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Texas Instruments LM2694SD/NOPB
- Part No.:
- LM2694SD/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 10-WFDFN Exposed Pad
- Datasheet:
-
LM2694SD/NOPB.pdf
- Description:
- IC REG BUCK ADJ 600MA 10WSON
- Quantity:
- Payment:
- Shipping:
Inventory:2,292
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Product details
Overview
LM2694SD/NOPB from Texas Instruments is a 30V, 600 mA step-down switching regulator with integrated N-channel buck switch and constant-on-time control architecture. It operates from 8V to 30V input, delivers adjustable output voltage via resistor divider feedback (2.5 V reference), and features valley current limit at 0.62 A - used in high-voltage POL supplies for telecom and industrial power rails.
For engineers reviewing the LM2694SD/NOPB datasheet, LM2694SD/NOPB pinout, LM2694SD/NOPB application, or LM2694SD/NOPB equivalent, key selection criteria include input voltage range (8–30 V), no-loop-compensation design, thermal shutdown (175 °C), WSON-10 package with exposed pad, and RON/SD programmable on-time control.
Technical Context
The LM2694SD/NOPB employs a constant-on-time control scheme where on-time is set by VIN and an external RON resistor, enabling stable switching frequency across line and load variations. Its regulation relies on a 2.5 V internal reference compared at the FB pin, with no external compensation required.
Current limiting occurs during off-time via ISEN pin sensing, with nominal threshold of 0.62 A and 180 mΩ internal sense resistance. The device integrates a startup regulator (VCC = 7.0 V ±0.4 V), gate drive UVLO (4.4 V typical), and soft-start controlled by internal 12 µA current source charging SS pin capacitor to 2.5 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 8 V to 30 V - supports wide-range industrial and telecom inputs without pre-regulation. |
| Output Current | Up to 600 mA - continuous load capability limited by valley current limit of 0.62 A. |
| Switching Frequency | ~1 MHz max - determined by VIN and RON; remains stable across load and input variation. |
| Feedback Reference | 2.500 V ±60 mV - sets output voltage via R1/R2 divider; enables precise adjustable regulation. |
| Thermal Shutdown | 175 °C activation - protects against sustained overload or poor heatsinking in compact layouts. |
| VCC Regulator | 7.0 V ±0.4 V - powers internal circuitry; externally bypassed with ≥0.1 µF ceramic capacitor. |
| Soft-Start Current | 12 µA - charges external SS capacitor linearly for controlled output ramp-up. |
Pinout & Package
LM2694SD/NOPB is packaged in a thermally enhanced 10-pin WSON (3 mm × 3 mm) with exposed pad (EP), optimized for high-power density and PCB heat dissipation. Pin 1 is SW; pin 10 is VIN; EP must be connected to PCB ground plane.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SW | Switching Node | Source of internal N-channel buck switch; connects to inductor, bootstrap capacitor (C4), and freewheeling diode. |
| BST | Bootstrap Supply | Charged from SW via internal diode during off-time; powers high-side gate driver using 0.022 µF capacitor to SW. |
| ISEN | Current Sense Output | Sinks recirculating inductor current during off-time; triggers valley current limit when >0.62 A flows out. |
| SGND | Current Sense Ground | Return path for ISEN current; separate from RTN to avoid noise coupling into current sensing. |
| RTN | Circuit Ground | Main ground return for internal logic, regulation comparators, and VCC regulator - not shared with ISEN path. |
| FB | Voltage Feedback Input | Compares output-derived voltage to 2.5 V reference; requires ≥25 mVpp ripple for stable operation. |
| SS | Soft-Start Control | Internally charged to 2.5 V via 12 µA current source; ramps reference to prevent inrush and overshoot. |
| RON/SD | On-Time Set / Shutdown | Resistor from VIN sets on-time; grounding disables regulator and discharges SS pin. |
| VCC | Startup Regulator Output | 7.0 V regulated supply for internal circuits; can be externally biased to reduce dissipation. |
| VIN | Main Input Supply | Accepts 8–30 V; powers both buck switch and internal start-up regulator; requires local 0.1 µF bypass. |
Key Features
| Feature | Design Value |
|---|---|
| No loop compensation required | Enables stable regulation with fast transient response and simplified BOM - eliminates external compensation network. |
| Valley current limit at 0.62 A | Provides smooth transition to constant-current mode under overload, avoiding foldback and maintaining predictable shutdown behavior. |
| Constant on-time control | Maintains stable switching frequency across input voltage (8–30 V) and load changes - simplifies EMI filtering design. |
| Integrated start-up regulator | Generates 7.0 V VCC directly from VIN up to 30 V - eliminates need for external bias supply in high-input applications. |
| Thermally enhanced WSON-10 | θJA = 33 °C/W (0 LFPM); exposed pad improves thermal performance in space-constrained industrial PCBs. |
Applications
| Telecom Point-of-Load Regulation | Industrial High-Voltage Post-Regulation |
|---|---|
Use Scenario: Converting 24 V or 48 V telecom distribution rail to 3.3 V or 5 V for FPGA I/O or microcontroller core logic. IC Role / Device Role / Timing Role: Primary non-isolated buck regulator delivering up to 600 mA with fast transient response to handle burst-mode digital loads. Use Value: Eliminates need for external compensation and reduces component count versus voltage-mode controllers - critical for dense telecom blade designs. | Use Scenario: Stepping down 28 V aircraft or industrial bus to 12 V for analog sensors, actuators, or isolated gate drivers. IC Role / Device Role / Timing Role: High-input-voltage buck converter operating reliably across wide temperature range (−40 °C to +125 °C junction). Use Value: Integrated 30 V N-channel switch and 7 V start-up regulator enable single-chip solution without auxiliary bias - reducing system cost and footprint. |
| Secondary Power for Isolated DC-DC | LED Driver Bias Supply |
Use Scenario: Generating 5 V bias for optocoupler feedback or PWM controller ICs in flyback or forward converters with 30 V+ primary-side rails. IC Role / Device Role / Timing Role: Auxiliary buck regulator powered from main transformer auxiliary winding or bulk DC bus. Use Value: Wide 8–30 V input range accommodates varying auxiliary winding voltages; shutdown (RON/SD) enables synchronized power sequencing. | Use Scenario: Providing stable 12 V or 15 V bias for LED driver ICs (e.g., LM3409, TPS92630) in automotive lighting or signage systems. IC Role / Device Role / Timing Role: Efficient, low-noise intermediate supply decoupled from noisy LED switching paths. Use Value: Ultra-fast transient response prevents LED current droop during rapid dimming transitions; thermal shutdown ensures robustness in enclosed fixtures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2694MM/NOPB | TSSOP-14 package (θJA = 40 °C/W); same electrical specs and pinout mapping except NC pins differ. | Less thermally efficient than WSON-10; preferred only when board layout requires through-hole or legacy TSSOP footprint. | Select LM2694MM/NOPB only if mechanical compatibility with existing TSSOP-14 land pattern is required. |
| TPS54202DRLR | 2.5–17 V input; 2 A output; integrated FETs; uses voltage-mode control with external compensation. | Lower input voltage ceiling and higher current rating - unsuitable for 24–30 V telecom rails but better for 12 V embedded systems. | Choose TPS54202DRLR for lower-input, higher-current applications where compensation flexibility is needed. |
Compared with LM2694MM/NOPB, LM2694SD/NOPB offers superior thermal performance (33 vs. 40 °C/W) in a smaller 3×3 mm footprint; versus TPS54202DRLR, it supports higher input voltage (30 V vs. 17 V) and eliminates compensation components but delivers lower output current (0.6 A vs. 2 A).
Availability
LM2694SD/NOPB is available at Aetrix Electronics and suitable for telecom point-of-load regulation, industrial high-voltage post-regulation, and secondary power for isolated DC-DC converters requiring stable component supply and long-term manufacturability.
Supply support for LM2694SD/NOPB 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 specializing in analog, embedded processing, and power management technologies, with decades of expertise in high-reliability power conversion ICs.
The LM2694 belongs to TI's high-voltage buck regulator product line, designed specifically for efficient, compact, and easy-to-implement DC-DC conversion in telecom, industrial, and automotive subsystems operating from 8 V to 30 V inputs.
FAQ
What is the maximum input voltage rating for LM2694SD/NOPB?
The absolute maximum input voltage (VIN to RTN) for LM2694SD/NOPB is 33 V, with recommended operating range of 8 V to 30 V. Exceeding 33 V risks permanent damage. The device includes internal protection against overvoltage transients common in industrial and telecom environments, but sustained operation above 30 V is not specified or guaranteed.
Does LM2694SD/NOPB require external compensation components?
No, LM2694SD/NOPB does not require external compensation components. Its constant-on-time control architecture eliminates the need for loop compensation networks, simplifying design and improving load transient response. Stability is inherently maintained across input voltage (8–30 V) and load conditions without adding resistors or capacitors to the feedback path.
How is output voltage set on LM2694SD/NOPB?
Output voltage on LM2694SD/NOPB is set using a resistor divider (R1 and R2) from VOUT to FB and FB to RTN. The formula is VOUT = 2.5 V × (R1 + R2)/R2. For example, equal 2.5 kΩ resistors yield 5 V output. The FB pin has <1 nA bias current, minimizing divider error, and requires ≥25 mVpp ripple for proper regulation.
What is the purpose of the RON/SD pin on LM2694SD/NOPB?
The RON/SD pin on LM2694SD/NOPB serves dual functions: connecting an external resistor (RON) from VIN sets the buck switch on-time, thereby determining operating frequency; grounding this pin forces shutdown - disabling the regulator, discharging the SS capacitor, and reducing quiescent current to ~180 µA. A rising voltage >0.8 V releases shutdown.
Can LM2694SD/NOPB operate in discontinuous conduction mode (DCM)?
Yes, LM2694SD/NOPB automatically operates in discontinuous conduction mode (DCM) at light loads. In DCM, inductor current falls to zero during part of the switching cycle, lowering operating frequency and maintaining high efficiency. The device regulates correctly in both continuous and discontinuous modes, with no mode-change circuitry or configuration required - behavior is inherent to its constant-on-time architecture.
LM2694SD/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 10-WFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 8V
- Voltage - Input (Max):
- 30V
- Voltage - Output (Min/Fixed):
- 2.5V
- Voltage - Output (Max):
- 24V
- Current - Output:
- 600mA
- Frequency - Switching:
- 1MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-WSON (3x3)
LM2694SD/NOPB FAQ
1.How can I place an order for LM2694SD/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2694SD/NOPB 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 LM2694SD/NOPB reliable?
The price and inventory of LM2694SD/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2694SD/NOPB is usually 5 days.
3.What payment methods are accepted for LM2694SD/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2694SD/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2694SD/NOPB?
LM2694SD/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2694SD/NOPB 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 LM2694SD/NOPB?
For technical support, including LM2694SD/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2694SD/NOPB requirements.
6.How does Aetrix verify that LM2694SD/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2694SD/NOPB 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 LM2694SD/NOPB meets industry standards.
7.What is the process for return or replacement of LM2694SD/NOPB?
All LM2694SD/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2694SD/NOPB, 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 LM2694SD/NOPB part is unused and in its original packaging.
Return procedure for LM2694SD/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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