MEAN WELL LDH-25-350 is a pin-mounted DC/DC step-up constant-current LED driver with 350 mA output and 25.2 W catalog rated power. Its output-voltage range is 12.5–72 VDC, subject to the required voltage difference above the 9.5–32 VDC input. It provides 0–10 V or PWM dimming for DC-source LED lighting.
Combined catalog pages 1–6; LDH-25 revision 2024-10-16.
| Complete model |
LDH-25-350 |
| Model code / construction |
LDH-25 identifies the driver series; the current code is in mA. No W suffix selects the pin-mounted form. Fully encapsulated, silicone-potted construction in a UL94-V0 flame-retardant plastic case. |
| Conversion / load type |
Step-up DC/DC conversion with constant-current output. Connect the driver directly to an LED string; the catalog does not recommend using additional drivers on its output. |
| Rated current / power |
350 mA / 25.2 W. The series number is not a substitute for this model’s actual output rating. |
| Output operating range |
12.5–72 VDC. Without dimming, output voltage must be at least 3 V above DC input. With dimming, output voltage must be at least twice the DC input voltage. Apply both the model voltage range and this input/output relationship. |
| DC input |
9.5–32 VDC. When input is below 11 V, output current can fall below the rated value; consult the static-characteristic curve and allow for cable voltage drop. |
| Typical current accuracy / ripple |
Accuracy: ±5% at 12 VDC and 24 VDC input. Current ripple: 5% at rated current. |
| Typical efficiency |
92% at 12 VDC input; 95% at 24 VDC input. Efficiency varies with the LED-string voltage/load; use the model-specific curves for the selected LED forward voltage. |
| Typical input current |
2.5 A at 12 VDC; 1.2 A at 24 VDC. |
| Typical shutdown input current |
7 mA at 12 VDC input with PWM dimming OFF. |
| Open-load / overvoltage behavior |
Overvoltage range: 73–100 V. At no load the output rises to the overvoltage threshold, then drops to approximately the input voltage; re-power to recover. |
| Output short-circuit warning |
Do not short the output. The detailed specification warns that an output short circuit will damage the power supply; do not rely on automatic short-circuit recovery. |
| Cooling / ambient temperature |
Free-air convection; −40 to +70°C, subject to the thermal and input-voltage derating curves. |
| Thermal derating |
At 12–18 VDC input, the 100% load curve extends to +60°C; at 18–32 VDC input it extends to +70°C. Observe the separate plotted boundaries; the graph does not specify a sloped extension beyond them. |
| Input-voltage derating |
The plotted load is 75% at 9.5 VDC, rising to 100% at 12 VDC; 100% from 12 to 32 VDC. Observe the output-voltage and temperature limits at the same time. |
| Working humidity |
20–90% RH, non-condensing. |
| Storage temperature / humidity |
−40 to +85°C; 10–95% RH. |
| Temperature coefficient |
±0.03%/°C over 0–50°C. |
| Vibration |
10–500 Hz, 2G; 10 minutes per cycle, 60 minutes along each of the X, Y and Z axes. |
| Altitude derating |
For this fanless design, reduce the allowed ambient temperature by 3.5°C per 1000 m above 2000 m altitude. |
| Lifetime / warranty |
Typical lifetime greater than 35,000 hours when the marked case-temperature point tc is about 80°C or lower. The catalog states a 3-year manufacturer warranty; warranty conditions remain those of the manufacturer. |
| Dimensions |
52.4 × 27.2 × 24 mm (L × W × H); drawing tolerance ±1 mm. |
| Input / output / dimming connections |
Bottom-view pins: 1 Vin+; 2 Vin−; 3 DIM+; 4 DIM−; 5 Vout−; 6 Vout+. Follow the numbered bottom-view drawing for the board layout. |
| Lead / pin geometry |
Pin diameter 1.04 mm; side view shows 3.5 ±1 mm pin projection. Use the catalog bottom view for exact pin coordinates. |
| Polarity and return wiring |
Observe input and LED polarity. Do not apply negative/reversed input voltage, and do not connect Vin− to Vout−; the catalog warns of damage from incorrect polarity. |
| Input cable sizing |
Account for the DC input current and wiring voltage drop so that the voltage at the module remains within its operating limits. |
| Soldering limits |
Wave soldering: 265°C for 5 seconds maximum. Manual soldering: 390°C for 3 seconds maximum. |
| DC-source EMC selection |
With a battery DC source, the catalog states BS EN/EN 55015 compliance without an additional input filter and capacitors. For a DC-bus source, follow the page 6 filter circuit: C1 = 100 µF / 35 V; LF1 common-mode choke = 11.5 mH. Its reference core is T16 × 12 × 8 mm, Mn-Zn, permeability 10000 ±30%, AL = 4600 nH/N²; winding reference 0.6 mm × 1 wire, 50 turns. Select and verify components for the complete installation. |
| Applications |
DC battery-source lighting, portable lighting, solar LED street lighting, greenhouse lighting and low-bay LED lighting, within the model operating limits. |
| DC input polarity and wiring drop |
Connect the positive and negative DC input terminals correctly. Do not apply a negative input voltage. Account for voltage drop in the input wiring because the input current can be high. |
| Input and output separation |
Do not connect Vin- to Vout-. Follow the pin or lead-wire diagram for this exact model; identical wire colors do not make the input and output negative connections interchangeable. |
| Dim-off output voltage |
When dimmed off, the output voltage falls to approximately the input voltage. Complete darkness requires an LED string that remains off at that input voltage; dim-off is not a zero-output-voltage isolation state. |
| Battery and DC-bus EMC |
The catalogue states battery-source compliance with BS EN/EN 55015 without additional input filters or capacitors. A DC-bus source requires the model-specific additional EMC filter circuit shown in the catalogue. |
| Installation reference scope |
The catalogue links the general LED installation manual, whose family list does not explicitly name LDH. Use this DC model's specific pinout and application limits; the general manual does not establish AC wiring or circuit-breaker ratings for this unit. |
| Short-circuit limitation |
The specification states that an output short circuit will damage the power supply. Do not treat the feature-page protection heading as a recoverable short-circuit guarantee. |
| Dimming connection boundary |
Connect LEDs directly; do not add a further driver at the output. Do not connect DIM- to Vo-. Leave unused dimming connections open. The minimum defined dimming level is about 8%; output current between 0% and 8% is undefined. |
| Output headroom |
For operation without dimming, the output must be at least 3 V above the DC input. For dimming operation, the catalogue requires the output voltage to be twice the input voltage. |
| Safety references |
LVD BS EN/EN 61347-1, BS EN/EN 61347-2-13 and EAC TP TC 004, as listed in the catalog. |
| EMC emission |
BS EN/EN 55015 and EAC TP TC 020. The stated EMI test layout uses a battery DC source; a DC-bus installation requires the additional filter network described above. |
| EMC immunity |
BS EN/EN 61547 and BS EN/EN 61000-4-2, -3, -4, -6 and -8; light-industry level; EAC TP TC 020. |
| MTBF |
12369.5 thousand hours minimum, Telcordia TR/SR-332 (Bellcore); 896.4 thousand hours minimum, MIL-HDBK-217F at 25°C. |
| Catalog unit mass |
50 g for this pin-mounted version, explicitly listed in the PACKING field. This is the per-unit catalog reference, not a measured shipping-package weight. |
| Measurement conditions |
Unless stated otherwise: 12 VDC input, rated load, 25°C and 70% RH ambient. Typical values are not guarantees across all operating conditions. |
