LTC4372HDD - Low Iq Ideal Diode Controller, 8-DFN | Analog Devices
부품 번호: LTC4372HDD ✓ 활성LTC4372HDD 개요
An ideal diode controller is a type of power management IC that uses an active MOSFET + control IC topology in place of a discrete Schottky diode, eliminating forward voltage drop and reducing power dissipation. Ideal diode controllers belong to the broader hierarchy of ORing controllers, which in turn fall under power management ICs. The LTC4372 specifically targets low-Iq applications where the controller itself consumes minimal current from the load when reverse current is blocked.
Key features include support for input voltages up to 28V, very low quiescent current, integrated SHDN (shutdown) pin, gate driver for external N-channel MOSFET, fast turn-off to prevent reverse current, and overvoltage protection. The DFN-8 exposed pad package provides low thermal resistance, enabling compact designs where the controller and its companion MOSFET operate with minimal heat generation.
The LTC4372 uses a continuous gate pull-up/pull-down architecture that monitors the voltage drop across the MOSFET and adjusts gate drive to regulate forward voltage. This produces a smooth transition from forward conduction to reverse blocking in microseconds, which is significantly faster than discrete Schottky diode reverse recovery. The shutdown pin allows quiescent current to be reduced to microamp levels when the load is disconnected.
Typical applications include N+1 redundant power supply ORing, high-side load sharing between battery and adapter, solar bypass diode replacement, automotive reverse polarity protection, and telecom -48V ORing rails where low Iq prevents battery drain.
When designing with the LTC4372, pay close attention to MOSFET selection: VDS rating must exceed maximum input voltage, VGS(th) must be compatible with the gate drive voltage, and Qg must allow switching within the controller's specified timing. Adequate input bypass capacitance is required to suppress ringing during load transients.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, providing actionable selection guidance for engineers evaluating the LTC4372 against competing ideal diode and ORing controller solutions.
드롭인 대체품: LTC4372HDD — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
LTC4373HDD#PBF
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
LTC4372HDD#TRPBF
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
LTC4372IDD#PBF
✅ 드롭인 ⚠️ 사양 미검증📋 참조 대체품 (카탈로그에 없음)
LTC4372HDD 최대 정격 & 전기적 특성
| Product Type | Ideal Diode / ORing Controller |
| 토폴로지 | N-Channel MOSFET driver (external) |
| Configuration | 1:1 (single ideal diode) |
| Shutdown Pin | Yes (SHDN) |
| MOSFET Type Driven | External N-Channel |
| 동작 온도 범위 | -40 C to +125 C (estimated H grade suffix) |
| 패키지 | 8-DFN (3x3 mm) with Exposed Pad |
| Package Code | DD |
| 실장 유형 | Surface Mount |
| RoHS 상태 | Compliant (PBF suffix indicates Pb-free) |
| Lead-Free | Yes (PBF suffix) |
| Manufacturer | Analog Devices (formerly Linear Technology) |
LTC4372HDD 핀 구성
| 핀 1 | SHDN — Shutdown input (active low) |
| 핀 2 | GND — Ground reference |
| 핀 3 | IN — Input supply voltage sense |
| 핀 4 | OUT — Output voltage sense (load side) |
| 핀 5 | GATE — Gate drive for external N-channel MOSFET |
| 핀 6 | VCC — Internal regulator bypass / supply |
| 핀 7 | NC — Not connected (per datasheet) |
| 핀 8 | EP — Exposed pad (thermal/electrical ground) |
일반적인 애플리케이션
LTC4372HDD 적합 용도: 7 애플리케이션s: N+1 Redundant Power Supply ORing, High-Side Load Sharing Between Battery and Adapter, Solar Panel Bypass Diode Replacement, Automotive Reverse Polarity Protection, Telecom -48V ORing Rail Protection, USB Power Delivery Source Switching, Industrial PLC Redundant 24V Rails.
N+1 Redundant Power Supply ORing
The LTC4372HDD drives an external N-channel MOSFET to OR two redundant power supplies, allowing hot-swappable failover in server and telecom systems. Its low quiescent current and shutdown pin ensure minimal parasitic draw on each rail. Compared to a discrete Schottky diode that drops 0.3-0.7V, the LTC4372 holds forward voltage at 20-50 mV, dissipating 5-10x less power at high currents. Engineers should size the MOSFET VDS rating above the maximum input voltage including transients.
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High-Side Load Sharing Between Battery and Adapter
The LTC4372HDD enables seamless load sharing between a wall adapter and a battery pack in portable and industrial equipment. The controller regulates forward voltage drop to ensure both sources share load current proportionally, and the shutdown pin allows the system to disconnect the battery for storage. The 8-DFN package occupies minimal board space while supporting up to 10A+ load currents when paired with appropriately sized MOSFETs.
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Solar Panel Bypass Diode Replacement
The LTC4372HDD replaces conventional Schottky bypass diodes in photovoltaic junction boxes, reducing power dissipation in partially shaded solar panels. A typical Schottky bypass diode drops 0.4-0.6V at 5-10A, dissipating 2-6W of waste heat inside the junction box. The LTC4372 + MOSFET combination holds forward drop under 50 mV, recovering 2-5% additional energy yield while reducing junction box operating temperature for longer system lifetime.
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Automotive Reverse Polarity Protection
The LTC4372HDD can be configured for reverse polarity protection in 12V and 24V automotive systems, blocking reverse current flow when battery terminals are connected incorrectly. The controller turns off the external MOSFET within microseconds of detecting reverse voltage, protecting downstream electronics from damage. Designers must select a MOSFET with VDS rating exceeding load-dump transients (up to 40V in 12V systems, 60V in 24V systems).
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Telecom -48V ORing Rail Protection
In telecom -48V distribution systems, the LTC4372HDD performs ORing between battery banks and rectifier outputs with minimal quiescent current consumption, preserving battery capacity during AC mains operation. The shutdown pin allows system controllers to fully disable the ORing path for maintenance. The wide operating temperature range and robust DFN package suit the demanding thermal environment of telecom equipment shelves.
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USB Power Delivery Source Switching
The LTC4372HDD enables clean source switching between USB-PD power sources, wall adapters, and battery inputs in USB-C powered devices. The low-Iq characteristic is critical when the device operates in standby mode, preserving battery life. The controller's fast turn-off prevents reverse current when sources are disconnected, protecting the USB-PD controller from voltage transients during source swaps.
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Industrial PLC Redundant 24V Rails
The LTC4372HDD provides reliable ORing in industrial PLC and DCS systems where two independent 24V supplies must combine for fault tolerance. The low-Iq controller consumes negligible current from each rail, and the exposed pad DFN-8 package ensures stable thermal operation in enclosed control cabinets. Engineers typically pair the LTC4372 with a current-sharing controller for paralleled supply modules in high-availability process automation.
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추천 제품 요약
엔지니어링 참조 데이터: LTC4372HDD — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | LTC4373HDD#PBF | LTC4372HDD#TRPBF | LTC4372IDD#PBF |
|---|---|---|---|---|
| Package | 8-DFN (3x3 mm) | 8-DFN (3x3 mm) - same | 8-DFN (3x3 mm) - same | 8-DFN (3x3 mm) - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Topology | Ideal Diode Controller (external N-FET) | Ideal Diode Controller (external N-FET) | Ideal Diode Controller (external N-FET) | Ideal Diode Controller (external N-FET) |
| Shutdown Pin | Yes | Yes | Yes | Yes |
| Operating Temperature | -40 C to +125 C (estimated H grade) | -40 C to +125 C | -40 C to +125 C | -40 C to +85 C (industrial) |
| RoHS Compliance | Yes (Pb-free PBF suffix) | Yes | Yes | Yes |
| Production Packaging | Tube / Tray | Tube / Tray | Tape & Reel (7-inch) | Tube / Tray |
주요 차별점
- Lowest quiescent current in ideal diode controller category (vs LTC4357)
- Integrated shutdown pin in DFN-8 package (vs LTC4357 (different package/pinout))
- Same-brand drop-in alternative with same package (vs LTC4373HDD#PBF)
설계 노트
Estimated: For a 5A ORing application with the LTC4372 driving a 30V VDS MOSFET, power dissipation in the MOSFET is approximately P = I x Vf = 5A x 0.03V = 0.15W at full load. Compared to a Schottky diode at the same current and 0.4V drop (P = 2W), the LTC4372 solution dissipates 13x less power. Select a MOSFET with low RDS(on) at the gate drive voltage produced by the controller.
Critical: Do not exceed the maximum input voltage rating of the LTC4372 controller or the external MOSFET VDS rating. During inductive load switching, voltage transients on the input rail can exceed the steady-state voltage. Add a TVS diode or RC snubber across the MOSFET to clamp transients. The exposed pad must be soldered to a sufficient ground copper pour for thermal dissipation and electrical reference.
Estimated: The DFN-8 (3x3 mm) package with exposed pad has a thermal resistance of approximately 40-50 C/W depending on PCB copper area. For designs operating at sustained high currents where ambient temperature exceeds 85 C, increase the PCB copper area beneath the exposed pad to at least 1 square inch and use thermal vias to inner ground planes. This keeps junction temperature within the 125 C maximum rating.
규정 준수 정보
PBF suffix indicates Pb-free / RoHS compliance per the verified distributor listings. Halogen-free status not explicitly confirmed in the verified data. Not AEC-Q100 qualified; contact Analog Devices for automotive-grade equivalents.
