LDO40LPU33RY - 400mA, 38V LDO, 3.3V Fixed, DFN-6 | STMicroelectronics
부품 번호: LDO40LPU33RY ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $1.7 | $1.70 |
| 10 | $1.53 | $15.30 |
| 100 | $1.36 | $136.00 |
| 500 | $1.19 | $595.00 |
| 1,000 | $1.02 | $1,020.00 |
| 3,000 | $0.85 | $2,550.00 |
LDO40LPU33RY 개요
An LDO (Low-Dropout) linear regulator is a DC voltage regulator that maintains a stable output voltage even when the input voltage is very close to the output voltage. Within the power management hierarchy, LDOs belong to the linear regulator family, which in turn is a subset of voltage regulators and ultimately of power management ICs. Unlike switching regulators, LDOs introduce no switching noise, providing a clean rail for analog and RF loads in exchange for higher conduction loss at large VIN-VOUT differentials.
Key features include 45 uA typical quiescent current, internal current limit and thermal shutdown protection, and stability with 1 uF (minimum) X5R/X7R ceramic output capacitors having ESR between 5 mOhm and 12 Ohm. The DFN-6 (3x3) exposed-pad package provides a low thermal resistance path, enabling sustained 400 mA output in confined PCB areas.
The LDO40LPU33RY's wide VIN tolerance (up to 38 V) and automotive-grade qualification make it well suited for always-on ECU supplies, body controllers, and sensor rails that must survive load-dump transients. The low Iq extends battery life in standby, an essential property for body and chassis ECUs that remain in active mode when ignition is off.
Typical applications include automotive body electronics, industrial sensor and PLC modules, post-regulation for noisy switching rails, and always-on microcontroller supplies. Compared with discrete zener or series-resistor solutions, the LDO40LPU33RY offers tighter regulation and far lower quiescent current.
When designing with this device, ensure the input capacitor ESR remains within the stability range defined by the datasheet and provide sufficient copper area beneath the exposed pad to keep junction temperature below 125 C under worst-case load. The enable logic and shutdown current behaviour should also be reviewed if the regulator powers a low-power standby domain.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes that are not consolidated in the ST LDO40L datasheet, giving engineers an actionable comparison across same-package and cross-brand options in the same 6-DFN footprint.
드롭인 대체품: LDO40LPU33RY — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
LDO40LPU50RY
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
LDO40LPU18RY
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
LDO40LPU25RY
✅ 드롭인 ⚠️ 사양 미검증📋 참조 대체품 (카탈로그에 없음)
LDO40LPU12RY
✅ 드롭인 ⚠️ 사양 미검증📋 참조 대체품 (카탈로그에 없음)
LDO40LPU00RY
✅ 드롭인 ⚠️ 사양 미검증📋 참조 대체품 (카탈로그에 없음)
LDO40LPU33RY 최대 정격 & 전기적 특성
| Regulator Type | LDO (Low-Dropout), Positive, Fixed |
| 출력 유형 | Fixed |
| Nominal Output Voltage | 3.3 V |
| 최대 출력 전류 | 400 mA |
| 입력 전압 범위 | 3.5 V to 38 V |
| Quiescent Current (typical) | 45 uA |
| Pass Element | P-channel MOSFET |
| Output Capacitor Stability | 1 uF (min) X5R/X7R ceramic, ESR 5 mOhm to 12 Ohm |
| 동작 온도 범위 | -40 C to +125 C |
| Thermal Protection | Thermal shutdown |
| 전류 제한 | Internal current limit |
| 패키지 | 6-pin DFN (3x3 mm) with exposed pad |
| 실장 유형 | Surface Mount |
| RoHS 상태 | Compliant |
| Automotive Grade | AEC-Q100 qualified (per distributor listing) |
LDO40LPU33RY 핀 구성
| 핀 1 | VIN — Input voltage supply (3.5 V to 38 V) |
| 핀 2 | GND — Ground reference |
| 핀 3 | NC / EN — No-connect or enable (per datasheet variant marking) |
| 핀 4 | NC — Not connected (per datasheet) |
| 핀 5 | VOUT — Regulated 3.3 V output |
| 핀 6 | EP — Exposed pad - thermal and electrical ground |
일반적인 애플리케이션
LDO40LPU33RY 적합 용도: 6 애플리케이션s: Automotive Body Electronics ECU, Industrial 24V Sensor and PLC Module, Post-Regulation for Noisy Switching Rails, Always-On Microcontroller Standby Rail, Smart Home and IoT Sensor Node, Test and Measurement Front-End.
Automotive Body Electronics ECU
The LDO40LPU33RY's 38 V VIN tolerance directly survives 12 V automotive load-dump transients while delivering clean 3.3 V to body-control MCUs and CAN transceivers. Its 45 uA quiescent current keeps always-on body modules (e.g., RKE receivers, BCM standby domains) below 1 mA total standby draw, preserving battery life during long parking periods. Placed near the ECU's MCU supply pin with a 1 uF X5R input cap and 1 uF X7R output cap, it eliminates the need for an external preregulator and survives -40 C to +125 C under-hood thermal stress.
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Industrial 24V Sensor and PLC Module
Industrial PLC digital-input modules and 24 V sensor front-ends benefit from the LDO40LPU33RY's 38 V max input, which tolerates large inductive transients on long sensor cables. The 400 mA output comfortably supplies a 3.3 V MCU plus a few op-amps or ADC front-ends, while the 45 uA Iq keeps idle-channel current low for distributed IO nodes. The 6-DFN (3x3) exposed pad dissipates heat efficiently when VIN is closer to 24 V and the dropout produces several hundred mW.
추천
Post-Regulation for Noisy Switching Rails
When a downstream analog or RF block requires low ripple, the LDO40LPU33RY placed after a switching converter's first stage removes high-frequency ripple and cleans the 3.3 V rail. Its high PSRR at low frequency is sufficient for ADC reference rails, audio codec supplies, or low-noise sensor signal chains. Compared with a second-stage LC filter, the LDO achieves similar ripple rejection with smaller PCB footprint and no inductor.
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Always-On Microcontroller Standby Rail
Battery-powered or always-on devices benefit from the LDO40LPU33RY's 45 uA quiescent current, which is several times lower than legacy 78xx regulators. Connected to a 12 V or 24 V system battery through a simple RC pre-filter, the regulator provides a stable 3.3 V rail to a sleep-mode MCU or RTC while consuming negligible standby power. The exposed-pad package supports continuous operation at moderate loads without a heatsink.
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Smart Home and IoT Sensor Node
Smart-home sensor nodes powered by 24 V distribution or solar-charged batteries can use the LDO40LPU33RY to drop to 3.3 V for low-power wireless MCUs. The wide VIN tolerance accommodates battery charging voltage swings, while the low Iq preserves battery life during RF-sleep intervals. The 6-DFN (3x3) package fits inside miniature sensor enclosures and requires only two 1 uF ceramic capacitors.
추천
Test and Measurement Front-End
Bench-top instruments and data-acquisition front-ends use the LDO40LPU33RY as a quiet 3.3 V rail for ADCs, DACs, and reference buffers. Its stable operation with X5R/X7R ceramic output capacitors and 5 mOhm to 12 Ohm ESR tolerance simplifies analog-stage design. AEC-Q100 qualification also makes the same part reusable for ruggedised field-instrument variants.
추천
추천 제품 요약
엔지니어링 참조 데이터: LDO40LPU33RY — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | LDO40LPU50RY | LDO40LPU18RY | LDO40LPU25RY | LDO40LPU12RY | LDO40LPU00RY |
|---|---|---|---|---|---|---|
| Package | 6-DFN (3x3) | 6-DFN (3x3) - same | 6-DFN (3x3) - same | 6-DFN (3x3) - same | 6-DFN (3x3) - same | 6-DFN (3x3) - same |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics |
| Output Voltage | 3.3 V (fixed) | 5.0 V (fixed) | 1.8 V (fixed) | 2.5 V (fixed) | 1.2 V (fixed) | Adjustable |
| Maximum Output Current | 400 mA | 400 mA | 400 mA | 400 mA | 400 mA | 400 mA |
| Input Voltage Range | 3.5 V to 38 V | 3.5 V to 38 V | 3.5 V to 38 V | 3.5 V to 38 V | 3.5 V to 38 V | 3.5 V to 38 V |
| Quiescent Current | 45 uA typical | 45 uA typical | 45 uA typical | 45 uA typical | 45 uA typical | 45 uA typical |
| Output Type | Fixed | Fixed | Fixed | Fixed | Fixed | Adjustable |
| Automotive Grade (AEC-Q100) | Yes | Yes | Yes | Yes | Yes | Yes |
주요 차별점
- Wide 38 V input voltage range with AEC-Q100 qualification (vs TPS7A4533 (TI))
- Family-level output voltage flexibility in same footprint (vs Generic 3.3 V LDO competitors in DFN-6)
- Low 45 uA quiescent current for always-on domains (vs Legacy LM78xx 1 A regulators)
설계 노트
Estimated: at VIN = 24 V, VOUT = 3.3 V, IOUT = 400 mA, the LDO40LPU33RY dissipates approximately (24 - 3.3) * 0.4 = 8.3 W. With the 6-DFN (3x3) exposed pad soldered to a minimum 1 square inch of 2-oz copper, the junction-to-ambient thermal resistance is typically around 50 C/W, yielding a junction temperature rise of ~415 C above ambient - well beyond the 125 C limit. Reduce VIN closer to 3.3 V headroom (e.g., add a pre-stage switching regulator) or derate output current if 24 V input is sustained at 400 mA.
Per the ST LDO40L datasheet, place the 1 uF X5R/X7R input capacitor and 1 uF X5R/X7R output capacitor within 1-2 mm of the respective pins to keep the control loop stable. Exposed pad (Pin 6) MUST be soldered to a continuous ground copper pour with thermal vias for heat extraction. Avoid routing noisy switching traces directly above the regulator's feedback node to prevent output ripple injection.
Do not use output capacitors with ESR outside the 5 mOhm to 12 Ohm datasheet window - low-ESR ceramics below 5 mOhm can cause instability, while high-ESR tantalum or electrolytic caps above 12 Ohm degrade transient response. If the source impedance is high (long cables, weak supplies), add a 1 uF input capacitor to prevent input-voltage ringing during load steps. The exposed pad must be electrically connected to ground; floating it disrupts thermal dissipation.
규정 준수 정보
RoHS compliant and AEC-Q100 automotive qualified per ST product page and distributor listings. Halogen-free status not explicitly stated in provided data - marked unknown.
