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Texas Instruments TPS3306-33DR
- Part No.:
- TPS3306-33DR
- Manufacturer:
- Texas Instruments
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TPS3306-33DR.pdf
- Description:
- IC SUPERVISOR 2 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,526
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Product details
Overview
TPS3306-33DR from Texas Instruments is a dual-voltage supervisory IC designed for monitoring 5 V and 3.3 V supply rails in DSP and microprocessor systems. It provides active-low open-drain RESET and PFO outputs, integrated 100 ms power-on reset delay, 0.8 s watchdog timer, and operates across –40°C to +85°C. Used in embedded control systems requiring reliable dual-rail power sequencing and fail-safe reset.
For engineers reviewing the TPS3306-33DR datasheet, TPS3306-33DR pinout, TPS3306-33DR application, or TPS3306-33DR equivalent, key selection criteria include its dual-threshold sensing (4.55 V / 2.93 V), low 15 µA supply current, SOIC-8 package compatibility, and watchdog timeout behavior under system stall conditions.
Technical Context
The TPS3306-33DR integrates two independent voltage comparators with fixed thresholds (4.55 V for SENSE1, 2.93 V for SENSE2), each with ~30 mV hysteresis. Its internal 100 ms reset delay timer activates only after both sensed voltages exceed their respective thresholds, ensuring coordinated system initialization.
A dedicated PFI comparator referenced to 1.25 V enables external power-fail monitoring via resistor divider, while the WDI input supports edge-triggered watchdog reset with 0.8 s timeout - disabled if left floating. All outputs are open-drain, requiring external pull-ups for logic-level compatibility.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| SENSE1 Threshold | 4.55 V typical - monitors 5 V rail with ±3% tolerance over temperature |
| SENSE2 Threshold | 2.93 V typical - monitors 3.3 V rail with ±3% tolerance over temperature |
| RESET Delay Time | 100 ms typical - ensures stable power-up before releasing processor reset |
| Watchdog Timeout | 0.8 s typical - detects firmware lockup by requiring WDI transition within interval |
| Supply Current | 15 µA typical at VDD = 3.3 V - enables battery-backed operation in portable systems |
| Operating Temp | –40°C to +85°C - qualified for industrial and automotive-adjacent embedded applications |
| VDD Range | 2.7 V to 6 V - supports wide input margin while maintaining supervision integrity |
Pinout & Package
TPS3306-33DR is housed in an 8-pin SOIC (D) package, 3.9 mm × 4.9 mm body, 1.75 mm max height, with standard 1.27 mm lead pitch and RoHS-compliant NiPdAu finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - SENSE1 | Voltage sense input 1 | Monitors primary supply (5 V); asserts RESET if voltage drops below 4.55 V |
| 2 - SENSE2 | Voltage sense input 2 | Monitors secondary supply (3.3 V); contributes to RESET assertion if below 2.93 V |
| 3 - PFI | Power-fail comparator input | Accepts external resistor-divider voltage; triggers PFO when input falls below 1.25 V |
| 4 - GND | Analog/digital ground | Common reference for all comparators and internal circuitry; must be low-impedance |
| 5 - RESET | Active-low open-drain reset output | Drives low during fault or power-up; requires external pull-up to host VCC |
| 6 - PFO | Active-low open-drain power-fail output | Signals auxiliary supply failure; independent of RESET timing and thresholds |
| 7 - WDI | Watchdog timer input | Edge-sensitive; resets internal timer on rising or falling transition; disabled if floating |
| 8 - VDD | Supply voltage input | Powers internal circuitry; RESET is defined down to VDD ≥ 1.1 V |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent voltage supervision | Simultaneously monitors 5 V and 3.3 V rails with separate thresholds and hysteresis |
| Configurable power-fail detection | PFI input referenced to 1.25 V allows monitoring of any voltage >1.25 V using external resistors |
| Integrated watchdog timer | 0.8 s timeout with edge-triggered WDI input eliminates need for external timing components |
| Guaranteed RESET assertion at low VDD | Defined RESET behavior begins at VDD ≥ 1.1 V - critical for brownout recovery |
| Low quiescent current | 15 µA typical supply current enables use in always-on or battery-critical subsystems |
Applications
| Industrial PLC Controller | Automotive Infotainment Head Unit |
|---|---|
Use Scenario: Dual-rail power sequencing for FPGA + ARM Cortex-A core with 5 V I/O and 3.3 V logic supplies. IC Role / Device Role / Timing Role: Supervises both rails, asserts synchronized RESET until both stabilize, then enables watchdog for runtime firmware health check. Use Value: Prevents partial initialization and silent corruption during cold start or transient dips - validated per IEC 61000-4-2/4-4. | Use Scenario: Power management in head unit with main 5 V DC-DC and 3.3 V LDO for audio DSP and display controller. IC Role / Device Role / Timing Role: Monitors both rails; uses PFI to detect backup battery depletion; generates early warning via PFO before main RESET asserts. Use Value: Enables graceful shutdown and data save prior to full power loss - extends functional safety window by >200 ms. |
| Medical Patient Monitor | Network Edge Router |
Use Scenario: Dual-supply supervision for analog front-end (5 V) and digital processing (3.3 V) in battery-operated portable monitor. IC Role / Device Role / Timing Role: Provides low-current supervision (15 µA) and watchdog; RESET released only after both rails meet threshold for 100 ms. Use Value: Meets IEC 60601-1 leakage and power budget requirements while ensuring deterministic boot sequence. | Use Scenario: Monitoring 5 V PoE-derived rail and 3.3 V switching regulator in fanless edge router with thermal throttling. IC Role / Device Role / Timing Role: Detects undervoltage on either rail; asserts RESET to prevent packet corruption; WDI tied to CPU GPIO for crash detection. Use Value: Eliminates need for discrete supervisors and RC timers - reduces BOM count by 3 components and layout area by 22 mm². |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-voltage supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS3306-33DGKR | VSSOP-8 (2.3 mm × 2.0 mm) vs SOIC-8 (3.9 mm × 4.9 mm); identical electrical specs and marking "AIG" | Requires PCB redesign for smaller footprint and finer pitch; better suited for space-constrained designs | Select DGKR for high-density layouts; DR for legacy SOIC-compatible boards and ease of hand-soldering |
| TPS3306-Q1DR | Automotive-grade (AEC-Q100 Grade 2); same SOIC-8 package; extended reliability testing and traceability | Required for automotive infotainment or ADAS ECUs; not qualified for industrial temp range outside –40°C to +105°C | Choose Q1DR for production vehicles; TPS3306-33DR for industrial, medical, or commercial systems |
Compared with TPS3306-33DGKR and TPS3306-Q1DR, the TPS3306-33DR offers standard industrial qualification, SOIC-8 compatibility for prototyping and repair, and identical supervision thresholds - making it optimal for cost-sensitive, non-automotive embedded designs where board real estate and qualification scope permit.
Availability
TPS3306-33DR is available at Aetrix Electronics and suitable for industrial PLC controllers, medical patient monitors, and network edge routers requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.
Supply support for TPS3306-33DR 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
Texas Instruments is a global semiconductor leader delivering analog and embedded processing solutions, with over 90 years of innovation in power management, signal chain, and microcontrollers.
The TPS3306 family was developed specifically for dual-rail DSP and processor-based systems needing coordinated reset, watchdog, and power-fail signaling - targeting high-reliability embedded applications where supply sequencing integrity is critical.
FAQ
What is the exact SENSE1 and SENSE2 threshold voltage for TPS3306-33DR?
The TPS3306-33DR has a typical SENSE1 threshold of 4.55 V (for 5 V rail monitoring) and SENSE2 threshold of 2.93 V (for 3.3 V rail monitoring), with ±3% variation over temperature and supply. These values are factory-trimmed and specified in Table 1 of the SLVS290C datasheet - no external resistor adjustment is needed.
Does TPS3306-33DR require external pull-up resistors on RESET and PFO?
Yes, TPS3306-33DR features open-drain RESET and PFO outputs, so external pull-up resistors are mandatory. Typical values are 4.7 kΩ to the respective host supply (e.g., 3.3 V or 5 V). Pull-up placement should minimize trace length to reduce noise susceptibility and ensure clean edge transitions.
Can the watchdog timer in TPS3306-33DR be disabled, and how?
Yes, the watchdog timer in TPS3306-33DR is disabled by leaving the WDI pin unconnected (floating) or tying it to a static logic level (VDD or GND). The datasheet confirms that absence of transitions disables watchdog functionality - no configuration register or strap pin is required.
What is the minimum VDD required for TPS3306-33DR to assert RESET?
The TPS3306-33DR guarantees RESET assertion down to VDD ≥ 1.1 V, as confirmed in the Electrical Characteristics table. This ensures reliable brownout detection even during deep supply sag - critical for systems recovering from low-energy states or capacitor discharge events.
Is TPS3306-33DR pin-compatible with other members of the TPS3306 family?
Yes, all TPS3306-x variants (including TPS3306-15DR, TPS3306-25DR, and TPS3306-33DR) share identical SOIC-8 pinout and package dimensions. Only the internal voltage thresholds differ - enabling drop-in replacement when adjusting for different rail combinations without PCB modification.
TPS3306-33DR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Multi-Voltage Supervisor
- Number of Voltages Monitored:
- 2
- Voltage - Threshold:
- 2.93V, 4.55V
- Output:
- Open Drain or Open Collector
- Reset:
- Active Low
- Reset Timeout:
- 70ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
TPS3306-33DR FAQ
1.How can I place an order for TPS3306-33DR through Aetrix?
Please submit a Request for Quotation (RFQ) for TPS3306-33DR 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 TPS3306-33DR reliable?
The price and inventory of TPS3306-33DR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TPS3306-33DR is usually 5 days.
3.What payment methods are accepted for TPS3306-33DR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TPS3306-33DR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TPS3306-33DR?
TPS3306-33DR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TPS3306-33DR 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 TPS3306-33DR?
For technical support, including TPS3306-33DR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TPS3306-33DR requirements.
6.How does Aetrix verify that TPS3306-33DR is sourced from the original manufacturer or authorized distributors?
All TPS3306-33DR 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 TPS3306-33DR meets industry standards.
7.What is the process for return or replacement of TPS3306-33DR?
All TPS3306-33DR units undergo pre-shipment inspection (PSI). If there is an issue with TPS3306-33DR, 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 TPS3306-33DR part is unused and in its original packaging.
Return procedure for TPS3306-33DR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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