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Analog Devices Inc. LTC2939CMS#TRPBF
- Part No.:
- LTC2939CMS#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Power Supply Controllers, Monitors
- Package:
- 16-TFSOP (0.118", 3.00mm Width)
- Datasheet:
-
LTC2939CMS#TRPBF.pdf
- Description:
- IC FOUR PWR SUPP MONITOR 16MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,986
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Product details
Overview
LTC2939CMS#TRPBF from Analog Devices (formerly Linear Technology) is a configurable 6-supply voltage monitor IC with integrated watchdog timer, reset output, and programmable threshold selection via external resistive divider. It monitors up to six independent supply rails-including 5V, 3.3V, 2.5V, 1.8V, 1.5V, 1.2V, and adjustable/–ADJ inputs-with ±1.5% threshold accuracy over temperature, 80μA typical supply current, and guaranteed RST operation down to VCC = 1V. It is used in multivoltage server power sequencing and telecom equipment supervision.
For engineers reviewing the LTC2939CMS#TRPBF datasheet, LTC2939CMS#TRPBF pinout, LTC2939CMS#TRPBF application, or LTC2939CMS#TRPBF equivalent, key selection criteria include six-rail monitoring capability, user-selectable 16 preset voltage combinations, adjustable reset/watchdog timeout via external capacitors, high-temperature operation to 125°C, and MSOP-16 package compatibility with industrial embedded systems.
Technical Context
The LTC2939CMS#TRPBF implements six independent high-impedance comparators-four with selectable fixed thresholds (5V/3.3V/2.5V/1.8V/1.5V/1.2V) and two (V5/V6) with fixed 0.5V reference for ADJ mode-each referenced to internal 1.210V buffered VREF. Configuration is performed once at power-up via VPG input sampling of a 1% resistive divider between VREF and GND, selecting one of sixteen predefined rail combinations.
Its watchdog circuit initiates on RST rising edge, requires periodic WDI transitions (rising/falling) within tWD to prevent timeout, and latches WDO low upon expiration-triggering RST low for one tRST period. Reset assertion occurs on any undervoltage event across monitored rails, with glitch immunity and guaranteed RST low state until all rails exceed thresholds plus configured tRST delay.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Monitoring Channels | 6 independent voltage inputs (V1–V6), supporting fixed thresholds (5V/3.3V/2.5V/1.8V/1.5V/1.2V) and adjustable/–ADJ modes |
| Threshold Accuracy | ±1.5% over full temperature range - ensures reliable reset without false triggering in ±5% supply systems |
| Reset Timeout (tRST) | Adjustable from ~20μs to >100ms using external CRT capacitor (2ms/nF scaling) - matches microprocessor power-on initialization timing |
| Watchdog Timeout (tWD) | Adjustable from ~200μs to >1s using external CWT capacitor (20ms/nF scaling) - aligns with software execution loop intervals |
| Supply Current | 80μA typical - enables use in always-on, battery-backed, or ultra-low-power supervisory applications |
| Operating Temperature | 0°C to 70°C (C-grade) - validated for commercial desktop, network server, and industrial control environments |
| VCC Minimum for RST | 1V - guarantees correct reset logic state during brownout and deep power-down conditions |
Pinout & Package
Package: 16-Lead Plastic MSOP (3mm × 4.9mm, 0.65mm pitch), exposed pad optional for thermal enhancement. Pin 1 marked by dot; pin numbering follows standard MSOP convention.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| V1 | Main supply input / VCC source | Primary voltage rail (5V or 3.3V); greater of V1/V2 sets internal VCC - must be bypassed with ≥0.1μF capacitor |
| V2 | Secondary supply input / VCC source | Secondary rail (3.3V/2.5V/1.8V/1.5V/1.2V); contributes to VCC and serves as internal pull-up reference for RST/WDO |
| V3–V6 | Configurable monitor inputs | V3/V4 support ADJ/–ADJ modes; V5/V6 are fixed 0.5V-threshold ADJ inputs - all high-impedance (>100MΩ) for minimal loading |
| VPG | Configuration select input | Samples resistive divider (VREF–GND) at power-up to select one of 16 voltage combinations - no capacitance allowed |
| VREF | Buffered reference output | 1.210V ±0.018V, capable of sourcing/sinking ±1mA - used for VPG programming and –ADJ level shifting |
| RST | Reset output | Open-drain with weak 6μA pull-up to V2; asserts low on undervoltage or watchdog timeout - requires external pull-up if V2 ≤2.5V |
| WDO | Watchdog output | Open-drain with weak 6μA pull-up to V2; latched low after watchdog timeout - cleared only by WDI transition or undervoltage |
| WDI | Watchdog input | Three-state logic input; toggling (low↔high) resets watchdog timer - floating disables watchdog function |
| CRT | Reset timeout capacitor terminal | Connects to GND via capacitor to set tRST (2ms/nF); unconnected yields ~20μs minimum delay |
| CWT | Watchdog timeout capacitor terminal | Connects to GND via capacitor to set tWD (20ms/nF); tied to GND disables watchdog |
| GND | Device ground reference | Analog/digital common return - recommended connection to PCB ground plane |
| NC | No internal connection | Pins 4 and 13 are unused - leave unconnected or float; no electrical function |
Key Features
| Feature | Design Value |
|---|---|
| 16 Preset Voltage Combinations | Single-pin configuration (VPG) selects among 16 fixed rail groupings - eliminates firmware or external logic for mode selection |
| Adjustable Watchdog & Reset Timing | Independent CRT/CWT capacitor-based timing - enables precise matching to processor boot time and software loop duration |
| Guaranteed Operation Down to 1V VCC | RST remains valid even during severe brownout - ensures system reset integrity when primary supplies collapse |
| High-Accuracy Thresholds (±1.5%) | Minimizes required system voltage margin - improves reliability vs. ±3% or ±5% supervisors in tight-tolerance power domains |
| Integrated –ADJ Mode Support | V4 comparator accepts negative supply monitoring via VREF-referenced divider - enables single-chip supervision of bipolar rails |
Applications
| Server Power Sequencing | Telecom Line Card Supervision |
|---|---|
Use Scenario: Monitors 12V, 5V, 3.3V, 2.5V, 1.8V, and 1.2V rails in a dual-CPU server backplane during cold start and hot-swap events. IC Role / Device Role / Timing Role: Acts as centralized power-good arbiter and watchdog enforcer; asserts RST until all rails stabilize, then enables CPU boot sequence. Use Value: Prevents premature CPU execution due to incomplete rail ramp-up; eliminates need for discrete supervisor per rail, reducing BOM count by 5×. | Use Scenario: Supervises +3.3V, +2.5V, +1.8V, +1.2V, –1.2V, and 1.2V ADJ rails on a 48V-powered telecom line card with FPGA and SerDes interfaces. IC Role / Device Role / Timing Role: Provides simultaneous positive/negative rail monitoring and watchdog oversight of FPGA configuration state. Use Value: Enables single-chip detection of –1.2V rail fault (via V4 –ADJ mode) and automatic recovery via WDI-triggered reset - avoids manual board reseat. |
| Industrial PLC Controller | Notebook Embedded Controller |
Use Scenario: Monitors 24V input, 5V system, 3.3V I/O, 2.5V memory, 1.8V core, and 1.2V PHY rails in an IP67-rated programmable logic controller operating at 85°C ambient. IC Role / Device Role / Timing Role: Serves as fail-safe power supervisor with extended temperature rating; uses external 47nF CRT/CWT to set 94ms/940ms timeouts aligned to PLC firmware watchdog window. Use Value: Guarantees deterministic reset under thermal stress; ±1.5% threshold accuracy prevents nuisance resets during 85°C sustained operation. | Use Scenario: Integrates into notebook EC firmware stack to supervise main 5V, 3.3V, 1.8V, 1.5V, 1.2V, and DDR termination (VTT) rails during sleep/resume cycles. IC Role / Device Role / Timing Role: Functions as low-power (80μA) supervisor enabling instant wake-from-suspend; WDO status read by EC confirms reset cause (power vs. software hang). Use Value: Reduces EC power budget by eliminating discrete 3.3V LDO supervisor; RST/WDO status differentiation enables optimized resume diagnostics. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar multi-rail supervisor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6816ESE+ | 4-channel monitor (not 6-channel); fixed 3.3V/2.5V/1.8V/1.5V thresholds; no –ADJ or programmable combinations | Suitable only for simpler 4-rail systems without negative rail or custom threshold needs | Select when cost sensitivity outweighs channel count and configurability requirements |
| TPS3808G33DBVR | Single-channel 3.3V supervisor; adjustable reset timeout only; no watchdog or multi-rail capability | Applicable only as point-supervisor replacement, not system-level 6-rail solution | Choose only for incremental upgrade of legacy 3.3V-only designs lacking watchdog or sequencing needs |
Compared with MAX6816ESE+ and TPS3808G33DBVR, the LTC2939CMS#TRPBF uniquely delivers six-rail monitoring, 16 programmable configurations, –ADJ capability, and integrated watchdog in a single MSOP-16 package - making it the sole option for compact, high-reliability multivoltage systems requiring coordinated reset and software hang detection.
Availability
LTC2939CMS#TRPBF is available at Aetrix Electronics and suitable for desktop computers, telecom equipment, and network servers requiring stable component supply with guaranteed long-term manufacturability and consistent parametric performance.
Supply support for LTC2939CMS#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. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, acquired Linear Technology in 2017 to strengthen its precision power and interface portfolio.
The LTC2939CMS#TRPBF belongs to ADI's Linear-supervised power management product line, designed specifically for high-accuracy, low-power, multi-rail system supervision in computing, communications, and industrial infrastructure where reliability under voltage transients and thermal stress is critical.
FAQ
What is the maximum number of supply rails the LTC2939CMS#TRPBF can monitor simultaneously?
The LTC2939CMS#TRPBF can monitor up to six supply rails simultaneously - V1 through V6 - with flexible configuration options including fixed thresholds (5V, 3.3V, 2.5V, 1.8V, 1.5V, 1.2V), adjustable (ADJ), and negative adjustable (–ADJ) modes. This distinguishes it from the pin-compatible 4-rail LTC2938 and makes the LTC2939CMS#TRPBF ideal for complex multivoltage systems such as dual-CPU servers and telecom line cards.
How does the LTC2939CMS#TRPBF achieve ±1.5% threshold accuracy over temperature?
The LTC2939CMS#TRPBF achieves ±1.5% threshold accuracy using a trimmed bandgap reference (1.210V ±0.018V) and laser-trimmed internal resistor ratios, validated across –40°C to 125°C. Its comparators reference this stable VREF, and threshold errors are specified over full temperature range - not just at 25°C - ensuring reliable reset behavior in automotive and industrial environments where thermal drift would compromise lower-accuracy supervisors.
Can the LTC2939CMS#TRPBF monitor a negative supply rail like –1.2V?
Yes, the LTC2939CMS#TRPBF supports negative rail monitoring via the V4 input in –ADJ mode, using VREF (1.210V) as a level-shift reference. A resistive divider between the negative supply and VREF sets the trip point, enabling direct supervision of rails such as –1.2V, –2V, or –5V without external op-amps. This functionality is explicitly documented for V4 in the datasheet and is a key differentiator versus most competing supervisors.
What happens to the RST output of the LTC2939CMS#TRPBF when VCC drops below 1V?
The RST output of the LTC2939CMS#TRPBF is guaranteed to remain in the correct logic-low state down to VCC = 1V, ensuring deterministic reset assertion during brownout. Below 1V, internal circuitry ceases operation and RST may float or become undefined - however, by that point, system power is insufficient for reliable operation regardless. The LTC2939CMS#TRPBF's 1V specification exceeds industry norms and provides critical margin in noisy or poorly regulated power environments.
Is the LTC2939CMS#TRPBF pin-compatible with other members of the LTC2938/LTC2939 family?
No, the LTC2939CMS#TRPBF is not pin-compatible with LTC2938 variants due to its 16-lead MSOP package (vs. 12-lead for LTC2938), which accommodates the additional V5 and V6 monitor inputs. While both share functional similarity and pin naming conventions (e.g., V1, V2, RST, WDO), physical layout differs - V5/V6 occupy pins 7/8 and V6 occupies pin 16 in the LTC2939CMS#TRPBF, whereas those positions are NC or unused in LTC2938 packages.
LTC2939CMS#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:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-MSOP
LTC2939CMS#TRPBF FAQ
1.How can I place an order for LTC2939CMS#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC2939CMS#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 LTC2939CMS#TRPBF reliable?
The price and inventory of LTC2939CMS#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC2939CMS#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC2939CMS#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC2939CMS#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC2939CMS#TRPBF?
LTC2939CMS#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC2939CMS#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 LTC2939CMS#TRPBF?
For technical support, including LTC2939CMS#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC2939CMS#TRPBF requirements.
6.How does Aetrix verify that LTC2939CMS#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC2939CMS#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 LTC2939CMS#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC2939CMS#TRPBF?
All LTC2939CMS#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC2939CMS#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 LTC2939CMS#TRPBF part is unused and in its original packaging.
Return procedure for LTC2939CMS#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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