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Analog Devices Inc. LTC2939IMS#TRPBF
- Part No.:
- LTC2939IMS#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Power Supply Controllers, Monitors
- Package:
- 16-TFSOP (0.118", 3.00mm Width)
- Datasheet:
-
LTC2939IMS#TRPBF.pdf
- Description:
- IC FOUR PWR SUPP MONITOR 16MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,941
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Product details
Overview
LTC2939IMS#TRPBF from Analog Devices (formerly Linear Technology) is a configurable six-supply voltage monitor IC with integrated watchdog timer, reset output, and 16 selectable threshold combinations for multivoltage systems. It monitors up to six supplies-including 5V, 3.3V, 2.5V, 1.8V, 1.5V, 1.2V, and ±adjustable inputs-with ±1.5% threshold accuracy over temperature, 80μA typical supply current, and guaranteed RST operation down to VCC = 1V. It is used in telecom servers requiring reliable power-up sequencing and fault detection.
For engineers reviewing the LTC2939IMS#TRPBF datasheet, LTC2939IMS#TRPBF pinout, LTC2939IMS#TRPBF application, or LTC2939IMS#TRPBF equivalent, key selection criteria include its 16-mode programmable configuration via VPG resistive divider, adjustable reset/watchdog timeouts using CRT/CWT capacitors, six independent high-impedance voltage inputs (V1–V6), ±1.5% threshold accuracy, and operation across –40°C to +85°C.
Technical Context
The LTC2939IMS#TRPBF implements six independent comparators referenced to either fixed thresholds (e.g., 4.675V for 5V, 3.086V for 3.3V) or a 0.5V internal reference for ADJ/–ADJ modes, with VPG selecting one of sixteen preset combinations via external resistor divider. Its bandgap reference (1.210V ±18mV) feeds both the VPG interface and negative-adjustable mode level-shifting.
Reset assertion is triggered when any monitored supply falls below its configured threshold; RST remains low for a user-defined tRST (2–4ms/nF on CRT), while WDO latches low after un serviced watchdog timeout tWD (20–40ms/nF on CWT). Both outputs feature weak 6μA pull-ups to V2, requiring external pull-ups for V2 ≤ 2.5V to meet downstream VIH requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Inputs | 6 independent high-impedance inputs (V1–V6); supports 5V/3.3V/2.5V/1.8V/1.5V/1.2V presets plus ADJ/–ADJ modes |
| Threshold Accuracy | ±1.5% over full temperature range - ensures reliable reset without false triggering in ±5% supply systems |
| Reset Timeout (tRST) | Adjustable 2–4 ms per nF on CRT pin - enables precise match to microprocessor reset timing requirements |
| Watchdog Timeout (tWD) | Adjustable 20–40 ms per nF on CWT pin - allows software execution window tuning without firmware changes |
| Supply Current | 80 μA typical - suitable for always-on monitoring in battery-backed or low-power embedded systems |
| Operating Temp | –40°C to +85°C (I-grade) - qualified for industrial and telecom infrastructure environments |
| VCC Minimum | 1 V - guarantees correct RST logic state during brownout, enabling fail-safe behavior before core logic fails |
Pinout & Package
Package: 16-Lead Plastic MSOP (3mm × 4.9mm, 0.65mm pitch), exposed pad optional for thermal enhancement.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| V1 | Main supply input / VCC source | Primary voltage input (5V or 3.3V); greater of V1/V2 sets internal VCC; must be bypassed with ≥0.1μF capacitor |
| V2 | Secondary supply input / VCC source | Second voltage input (3.3V/2.5V/1.8V/1.5V/1.2V); contributes to VCC; all status outputs weakly pulled up to this rail |
| V3–V6 | Configurable voltage monitor inputs | High-impedance comparator inputs; V3/V4 support ADJ/–ADJ; V5/V6 fixed 0.5V threshold for LTC2939-only six-input operation |
| VPG | Configuration select input | Accepts resistive divider from VREF to GND to select one of 16 voltage-monitoring combinations; no capacitance allowed |
| VREF | Buffered reference output | 1.210V ±18mV buffered reference; sources/sinks ±1mA; used for VPG programming and –ADJ level shifting |
| RST | Reset output | Open-drain output with 6μA weak pull-up to V2; asserts low on undervoltage or watchdog timeout; requires external pull-up for V2 ≤ 2.5V |
| WDO | Watchdog output | Open-drain watchdog status output; latched low after un serviced timeout; cleared by WDI edge or undervoltage event |
| WDI | Watchdog input | Three-state input; toggling within tWD prevents WDO assertion; floating or constant level disables watchdog |
| CRT | Reset timeout capacitor terminal | Connects to GND via capacitor to set tRST = 2ms/nF; open-circuit yields ~20μs minimum delay |
| CWT | Watchdog timeout capacitor terminal | Connects to GND via capacitor to set tWD = 20ms/nF; grounded to disable watchdog function |
| GND | Device ground reference | Analog and digital ground return; exposed pad (MSOP) may be connected to PCB GND for improved thermal performance |
| NC | No internal connection | Pins 4 and 13 are unconnected; must not be tied to any signal or power rail |
Key Features
| Feature | Design Value |
|---|---|
| 16-Mode Programmable Configuration | Selects exact combination of 6 supply thresholds (e.g., 5V/3.3V/2.5V/1.8V/1.2V/ADJ) via single VPG resistive divider - eliminates BOM variants and simplifies design reuse |
| ±1.5% Threshold Accuracy Over Temperature | Guarantees reset activation only outside system supply tolerance band - prevents nuisance resets in 5% rails like 5V (4.600–4.750V window) |
| Independent ADJ and –ADJ Inputs | V4 supports negative voltage monitoring (e.g., –12V at –11.30V trip) using VREF as level-shift reference - enables single-chip supervision of bipolar supplies |
| Glitch-Immune Comparators | Internal filtering rejects short transients (<150μs) on V1–V6 - avoids false resets from switching noise or load dumps |
| Low-Power Operation (80μA) | Enables continuous monitoring in always-on subsystems (e.g., baseband processors, clock domains) without impacting system quiescent budget |
| Guaranteed RST Below 1V VCC | Maintains valid reset assertion during deep brownout - ensures controlled shutdown even as main supplies collapse |
Applications
| Telecom Network Server | Automotive ADAS Controller |
|---|---|
|
Use Scenario: Monitors 12V, 5V, 3.3V, 2.5V, 1.8V, and 1.2V rails in a 1U rack-mounted packet switch with hot-swap capability. IC Role / Device Role / Timing Role: Six-rail supervisor providing synchronized power-on reset, brownout detection, and watchdog supervision of control FPGA and management MCU. Use Value: Eliminates need for six discrete supervisors; ±1.5% accuracy prevents false resets during line-card insertion transients. |
Use Scenario: Supervises power rails in a vision-processing ECU powering image sensor, ISP, and safety MCU under ISO 16750-2 load-dump conditions. IC Role / Device Role / Timing Role: Configured for 5V/3.3V/2.5V/1.8V/1.2V/ADJ to cover analog front-end, digital core, and I/O supplies; uses –ADJ mode for CAN transceiver bias. Use Value: Single-chip solution meets ASIL-B diagnostic coverage requirements via integrated watchdog and deterministic reset timing. |
| Industrial PLC Backplane | Desktop CPU Power Sequencing |
|
Use Scenario: Ensures safe startup/shutdown of modular I/O cards with mixed 24V, 12V, 5V, 3.3V, 1.8V, and 1.2V supplies across DIN-rail chassis. IC Role / Device Role / Timing Role: Acts as centralized power-good arbiter; asserts global RST only when all six rails stabilize within spec; uses CRT to align with FPGA configuration time. Use Value: Reduces board space vs. discrete solutions; 80μA current enables local supervision without burdening auxiliary LDOs. |
Use Scenario: Validates core, memory, and I/O voltages (VCCIO, VDDQ, VDD, VDDA, VDDSB, VDD_1P2) in high-end desktop motherboard VRM chains. IC Role / Device Role / Timing Role: Configured via VPG for 1.2V/1.8V/2.5V/3.3V/5V/ADJ; uses WDI to confirm BIOS initialization progress; RST holds CPU in reset until all rails settle. Use Value: Replaces legacy 4-supply supervisors with extended flexibility for next-gen multi-rail CPU power architectures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar six-supply monitoring applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6816ESE+ | 4-supply monitor only; no watchdog; fixed 3.0V/3.3V/5.0V thresholds; no ADJ/–ADJ capability | Cannot replace LTC2939IMS#TRPBF in six-rail or adjustable-threshold designs; limited to simpler 4-rail systems | Select only if system has ≤4 supplies and no watchdog or adjustable monitoring required. |
| TPS3808G33DBVR | Single-supply supervisor; 3.3V fixed threshold; adjustable reset delay only; no multi-rail or watchdog functionality | Requires six separate devices to monitor same rails; no coordination between resets; no system-level watchdog capability | Use only for point-of-load supervision where centralized six-rail control is unnecessary. |
Compared with MAX6816ESE+ and TPS3808G33DBVR, the LTC2939IMS#TRPBF uniquely integrates six independent, programmable voltage monitors with adjustable watchdog and reset timing in a single 16-pin MSOP - reducing component count, PCB area, and inter-rail timing skew in complex multivoltage systems.
Availability
LTC2939IMS#TRPBF is available at Aetrix Electronics and suitable for telecom equipment, automotive control systems, and network servers requiring stable component supply, long-term lifecycle support, and industrial-grade temperature performance.
Supply support for LTC2939IMS#TRPBF 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
Analog Devices, Inc. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors.
The LTC2939IMS#TRPBF belongs to the Linear Technology LTC® supervisor family, designed specifically for robust, low-power, multi-rail power monitoring in mission-critical infrastructure where reliability, accuracy, and configurability outweigh cost-driven integration trade-offs.
FAQ
What is the operating temperature range for the LTC2939IMS#TRPBF?
The LTC2939IMS#TRPBF is rated for –40°C to +85°C (I-grade), making it suitable for industrial and telecom applications. This range is confirmed in the "Order Information" table and "Absolute Maximum Ratings" section of the official datasheet. The device maintains full specification compliance-including ±1.5% threshold accuracy and 80μA supply current-across this entire range.
How many voltage inputs does the LTC2939IMS#TRPBF support, and what types are they?
The LTC2939IMS#TRPBF supports six voltage inputs: V1 through V6. V1 and V2 accept standard rails (5V, 3.3V, 2.5V, etc.) and also define internal VCC. V3 and V4 support fixed thresholds or ADJ/–ADJ modes. V5 and V6 are dedicated high-impedance inputs with 0.5V nominal threshold-exclusive to the LTC2939 and enabling true six-supply monitoring beyond the LTC2938's four-input limit.
Can the LTC2939IMS#TRPBF monitor negative voltages?
Yes-the LTC2939IMS#TRPBF supports negative voltage monitoring via the –ADJ mode on V4. In this configuration, an external resistive divider connects between the negative supply and VREF (1.210V), enabling precise trip points such as –11.30V for a –12V rail. This capability is explicitly documented in the "Voltage Configuration Table," "Applications Information," and "PIN FUNCTIONS" sections of the datasheet.
What is the role of the VPG pin on the LTC2939IMS#TRPBF?
The VPG pin on the LTC2939IMS#TRPBF selects one of sixteen predefined voltage-monitoring combinations using an external resistive divider from VREF to GND. During a ~150μs configuration window at power-up, the device samples VPG voltage and configures comparators accordingly. The datasheet provides exact 1% resistor values (e.g., R1=59kΩ/R2=40.2kΩ for Mode 6: 5V/3.3V/2.5V/1.8V) to ensure accurate mode selection.
Does the LTC2939IMS#TRPBF require external pull-up resistors on RST and WDO?
Yes-external pull-up resistors are required on RST and WDO when V2 is configured to monitor 2.5V or lower (e.g., 1.8V, 1.5V, 1.2V). The internal 6μA pull-up to V2 cannot guarantee VOH above typical VIH thresholds (e.g., >2.0V for 3.3V logic). The datasheet explicitly states: "For V2 configured to monitor 1.2V, 1.5V, 1.8V and 2.5V supplies, external pull-up resistors are required."
LTC2939IMS#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-TFSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Applications:
- Six Power Supply Monitor
- Voltage - Input:
- -
- Voltage - Supply:
- 1V ~ 5V
- Current - Supply:
- -
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-MSOP
LTC2939IMS#TRPBF FAQ
1.How can I place an order for LTC2939IMS#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC2939IMS#TRPBF 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 LTC2939IMS#TRPBF reliable?
The price and inventory of LTC2939IMS#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC2939IMS#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC2939IMS#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC2939IMS#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC2939IMS#TRPBF?
LTC2939IMS#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC2939IMS#TRPBF 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 LTC2939IMS#TRPBF?
For technical support, including LTC2939IMS#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC2939IMS#TRPBF requirements.
6.How does Aetrix verify that LTC2939IMS#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC2939IMS#TRPBF 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 LTC2939IMS#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC2939IMS#TRPBF?
All LTC2939IMS#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC2939IMS#TRPBF, 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 LTC2939IMS#TRPBF part is unused and in its original packaging.
Return procedure for LTC2939IMS#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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