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Texas Instruments TPS3618-50DGKT
- Part No.:
- TPS3618-50DGKT
- Manufacturer:
- Texas Instruments
- Category:
- Supervisors
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
TPS3618-50DGKT.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8VSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:240
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Product details
Overview
TPS3618-50DGKT from Texas Instruments is a battery-backup supervisor IC designed for RAM retention in 5-V systems. It provides precision 4.55-V supply monitoring, 800-ms watchdog timeout, 100-ms power-on reset delay, and seamless VDD-to-VBAT switchover with ≤1-Ω on-resistance (VDD→VOUT) and ≤15-Ω (VBAT→VOUT). It serves as the critical power-fail and data-retention controller in portable battery-powered equipment.
For engineers reviewing the TPS3618-50DGKT datasheet, TPS3618-50DGKT pinout, TPS3618-50DGKT application, or TPS3618-50DGKT equivalent, key selection considerations include its 40 µA max supply current, 100 nA max battery supply current, –40°C to +125°C operating range, MSOP-8 package, and dual-supply switchover architecture supporting lithium backup cells exceeding VDD voltage.
Technical Context
The TPS3618-50DGKT integrates a precision voltage monitor with 4.55-V threshold (±1.5% over temperature), a push-pull active-low RESET output with 100-ms fixed delay, and a dedicated watchdog timer with 0.8-s typical timeout. Its internal switchover logic ensures VOUT transitions from VDD to VBAT only when VDD falls below VIT *and* VBAT > VDD-preventing reverse current and enabling higher-voltage backup batteries.
It features independent PFI/PFO pins for external power-fail detection at 1.15-V reference, WDI input compatible with TTL/CMOS logic levels (VIH = 0.7×VDD), and dual-mode operation: normal (VDD-powered) and battery-backup (VBAT-powered), each with validated on-resistance and propagation timing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VDD Threshold (VIT) | 4.55 V ±1.5% - precise brownout detection point for 5-V systems, ensuring reliable reset assertion before MCU instability. |
| Supply Current (IDD) | 40 µA max - enables ultra-low-power operation in always-on supervisory circuits without burdening main supply. |
| Battery Supply Current (IBAT) | 100 nA max - preserves backup battery life for multi-year RAM retention in standby applications. |
| Watchdog Timeout (ttimeout) | 0.8 s typical - provides robust software execution monitoring for microcontrollers in embedded systems. |
| VDD→VOUT RDS(on) | ≤1 Ω - minimizes voltage drop and power loss during primary supply mode, supporting ≥300 mA continuous load. |
| VBAT→VOUT RDS(on) | ≤15 Ω - enables efficient switchover to 3.3–3.6 V lithium backup cells while maintaining stable VOUT under load. |
| Operating Temperature | –40°C to +125°C - qualified for automotive and industrial environments where extended thermal range is required. |
| Reset Delay Time (td) | 100 ms fixed - guarantees sufficient power stabilization time before releasing reset to microcontroller after power-up. |
Pinout & Package
TPS3618-50DGKT is housed in an 8-pin VSSOP (DGK) package, 3.05 mm × 4.98 mm footprint, 1.1 mm max height, with exposed pad for thermal performance. Pin 1 index located at top-left corner per JEDEC MO-187.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VOUT (Pin 1) | Power output | Switched supply output connected to VDD or VBAT depending on switchover state; supports up to 300 mA continuous load. |
| VDD (Pin 2) | Main supply input | Primary 5-V system supply input; monitored for undervoltage; powers internal circuitry when active. |
| GND (Pin 3) | Ground reference | Common return path for all analog and digital functions; must be low-impedance for accurate threshold sensing. |
| PFI (Pin 4) | Power-fail comparator input | External voltage monitoring input referenced to 1.15-V internal threshold; used for secondary supply or battery-level supervision. |
| PFO (Pin 5) | Power-fail comparator output | Active-low push-pull output asserting when PFI < 1.15 V; requires no external pull-up. |
| WDI (Pin 6) | Watchdog input | Edge-triggered watchdog enable; toggling within 0.8 s resets internal timer; floating disables watchdog function. |
| RESET (Pin 7) | Reset output | Active-low push-pull reset signal with 100-ms delay; drives MCU reset pin directly without external components. |
| VBAT (Pin 8) | Battery backup input | Backup supply input (1.5–5.5 V); automatically selected when VDD fails; supports voltages exceeding VDD for lithium cell use. |
Key Features
| Feature | Design Value |
|---|---|
| Auto switchover with VBAT > VDD support | Enables use of 3.6-V lithium backup cells without diode drop or external FETs, preserving full backup voltage at VOUT. |
| Ultra-low battery supply current | 100 nA max IBAT ensures >10-year battery life for CMOS RAM retention in long-term monitoring equipment. |
| Integrated 100-ms POR generator | Eliminates need for external RC timing network; guarantees deterministic reset release timing across temperature and voltage. |
| Dual independent comparators | Separate VDD monitor (4.55 V) and PFI monitor (1.15 V) allow simultaneous supervision of main and auxiliary supplies. |
| Push-pull RESET and PFO outputs | No external pull-ups required; reduces BOM count and improves noise immunity in noisy industrial environments. |
| MSOP-8 thermal performance | Exposed pad and low RθJA support operation up to +125°C ambient without derating in compact PCB layouts. |
Applications
| Portable Battery-Powered Equipment | Automotive Systems |
|---|---|
Use Scenario: Handheld medical monitors requiring nonvolatile RAM storage during battery swaps or AC power loss. IC Role / Device Role / Timing Role: Supervises 5-V main rail and switches RAM supply to 3.6-V lithium coin cell within 3 µs of VDD collapse; asserts RESET to halt processor before data corruption. Use Value: Guarantees zero-data-loss RAM retention for >5 years using standard BR2032 battery, enabled by 100 nA IBAT and VBAT > VDD architecture. | Use Scenario: Engine control unit (ECU) black-box logging that retains crash-event data after ignition-off power decay. IC Role / Device Role / Timing Role: Monitors 5-V system rail; triggers immediate VOUT switchover to backup supercapacitor or Li-ion cell upon VDD sag; holds RESET until stable recovery. Use Value: Supports –40°C to +125°C operation and meets AEC-Q100 stress requirements via TI's qualified production flow and extended temp grading. |
| Fax Machines | Point-of-Sale Equipment |
Use Scenario: Legacy fax machines retaining configuration and memory dial lists during brief AC outages. IC Role / Device Role / Timing Role: Provides 100-ms POR delay and 4.55-V threshold detection to prevent spurious resets during line-voltage sags; manages switchover to onboard NiMH backup. Use Value: Eliminates need for discrete reset IC + external MOSFET switch, reducing board space by 40% versus discrete solutions. | Use Scenario: Retail POS terminals preserving transaction buffers and encryption keys during short grid interruptions. IC Role / Device Role / Timing Role: Uses PFI/PFO to monitor 3.3-V I/O rail independently; asserts PFO to trigger firmware save-to-EEPROM before main 5-V rail collapse. Use Value: Dual-comparator capability enables coordinated power-fail response across multiple voltage domains, preventing partial writes or key loss. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar battery-backup supervisor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS3617-50DGKR | Identical functionality but rated for –40°C to +85°C; lacks battery freshness seal (not applicable to TPS3618). | Targeted at commercial/industrial applications without extended temperature requirement. | Select when cost sensitivity outweighs 125°C qualification; same pinout and electrical behavior in shared operating range. |
| MAX6361KA29+T | 4.63-V threshold, 1.6-µA quiescent current, no VBAT > VDD support, no PFI/PFO, SO-8 package. | Limited to basic reset-only applications without switchover or auxiliary monitoring. | Choose only if switchover and dual-comparator features are unnecessary and lower cost is prioritized over battery life and flexibility. |
Compared with TPS3617-50DGKR, the TPS3618-50DGKT adds extended temperature qualification (+125°C) and identical switchover performance; compared with MAX6361KA29+T, it delivers 40× lower battery current, integrated switchover, and dual-monitoring capability-making it superior for long-life, multi-rail, high-reliability designs.
Availability
TPS3618-50DGKT is available at Aetrix Electronics and suitable for portable battery-powered equipment, automotive black-box loggers, fax machines, and point-of-sale terminals requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for TPS3618-50DGKT 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 company delivering analog and embedded processing solutions, with leadership in power management, signal chain, and high-reliability ICs.
The TPS361x family is designed specifically for battery-backed RAM retention in mission-critical systems, emphasizing ultra-low IBAT, precise VIT stability over temperature, and robust switchover control-enabling data integrity in power-interrupted environments.
FAQ
What is the exact supply voltage threshold (VIT) for TPS3618-50DGKT?
The TPS3618-50DGKT has a nominal supply voltage threshold of 4.55 V, with ±1.5% tolerance over the full –40°C to +125°C operating temperature range. This value is factory-trimmed and specified in the Electrical Characteristics table of the SLVS339D datasheet. The threshold remains stable under varying load and input ripple conditions due to internal hysteresis of 60 mV.
Does TPS3618-50DGKT support backup batteries with voltage higher than the main supply?
Yes, the TPS3618-50DGKT explicitly supports VBAT > VDD operation. Its internal switchover logic connects VBAT to VOUT only when VDD falls below VIT *and* VBAT exceeds VDD-enabling direct use of 3.6-V lithium cells without external diodes or level-shifting. This feature is confirmed in the Functional Description and Figure 14 (VDD–VBAT Switchover) of the datasheet.
What is the maximum continuous output current supported by TPS3618-50DGKT at VOUT?
The TPS3618-50DGKT supports up to 300 mA continuous output current at VOUT in both VDD-powered and VBAT-powered modes. In VDD mode, RDS(on) is ≤1 Ω (ensuring <300 mV drop at 300 mA); in VBAT mode, RDS(on) is ≤15 Ω (ensuring <4.5 V drop at 300 mA with 3.6-V input). These values are validated across temperature in the Electrical Characteristics tables.
How does the watchdog timer in TPS3618-50DGKT operate, and what is its timeout period?
The watchdog timer in TPS3618-50DGKT has a typical timeout period of 0.8 s, with min/max values of 0.48 s and 1.12 s over temperature. It is edge-triggered: either a rising or falling edge on WDI resets the timer. If unused, WDI may be left floating. The timer is disabled when WDI is held static, and its behavior is detailed in the Watchdog section and Figure 13 of the SLVS339D datasheet.
Is TPS3618-50DGKT pin-compatible with TPS3617-50DGKR?
Yes, TPS3618-50DGKT is pin-compatible with TPS3617-50DGKR: both use the same 8-pin VSSOP (DGK) package, identical pinout, and share identical functional terminal assignments per Table 3 (Terminal Functions) in the datasheet. The only differences are temperature rating (–40°C to +125°C vs. –40°C to +85°C) and part marking (ANK vs. ASD); no PCB layout changes are required for substitution within the shared operating range.
TPS3618-50DGKT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Battery Backup Circuit
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 4.55V
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- 60ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-VSSOP
TPS3618-50DGKT FAQ
1.How can I place an order for TPS3618-50DGKT through Aetrix?
Please submit a Request for Quotation (RFQ) for TPS3618-50DGKT 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 TPS3618-50DGKT reliable?
The price and inventory of TPS3618-50DGKT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TPS3618-50DGKT is usually 5 days.
3.What payment methods are accepted for TPS3618-50DGKT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TPS3618-50DGKT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TPS3618-50DGKT?
TPS3618-50DGKT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TPS3618-50DGKT 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 TPS3618-50DGKT?
For technical support, including TPS3618-50DGKT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TPS3618-50DGKT requirements.
6.How does Aetrix verify that TPS3618-50DGKT is sourced from the original manufacturer or authorized distributors?
All TPS3618-50DGKT 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 TPS3618-50DGKT meets industry standards.
7.What is the process for return or replacement of TPS3618-50DGKT?
All TPS3618-50DGKT units undergo pre-shipment inspection (PSI). If there is an issue with TPS3618-50DGKT, 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 TPS3618-50DGKT part is unused and in its original packaging.
Return procedure for TPS3618-50DGKT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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