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NXP Semiconductors TDA3681JR/N2S
- Part No.:
- TDA3681JR/N2S
- Manufacturer:
- NXP Semiconductors
- Category:
- Power Management - Specialized
- Package:
- 17-SIP Formed Leads
- Datasheet:
-
TDA3681JR/N2S.pdf
- Description:
- IC REG MULTIPLE VOLTAGE SOT475
- Quantity:
- Payment:
- Shipping:
Inventory:3,879
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Product details
Overview
TDA3681JR/N2S from NXP Semiconductors (formerly Philips) is a 17-pin automotive-grade multiple-output voltage regulator IC with integrated power switch and ignition buffer, designed for car radio systems. It delivers four regulated outputs (8.5 V/600 mA, 5.0 V/300 mA, 5.0 V/1400 mA, 3.3 V/1 A), supports load dump protection up to 50 V, operates from −18 V to +50 V supply, and features hold/reset logic for microcontroller interfacing.
For engineers reviewing the TDA3681JR/N2S datasheet, TDA3681JR/N2S pinout, TDA3681JR/N2S application, or TDA3681JR/N2S equivalent, key selection considerations include its dual-supply architecture (VP1/VP2), foldback current limiting across all regulators, ignition Schmitt trigger with push-pull output, and thermal/load-dump-triggered hold functionality in automotive power management designs.
Technical Context
The TDA3681JR/N2S integrates four independent linear regulators with foldback current protection, a protected high-current power switch (3 A peak, 1.8 A continuous), and an ignition input/output buffer with hysteresis. Regulators 1, 3, and 4 are VP1/VP2-controlled and enableable via shared (EN1/3) or dedicated (EN4) inputs, while regulator 2 remains active during load dump and thermal shutdown.
Its hold output (open-collector, active LOW) aggregates fault conditions-including regulator undervoltage, thermal shutdown, load dump detection, and power switch foldback-via internal OR logic. The reset output (push-pull, active LOW) provides adjustable delay via external capacitor CRES and releases the microcontroller only after regulator 2 stabilizes above 4.75 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Range | −18 V to +50 V (reverse polarity safe to −18 V; load dump tolerant to 50 V for ≤50 ms) |
| Regulator Outputs | REG1: 8.5 V ±0.5 V / 600 mA; REG2: 5.0 V ±2.5% / 300 mA (active during load dump); REG3: 5.0 V ±2.5% / 1400 mA; REG4: 3.3 V ±0.16 V / 1 A |
| Power Switch | Vdrop = 0.45 V @ 1 A; 1.0 V @ 1.8 A; clamped at 16 V when VP1 ≥17 V; peak current = 3 A |
| Quiescent Current | 110 µA typical in standby mode (all regulators and switch disabled, IGNIN low) |
| Hold & Reset Logic | HOLD: open-collector active LOW, triggered by any regulator out-of-regulation, thermal event, or load dump; RES: push-pull active LOW with 20–70 ms delay (CRES = 47 nF) |
| Ignition Interface | IGNIN Schmitt trigger (Vth,r = 2.2 V typ, hysteresis = 0.2 V); IGNOUT push-pull (VOH = 5.0 V, IOH = 2.0 mA) |
Pinout & Package
Package: DBS17P - plastic DIL-bent-SIL power package, 17 leads, lead length 12 mm (SOT475-1), heat tab internally connected to GND.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (REG1) | Regulator 1 output | 8.5 V fixed output, 600 mA max, foldback protected |
| 2 (REG3) | Regulator 3 output | 5.0 V fixed output, 1400 mA max, second supply VP2 referenced |
| 3 (VP2) | Second supply voltage input | Input for regulators 3 and 4; reduces power dissipation when supplied ≤14.4 V (e.g., from DC-DC converter) |
| 4 (REG4) | Regulator 4 output | 3.3 V fixed output, 1 A max, VP2-referenced, foldback protected |
| 5 (IGNIN) | Ignition input | Schmitt-triggered control input (1.9–2.5 V rising threshold) for system wake-up |
| 6 (IGNOUT) | Ignition output | Push-pull active HIGH buffer for microcontroller or peripheral enable signaling |
| 7 (RES) | Reset output | Push-pull active LOW; asserts until regulator 2 reaches stable 5.0 V, delay set by CRES |
| 8 (CRES) | Reset delay capacitor connection | External capacitor (e.g., 47 nF) sets reset release delay (20–70 ms) and power switch foldback timing |
| 9 (EN4) | Enable input for regulator 4 | Active HIGH digital control; disables REG4 and disables its contribution to HOLD signal |
| 10 (EN1/3) | Enable input for regulators 1 and 3 | Shared active HIGH control; disables both REG1 and REG3 simultaneously |
| 11 (ENSW) | Enable input for power switch | Active HIGH control for main switched output; foldback protection delayed via CRES |
| 12 (HOLD) | Hold output | Open-collector active LOW; requires external pull-up; signals system fault (regulator failure, thermal, load dump) |
| 13 (GND) | Ground reference | Main ground terminal; heat tab internally tied to this pin |
| 14 (BU) | Backup switch output | Supplies regulator 2 during VP1 dropout; supports backup capacitor for microcontroller brownout recovery |
| 15 (REG2) | Regulator 2 output | 5.0 V ±2.5%, 300 mA, remains active during load dump and thermal shutdown |
| 16 (SW) | Power switch output | Main switched output; 3 A peak, 1.8 A continuous, clamped at 16 V above 17 V VP1 |
| 17 (VP1) | Primary supply voltage input | Main battery input; withstands −18 V reverse, 50 V load dump, and 30 V jump-start pulses |
Key Features
| Feature | Design Value |
|---|---|
| Four independent regulators with foldback current limiting | Prevents thermal runaway during short-circuit; limits power dissipation without latch-up (e.g., REG3 sustains 1400 mA then folds back) |
| Dual-supply architecture (VP1/VP2) | Enables lower-power operation for REG3/REG4 by feeding them from a DC-DC converter (≥6.5 V), reducing total thermal load |
| Load dump and reverse polarity protection | Operates continuously under −18 V reverse bias and survives 50 V/50 ms transients without shutdown or damage |
| Microcontroller-safe reset and hold signaling | RES releases only after REG2 stabilizes; HOLD aggregates faults into single active-LOW alert, simplifying system-level fault response |
| Ignition Schmitt trigger with push-pull buffer | Eliminates noise-induced false wake-ups; provides robust 2 mA drive capability for downstream logic or power sequencing |
Applications
| Car Radio Power Management | Microcontroller-Based Infotainment System |
|---|---|
Use Scenario: Central power supply for analog/digital audio stages, DSP, display backlight, and tuner modules in OEM car radios. IC Role / Device Role / Timing Role: Primary multi-rail regulator delivering 8.5 V (analog front-end), 5.0 V (DSP core), 5.0 V (audio codec), and 3.3 V (digital interface), with VP2-fed efficiency optimization. Use Value: Eliminates need for discrete LDOs and external protection circuitry; enables single-chip compliance with ISO 7637-2 pulse 5a (load dump) and reverse-battery requirements. | Use Scenario: Power and supervision subsystem for ARM Cortex-M or 8-bit MCU-based head units with boot sequencing and brownout recovery. IC Role / Device Role / Timing Role: Provides regulated 5.0 V to MCU (REG2), generates synchronized reset (RES), asserts system hold (HOLD) on fault, and manages ignition wake-up (IGNIN/IGNOUT). Use Value: Enables deterministic MCU startup via adjustable reset delay; backup switch (BU) sustains REG2 during battery dropout, allowing graceful firmware save before shutdown. |
| Automotive Audio Amplifier Bias Supply | Aftermarket Head Unit Power Controller |
Use Scenario: Generating stable bias rails for Class AB/D amplifier stages in vehicle audio amplifiers subject to wide battery variation. IC Role / Device Role / Timing Role: Supplies 8.5 V (preamp stage), 5.0 V (control logic), and 3.3 V (I²C interface) with line/load regulation <75 mV and ripple rejection >60 dB. Use Value: Maintains amplifier SNR under 9.5–18 V battery swing and rejects alternator ripple; foldback protection prevents thermal failure during speaker short events. | Use Scenario: Integrated power management in plug-and-play aftermarket head units requiring ignition-synchronized operation and load dump resilience. IC Role / Device Role / Timing Role: Accepts raw vehicle battery (VP1), interprets ignition key signal (IGNIN), powers sub-systems (REG1–REG4), and controls main load switch (SW) with foldback current limiting. Use Value: Simplifies design of CE-compliant units by integrating ESD, load dump, reverse polarity, and thermal protections per AEC-Q100 stress categories. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar multiple-output automotive regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLF35584QVVS1 | 3-channel LDO + watchdog + SPI interface; no integrated power switch or ignition buffer; requires external switch for high-current loads | Targeted at ASIL-B safety-critical domains (e.g., ADAS ECUs); lacks ignition interface and backup switch functionality | Select when functional safety (ISO 26262) and diagnostics are required over ignition control and backup power |
| MAX16922ATP+T | 3-output regulator (5 V/300 mA, 3.3 V/300 mA, 1.8 V/250 mA) + watchdog; no REG1 (8.5 V) or ignition buffer; smaller 20-pin TQFN | Optimized for compact infotainment displays; missing high-voltage regulator and automotive-grade load dump tolerance (max 42 V) | Select for space-constrained non-radio applications where 8.5 V rail and ignition wake-up are not needed |
Compared with TLF35584QVVS1 and MAX16922ATP+T, the TDA3681JR/N2S uniquely combines an 8.5 V regulator, ignition Schmitt trigger with push-pull output, backup switch for brownout hold, and integrated 3 A power switch-making it purpose-built for cost-sensitive, feature-complete car radio power architectures without safety certification overhead.
Availability
TDA3681JR/N2S is available at Aetrix Electronics and suitable for automotive infotainment systems, car radio power supplies, microcontroller-based head units, and aftermarket audio controllers requiring stable component supply across extended temperature and harsh electrical environments.
Supply support for TDA3681JR/N2S includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
NXP Semiconductors is a global semiconductor leader focused on automotive, industrial, and IoT applications, with deep expertise in high-reliability analog and power management ICs.
The TDA3681JR/N2S belongs to NXP's legacy automotive power management portfolio, specifically engineered for cost-effective, robust power sequencing and protection in car audio systems-prioritizing load dump resilience, microcontroller supervision, and ignition-aware operation over functional safety certification.
FAQ
What is the maximum load dump voltage the TDA3681JR/N2S can withstand?
The TDA3681JR/N2S withstands load dump transients up to 50 V for durations ≤50 ms with rise time ≥2.5 ms on both VP1 and VP2 pins, per ISO 7637-2 Pulse 5a requirements. During such events, regulators 1, 3, and 4 shut down automatically, while regulator 2 remains operational to sustain microcontroller function. This behavior is confirmed in the Quick Reference Data and Limiting Values sections of the official datasheet.
How does the hold output (HOLD) of the TDA3681JR/N2S behave during thermal shutdown?
During thermal shutdown, the TDA3681JR/N2S asserts the HOLD pin LOW (active state) as part of its integrated fault aggregation logic. HOLD is driven by an internal OR gate combining outputs from regulator undervoltage detectors, temperature protection, and load dump sensing. This ensures immediate system-level notification-without requiring external monitoring-whenever junction temperature exceeds 150 °C. The TDA3681JR/N2S datasheet confirms HOLD activation under "temperature protection" in the Functional Description and Fig.5 block diagram.
Can the TDA3681JR/N2S operate with only VP1, or is VP2 mandatory?
The TDA3681JR/N2S can operate with only VP1 applied; VP2 is optional and required only if regulators 3 or 4 are used. Regulators 3 and 4 are referenced to VP2, so they remain inactive unless VP2 ≥6.5 V. Regulators 1 and 2, the power switch, ignition buffer, and reset/hold logic all function solely from VP1. This flexibility allows designers to omit VP2 and its associated DC-DC converter when only the 8.5 V and 5.0 V rails are needed.
What is the purpose of the backup switch (BU) pin on the TDA3681JR/N2S?
Pin BU on the TDA3681JR/N2S provides a dedicated output to charge an external backup capacitor that sustains regulator 2 (REG2) during VP1 dropout-enabling the microcontroller to execute controlled shutdown or save critical data. When VP1 collapses, BU continues supplying REG2 from the stored energy, maintaining 5.0 V output for tens to hundreds of milliseconds depending on capacitor size. This function is explicitly defined in the General Description and Functional Description sections of the TDA3681JR/N2S datasheet.
Does the TDA3681JR/N2S support simultaneous enablement of regulators 1 and 3?
Yes, the TDA3681JR/N2S supports simultaneous enablement of regulators 1 and 3 via the shared EN1/3 pin (pin 10). Applying a logic HIGH signal to EN1/3 activates both regulators together, simplifying power sequencing in systems where these rails must be powered in lockstep. This shared control is documented in the FEATURES list ("Combined control pin for switching regulators 1 and 3") and verified in the Pinning table and Functional Description section of the TDA3681JR/N2S datasheet.
TDA3681JR/N2S Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- -
- Package/Case:
- 17-SIP Formed Leads
- Packaging:
- Tube
- Product Status:
- Obsolete
- Applications:
- Ignition Buffer, Regulator
- Current - Supply:
- 110µA
- Voltage - Supply:
- 9.5V ~ 18V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 17-PDBS
TDA3681JR/N2S FAQ
1.How can I place an order for TDA3681JR/N2S through Aetrix?
Please submit a Request for Quotation (RFQ) for TDA3681JR/N2S on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for TDA3681JR/N2S reliable?
The price and inventory of TDA3681JR/N2S are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TDA3681JR/N2S is usually 5 days.
3.What payment methods are accepted for TDA3681JR/N2S?
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4.How is shipping managed for TDA3681JR/N2S?
TDA3681JR/N2S orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TDA3681JR/N2S order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for TDA3681JR/N2S?
For technical support, including TDA3681JR/N2S datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TDA3681JR/N2S requirements.
6.How does Aetrix verify that TDA3681JR/N2S is sourced from the original manufacturer or authorized distributors?
All TDA3681JR/N2S products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that TDA3681JR/N2S meets industry standards.
7.What is the process for return or replacement of TDA3681JR/N2S?
All TDA3681JR/N2S units undergo pre-shipment inspection (PSI). If there is an issue with TDA3681JR/N2S, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The TDA3681JR/N2S part is unused and in its original packaging.
Return procedure for TDA3681JR/N2S:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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