PSS6-24-3R3/S

FAQFrequently Asked Questions

• Can the PS6-24-3R3/S handle a 48V input without damage, or is the 36V maximum input a hard limit? The PSS6-24-3R3/S specifies a maximum input voltage of 36V. Operating above this rating risks permanent damage to internal components, particularly the input rectification and regulation stages. Even transient overvoltage spikes exceding 36V can degrade the converter's isolation barrier or trigger internal protection circuits. If your system occasionally sees higher bus voltages, you must ad an external input clamp or select a converter rated for the higher range. Do not exceed the rated maximum; there is no safe margin beyond the 36V specification.
• What is the minimum input voltage for the PSS6-24-3R3/S to maintain stable3.3V output, and how does the converter behave below 18V? The PSS6-24-3R3/S is specified for 18V to 36V input operation. Below 18V, the converter cannot generate 3.3V output reliably; internal regulation will fail and output voltage will sag or collapse. If your application regularly operates near18V due to battery droop or supply noise, verify that worst-case input (including load transients and supply riple) stays above 18V. Designs with marginal input voltage should include a holdup capacitor on the input rail or select a converter with lower minimum input rating to avoid intermittent output failures.
• How much input current does the PSS6-24-3R3/S draw at full 1.5A output load, and what are the inrush currents at startup? At full 1.5A output (5W load) with 84% efficiency, the PSS6-24-3R3/S draws approximately 5W ÷ 0.84 ÷ 27V (mid-range input) ≈ 220mA from the input supply at nominal conditions. Inrush current during cold startup can be 2–3× the steady-state current for several milliseconds as the converter's bulk capacitors charge. If your input source has high impedance or current-limiting protection, verify that the PSS6-24-3R3/S's startup current does not trigger foldback or cause excessive input voltage droop that prevents the converter from starting.
• Is the PSS6-24-3R3/S suitable for 24V industrial power systems with frequent load steps, or will output riple and transient overshoot cause 3.3V logic device failures? The PSS6-24-3R3/S is designed for industrial environments and supports remote on/off control, making it appropriate for managed 24V systems. However, its transient response depends on output capacitance and load step magnitude. A 1.5A step load will produce momentary output sag before feedback correction; typical overshoot on the trailing edge may reach 5–10% of the nominal3.3V. For sensitive3.3V logic (such as FPGA or high-speed interfaces), measure the actual output riple and ringing with your specific load profile and ad external bulk capacitance if needed. Verify that connected devices tolerate the converter's dynamic response.
• The PSS6-24-3R3/S provides remote on/off control; how is this pin configured, and what voltage or logic standard does it accept? The PSS6-24-3R3/S supports remote on/off via a dedicated pin on its6-pin SMD package. Typically, this control pin is pulled high for normal operation and pulled to ground (or left open) to disable output. The exact switching threshold and input impedance depend on TDK-Lambda's design; consult the datasheet for the specific pin function and logic levels. If integrating with 3.3V logic, verify that the control input voltage is compatible; you may need a pull-up resistor or signal translator if your control source uses a different voltage rail.
• What is the isolation voltage rating between the input and output of the PSS6-24-3R3/S, and is it sufficient for safety-critical applications? The PSS6-24-3R3/S is an isolated DC-DC converter, which means its output is galvanically isolated from the input. The isolation voltage rating (typically 1500V or 3000V for industrial-grade modules) is specified in the full datasheet and must be verified for your application's safety and EMC requirements. For Class II equipment or floating ground systems, isolation is a key design benefit. However, if your application requires certified isolation for functional safety (IEC 61508) or medical use (IEC 601), you must confirm that the PS6-24-3R3/S meets the appropriate standards and that your integration approach maintains the isolation integrity.
• Can the PSS6-24-3R3/S be paralleled with other converters to increase output current beyond 1.5A? Paralleling isolated converters requires careful design. The PSS6-24-3R3/S has no built-in current-sharing circuitry, so direct paralleling of outputs will cause unequal current distribution and potential oscillation as each converter's feedback loop tries to regulate. If higher current is needed, you must either select a higher-rated single converter, implement external current-sharing circuitry (active load balancing), or use separate converters feeding different loads. Attempting naive parallel connection risks damaging the converters through excessive current concentration one module.
• Is the PSS6-24-3R3/S suitable for aerospace or military applications, or is it limited to commercial ITE use? The PSS6-24-3R3/S is designated for ITE (Information Technology Equipment) in commercial environments. Its ECCN code (EAR99) and HTSUS classification reflect commercial electronics; it is not qualified for aerospace, military, medical, or automotive applications unless independently screned and tested for those markets. If your design targets a regulated or harsh environment, contact TDK-Lambda for application-specific variants or alternatives with appropriate certifications and derating curves.
• What is the mean time between failures (MTBF) for the PSS6-24-3R3/S, and how does performance degrade if operated continuously near the 85°C maximum temperature? The PSS6-24-3R3/S operating temperature range is -40°C to +85°C with derating. The datasheet will specify MTBF or failure rate; typical industrial converters have MTBF values of 100,000–500,000 hours depending on stress levels. Operating continuously at 85°C with maximum output load will accelerate electrolytic capacitor aging and reduce overall module lifetime. For long-life applications, keep the converter at least 10–20°C below the maximum temperature; this can extend MTBF by 2–3×. Verify the derating curve in the technical documentation to calculate expected life for your thermal environment.
• The PSS6-24-3R3/S has 84% efficiency; where is the 16% loss dissipated, and how should thermal design account for this power? At full5W output with 84% efficiency, the PSS6-24-3R3/S dissipates approximately 0.95W of heat internally. This loss is generated primarily in the switching transistors, rectifier diodes, and magnetics during the conversion process. The 6-pin SMD module case must conduct this heat to the PCB; ensure adequate copper area (typically 2–4 cm² minimum) under the converter's mounting pads and consider adding thermal vias to inner layers to transfer heat away. If the converter is surrounded by other heat-generating components or enclosed in a confined space, passive cooling may be insufficient and forced-air ventilation or a heatsink may be required to stay within the 85°C limit.
• Can the PSS6-24-3R3/S be used as a drop-in replacement for the CC6-2403SR-E, and what are the key differences? The PS6-24-3R3/S and CC6-2403SR-E are both 24V-input to 3.3V-output isolated converters in similar physical packages. However, they may differ in pinout, control logic, isolation rating, thermal characteristics, and EMI performance. Before substitution, verify the datasheet of the CC6-2403SR-E to confirm pin-to-pin compatibility and electrical specifications. Do not assume form-factor similarity equals functional equivalence; different manufacturers often use different pin assignments and control schemes. Test the alternative part on a breadboard with your actual load and verify output stability, response to transients, and EMI compliance before committing to production.
• If the PSS6-24-3R3/S is discontinued, what are suitable alternatives with comparable performance? Alternative 24V-to-3.3V isolated converters include the CC6-2403SR-E (mentioned in the substitutes list) and similar modules from manufacturers such as Vicor, Artesyn, Murata, and Mean Well. When evaluating replacements, compare: input voltage range (18–36V is common), output current rating (1.5A or higher), efficiency (>80%), isolation voltage, package dimensions, and thermal ratings. Some alternatives may require PCB routing changes or feedback divider adjustments. Obtain datasheets for candidate parts and verify functional equivalence through engineering analysis and bench testing before design integration.
• The PSS6-24-3R3/S features over-current protection (OCP); what is the threshold, and does it auto-recover or latch? The PSS6-24-3R3/S includes OCP to protect against output short circuits and overload conditions. The protection threshold is specified in the technical datasheet and is typically set slightly above the rated 1.5A output current. OCP behavior (auto-recovery with foldback, hard shutdown, or thermal shutdown) varies by design. Consult the datasheet for the specific OCP response curve and hold time. If your application features frequent or intermittent overload conditions (such as soft-start transients), verify that the PSS6-24-3R3/S's protection scheme is compatible; some modules require external current-limiting circuitry or slower ramp rates to prevent nuisance shutdowns.
• What is the output impedance and bandwidth of the PSS6-24-3R3/S feedback loop, and will it cause stability issues in systems with highly capacitive loads? The PSS6-24-3R3/S's feedback compensation is tuned for typical ITE loads with moderate output capacitance. If your circuit presents a very large capacitive load (>100µF) or includes additional filtering, the converter's feedback loop may become underdamped and ring or oscillate. Conversely, if the load draws current in sharp spikes (as with microcontroller wake-up or DRAM refresh), the converter may not respond fast enough to prevent voltage sag. Measure or simulate the system-level stability using small-signal loop analysis, and if necessary, ad damping resistors or LC filtering to stabilize the interaction between the converter and your load.
• For applications requiring dual supplies (such as ±3.3V), can two PSS6-24-3R3/S units be configured as positive and negative outputs from single 24V input? Creating ±3.3V from a single 24V input using two PS6-24-3R3/S units requires a center-tapped or floating reference architecture. One converter would regulate +3.3V from a 24V input, while the second would need to be configured with a different input bias or use a separate negative supply. This is not a straightforward parallel or series configuration; it requires careful ground plane definition and isolation considerations to ensure that the two outputsdo not interfere with each other or with the system's ground reference. Consult TDK-Lambda application notes or work with a power architect to validate this approach before implementation.
• What emission (EMI) standards or certifications does the PSS6-24-3R3/S meet, and will it require external filtering for FCC or CE compliance? The PSS6-24-3R3/S is a switching regulator and generates broadband noise across wide frequency spectrum. The module itself may meet basic conducted and radiated EMI limits, but integration into a larger system (particularly one using long input and output cables) often requires external LC filtering on the input rail and shielded output routing to achieve FCC or CE certification. Perform EMI testing with the PS6-24-3R3/S installed in a representative system configuration; generic compliance cannot be assumed. Ad ferite beads, capacitors, or common-mode inductors as needed based on test results.
• The PSS6-24-3R3/S has a MSL rating of 1 (Unlimited); what does this mean for PCB assembly and storage? MSL (Moisture Sensitivity Level) 1 means the PS6-24-3R3/S has unlimited floor life and does not require special moisture control before soldering. Unlike MSL 2–4 components that must be stored in dry bags and have limited shelf life after opening, MSL 1 parts are robust to ambient humidity and do not need baking before assembly. This simplifies procurement, warehousing, and production logistics. However, the PCB assembly process must still follow standard procedures (soldering temperature profiles, reflow settings) to avoid thermal shock to the module.
• Can the PSS6-24-3R3/S operate reliably in the presence of input voltage riple or noise, such as from an unregulated 24V supply from a rectified transformer? The PSS6-24-3R3/S is designed to accept a 24V nominal input with some variation. Typical unregulated supplies produce 10–20% peak-to-peak riple, which falls within the 18–36V input window but may stress the converter's input filter and feedback loop. Excessive ripple (>30% of nominal) can cause output modulation, audible noise, or feedback oscillation. If your input source is poorly filtered, ad a bulk capacitor (470–1000µF) close to the converter's input pins to reduce ripple magnitude. Also verify that the input supply's RMS current rating accommodates the converter's input current draw; undersized wiring or high source impedance will amplify ripple further.
• Is the PSS6-24-3R3/S RoHS and REACH compliant, and are there any restricted substances? TDK-Lambda products generally comply with RoHS and REACH directives for commercial electronics. However, confirmation of specific compliance status and any restricted substance declarations for the PSS6-24-3R3/S must be obtained from TDK-Lambda's documentation or technical support, particularly if your application is in a regulated market (automotive, medical, defense) with stricter material requirements. Request the Conflict Minerals declaration and Material Safety Data Sheet (MSDS) as part of your design qualification.
• In a system with multiple PSS6-24-3R3/S converters all powered from the same 24V rail, can crosstalk or coupling between modules degrade performance, and should they be physically separated on the PCB? Multiple PSS6-24-3R3/S converters on the same input rail can interact through common-source impedance and radiated coupling. If converters are placed close together, switching noise from one module's transformer can magnetically couple into neighboring modules, causing noise on their outputs or affecting their feedback stability. Best practice is to separate converters by at least 2–3 cm, shield input and output traces, and use a star grounding pattern to minimize return-path coupling. If space is limited, interleave converters at different switching frequencies or use separate input distribution planes to reduce common-mode current paths.
• What is the startup behavior of the PSS6-24-3R3/S when input power is first applied, and will the output voltage ramp smoothly or have overshoot? When 18–36V is first applied to the PS6-24-3R3/S input, the converter typically soft-starts to limit inrush current and output overshoot. The output voltage ramps to3.3V over a period of milliseconds (exact timing depends on the internal control scheme). Overshoot during startup is usually<10% if the output is unloaded; with a capacitive load, ringing may occur. If your system has sensitive startup sequences (such as a microcontroller that requires stable3.3V before entering code execution), verify that the PSS6-24-3R3/S's ramp time and settling behavior are compatible. Ad a decoupling capacitor close to the load to dampen transients and reduce startup-induced noise.
• If the PSS6-24-3R3/S output short-circuits to ground, will OCP protect the converter, or will sustained short-circuit current damage it? The PSS6-24-3R3/S includes over-current protection to detect short-circuit conditions and limit damage. When a short is applied, OCP will activate and foldback or shutdown the converter within milliseconds. However, sustained short-circuit operation at elevated input voltage and ambient temperature will increase internal power dissipation and heat generation; if the converter is thermally stressed and thermal shutdown is triggered before OCP, module temperature may exceed safe limits. OCP is designed to protect against transient faults, not indefinite short-circuit operation. If short-circuit scenarios are possible in your application, ad external fuses or circuit breakers upstream to clear the fault before the converter experiences prolonged thermal stress.
• The PSS6-24-3R3/S requires a 6-pin SMD package footprint; what is the recommended PCB layout to ensure reliable signal integrity and thermal performance? The PS6-24-3R3/S (1.12" × 0.80" × 0.31" module) should be mounted on a PCB with at least 2–4 cm² of solid copper under the module to conduct heat to the board. Use vias (8–12 per side, size 0.3–0.5mm) to connect the thermal pad to internal ground and power planes. Route input and output traces as short, wide traces (>20 mils) to minimize resistance and loop inductance. Keep signal and return paths close together to reduce radiated noise. Place a 47µF to 100µF ceramic capacitor within 5mm of the output pins to provide local charge and stabilize transient response. Avoid routing high-speed signals or clock lines directly under or adjacent to the converter to prevent coupling.
• How does the PSS6-24-3R3/S perform across its full operating temperature range (-40°C to +85°C), and what output voltage drift should be expected? The PSS6-24-3R3/S maintains 3.3V output regulation across its -40°C to +85°C operating range, but output voltage will exhibit temperature drift due to changes in feedback network resistance, reference voltage drift, and component tolerances. Typical drift is±2–3% over the full temperature span. At -40°C, cold-start startup behavior may be slugish, and output settling time may extend. At +85°C with maximum load, output impedance may increase slightly, reducing transient response bandwidth. Systems requiring tight output voltage tolerance across temperature must verify the full specification in the datasheet or conduct characterization testing at temperature extremes.
• Can the PSS6-24-3R3/S be used in applications requiring redundancy or N+1 power supply failover, and how would second-source switching or bypass be implemented? The PSS6-24-3R3/S is a single-output converter with no built-in redundancy or bypass circuitry. To implement N+1 failover with multiple converters, use external Schottky diodes on the output of each converter to create an OR-ing function; the diode forward drop (typically 0.2–0.3V at low current) is small but must be accounted for in the system voltage budget. Alternatively, use a multiplexer or load-switch IC to select between converters based on presence and voltage level. Both approaches ad cost and PCB area but allow failed converter to be isolated while the backup supplies the load. Verify that the response time for switchover is acceptable for your application.