LD1117S25TR - 800mA Low Dropout Positive Regulator | STMicroelectronics
Référence : LD1117S25TR ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $0.35 | $0,35 |
| 10 | $0.3 | $3,00 |
| 100 | $0.25 | $25,00 |
| 500 | $0.2 | $100,00 |
| 1 000 | $0.18 | $180,00 |
LD1117S25TR Présentation
A low dropout regulator (LDO) is a type of linear voltage regulator that maintains a stable output voltage even when the input voltage is only slightly higher than the output. Unlike standard linear regulators, LDOs achieve a low dropout voltage by using a PNP pass transistor or a PMOS device, allowing them to operate efficiently in applications where the input-to-output voltage difference is small. LDOs are a subset of linear regulators, which in turn are part of the broader category of voltage regulators within power management integrated circuits (ICs).
Key features of the LD1117S25TR include a fixed 2.5V output, a maximum output current of 800mA, and a dropout voltage of 1.1V at full load. The device also offers internal current limiting and thermal shutdown protection, ensuring safe operation under fault conditions. The SOT-223 package provides a compact footprint with a thermal resistance of approximately 50°C/W, enabling moderate power dissipation without external heatsinking.
The LD1117S25TR utilizes a PNP pass transistor architecture, which allows for low dropout operation and stable output with a minimum output capacitor of 10µF. The device is designed to be stable with tantalum or aluminum electrolytic capacitors, and it includes a bandgap reference for accurate output voltage regulation. The internal current limit and thermal shutdown circuits protect the device from overcurrent and overtemperature conditions, enhancing system reliability.
Typical applications for the LD1117S25TR include post-regulation for switching power supplies, battery-powered equipment, and low-voltage logic supplies. Its fixed 2.5V output is commonly used to power microcontrollers, memory ICs, and other digital circuits that require a stable 2.5V rail. The low dropout voltage and low quiescent current make it suitable for portable devices where power efficiency is critical.
When designing with the LD1117S25TR, ensure that the input voltage is at least 1.1V above the output voltage to maintain regulation. The output capacitor should be placed close to the output pin to minimize parasitic inductance and ensure stability. Additionally, the thermal pad of the SOT-223 package should be connected to a copper area on the PCB to improve heat dissipation.
Alternatives de remplacement direct pour LD1117S25TR — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec LD1117S25TR (même facteur de forme et même empreinte) — différant par Output Voltage, Dropout Voltage, Input Voltage Range, Line Regulation, Load Regulation.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
LD1117S25TR
✅ Remplacement direct✓ En stock
$0.18 / unité
Voir la fiche technique →LD1117S33TR
✅ Remplacement direct ⚠️ Spécifications non vérifiées✓ En stock
$0.2 / unité
Voir la fiche technique →LD1117S18TR
✅ Remplacement direct ⚠️ Spécifications non vérifiées✓ En stock
$0.15 / unité
Voir la fiche technique →AMS1117-2.5
✅ Remplacement direct ⚠️ Spécifications non vérifiées📋 Alternative de référence (hors catalogue)
NCP1117ST25T3G
✅ Remplacement direct ⚠️ Spécifications non vérifiées📋 Alternative de référence (hors catalogue)
AP1117-2.5
✅ Remplacement direct ⚠️ Spécifications non vérifiées📋 Alternative de référence (hors catalogue)
LD1117S25TR Valeurs maximales et caractéristiques électriques
| Type de sortie | Fixed |
| Tension de sortie | 2.5 V |
| Courant de sortie maximal | 800 mA |
| Plage de tension d'entrée | Up to 15 V |
| Tension de déchet | 1.1 V at 800 mA |
| Courant de repos | 5 mA |
| Line Regulation | 0.2% (typical) |
| Load Regulation | 0.4% (typical) |
| Output Capacitor | 10 µF (minimum) |
| Plage de température de fonctionnement | 0°C to +125°C |
| Boîtier | SOT-223 |
| Type de montage | Surface Mount |
| Thermal Resistance (θJA) | 50 °C/W |
| Statut RoHS | Compliant |
| Lead-Free | Yes |
Configuration des broches de LD1117S25TR
| Broche 1 | IN — Input voltage pin |
| Broche 2 | GND — Ground pin |
| Broche 3 | OUT — Regulated output voltage |
| Broche 4 | TAB — Thermal pad, connected to OUT |
Applications typiques
LD1117S25TR convient pour 6 applications: Post-Regulation for Switching Power Supplies, Battery-Powered Equipment, Low-Voltage Logic Supplies, Consumer Electronics, Industrial Control Systems, Telecommunication Equipment.
Post-Regulation for Switching Power Supplies
The LD1117S25TR is used as a post-regulator to provide a clean 2.5V rail from a noisy switching converter output. Its low dropout voltage of 1.1V allows it to operate with minimal headroom, and its 800mA output current is sufficient for many digital loads. The device's internal current limiting and thermal shutdown protect the downstream circuitry from faults. In a typical application, the LD1117S25TR is placed after a buck converter, with a 10µF output capacitor to ensure stability. The low output noise and good line/load regulation make it suitable for powering sensitive analog and digital circuits.
Recommandé
Battery-Powered Equipment
In battery-powered devices, the LD1117S25TR regulates a 2.5V rail from a battery voltage that may drop as low as 3.6V. Its low quiescent current of 5mA helps extend battery life, and the low dropout voltage ensures efficient operation even when the battery is nearly discharged. The SOT-223 package is compact, making it suitable for portable devices. The device's thermal shutdown prevents damage from excessive power dissipation, which is important in small enclosures. For a 3.7V Li-ion battery, the LD1117S25TR can provide a stable 2.5V output until the battery voltage falls below 3.6V.
Recommandé
Low-Voltage Logic Supplies
The LD1117S25TR provides a stable 2.5V supply for low-voltage logic ICs, such as FPGAs, CPLDs, and memory devices. Its 800mA output current can power multiple logic devices, and the fixed 2.5V output eliminates the need for external resistor dividers. The device's fast transient response ensures stable operation during rapid load changes. In a typical application, the LD1117S25TR is connected to a 3.3V rail, and the output is decoupled with a 10µF capacitor. The low dropout voltage allows the regulator to maintain regulation even if the 3.3V rail dips slightly.
Recommandé
Consumer Electronics
The LD1117S25TR is widely used in consumer electronics such as set-top boxes, routers, and gaming consoles to provide a clean 2.5V rail for various ICs. Its low cost and availability in the SOT-223 package make it a popular choice for high-volume production. The device's thermal shutdown and current limiting ensure reliable operation in consumer environments. In a typical application, the LD1117S25TR is powered from a 5V adapter, and the output is filtered with a 10µF capacitor. The low dropout voltage allows the regulator to operate efficiently even with a 5V input.
Recommandé
Industrial Control Systems
In industrial control systems, the LD1117S25TR provides a stable 2.5V reference for analog-to-digital converters (ADCs), sensors, and microcontrollers. Its wide input voltage range up to 15V allows it to be powered from industrial 24V buses with a pre-regulator. The device's low output noise and good line regulation ensure accurate measurements. In a typical application, the LD1117S25TR is used to power an ADC reference, with a 10µF output capacitor and a 0.1µF bypass capacitor for noise reduction. The device's thermal shutdown protects it from overtemperature conditions in harsh industrial environments.
Recommandé
Telecommunication Equipment
The LD1117S25TR is used in telecommunication equipment to provide a clean 2.5V rail for line drivers, transceivers, and digital signal processors. Its low dropout voltage and high output current make it suitable for powering multiple ICs. The device's low quiescent current is beneficial in always-on communication modules. In a typical application, the LD1117S25TR is powered from a 3.3V rail, and the output is decoupled with a 10µF capacitor. The device's thermal shutdown ensures reliable operation in equipment that may be exposed to high ambient temperatures.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour LD1117S25TR — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | LD1117S33TR | AMS1117-2.5 | NCP1117ST25T3G |
|---|---|---|---|---|
| Package | SOT-223 | SOT-223 | SOT-223 | SOT-223 |
| Brand | STMicroelectronics | STMicroelectronics | Advanced Monolithic Systems | onsemi |
| Output Voltage | 2.5V | 3.3V | 2.5V | 2.5V |
| Maximum Output Current | 800mA | 800mA | 1A | 1A |
| Dropout Voltage | 1.1V at 800mA | 1.1V at 800mA | 1.1V at 1A | 1.1V at 1A |
| Quiescent Current | 5mA | 5mA | 5mA | 5mA |
| Input Voltage Range | Up to 15V | Up to 15V | Up to 15V | Up to 15V |
| Operating Temperature Range | 0°C to +125°C | 0°C to +125°C | 0°C to +125°C | 0°C to +125°C |
Principaux différenciateurs
- Fixed 2.5V output with 800mA current capability (vs LD1117S33TR)
- Low dropout voltage of 1.1V at full load (vs AMS1117-2.5)
- SOT-223 package with thermal pad (vs NCP1117ST25T3G)
Notes de conception
The SOT-223 package has a thermal resistance of approximately 50°C/W. At maximum output current of 800mA and a dropout voltage of 1.1V, the power dissipation is 0.88W, resulting in a temperature rise of 44°C above ambient. Ensure adequate copper area on the PCB to dissipate heat, especially in high-temperature environments.
Place the input and output capacitors as close to the LD1117S25TR pins as possible. A minimum output capacitor of 10µF is required for stability, and a 0.1µF ceramic capacitor should be placed in parallel for high-frequency noise bypass. The thermal pad (tab) should be connected to a large copper area to improve heat dissipation.
Do not exceed the maximum input voltage of 15V. Ensure the input voltage is at least 1.1V above the output voltage to maintain regulation. The output capacitor must be placed close to the output pin to avoid instability. Use a capacitor with low ESR, such as a tantalum or aluminum electrolytic capacitor, as specified in the datasheet.
Informations de conformité
RoHS compliant per STMicroelectronics product page. Not AEC-Q100 qualified. Lead-free and conflict minerals compliant.
