PTB48560AAH

PTB48560A TI | Alldatasheet

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www.ti.com FEATURES APPLICATIONS

DESCRIPTION

PTB48560A, PTB48560B PTB48560C SLTS236A–MARCH 2005–REVISED OCTOBER 2005 30-W, 48-V INPUT DC/DC CONVERTERS WITH AUTO-TRACK™ SEQUENCING

Intermediate Bus Architectures• Input Voltage: 36 V to 75 V
Telecom, High-End Computing Platforms• 30-W Total Output Power
Multi-Rail Power Systems with• Output Voltages: 3.3 V, 5 V, and 12 V Power-Up Sequencing• Wide-Output Adjust/Trim
Up To 88% Efficiency
Overcurrent Protection
Overtemperature Shutdown
Undervoltage Lockout
Input Overvoltage Protection
Auto-Track™ Power-Up Sequencing (Includes Sequenced Output with PTB48560B)
Smart-Sense Remote Sensing (PTB48560B)
Dual-Logic Enable Control
Space-Saving 1×2 Footprint
Surface Mount Package
1500-Vdc Isolation
Agency Approvals (Pending): UL/cUL 60950, EN 60950 The PTB48560x is a series of 30–W rated isolated dc/dc converters, designed to operate from a standard -48–V telecom central office (CO) supply. Housed in a 1×2 package, each model has a wide-adjust output voltage that can be set to one of the common intermediate bus voltages of 3.3 V, 5 V, or 12 V. The PTB48560 series incorporates Auto-Track™, a feature that simplifies the power-up sequencing of multiple power modules and operates from the same intermediate bus. During a power-up cycle, modules with this feature have the capability of following a common ramp voltage applied to an input called Track. The PTB48560 series is specifically designed to control the Track voltage of any number of nonisolated downstream modules powered from its output. This ensures that the outputs of the downstream modules all rise simultaneously during power up. The PTB48560B (3.3 V) has an additional sequenced output, V O Seq, which also rises with the Track voltage. This allows the VO Seq output to power up simultaneously with the outputs from other power modules under the control of Auto-Track. Whether used to facilitate power-up sequencing, or operated as a stand-alone module, the PTB48560 series includes many other features expected of high-performance dc/dc converter modules. Precise output voltage regulation is ensured with a differential remote sense. Operational features include an input undervoltage lockout (UVLO) and a dual-logic output enable control. Overcurrent and overtemperature protection ensure survival against load faults.Typical applications include distributed power architectures in both telecom and computing environments, particularly complex digital systems requiring power sequencing of multiple power supply rails. 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. Auto-Track is a trademark of Texas Instruments. PRODUCTION DATA information is current as of publication date. Copyright © 2005, Texas Instruments Incorporated Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters.

www.ti.com Simultaneous Power-Up V SeqO # Auto-Track POL Module Track GND Adjust VO Auto-Track POL Module Track GND Adjust V Seq (3.3 V)O # V1POL V1POL V2POL V2POL CO CO CO RSET RSET RSET (Required) To Other POL Modules PTB48560x NEN Track PEN +VI +VI VI VI -VI -VI - Sense V COMO V AdjustO V SeqO V BusO +Sense* See Note (*) * The +Sense can be connected to either the V Seq or V Bus output of the PTB48560B.OO # Sequenced output is only available with the PTB48560B. CI CI VO The PTB48560x modules require a minimum total output capacitance for proper operation; see the for the value required by each model.Electrical Characterisitics R is required to set the output voltage higher than the minimum value; see the for values.SET Application Information† PTB48560A, PTB48560B PTB48560C SLTS236A–MARCH 2005–REVISED OCTOBER 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. Typical Circuit

www.ti.com ABSOLUTE MAXIMUM RATINGS PACKAGE SPECIFICATIONS PTB48560A, PTB48560B PTB48560C SLTS236A–MARCH 2005–REVISED OCTOBER 2005

ORDERING INFORMATION

PTB48560 (Base Pt. Number) Output Voltage Range Part Number DESCRIPTION Pb – free and RoHS Package Ref. (1) Compatible PTB48560AAH Horizontal T/H Yes ERW 3.6 V to 5.5 V PTB48560AAS Standard SMD (2) No ERY PTB48560AAZ Optional SMD (3) Yes PTB48560BAH (4) Horizontal T/H Yes ERW 1.8 V to 3.6 V PTB48560BAS (4) Standard SMD (2) No ERY PTB48560BAZ (4) Optional SMD (3) Yes PTB48560CAH Horizontal T/H Yes ERW 9 V to o13.2 V PTB48560CAS Standard SMD (2) No ERY PTB48560CAZ Optional SMD (3) Yes (1) See the applicable package reference drawing for the dimensions and PC board layout. (2) Standard option specifies 63/37, Sn/Pb pin solder material. (3) Lead (Pb) – free optionspecifies Sn/Ag pin solder material. (4) Includes an Auto-Track compatible output, VO Seq, which sequences with the Track control during power up. PTB48560x UNIT Continuous 75 VI Input Voltage Surge, 1 s max 100 (1) V V(Track) Track input voltage 0t oV O B u s+0 . 3 I(Track) max Track input current From external source 10 (2) mA TA 1 Operating temperature range Over V I range –40 to 85 Overtemperature protection PCB temperature (near pin 1) 115 Surface temperature of module PTB48560xAH 260 (3) T(WAVE) Wave solder temperature or pins (5 seconds) °C PTB48560xAS 235 (3)Surface temperature of moduleT(REFLOW) Solder reflow temperature or pins PTB48560xAZ 260 (3) Tstg Storage temperature –40 to 125 (1) The converter's internal protection circuitry may cause the output to turn off when the applied input voltage is greater than 75 V. (2) When the Track input is fed from an external voltage source, the input current must be limited. A 2.74-k Ω value series resistor is recommended. (3) During solder reflow of SMD package version, do not elevate the module PCB, pins, or internal component temperatures this peak temperature. PTB48560x (Suffixes AH and AS) Weight 13.6 grams Flammability Meets UL94V-O Horizontal T/H (Suffix AH) 500 Gs (1)Per Mil-STD-883D, Method 2002.3, 1 ms,Mechanical shock 1/2 Sine, mounted Horizontal SMD (Suffix AS) 250 G (1) Horizontal T/H (Suffix AH) 20 G (1)Mil-STD-883D, Method 2007.2, 20-2000 Hz,Mechanical vibration PCB mounted Horizontal SMD (Suffix AS) 5 G (1) (1) Qualification limit.

www.ti.com PTB48560B ELECTRICAL CHARACTERISTICS PTB48560A, PTB48560B PTB48560C SLTS236A–MARCH 2005–REVISED OCTOBER 2005 (Unless otherwise stated, TA = 25°C, VI =4 8V ,V O = 3.3 V, CO = 220 µF, and IO =I Omax) PTB48560B PARAMETER TEST CONDITIONS UNIT MIN TYP MAX Over VI range I O Bus 0.25 (1) 8 (2) IO Output current I O Seq 0 4 (3) A Sum total, (IO B u s+IO Seq) 0.25 8 VI Input voltage range Over I O range 36 48 75 V Set-point voltage tolerance ±1 (4) %VO Temperature variation -40°C ≤ TA ≤ 85°C ±0.5 %V O Line regulation Over V I range ±7 ±33 mV VO Load regulation Over I O range ±13 ±33 mV Total output voltage variation Includes set-point, line, load, –40°C ≤ TA ≤ 85°C ±2 ±3 (4) %VO Adjust range Over V I range 1.8 3.6 V RSET =5 . 3 6kΩ,V O = 3.3 V 82% η Efficiency R SET = 40.2 kΩ,V O = 2.5 V 79% RSET = open , VO = 1.8 V 74% VO Ripple (peak-to-peak) 20-MHz bandwidth 50 mV pp

0.1 A/µs load step, Recovery time 100 µs

Transient response 50% to 100% VO over/undershoot ±150 mVIOmax Input current Track connected to -Sense -0.13 mA Track input (pin 5) Open-circuit voltage 0 V O Bus Input slew rate limits 0.1 (5) 1V / m s Referenced to -VI Input high voltage (VIH) 2 Open (6) V Output enable inputs (pins 2, 3) Input low voltage (V IL)- 0 . 2 0 . 8 Input low current (IIL)0 . 4 8 m A Standby input current Pins 2 and 3 open 8 16 mA IO (tot) Overcurrent threshold Shutdown, followed by autorecovery 12 A VI increasing 34 UVLO Undervoltage lockout V VI decreasing 33 ƒS Switching frequency Over V I range 400 500 600 kHz Internal input capacitance 1µ F External output capacitance Between both outputs and V O COM 220 5,000 µF Isolation voltage Input-output 1,500 Vdc Isolation capacitance Input-output 2,000 pF Isolation resistance Input-output 10 M Ω Telcordia SR-332 50% stress, T A = 40°C, groundMTBF Reliability 3.6 10 6 Hrbenign (1) The converter requires a minimum load current at either the VO Seq or VO Bus output for proper operation. The converter is not damaged when operated under a no-load condition. (2) See temperature derating curves for safe operating area (SOA), to determine output current derating at elevated ambient temperatures. (3) When load current is supplied from the V O Seq output, the module exhibits higher power dissipation and slightly lower operating efficiency. (4) The set-point voltage tolerance is affected by the tolerance and stability of R SET. The stated limit is unconditionally met if R SET has a tolerance of 1%, with 100 ppm/°C temperature stability. (5) When controlling the Track input from an external source, the slew rate of the applied signal must be greater than the minimum limit. Failure to allow the voltage to completely rise to the voltage at the V O (bus) output, at no less than the minimum specified rate, may thermally overstress the converter. (6) The PEN and NEN inputs each have an internal pullup resistor. If the enable feature is not used, the PEN input (pin 2) should be left open circuit and the NEN input (pin 3) permanently connected to –V I. A discrete MOSFET or bipolar transistor is recommended for the enable control. The open-circuit voltage is less than 10 V. See the Application Informationfor a more detailed description.

www.ti.com PTB48560A ELECTRICAL CHARACTERISTICS PTB48560A, PTB48560B PTB48560C SLTS236A–MARCH 2005–REVISED OCTOBER 2005 (Unless otherwise stated, TA = 25°C, VI =4 8V ,V O = 5 V, CO = 220 µF, and IO =I Omax) PTB48560A PARAMETER TEST CONDITIONS UNIT MIN TYP MAX IO Output current Over V I range I O Bus 0.25 (1) 6 (2) A VI Input voltage range Over I O range 36 48 75 V Set-point voltage tolerance ±1 (3) %VO Temperature variation -40°C ≤ TA ≤ 85°C ±0.5 %V O Line regulation Over V I range ±0.2 ±1 %V OVO Load regulation Over I O range ±0.4 ±1 %V O Total output voltage variation Includes set-point, line, load, –40°C ≤ TA ≤ 85°C ±2 ±3 (3) %VO Adjust range Over V I range 3.6 5.5 V η Efficiency R SET = 14.3 kΩ,V O =5 V 84% VO Ripple (peak-to-peak) 20-MHz bandwidth 1 %V O Transient response 50% to 100% VO over/undershoot ±150 mVIOmax Input current Track connected to -Sense –0.2 mA Track input (pin 5) Open-circuit voltage 0 V O Bus Referenced to -VI Input high voltage (VIH) 2 Open (4) V Output enable inputs (pins 2, 3) Input low voltage (V IL)- 0 . 2 0 . 8 Input low current (IIL)0 . 4 8 m A Standby input current Pins 2 and 3 open 8 16 mA IO Bus Overcurrent threshold Shutdown, followed by autorecovery 9 A VI increasing 34 UVLO Undervoltage lockout V VI decreasing 33 ƒS Switching frequency Over V I range 400 500 600 kHz Internal input capacitance 1µ F External output capacitance Between both outputs and V O COM 220 5,000 µF Isolation voltage Input-output 1,500 Vdc Isolation capacitance Input-output 2,000 pF Isolation resistance Input-output 10 M Ω Telcordia SR-332 50% stress, T A = 40°C, groundMTBF Reliability 3.6 10 6 Hrbenign (1) The converter requires a minimum load current for proper operation. The converter is not damaged when operated under a no-load condition. (2) See temperature derating curves for safe operating area (SOA), to determine output current derating at elevated ambient temperatures. (3) The set-point voltage tolerance is affected by the tolerance and stability of R SET. The stated limit is unconditionally met if R SET has a tolerance of 1%, with 100 ppm/°C temperature stability. (4) The PEN and NEN inputs each have an internal pullup resistor. If the enable feature is not used, the PEN input (pin 2) should be left open circuit and the NEN input (pin 3) permanently connected to –V I. A discrete MOSFET or bipolar transistor is recommended for the enable control. The open-circuit voltage is less than 10 V. See the Application Informationfor a more detailed description.

www.ti.com PTB48560C ELECTRICAL CHARACTERISTICS PTB48560A, PTB48560B PTB48560C SLTS236A–MARCH 2005–REVISED OCTOBER 2005 (Unless otherwise stated, TA = 25°C, VI =4 8V ,V O =1 2V ,C O = 100 µF, and IO =I Omax) PTB48560C PARAMETER TEST CONDITIONS UNIT MIN TYP MAX IO Output current Over V I range I O Bus 0.1 (1) 2.5 (2) A VI Input voltage range Over I O range 36 48 75 V Set-point voltage tolerance ±1 (3) %VO Temperature variation -40°C ≤ TA ≤ 85°C ±0.5 %V O Line regulation Over V I range ±0.2 ±1 %V OVO Load regulation Over I O range ±0.4 ±1 %V O Total output voltage variation Includes set-point, line, load, –40°C ≤ TA ≤ 85°C ±2 ±3 (3) %VO Adjust range Over V I range 9 13.2 V RSET =9 . 0 9kΩ,V O =12 V 88% η Efficiency RSET = open, VO = 9 V 86% VO Ripple (peak-to-peak) 20-MHz bandwidth 1 %V O Transient Response 50% to 100% VO over/undershoot ±150 mVIOmax Input current Track connected to -Sense 0.48 mA Track input (pin 5) Open-circuit voltage 0 V O Bus Referenced to -VI Input high voltage (VIH) 2 Open (4) V Output enable inputs (pins 2, 3) Input low voltage (V IL)- 0 . 2 0 . 8 Input low current (IIL) –0.48 mA Standby input current Pins 2 and 3 open 8 16 mA IO Bus Overcurrent threshold Shutdown, followed by autorecovery 3.75 A VI increasing 34 UVLO Undervoltage lockout V VI decreasing 33 ƒS Switching frequency Over V I range 400 500 600 kHz Internal input capacitance 1µ F External output capacitance Between both outputs and V O COM 100 1,500 µF Isolation voltage Input-output 1,500 Vdc Isolation capacitance Input-output 2,000 pF Isolation resistance Input-output 10 M Ω Telcordia SR-332 50% stress, T A = 40°C, groundMTBF Reliability 3.4 10 6 Hrsbenign (1) The converter requires a minimum load current for proper operation. The converter is not damaged when operated under a no-load condition. (2) See temperature derating curves for safe operating area (SOA), to determine output current derating at elevated ambient temperatures. (3) The set-point voltage tolerance is affected by the tolerance and stability of R SET. The stated limit is unconditionally met if R SET has a tolerance of 1%, with 100 ppm/°C temperature stability. (4) The PEN and NEN enable inputs each have an internal pullup resistor. If the enable feature is not used, the PEN input (pin 2) should be left open circuit and the NEN input (pin 3) permanently connected to –V I. A discrete MOSFET or bipolar transistor is recommended for the enable control. The open-circuit voltage is less than 10 V. See the Application Informationfor a more detailed description.

www.ti.com PTB48560A, PTB48560B PTB48560C SLTS236A–MARCH 2005–REVISED OCTOBER 2005 TERMINAL FUNCTIONS TERMINAL NAME NO. The positive input for the module with respect to -V I. When powering the module from a negative input voltage,+VI(1) 1 this input is connected to the input source ground. The negative input supply for the module, and the 0-V reference for the PEN and NEN enable inputs. When-VI(1) 4 powering the module from a positive source, this input is connected to the input source return. An open-collector (open-drain) positive logic input that is referenced to -V I. When this input is pulled to -V I PEN (1) 2 potential the converter output is disabled. This input must be open circuit for the converter to operate. The converter then produces an output whenever a valid input source is applied. An open-collector (open-drain) negative logic input that is referenced to -V I. This input must be pulled to -V I potential to enable the converter. When the input is open circuit, the converter output is disabled. If the enableNEN (1)(2) 3 feature is not used, this input should be permanently connected to -V I. The module then produces an output whenever a valid input source is applied. This is the positive power output with respect to VO COM, and the main output from the converter. It is dc isolated from the input power pins and produces a valid output voltage approximately 20 ms before the voltage at theVO Bus 10 Track terminal is allowed to rise. This provides the required standby power source to any downstream nonisolated modules in power-up sequencing applications. This is a sequenced output voltage from the converter that is controlled by the Track terminal during power-up transitions. It is only available to the PTB48560B, and used with the output voltage set to 3.3 V (an I/O supplyVO Seq 11 voltage). During power up, the voltage at VO Seq rises with the Track terminal, typically 20 ms after the VO Bus output has reached regulation. This is the output power return for both the VO Bus and VO Seq output voltages. This terminal should beVO COM 6 connected to the common of the load circuit. This terminal is used in power-up sequencing applications to control the output voltage of Auto-Track compatible modules, powered from the converter VOBus output. This includes the converter VOSeq output on the PTB48560B. The converter Track control has an internal transistor, which holds the voltage close to VOCOMTrack 5 potential for approximately 20 ms (40 ms with the PTB48560C) after the VOBus output is in regulation. Following this delay, the Track voltage and VOSeq rises simultaneously with the output voltage of all other modules controlled by Auto-Track. Provides the converter with a remote sense capability when used with +Sense. For optimum output voltage –Sense 7 accuracy, this pin should always be connected to VOCOM, close to the load circuit. This terminal is also the reference connection for both the output voltage set-point resistor and Track control. A resistor must be connected between this terminal and -Sense to set the converter output voltage. A 0.05-W rated resistor may be used, with tolerance and temperature stability of 1% and 100 ppm/°C, respectively. If leftVO Adjust 8 open circuit, the converter output voltage defaults to its lowest value. The specification table gives the standard resistor values for the most common output voltages. The +Sense pin can be connected to VOBus (or VOSeq) output. When connected to VOSeq, remote sense compensation is delayed until the converter's power-up sequence is complete. The voltage at VOBus is also+Sense 9 raised slightly. The +Sense input may be left open circuit, but connecting it to one of the output terminals improves load regulation of that output. (1) These functions indicate signals electrically common with the input. (2) Denotes negative logic: Low (–V I) = Normal operation, Open = Output off

400 LFM

200 LFM

100 LFM

Figure 1. Figure 2. Figure 3. Figure 4. typical data for the dc-dc converter. rated operating temperature. Derating limits apply to modules soldered directly to a 100–mm × 100–mm, double-sided PCB with 2 oz. copper. For surface mount packages, multiple vias (plated through holes) are required to add thermal paths around the power pins. Please refer to the mechanical specification for more information. Applies to Figure 4.

Figure 5. Figure 6. Figure 7. Figure 8. typical data for the dc-dc converter. rated operating temperature. Derating limits apply to modules soldered directly to a 100–mm × 100–mm, double-sided PCB with 2 oz. copper. For surface mount packages, multiple vias (plated through holes) are required to add thermal paths around the power pins. Please refer to the mechanical specification for more information. Applies to Figure 8.

400 LFM200 LFM

Figure 9. Figure 10. Figure 11. Figure 12. typical data for the dc-dc converter. rated operating temperature. Derating limits apply to modules soldered directly to a 100–mm × 100–mm, double-sided PCB with 2 oz. copper. For surface mount packages, multiple vias (plated through holes) are required to add thermal paths around the power pins. Please refer to the mechanical specification for more information. Applies to Figure 12.

www.ti.com Input Overvoltage Protection Differential Output Voltage Sense Overtemperature Protection Output Voltage Adjustment PTB48560A, PTB48560B PTB48560C SLTS236A–MARCH 2005–REVISED OCTOBER 2005 APPLICATION INFORMATION (continued) output that exceeds the converter overcurrent threshold (see applicable specification) causes the output voltage to momentarily fold back, and then shut down. Following shutdown, the module periodically attempts to automatically recover by initiating a soft-start power up. This is often described as a hiccup mode of operation, whereby the module continues in the cycle of successive shutdown and power up until the load fault is removed. Once the fault is removed, the converter automatically recovers and returns to normal operation. The converter protects itself against input voltage surges and transients of up to 100 V. This is above the maximum continuous operating input voltage of 75 V. In order to protect itself, the converter output is disabled at some voltage above 75 V. This is to ensure that the converter internal components are not exposed to voltages above their stress ratings. The converter output remains off for some of the period that the input voltage is above the maximum continuous rating. Once the overvoltage event has passed, the output from the converter automatically restarts by executing a soft-start power up. A differential remote sense allows a converter regulation circuitry to compensate for limited amounts of IR drop, that may be incurred between the converter and load, in either the positive or return PCB traces. Connecting the +Sense and –Sense pins to the respective positive and ground reference of the load terminals improves the load regulation of the converter output voltage at that connection point. The –Sense pin should always be connected to the V O COM.T h e+Sense pin may be connected to either the +VO Bus or +VO Seq outputs. When the +Sense pin is connected to the VO Seq output, the voltage at VO Bus voltage regulates slightly higher. Depending on the load conditions on the VO Seq output, the voltage at VO Bus may be up to 100 mV higher than the converter set-point voltage. In addition, the Smart-Sense feature (incorporated into the converter) only engages sense compensation to the V O Seq output when that output voltage is close to the set-point. During a power-up sequencing event, the sense circuit automatically defaults to sensing the VO Bus voltage, internal to the converter. Leaving the +Sense and –Sense pins open does not damage the converter or load circuit. The converter includes default circuitry that keeps the output voltage in regulation. However, if the remote sense feature is not used, the –Sense pin should still be connected to V OCOM. 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 sense pin connections, they are effectively placed inside the regulation control loop, which can adversely affect the stability of the converter. Overtemperature protection is provided by an internal temperature sensor, which monitors the temperature of the converter PCB (close to pin 1). If the PCB temperature exceeds a nominal 115°C, the converter shuts down. The converter then automatically restarts when the sensed temperature falls to approximately 105°C. When operated outside its recommended thermal derating envelope (see data sheet derating curves), the converter typcially cycles on and off at intervals from a few seconds to one or two minutes. This is to ensure that the internal components are not permanently damaged from excessive thermal stress. An external resistor is required to set the nominal output voltage(s) of the converter to a voltage higher than its minimum value. The resistor, R SET, must be connected directly between the VO Adjust (pin 8) and –Sense (pin 7) terminals. A 0.05-W rated resistor can be used. The tolerance should be 1%, with a temperature stability of 100 ppm/°C (or better). Place the resistor close to the converter and connect it using dedicated PCB traces (see Figure 14). Table 1 gives the nearest standard value of external resistor for the common voltages within each model's adjust range. The actual output voltage that the resistor value provides is also provided.

220 F/c109

Table 1. Standard Values of RSET for Common Output Voltages For other output voltages, the value of the required adjust resistor may be calculated using Equation 1. the formula along with the desired output voltage. Table 2. Adjust Ranges and Equation Constants Figure 14. Output Voltage Adjustment

implemented with a current limited Hot-Swap controller. SOA is the area beneath the applicable airflow rate curve on the graph of temperature derating vs output current. components are at or below their stated maximum operating temperatures. the converter. The enable pins are ideally controlled with an open-collector (or open-drain) discrete transistor. the module. If they are added, the maximum input voltage for these inputs must be limited to a maximum of 60 V. I (see the Electrical Characteristics table). to pin 2 disables the converter output. Figure 15 gives an example circuit that uses a MOSFET transistor. Figure 15. Positive Enable Configuration to enable an output from the converter. An example of this configuration is detailed in Figure 16.

www.ti.com Sequenced Power Up with POL Modules Overview Auto-Track Features PTB48560A, PTB48560B PTB48560C SLTS236A–MARCH 2005–REVISED OCTOBER 2005 The main output from the PTB48560x converters is V OBus. In power sequencing applications, V OBus is used as the intermediate supply voltage for powering one or more downstream nonisolated power modules that incorporate Auto-Track™ 1. The output voltage from Auto-Track compliant modules can be sequenced using a control input called Track. The Track input directly controls the output of a module from zero to its set-point voltage. The control is on a volt-for-volt basis, and allows multiple modules to follow a common analog signal during power-up events. The Track signal attempts to start rising when the nonisolated modules are first powered from V OBus. However, for proper sequencing, the voltage must be held at ground potential for at least 20 ms (40 ms for 12-V input modules) after V OBus is in regulation. This is necessary to allow time for the nonisolated modules to complete their power-up initialization. The Track pin of each PTB48560x converter has an internal open-drain transistor that automatically holds the Track signal at ground potential to comply with this requirement. The PTB48560B (1.8 V to 3.6 V) has a V OSeq output. V OSeq is internally derived from V OBus and regulated to the same set-point voltage. It has the added feature of being controlled by the Track input. During power up, this output can sequence with the outputs of the nonisolated modules powered from V OBus. Figure 18 shows a block diagram of the converter Auto-Track features. The components shaded are only present in the PTB48560B. During power up, V OBus rises promptly, after the converter is connected to a valid input source and its output is enabled. V OSeq (PTB48560B) is the Auto-Track compatible output that is controlled by the voltage presented at the Track terminal. The control is active from 0 V up to a voltage just below the V OBus output. Between these limits, the voltage at V OSeq follows that at the Track terminal. Once the Track voltage is at the VOBus voltage, raising it higher has no further effect. The voltage at V OSeq cannot go higher than V OBus, and if connected to +Sense, it regulates at the set-point voltage. 2 The Track input to the PTB48560x series of converters include a pullup resistor (R TRK)t oV OBus, and a 1-µF capacitor (CTRK) to -Sense. These components are standard on all Auto-Track compatible modules. They form an R–C time constant that cause the Track voltage to rise when the internal MOSFET is turned off. The unity-gain relationship between V OSeq and the Track input is the same as all other Auto-Track compliant outputs.3 The VOSeq output also follows a compatible external ramp waveform applied to the Track pin. 4, 5 The internal MOSFET is designed to hold the Track voltage at ground potential for the required period after the V OBus output is in regulation.

Note: The shaded functions are only available with the PTB48560B (3.3-V output). Figure 18. Block Diagram of Auto-Track Features

Auto-Track compatible modules incorporate a Track input that can take direct control of the output voltage

a common control voltage during power up.

When +Sense is connected to the V

the set-point voltage. In this configuration, the voltage at the V OBus output is up to 100 mV higher.

The V OSeq output on the PTB48560B cannot sink load current. This constraint does not allow the module to

coordinate a sequenced power down.

The slew rate for the Track input signal must be between 0.1 V/ms and 1 V/ms. Above this range, the V OSeq

the internal R-C time constant of the modules being sequenced.

If an external voltage is used to control the Track terminal, the source current must be limited. A resistance

100 F/c109

3 NEN

47 F/c109

must be supplied by the PTB48560B, and cannot exceed that available at the V OBus output. Figure 19. Power-Up Sequencing With Nonisolated POL Modules must always be set to 3.3 V (R1 = 5.36 k Ω). This sets the output voltage of both the V OBus and VOSeq outputs. are simply connected together. modules, until it reaches its set-point voltage.

Figure 20. Power-Up Waveforms with POL Modules

Figure 21. Power-Up Sequencing With Nonisolated POL Modules Figure 21 when the Track control of all three modules are simply connected together. the two nonisolated modules then rise simultaneously to their respective set-point voltages.

Figure 22. Power-Up Waveform

Orderable Device Status(1) Package Type Package Drawing Pins Package Qty Eco Plan(2) Lead/Ball FinishMSL Peak Temp (3) PTB48560AAH ACTIVE DIP MOD ULE ERW 11 12 TBD Call TI Level-1-235C-UNLIM PTB48560AAS ACTIVE DIP MOD ULE ERY 11 12 TBD Call TI Level-1-235C-UNLIM PTB48560AAZ ACTIVE DIP MOD ULE ERY 11 12 Pb-Free (RoHS) Call TI Level-3-260C-168 HR PTB48560BAH ACTIVE DIP MOD ULE ERW 11 12 TBD Call TI Level-1-235C-UNLIM PTB48560BAS ACTIVE DIP MOD ULE ERY 11 12 TBD Call TI Level-1-235C-UNLIM PTB48560BAZ ACTIVE DIP MOD ULE ERY 11 12 Pb-Free (RoHS) Call TI Level-3-260C-168 HR PTB48560CAH ACTIVE DIP MOD ULE ERW 11 12 TBD Call TI Level-1-235C-UNLIM PTB48560CAS ACTIVE DIP MOD ULE ERY 11 12 TBD Call TI Level-1-235C-UNLIM PTB48560CAZ ACTIVE DIP MOD ULE ERY 11 12 Pb-Free (RoHS) Call TI Level-3-260C-168 HR (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/productcontentfor 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 to Customer on an annual basis. PACKAGE OPTION ADDENDUM www.ti.com 18-Jul-2006 Addendum-Page 1

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Summary

30-W, 48-V INPUT DC/DC CONVERTERS WITH AUTO-TRACK TM SEQUENCING

Description