.5 V (Adjustable) PTV12020WAH Vertical T/H EVC 0.8 V – 1.8 V (Adjustable) PTV12020LAH Vertical T/H EVC See the applicable package drawing for dimensions and PC board layout. ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range unless otherwise noted (1) UNIT V(Track) Track input TA Operating temperature range Over VI range Lead temperature 5 seconds Tstg Storage temperature V(Inhibit) Inhibit (pin 12) input voltage (1) (2) –0.3 V to VI +0.3 V –40°C to 85°C 260°C (2) –55°C to 125°C –0.3 V to 7 V 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. This product is not compatible with surface-mount reflow solder processes. PACKAGE SPECIFICATIONS PTV12020x (Suffix AH) Weight 5.5 grams Flammability Meets UL 94 V-O Mechanical shock Per Mil-STD-883D, Method 2002.3, 1 ms, 1/2 sine, mounted 500 Gs Mechanical vibration Mil-STD-883D, Method 2007.2, 20 Hz - 2000 Hz 10 Gs (1) 2 (1) (1) Qualification limit. Submit Documentation Feedback Copyright © 2004–2007, Texas Instruments Incorporated Product Folder Links :PTV12020W/L PTV12020W/L www.ti.com SLTS231C – NOVEMBER 2004 – REVISED FEBRUARY 2007 ELECTRICAL CHARACTERISTICS operating at 25°C free-air temperature, VI = 12 V, VO = 3.3 V, C1 = 560 µF, C2 = 22 µF, C3 = 0 µF, and IO = IO(max) (unless otherwise noted) PARAMETER PTV12020W TEST CONDITIONS IO Output current Natural convection airflow VI Input voltage range Over IO load range MIN TYP 0 10.8 η –40°C < TA < 85°C Line regulation Over VI range ±5 Load regulation Over IO range ±10 Total output variation Includes set-point, line, load, –40°C ≤ TA ≤ 85°C Adjust range Over VI range Efficiency IO (trip) A 13.2 V ±2% Temperature variation UNIT (1) 16 Set-point voltage tolerance VO MAX (2) ±0.5% Output voltage ripple (pk-pk) 20-MHz bandwidth Overcurrent threshold Reset, followed by auto-recovery mV ±3 1.2 IO = IO max mV (2) 5.5 RSET = 280 Ω, VO = 5 V 93% RSET = 2.0 kΩ, VO = 3.3 V 91% RSET = 4.32 kΩ, VO = 2.5 V 89% RSET = 11.5 kΩ, VO = 1.8 V 86% RSET = 24.3 kΩ, VO = 1.5 V 84% RSET = open cct., VO = 1.2 V 81% VO ≤ 2.5 V 1 VO > 2.5 V 1.5 %Vo V %VO 30 A 1-A/µs load step, 50 to 100% IO max, C3 = 330 µF Transient response Track control (pin 9) UVLO Undervoltage lockout 70 µs 100 mV IIL Input low current Pin to GND Control slew-rate limit C3 ≤ C3 (max) –0.13 1 VI increasing 9.5 VI decreasing VIH Input high voltage Inhibit control (pin 12) Recovery time Vo over/undershoot VIL Input low voltage IIL Input low current 8.8 Open Referenced to GND –0.2 Pin to GND –0.24 Input standby current Inhibit (pin 12) to GND, Track (pin 9) open 10 ƒS Switching frequency Over VI and IO ranges External output capacitance (C3) 250 Nonceramic (C1) 560 (4) Ceramic (C2) 22 (4) Capacitance value Nonceramic 0 Ceramic 0 Equivalent series resistance (nonceramic) MTBF (1) (2) (3) (4) (5) (6) (7) Reliability Per Telcordia SR-332, 50% stress, TA = 40°C, ground benign 4 325 V (3) 0.6 II (stby) External input capacitance 10.4 9 mA V/ms V mA mA 400 kHz µF 330 (5) 6,600 (6) 300 (7) 4.9 µF mΩ 106 Hrs See thermal derating curves for safe operating area (SOA), or consult factory for appropriate derating. 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 is pulled up to an internal supply voltage. To avoid risk of damage to the module, do not apply an external voltage greater than 7 V. If this input is left open-circuit, the module operates when input power is applied. A small low-leakage (2.1V & IO≤10A) FX, OS-Con (SMD) 16 330 0.018 4500 10 × 10.5 2 ≤3 16FX330M PS, Poly-Aluminum (Radial) 16 330 0.014 5060 10 × 12.5 2 ≤2 16PS330MJ12 PXA, Poly-Aluminum (SMD) 16 330 0.014 5050 10 × 12.2 2 ≤3 PXA16VCMJ12 Nichicon, Aluminum 25 560 0.060 1060 12.5 × 15 1 1 UPM1E561MHH6 (VO≤3.4V) PM (Radial) 35 560 0.048 1360 16 × 15 1 1 UPM1V561MHH6 HD (Radial) 25 680 0.038 1430 10 × 16 1 1 UHD1C681MHR Panasonic, Poly-Aluminum WA (SMD) 16 330 0.022 4100 10 × 10.2 ≤3 EEFWA1C331P S/SE (SMD) 6.3 180 0.005 4000 7.3× 4.3× 4.2 N/R (1) ≤1 EEFSE0J181R (VO≤5.1V) Sanyo TP, Poscap 10 330 0.025 3000 7.3× 4.3× 3.8 N/R (1) ≤4 10TPE330M ≤3 16SP270M ≤3 16SVP330M Capacitor Vendor, Type/Series (Style) Panasonic, Aluminum FC (Radial) FK (SMD) Vendor Part Number Physical Size (mm) Input Bus Optional Output Bus 10 × 12.5 2 1 EEUFC1E331 (VO≤ 2.1V, or VO>2.1V & IO≤ 10A) 2 (2) SP, Os-Con 16 270 0.018 >3500 10 × 10.5 SVP, Os-Con (SMD) 16 330 0.016 4700 11 × 12 AVX, Tantalum, Series III 10 470 0.045 >1723 7.3× 5.7× 4.1 N/R (1) ≤5 TPSE477M010R0045 (VO≤5.1V) TPS (SMD) 10 330 0.045 >1723 7.3× 5.7× 4.1 N/R (1) ≤5 TPSE337M010R0045 (VO≤5.1V) Kemet (SMD) T520, Poly-Tant 10 330 0.040 1800 7.3× 4.3× 4 N/R (1) ≤5 T520X337M010AS T530, Poly-Tant/Organic 10 330 0.010 >3800 7.3× 4.3× 4 N/R (1) ≤1 T530X337M010ASE010 6.3 470 0.010 4200 7.3× 4.3× 4 N/R (1) ≤1 T530X477M006ASE010 (VO≤5.1V) Vishay-Sprague 595D, Tantalum (SMD) 10 470 0.100 1440 7.2× 6× 4.1 N/R (1) ≤5 595D477X0010R2T (VO≤5.1V) 94SA, Os-Con (Radial) 16 1,000 0.015 9740 16 × 25 ≤2 94SA108X0016HBP Kemet, Ceramic X5R (SMD) 16 10 0.002 — 3225 ≥2 ≤5 C1210C106M4PAC 6.3 47 0.002 3225 N/R (1) ≤5 C1210C476K9PAC 6.3 100 0.002 3225 N/R (1) ≤3 GRM32ER60J107M 6.3 47 3225 N/R (1) ≤5 GRM32ER60J476M 16 22 Murata, Ceramic X5R (SMD) TDK, Ceramic X5R (SMD) (1) (2) (3) — 2 2 1 ≥1 (3) ≤5 GRM32ER61C226K ≥2 (3) ≤5 GRM32DR61C106K 3225 N/R (1) ≤3 C3225X5R0J107MT 3225 N/R (1) ≤5 C3225X5R0J476MT (3) ≤5 C3225X5R1C226MT (3) ≤5 C3225X5R1C106MT 16 10 6.3 100 6.3 47 16 22 ≥1 16 10 ≥2 0.002 — (3) N/R – Not recommended. The voltage rating does not meet the minimum operating limits. Total capacitance of 540 µF is acceptable based on the combined ripple current rating. Ceramic capacitors are required to complement electrolytic types at the input and to reduce high-frequency ripple current. Submit Documentation Feedback Copyright © 2004–2007, Texas Instruments Incorporated Product Folder Links :PTV12020W/L 11 PTV12020W/L SLTS231C – NOVEMBER 2004 – REVISED FEBRUARY 2007 www.ti.com Designing for Fast 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 optional value of output capacitance. As the di/dt of a transient is increased, the response of a converter regulation circuit ultimately depends on its output capacitor decoupling network. This is an inherent limitation with 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 that specified in the data sheet, or the total amount of load capacitance is above 3,000 µF, the selection of output capacitors becomes more important. Features of the PTH Family of Non-Isolated Wide Output Adjust Power Modules Introduction The PTH/PTV family of non-isolated, wide-output adjustable power modules are optimized for applications that require a flexible, high performance module that is small in size. Each of these products are POLA™ compatible. POLA-compatible products are produced by a number of manufacturers, and offer customers advanced, nonisolated modules with the same footprint and form factor. POLA parts are also ensured to be interoperable, thereby, providing customers with second-source availability. From the basic, Just Plug it In functionality of the 6-A modules, to the 30-A rated feature-rich PTHxx030, these products were designed to be very flexible, yet simple to use. The features vary with each product. Table 5 provides a quick reference to the features by product series and input bus voltage. Table 5. Operating Features by Series and Input Bus Voltage Series PTHxx050 PTHxx060 PTHxx010 PTVxx010 PTHxx020 PTVxx020 PTHxx030 Input Bus (V) IO (A) Adjust (Trim) On/Off Inhibit OverCurrent Prebias Startup AutoTrack™ Margin Up/Down Output Sense 3.3 6 • • • • • 5 6 • • • • • 12 6 • • • • • 3.3 / 5 10 • • • • 12 10 • • • • • • • • • 3.3 / 5 15 • • • • • • • 12 12 • • • • • • • • Thermal Shutdown 5 8 • • • • • 12 8 • • • • • 3.3 / 5 22 • • • • • • • • 12 18 • • • • • • • • 5 18 • • • • • • • 12 16 • • • • • • • 3.3 / 5 30 • • • • • • • • 12 26 • • • • • • • • For simple point-of-use applications, the PTH12050 (6A) provides operating features such as an on/off inhibit, output voltage trim, prebias start-up and overcurrent protection. The PTH12060 (10A), and PTH12010 (12A) include an output voltage sense, and margin up/down controls. Then the higher output current, PTH12020 (18A) and PTH12030 (26A) products incorporate overtemperature shutdown protection. The PTV12010 and PTV12020 are similar parts offered in a vertical, single in-line pin (SIP) profile, at slightly lower current ratings. All of the products referenced in Table 5 include Auto-Track™. This feature was specifically designed to simplify the task of sequencing the supply voltages in a power system. This and other features are described in the following sections. 12 Submit Documentation Feedback Copyright © 2004–2007, Texas Instruments Incorporated Product Folder Links :PTV12020W/L PTV12020W/L www.ti.com SLTS231C – NOVEMBER 2004 – REVISED FEBRUARY 2007 POWER-UP INTO A NON-PREBIASED OUTPUT — AUTO-TRACK™ FUNCTION The Auto-Track function is unique to the PTH/PTV family, and is available with all POLA products. Auto-Track was designed to simplify the amount of circuitry required to make the output voltage from each module power up and power down in sequence. The sequencing of two or more supply voltages during power up is a common requirement for complex mixed-signal applications that use dual-voltage VLSI ICs such as the TMS320™ DSP family, microprocessors, and ASICs. Basic Power-Up Using Auto-Track™ For applications requiring output voltage on/off control, each series of the PTH family incorporates the track control pin. The Auto-Track feature should be used instead of the inhibit feature wherever there is a requirement for the output voltage from the regulator to be turned on/off. Figure 12 shows the typical application for basic start-up. Note the discrete transistor (Q1). The track input has its own internal pull-up to a potential of 5 V to 13.2 V The input is not compatible with TTL logic devices. An open-collector (or open-drain) discrete transistor or supply voltage supervisor (TPS3808 or TPS7712) is recommended for control. 10 Margin Up 9 3 5 Margin Down Inhibit VOSense VO 2 Track GND GND VoAdj 8 1 7 4 + CI 560 µF 1=Turn−Off VO PTH12060W VI 6 RSET 2 kΩ 0.1 W 1% Q1 BSS138 L O A D + CO 330 µF GND UDG−06074 Figure 12. Basic Start-up Control Circuit Turning on Q1 applies a low voltage to the track control pin and disables the output of the module. If Q1 is then turned off, the output ramps immediately to the regulated output voltage. A regulated output voltage is produced within 35 ms. With the initial application of the input source voltage, the track pin must be held low (Q1 turned ON) for at least 40 ms. Figure 13 shows the typical rise in both the output voltage and input current, following the turn off of Q1. The turn off of Q1 corresponds to the rise in the waveform, Q1 Vds. The waveforms were measured with a 10-A constant current load. Submit Documentation Feedback Copyright © 2004–2007, Texas Instruments Incorporated Product Folder Links :PTV12020W/L 13 PTV12020W/L SLTS231C – NOVEMBER 2004 – REVISED FEBRUARY 2007 www.ti.com Q1VDS (2 V/div) VO (2 V/div) II (2 A/div) t − Time − 40 ms/div Figure 13. Power-Up from Track Control NOTE If a prebias condition is not present, it is highly recommended that the Track control pin be used for controlled power-up and power-down. If Track control is not used, the output voltage starts up and overshoots by as much as 10%, before settling at the output voltage setpoint. How Auto-Track™ Works Auto-Track works by forcing the module output voltage to follow a voltage presented at the Track control pin (1). This control range is limited to between 0 V and the module set-point voltage. Once the track-pin voltage is raised above the set-point voltage, the module output remains at its set-point (2). As an example, if the Track pin of a 2.5-V regulator is at 1 V, the regulated output is 1 V. If the voltage at the Track pin rises to 3 V, the regulated output does not go higher than 2.5 V. When under Auto-Track control, the regulated output from the module follows the voltage at its Track pin on a volt-for-volt basis. By connecting the Track pin of a number of these modules together, the output voltages follow a common signal during power up and power down. The control signal can be an externally generated master ramp waveform, or the output voltage from another power supply circuit (3). For convenience, the Track input incorporates an internal RC-charge circuit. This operates off the module input voltage to produce a suitable rising waveform at power up. 14 Submit Documentation Feedback Copyright © 2004–2007, Texas Instruments Incorporated Product Folder Links :PTV12020W/L PTV12020W/L www.ti.com SLTS231C – NOVEMBER 2004 – REVISED FEBRUARY 2007 Typical Auto-Track Application The basic implementation of Auto-Track allows for simultaneous voltage sequencing of a number of Auto-Track compliant modules. Connecting the Track inputs of two or more modules forces their track input to follow the same collective RC-ramp waveform, and allows their power-up sequence to be coordinated from a common Track control signal. This can be an open-collector (or open-drain) device, such as a power-up reset voltage supervisor IC. See U3 in Figure 14. To coordinate a power-up sequence, the Track control must first be pulled to ground potential through RTRK as defined in Figure 14. This should be done at or before input power is applied to the modules. The ground signal should be maintained for at least 40 ms after input power has been applied. This brief period gives the modules time to complete their internal soft-start initialization (4), enabling them to produce an output voltage. A low-cost supply voltage supervisor IC, that includes a built-in time delay, is an ideal component for automatically controlling the Track inputs at power up. Figure 14 shows how the TL7712A supply voltage supervisor IC (U3) can be used to coordinate the sequenced power up of two 12-V input Auto-Track modules. The output of the TL7712A supervisor becomes active above an input voltage of 3.6 V, enabling it to assert a ground signal to the common track control well before the input voltage has reached the module's undervoltage lockout threshold. The ground signal is maintained until approximately 43 ms after the input voltage has risen above U3's voltage threshold, which is 10.95 V. The 43-ms time period is controlled by the capacitor C3. The value of 3.3 µF provides sufficient time delay for the modules to complete their internal soft-start initialization. The output voltage of each module remains at zero until the track control voltage is allowed to rise. When U3 removes the ground signal, the track control voltage automatically rises. This causes the output voltage of each module to rise simultaneously with the other modules, until each reaches its respective set-point voltage. Figure 15 shows the output voltage waveforms from the circuit of Figure 14 after input voltage is applied to the circuit. The waveforms, VO1 and VO2, represent the output voltages from the two power modules, U1 (3.3 V) and U2 (1.8 V), respectively. VTRK, VO1, and VO2 are shown rising together to produce the desired simultaneous power-up characteristic. The same circuit also provides a power-down sequence. When the input voltage falls below U3's voltage threshold, the ground signal is re-applied to the common track control. This pulls the track inputs to zero volts, forcing the output of each module to follow, as shown in Figure 16. In order for a simultaneous power-down to occur, the track inputs must be pulled low before the input voltage has fallen below the modules' undervoltage lockout. This is an important constraint. Once the modules recognize that a valid input voltage is no longer present, their outputs can no longer follow the voltage applied at their track input. During a power-down sequence, the fall in the output voltage from the modules is limited by the maximum output capacitance and the Auto-Track slew rate. If the Track pin is pulled low at a slew rate greater than 1 V/ms, the discharge of the output capacitors will induce large currents which could exceed the peak current rating of the module. This will result in a reduction in the maximum allowable output capacitance as listed in the Electrical Characteristics table. When controlling the Track pin of the PTH12060W using a voltage supervisor IC, the slew rate is increased, therefore CO(max) is reduced to 2200 μF. Notes on Use of Auto-Track™ 1. The Track pin voltage must be allowed to rise above the module set-point voltage before the module regulates at its adjusted set-point voltage. 2. The Auto-Track function tracks almost any voltage ramp during power up, and is compatible with ramp speeds of up to 1 V/ms. 3. The absolute maximum voltage that may be applied to the Track pin is the input voltage VI. 4. The module cannot follow a voltage at its track control input until it has completed its soft-start initialization. This takes about 40 ms from the time that a valid voltage has been applied to its input. During this period, it is recommended that the Track pin be held at ground potential. 5. The Auto-Track function is disabled by connecting the Track pin to the input voltage (VI). When Auto-Track is disabled, the output voltage rises at a quicker and more linear rate after input power has been applied. Submit Documentation Feedback Copyright © 2004–2007, Texas Instruments Incorporated Product Folder Links :PTV12020W/L 15 PTV12020W/L SLTS231C – NOVEMBER 2004 – REVISED FEBRUARY 2007 www.ti.com 2 U1 Track VI = 12 V 3 Vo 1 = 3.3 V 6 VI VO PTH12050W Inhibit GND 4 1 Adjust 5 + + CI1 CO1 RSET1 2.0 kΩ 8 U3 VCC 7 SENSE RESET 2 5 RTRK # RESIN 1 3 50 Ω TL7712A REF 0.1 µF 9 Up Dn RESET 8 5 Track Sense CT 2 GND CREF 10 U2 6 CT 3.3 µF 4 VI VO PTH12060W Vo 2 = 1.8 V 6 RRST 10 kΩ Inhibit 3 # RTRK = 100 Ω / N N = Number of Track pins connected together Adjust GND 1 7 4 + C I2 RSET2 + CO2 11.5 kΩ Figure 14. Sequenced Power Up and Power Down Using Auto-Track 16 Submit Documentation Feedback Copyright © 2004–2007, Texas Instruments Incorporated Product Folder Links :PTV12020W/L PTV12020W/L www.ti.com SLTS231C – NOVEMBER 2004 – REVISED FEBRUARY 2007 VTRK (1 V/div) VTRK (1 V/div) V01 (1 V/div) V01 (1 V/div) V02 (1 V/div) V02 (1 V/div) t − Time − 400 µs/div t − Time − 20 ms/div Figure 15. Simultaneous Power Up With AutoTrack Control Figure 16. Simultaneous Power Down with AutoTrack Control POWER-UP INTO A PREBIASED OUTPUT — START-UP USING INHIBIT CONTROL The capability to start up into an output prebias condition is now available to all the 12-V input, PTH series of power modules. (Note that this is a feature enhancement for the many of the W-suffix products) [1]. A prebias startup condition occurs as a result of an external voltage being present at the output of a power module prior to its output becoming active. This often occurs in complex digital systems when current from another power source is backfed through a dual-supply logic component, such as an FPGA or ASIC. Another path might be via clamp diodes, sometimes used as part of a dual-supply power-up sequencing arrangement. A prebias can cause problems with power modules that incorporate synchronous rectifiers. This is because under most operating conditions, such modules can sink as well as source output current. The 12-V input PTH modules all incorporate synchronous rectifiers, but does not sink current during startup, or whenever the Inhibit pin is held low. Conditions for Prebias Holdoff In order for the module to allow an output prebias voltage to exist (and not sink current), certain conditions must be maintained. The module holds off a prebias voltage when the Inhibit pin is held low, and whenever the output is allowed to rise under soft-start control. Power up under soft-start control occurs upon the removal of the ground signal to the Inhibit pin (with input voltage applied), or when input power is applied with Auto-Track disabled [2]. To further ensure that the regulator doesn’t sink output current, (even with a ground signal applied to its Inhibit), the input voltage must always be greater than the applied prebias source. This condition must exist throughout the power-up sequence [3]. The soft-start period is complete when the output begins rising above the prebias voltage. Once it is complete the module functions as normal, and sinks current if a voltage higher than the nominal regulation value is applied to its output. Note: If a prebias condition is not present, the soft-start period is complete when the output voltage has risen to either the set-point voltage, or the voltage applied at the module's Track control pin, whichever is lowest. to its output. Prebias Demonstration Circuit Figure 17 shows the startup waveforms for the demonstration circuit shown in Figure 18. The initial rise in VO2 is the prebias voltage, which is passed from the VCCIO to the VCORE voltage rail through the ASIC. Note that the output current from the PTH12010L module (IO2) is negligible until its output voltage rises above the applied prebias. Submit Documentation Feedback Copyright © 2004–2007, Texas Instruments Incorporated Product Folder Links :PTV12020W/L 17 PTV12020W/L SLTS231C – NOVEMBER 2004 – REVISED FEBRUARY 2007 www.ti.com VO1 (1 V/div) VO2 (1 V/div) IO2 (5 V/div) t − Time − 10 ms/div Figure 17. Prebias Startup Waveforms 10 9 Up VI = 12 V 2 VI 5 Sense GND 7 1 C1 330 mF 10 9 R3 11 k0 TL7702B 8 7 R4 100 kW C5 0.1 mF PTH12010L Inhibit 3 8 VCC SENSE 5 RESET 2 RESIN 1 REF 6 RESET 3 CT GND 4 R5 C6 10 k0 0.68 mF VI GND 7 1 6 Adjust 4 R1 2 kW Tra ck 2 VO PTH12020W Inhibit 3 + 8 Dn Tra ck VO1 = 3.3 V + C2 330 mF 5 Sense VO 6 Vadj 4 VO2 = 1.8 V + IO2 R1 130 W + C3 330 mF VC ORE + C4 330 mF VC CI O ASIC Figure 18. Application Circuit Demonstrating Prebias Startup Notes: 1. Output prebias holdoff is an inherent feature to all PTH120x0L and PTV120x0W/L modules. It has now been incorporated into all modules (including W-suffix modules with part numbers of the form PTH120x0W), with a production lot date code of 0423 or later. 2. The prebias start-up feature is not compatible with Auto-Track. If the rise in the output is limited by the 18 Submit Documentation Feedback Copyright © 2004–2007, Texas Instruments Incorporated Product Folder Links :PTV12020W/L PTV12020W/L www.ti.com SLTS231C – NOVEMBER 2004 – REVISED FEBRUARY 2007 voltage applied to the Track control pin, the output sinks current during the period that the track control voltage is below that of the back-feeding source. For this reason, it is recommended that Auto-Track be disabled when not being used. This is accomplished by connecting the Track pin to the input voltage, VI. This raises the Track pin voltage well above the set-point voltage prior to the module’s start up, thereby, defeating the Auto-Track feature. 3. To further ensure that the regulator's output does not sink current when power is first applied (even with a ground signal applied to the Inhibit control pin), the input voltage must always be greater than the applied prebias source. This condition must exist throughout the power-up sequence of the power system. Submit Documentation Feedback Copyright © 2004–2007, Texas Instruments Incorporated Product Folder Links :PTV12020W/L 19 PTV12020W/L SLTS231C – NOVEMBER 2004 – REVISED FEBRUARY 2007 www.ti.com Remote Sense Products with this feature incorporate an output voltage sense pin, VOSense. A remote sense improves the load regulation performance of the module by allowing it to compensate for any IR voltage drop between its output and the load. An IR drop is caused by the high output current flowing through the small amount of pin and trace resistance. To use this feature simply connect the VOSense pin to the VO node, close to the load circuit (see data sheet standard application circuit). If a sense pin is left open-circuit, an internal low-value resistor (15-Ω or less) connected between the pin and the output node, ensures the output remains in regulation. With the sense pin connected, the difference between the voltage measured directly between the VO and GND pins, and that measured from VOSense to GND, is the amount of IR drop being compensated by the regulator. This should be limited to a maximum of 0.3 V. Note: The remote sense feature is not designed to compensate for the forward drop of nonlinear or frequency dependent components that may be placed in series with the converter output. Examples include OR-ing diodes, filter inductors, ferrite beads, and fuses. When these components are enclosed by the remote sense connection, they are effectively placed inside the regulation control loop, which can adversely affect the stability of the regulator. Overcurrent Protection For protection against load faults, all modules incorporate output overcurrent protection. Applying a load that exceeds the regulator's overcurrent threshold causes the regulated output to shut down. Following shutdown, a module periodically attempts to recover by initiating a soft-start power-up. This is described as a hiccup mode of operation, whereby, the module continues in a cycle of successive shutdown and power up until the load fault is removed. During this period, the average current flowing into the fault is significantly reduced. Once the fault is removed, the module automatically recovers and returns to normal operation. Overtemperature Protection (OTP) The PTH12020, PTV12020, and PTH12030 products have overtemperature protection. These products have an on-board temperature sensor that protects the module's internal circuitry against excessively high temperatures. A rise in the internal temperature may be the result of a drop in airflow, or a high ambient temperature. If the internal temperature exceeds the OTP threshold, the module's Inhibit control is internally pulled low. This turns the output off. The output voltage drops as the external output capacitors are discharged by the load circuit. The recovery is automatic, and begins with a soft-start power up. It occurs when the sensed temperature decreases by about 10°C below the trip point. Note: The overtemperature protection is a last resort mechanism to prevent thermal stress to the regulator. Operation at or close to the thermal shutdown temperature is not recommended and will reduce the longterm reliability of the module. Always operate the regulator within the specified Safe Operating Area (SOA) limits for the worst-case conditions of ambient temperature and airflow. 20 Submit Documentation Feedback Copyright © 2004–2007, Texas Instruments Incorporated Product Folder Links :PTV12020W/L PACKAGE OPTION ADDENDUM www.ti.com 16-Jul-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) (3) Device Marking (4/5) (6) PTV12020LAH ACTIVE SIP MODULE EVC 12 40 RoHS Exempt & Green SN N / A for Pkg Type -40 to 85 PTV12020WAD ACTIVE SIP MODULE EVC 12 40 RoHS Exempt & Green SN N / A for Pkg Type -40 to 85 PTV12020WAH ACTIVE SIP MODULE EVC 12 40 RoHS Exempt & Green SN N / A for Pkg Type -40 to 85 (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) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of