LDL1117S50R
STMicroelectronics
Needs validationhigh risk
A modern LDO with matching temp range, but requires board redesign and has higher power use.
Best Alternatives to HT7850-A
Finding a replacement for the HT7850-A, a 5V low-dropout regulator, is challenging due to its ultra-low quiescent current (2µA) and low dropout voltage. These features are critical for power-sensitive and battery-operated applications.
AI replacement insight
Electrical riskhigh
Massive increase in quiescent current and dropout voltage will impact system power budget and operating voltage range.
Package riskhigh
All candidates have different packages/footprints, requiring a mandatory board redesign.
Sourcing risklow
While these specific candidates are poor fits, many 5V LDOs exist, but finding one with matching low-power specs is key.
Can it be replaced directly?
No direct or pin-compatible replacement for the HT7850-A was found among the candidates. The target's ultra-low power consumption is a critical feature that is not matched.
Best replacement path
Search for a 5V LDO with quiescent current under 10µA, dropout voltage under 200mV, and a matching SOT-23, SOT-89, or TO-92 package.
Main risk
A replacement will likely consume significantly more power, reducing battery life, and will require a PCB redesign due to package differences.
Recommended alternatives
4Alternative comparison matrix
| Feature / factor | HT7850-A | LDL1117S50R | SCJT1117B-5.0 | L78M05CDT-TR(JSM) | Compatibility / risk |
|---|---|---|---|---|---|
| Package | SOT-23, SOT-89, TO-92 | SOT223 | SOT-223 | TO-252-2L | SOT223 / SOT-223 / TO-252-2L / DPAK (TO-252) — Requires PCB redesign.; SCJT1117B-5.0: Requires PCB redesign.; L78M05CDT-TR(JSM): Requires PCB redesign.; LR7805D: Requires PCB redesign. |
| Current | 0.45 A | 1.2 A | 1.0 A | 0.5 A | 1.2 A / 1.0 A / 0.5 A — Higher output current capability.; SCJT1117B-5.0: Higher output current capability.; L78M05CDT-TR(JSM): Slightly higher output current.; LR7805D: Higher output current capability. |
| Dropout Voltage | 60 mV | 350 mV | 1.3 V | 1.8 V | 350 mV / 1.3 V / 1.8 V / 2.0 V — Significantly higher dropout, impacts low Vin operation.; SCJT1117B-5.0: Significantly higher dropout, impacts low Vin operation.; L78M05CDT-TR(JSM): Very high dropout, requires much higher input voltage.; LR7805D: Very high dropout, requires much higher input voltage. |
| Quiescent Current | 2 µA | 250 µA | Typ. 5mA (est.) | 4 mA | 250 µA / Typ. 5mA (est.) / 4 mA / Typ. 4-8mA (est.) — Much higher power consumption, unsuitable for battery apps.; SCJT1117B-5.0: Much higher power consumption, unsuitable for battery apps.; L78M05CDT-TR(JSM): Extremely high power consumption vs target.; LR7805D: Extremely high power consumption vs target. |
| Temperature | -40°C to 85°C | -40°C to 125°C | -20°C to 125°C | -40°C to 125°C | -40°C to 125°C / -20°C to 125°C / 0°C to 150°C — Wider operating range.; SCJT1117B-5.0: Narrower operating range at low temperatures.; L78M05CDT-TR(JSM): Wider operating range.; LR7805D: Commercial temp range, not for industrial use. |
Application & sourcing insights
Questions & answers
Among the reviewed parts, LDL1117S50R is the closest functional alternative, but it is not a good replacement. It requires a board redesign and has much higher quiescent current (250µA vs 2µA) and dropout voltage. A better approach is to search for another ultra-low Iq LDO.