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Texas Instruments TPS3306-33D
- Part No.:
- TPS3306-33D
- Manufacturer:
- Texas Instruments
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TPS3306-33D.pdf
- Description:
- IC SUPERVISOR 2 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:229
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Product details
Overview
TPS3306-33D from Texas Instruments is a dual-voltage supervisory IC designed for systems requiring independent monitoring of 5 V and 3.3 V rails, featuring open-drain RESET and PFO outputs, a 0.8 s watchdog timer, 100 ms power-on reset delay, and operation from –40°C to +85°C in an SOIC-8 package. It is used in DSP-based industrial controllers where reliable dual-rail power sequencing and fail-safe reset are critical.
For engineers reviewing the TPS3306-33D datasheet, TPS3306-33D pinout, TPS3306-33D application, or TPS3306-33D equivalent, key selection considerations include its dual-threshold SENSE1/SENSE2 inputs (4.55 V / 2.93 V), low 15 µA supply current, defined RESET assertion down to VDD ≥ 1.1 V, and compatibility with microprocessor watchdog supervision in space-constrained embedded designs.
Technical Context
The TPS3306-33D integrates two independent voltage comparators with fixed thresholds (4.55 V on SENSE1, 2.93 V on SENSE2), a power-fail comparator referenced to 1.25 V, and a retriggerable watchdog timer with 0.8 s timeout. Its RESET output remains active until both sensed voltages exceed their respective thresholds and the internal 100 ms delay expires.
It operates across VDD = 2.7–6 V, supports open-drain outputs with 5 mA sink capability, and features hysteresis (30–40 mV) on SENSE inputs to prevent chatter during voltage transitions. The WDI input accepts either edge-triggering and disables automatically when left floating.
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 in real-time control loops |
| Supply Current | 15 µA typical at 3.3 V - enables battery-backed operation for >10 years |
| Operating Temp | –40°C to +85°C - qualified for industrial ambient environments |
| VDD Range | 2.7 V to 6 V - supports wide-input auxiliary supplies and brownout resilience |
Pinout & Package
TPS3306-33D is housed in an 8-pin SOIC (D) package, 3.9 mm × 4.9 mm, 1.75 mm max height, RoHS-compliant with NiPdAu lead finish and MSL Level-1 rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - SENSE1 | Voltage monitor input 1 | Connects to 5 V rail; asserts RESET if voltage drops below 4.55 V |
| 2 - SENSE2 | Voltage monitor input 2 | Connects to 3.3 V rail; asserts RESET if voltage drops below 2.93 V |
| 3 - PFI | Power-fail comparator input | Monitors external voltage (e.g., backup battery) against 1.25 V reference |
| 4 - GND | Ground reference | Analog/digital common return; requires low-impedance PCB connection |
| 5 - RESET | Active-low open-drain reset output | Pulls low during fault or power-up; requires external pull-up to system VCC |
| 6 - PFO | Active-low open-drain power-fail output | Signals external supply failure independently of main rails |
| 7 - WDI | Watchdog timer input | Edge-triggered; resets watchdog on rising or falling transition; disabled if floating |
| 8 - VDD | Supply input | Power source for internal circuitry; must be ≥1.1 V for RESET functionality |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent voltage supervision | Simultaneously monitors 5 V and 3.3 V rails with dedicated thresholds and hysteresis |
| Integrated watchdog timer | 0.8 s timeout with edge-triggered WDI input eliminates need for external timing components |
| Open-drain RESET and PFO outputs | Enables wired-OR configuration and level-shifting across mixed-voltage systems |
| Low quiescent current | 15 µA typical allows integration into always-on subsystems without compromising battery life |
| Defined RESET behavior at low VDD | Guarantees valid reset assertion even as supply decays to 1.1 V - critical for graceful shutdown |
Applications
| Industrial PLC Controller | DSP-Based Motor Drive |
|---|---|
Use Scenario: Monitors dual power rails (5 V I/O, 3.3 V logic) in programmable logic controller backplane under variable load and thermal stress. IC Role / Device Role / Timing Role: Dual-supply supervisor ensuring synchronized reset release and watchdog supervision of firmware execution. Use Value: Prevents spurious startup and runtime lockup by enforcing 100 ms minimum reset hold time and detecting stalled code via 0.8 s watchdog timeout. | Use Scenario: Embedded in servo drive board where 5 V analog front-end and 3.3 V DSP core require independent brownout detection. IC Role / Device Role / Timing Role: Voltage supervisor with separate SENSE1/SENSE2 inputs and open-drain outputs compatible with mixed-voltage signal routing. Use Value: Enables clean power-cycle recovery and avoids erratic ADC sampling or PWM glitches caused by undervoltage on either rail. |
| Automotive Body Control Module | Medical Diagnostic Instrument |
Use Scenario: Supervises 5 V MCU supply and 3.3 V sensor interface rail in non-safety-critical automotive ECUs operating across extended temperature range. IC Role / Device Role / Timing Role: Dual-rail supervisor with automotive-grade temp range (–40°C to +85°C) and robust ESD protection. Use Value: Ensures deterministic boot sequence and prevents field failures due to marginal supply conditions during cold cranking or load dump events. | Use Scenario: Used in portable ultrasound device to supervise main 5 V battery-derived rail and 3.3 V FPGA logic supply during battery discharge cycles. IC Role / Device Role / Timing Role: Low-current (15 µA) supervisor enabling multi-year battery life while maintaining reliable reset integrity. Use Value: Extends operational runtime without sacrificing power-on reliability or watchdog safety coverage for real-time image processing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-supply supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS3306-33DGK | VSSOP-8 package (2.3 mm × 2.0 mm); same electrical specs and pinout mapping | Preferred for high-density PCB layouts where SOIC footprint is prohibitive | Select DGK for space-constrained designs; verify thermal derating (271 mW vs D's 377 mW at +85°C) |
| TPS3823-33DBVR | Single 3.3 V supervisor (no SENSE1); includes manual reset input; 3.5 µA supply current | Lacks dual-rail monitoring; suited only for single-rail systems with manual reset requirement | Choose only if monitoring one rail and needing ultra-low current; not functionally equivalent for dual-rail use |
Compared with TPS3306-33DGK, the TPS3306-33D offers higher power dissipation margin in SOIC packaging but occupies more board area; compared with TPS3823-33DBVR, it provides essential dual-threshold supervision missing in the single-rail alternative, making it irreplaceable in 5 V/3.3 V coexistence architectures.
Availability
TPS3306-33D is available at Aetrix Electronics and suitable for industrial automation, motor control, and medical instrumentation requiring stable component supply, long-term lifecycle support, and guaranteed traceability.
Supply support for TPS3306-33D 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, embedded processing, and connectivity solutions for industrial, automotive, and personal electronics markets.
The TPS3306 family is engineered for dual-supply initialization in DSP and microprocessor systems, emphasizing precise threshold accuracy, low-power supervision, and integrated watchdog functionality for mission-critical embedded control.
FAQ
What is the exact SENSE1 and SENSE2 threshold voltage for TPS3306-33D?
The TPS3306-33D has a nominal SENSE1 threshold of 4.55 V (for 5 V rail monitoring) and SENSE2 threshold of 2.93 V (for 3.3 V rail monitoring), both specified at 25°C with ±3% variation over –40°C to +85°C. These values are factory-trimmed and documented in Table 1 of the SLVS290C datasheet.
Does TPS3306-33D require external components to operate?
No, the TPS3306-33D operates autonomously with only external pull-up resistors on RESET and PFO (open-drain outputs), and optional resistor dividers on PFI for custom power-fail detection. No external capacitors or timing components are needed for its core supervision or watchdog functions.
Can TPS3306-33D be used with a 2.5 V supply rail?
No - the TPS3306-33D is specifically configured for 5 V / 3.3 V dual-rail supervision. For 2.5 V monitoring, TI offers the TPS3306-25D variant with SENSE2 threshold of 2.25 V. Using TPS3306-33D on a 2.5 V rail would cause continuous RESET assertion since 2.5 V < 2.93 V.
What happens to RESET output when VDD falls below 1.1 V?
When VDD drops below 1.1 V, the TPS3306-33D guarantees active-low RESET assertion regardless of SENSE1/SENSE2 states. This ensures fail-safe behavior during deep brownout or power loss, providing clean system shutdown signaling before internal logic becomes unreliable.
Is TPS3306-33D pin-compatible with other TPS3306 variants?
Yes - all TPS3306-x variants (including TPS3306-33D, TPS3306-25D, TPS3306-18D) share identical SOIC-8 pinout, electrical interface, and functional block diagram. Only the internal voltage thresholds differ; no PCB redesign is required when substituting within the same package type.
TPS3306-33D Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- 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
TPS3306-33D FAQ
1.How can I place an order for TPS3306-33D through Aetrix?
Please submit a Request for Quotation (RFQ) for TPS3306-33D 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 TPS3306-33D reliable?
The price and inventory of TPS3306-33D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TPS3306-33D is usually 5 days.
3.What payment methods are accepted for TPS3306-33D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TPS3306-33D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TPS3306-33D?
TPS3306-33D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TPS3306-33D 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 TPS3306-33D?
For technical support, including TPS3306-33D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TPS3306-33D requirements.
6.How does Aetrix verify that TPS3306-33D is sourced from the original manufacturer or authorized distributors?
All TPS3306-33D 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 TPS3306-33D meets industry standards.
7.What is the process for return or replacement of TPS3306-33D?
All TPS3306-33D units undergo pre-shipment inspection (PSI). If there is an issue with TPS3306-33D, 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 TPS3306-33D part is unused and in its original packaging.
Return procedure for TPS3306-33D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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