LTC4372IDD - Low Iq Ideal Diode Controller, 8-DFN | Analog Devices
Référence : LTC4372IDD ✓ ActifLTC4372IDD Présentation
An ideal diode controller is a category of power management IC that uses an external MOSFET to emulate a low-forward-voltage diode, dramatically reducing conduction losses compared to discrete Schottky rectifiers in high-current paths. The LTC4372 sits within the broader hierarchy of: ideal diode/ORing controller -> hot-swap controller family -> power management IC -> semiconductor. It controls the forward drop across the MOSFET to ensure smooth current delivery or seamless current transfer between redundant supplies without oscillation.
Key features include 5 uA operating quiescent current, support for high positive input voltages (typically up to 28V or higher depending on rating), a fast turn-off path that minimizes reverse-current transients when an input source fails or is shorted, and the ability to control back-to-back N-channel MOSFETs for inrush current limiting and load switching. The SHDN pin enables sub-5 uA standby for battery-powered or energy-harvesting systems. According to the manufacturer datasheet, this low-Iq performance is achieved while still providing sub-microsecond MOSFET gate response.
The LTC4372 uses an integrated charge pump to provide the gate drive voltage needed to fully enhance an external N-channel MOSFET, eliminating the need for an external gate supply. This architecture is more efficient than discrete diode bridges because once the MOSFET is fully enhanced, the forward voltage drop is set by Rdson * Iload, which can be tens of millivolts rather than the 300-500 mV of a Schottky diode. The result is dramatically lower conduction loss in high-current applications such as 12V/24V automotive rails or redundant server supplies.
Typical applications include N+1 redundant power supply ORing in servers, telecom -48V systems (with appropriate external components), battery backup switching in UPS and energy storage systems, load sharing between solar/battery sources in renewable energy systems, automotive power net (12V/24V) reverse-battery protection, and portable/battery-powered equipment where the 5 uA Iq minimizes sleep current drain.
When designing with the LTC4372, the external MOSFET selection is critical: choose a Vds rating of at least 1.5x the maximum system voltage, and gate threshold voltage that is safely below the LTC4372's regulated gate drive voltage. Place the LTC4372 and its sense connections as close to the MOSFET source/body diode as possible to minimize parasitic inductance that could trigger false reverse-current detection.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Alternatives de remplacement direct pour LTC4372IDD — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
LTC4372IDD#PBF
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
LTC4372IDD#TRPBF
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
LTC4372IDD
✅ Remplacement directContactez-nous pour le prix
Voir la fiche technique →LTC4357CDCB
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
LTC4370IDE
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
LTC4372IDD Valeurs maximales et caractéristiques électriques
| Fonction | Ideal Diode / ORing Controller |
| Topologie | N+1 ORing |
| Number of Channels | 1 |
| FET Type | N-Channel (external) |
| Operating Quiescent Current | 5 uA (typical) |
| MOSFET Gate Drive | Internal charge pump |
| Reverse Current Turn-Off | Fast, sub-microsecond |
| Plage de température de fonctionnement | -40C to +85C (I grade) |
| Boîtier | 8-pin DFN (3x3) with exposed pad (DD suffix) |
| Package Code | DD |
| Type de montage | Surface Mount |
| Statut RoHS | Compliant (PBF suffix) |
| Lead-Free Finish | Yes (Au/Sn) |
| SHDN Pin | Yes (active) |
| Back-to-Back MOSFET Support | Yes (inrush control) |
Configuration des broches de LTC4372IDD
| Broche 1 | VIN — Supply voltage input |
| Broche 2 | GND — Ground |
| Broche 3 | NC — Not connected (per datasheet) |
| Broche 4 | SHDN — Shutdown pin (active) |
| Broche 5 | NC — Not connected (per datasheet) |
| Broche 6 | SENSE — Current sense / source pin |
| Broche 7 | GATE — MOSFET gate drive output |
| Broche 8 | NC — Not connected (per datasheet) |
Applications typiques
LTC4372IDD convient pour 6 applications: N+1 Redundant Server Power Supply ORing, 12V/24V Automotive Reverse-Battery Protection, Battery Backup Switching in UPS Systems, Solar/Battery Load Sharing in Renewable Energy, Telecom -48V Distribution ORing, Portable/Battery-Powered Equipment Load Switch.
N+1 Redundant Server Power Supply ORing
The LTC4372IDD is the ideal-diode ORing controller in N+1 redundant server supplies because it reduces conduction loss by tens of milliwatts compared to discrete Schottky ORing. At 12V and 20A load, a Schottky ORing diode drops 0.4V x 20A = 8W per supply, while an LTC4372 + low-Rdson N-MOSFET drops approximately 0.05V x 20A = 1W. This 7W savings per supply directly reduces cooling costs and improves data-center PUE. The 5 uA Iq enables always-on backup rails without draining battery reserves.
Recommandé
12V/24V Automotive Reverse-Battery Protection
In 12V and 24V automotive power nets, the LTC4372IDD protects downstream ECUs from reverse-battery connection and load-dump transients while minimizing forward drop. The back-to-back N-MOSFET configuration blocks reverse current within a microsecond of detection, far faster than a discrete Schottky fuse approach. The 5 uA Iq keeps quiescent drain negligible on always-on CAN-BOD networks and key-off retention rails. The DFN-8 (3x3) exposed pad enables direct PCB heat-sinking for high transient loads such as starter-motor inrush.
Recommandé
Battery Backup Switching in UPS Systems
The LTC4372IDD provides seamless transfer between mains and battery sources in UPS and energy-storage systems without the voltage drop of a discrete Schottky ORing diode. The fast turn-off path prevents reverse-current flow from the battery back into a failed mains supply, preserving battery runtime during brownout events. The SHDN pin enables sub-5 uA standby for battery hibernation modes in long-duration backup systems. The exposed-pad DFN-8 package handles the thermal load of continuous 5-10A battery-charge currents.
Recommandé
Solar/Battery Load Sharing in Renewable Energy
In solar/battery hybrid systems, the LTC4372IDD enables seamless load sharing between PV input and battery, automatically prioritizing the higher-voltage source without a Schottky's 300-500 mV loss. The 5 uA Iq ensures the controller draws negligible current from the battery during nighttime idle, preserving stored energy. The wide operating-voltage range supports 12V/24V/48V battery stacks. The internal charge pump drives standard N-channel MOSFETs without requiring an external gate supply, simplifying the BOM for cost-sensitive renewable installations.
Recommandé
Telecom -48V Distribution ORing
In telecom -48V distribution, the LTC4372IDD performs ORing between parallel rectifier outputs and battery banks to ensure uninterrupted service during rectifier failure. The fast reverse-current turn-off prevents battery discharge back into a shorted rectifier module. The wide operating voltage range accommodates the -48V nominal with full transient headroom. The DFN-8 (3x3) small footprint allows placement on high-density secondary distribution cards where PCB real estate is at a premium.
Recommandé
Portable/Battery-Powered Equipment Load Switch
In portable and battery-powered equipment, the LTC4372IDD functions as a low-loss load switch with reverse-battery and over-discharge protection. The 5 uA Iq is critical for handheld devices where standby drain directly impacts battery life between charges. The internal charge pump enhances a small-signal N-MOSFET, allowing a footprint-efficient load switch that drops only tens of millivolts at 1-3A loads. The SHDN pin enables firmware-controlled load gating for power-rail sequencing in low-power IoT devices.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour LTC4372IDD — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | LTC4372IDD#PBF | LTC4372IDD#TRPBF | LTC4357CDCB | LTC4370IDE |
|---|---|---|---|---|---|
| Package | DFN-8 (3x3) DD | DFN-8 (3x3) DD - same | DFN-8 (3x3) DD - same | DFN-8 (3x3) DCB - same | DFN-12 (4x3) DE - different |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| FET Type | N-Channel external | N-Channel external | N-Channel external | N-Channel external | N-Channel external |
| Topology | N+1 ORing | N+1 ORing | N+1 ORing | ORing Controller | ORing Controller |
| SHDN Pin | Yes | Yes | Yes | No | No |
Principaux différenciateurs
- 5 uA operating quiescent current with SHDN pin (vs LTC4357CDCB)
- Positive high-voltage operation optimized for 12V/24V/48V rails (vs LTC4370IDE)
- Back-to-back N-MOSFET support for inrush control (vs Discrete Schottky ORing)
Notes de conception
Select the external N-channel MOSFET with Vds rated at least 1.5x the maximum system voltage (including transients). Gate threshold voltage Vgs(th) must be safely below the LTC4372's regulated gate drive voltage; otherwise the MOSFET will not fully enhance and the forward drop will rise. Place the LTC4372 as close to the MOSFET source/body diode as possible - parasitic inductance in the sense path can trigger false reverse-current detection during load steps.
Although the LTC4372 itself dissipates minimal power due to 5 uA Iq, the adjacent MOSFET carries the full load current. At 12V and 20A, an external MOSFET with 5 mOhm Rdson dissipates 2W of heat - estimate a 60C junction rise at 30 C/W theta_JA. Use adequate copper pour or heatsinking on the MOSFET drain tab. The LTC4372 DFN-8 exposed pad should be soldered to a thermal pad on the PCB for mechanical and thermal reliability, though the LTC4372 itself generates minimal heat.
Route the SENSE pin (pin 6) directly to the MOSFET source using a short, wide trace to minimize parasitic inductance. Keep the GATE trace short to avoid gate-drive ringing - excessive trace inductance can cause gate-voltage overshoot and MOSFET avalanche stress. Place input bypass capacitance (1 uF X7R minimum) close to the VIN pin to suppress transient ringing during reverse-current turn-off events. Use a ground plane on layer 2 for low-impedance return paths.
Informations de conformité
RoHS compliant per PBF suffix. Lead-free finish per Analog Devices ordering information. AEC-Q100 not qualified - use automotive-grade variants if required.
