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Texas Instruments LM3687TLX-1812/NOPB
- Part No.:
- LM3687TLX-1812/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Regulators - Linear + Switching
- Package:
- 9-WFBGA, DSBGA
- Datasheet:
-
LM3687TLX-1812/NOPB.pdf
- Description:
- IC REG DL BUCK/LNR SYNC 9TUSMD
- Quantity:
- Payment:
- Shipping:
Inventory:2,406
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Product details
Overview
LM3687TLX-1812/NOPB from Texas Instruments is a dual-rail power management IC integrating a 1.8V synchronous step-down DC-DC converter (750mA max) and a 1.2V low-dropout linear regulator (350mA max), optimized for post-regulation in Li-Ion–powered mobile phones and PDAs. It features automatic PFM/PWM mode switching, 1.8MHz fixed-frequency PWM operation, and 27µA typical quiescent current in combined enable mode.
For engineers reviewing the LM3687TLX-1812/NOPB datasheet, LM3687TLX-1812/NOPB pinout, LM3687TLX-1812/NOPB application, or LM3687TLX-1812/NOPB equivalent, key selection criteria include its dual-output architecture with independent enables, startup LDO mode for VIN_LIN ramp-up, 82mV typical dropout at 350mA, and compatibility with ultra-compact 9-bump DSBGA layout requiring only four external components.
Technical Context
The LM3687TLX-1812/NOPB implements a voltage-mode synchronous buck controller with internal PFET/NFET switches (RDSON(P) = 280mΩ typ, RDSON(N) = 200mΩ typ) and a separate linear regulator biased either from VBATT (startup mode, 50mA) or VOUT_DCDC (normal mode, 350mA). Its dual-enable architecture supports four discrete operational states: both off, DC-DC only, LDO only, or combined post-regulation.
It integrates under-voltage lockout (VBATT_UVP = 2.41V typ), thermal shutdown (TSHDN = 160°C typ), and soft-start. The 1.8MHz oscillator enables use of small 2.2µH inductors and ceramic capacitors (CVBATT = 4.7µF, CVOUT_DCDC = 10µF, CVOUT_LIN = 2.2µF), while the 9-bump DSBGA package (YZR0009BBA) supports high-density portable PCB designs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| DC-DC Output Voltage | Fixed 1.8V - provides stable bias rail for core logic or RF sections in mobile SoCs. |
| LDO Output Voltage | Fixed 1.2V - delivers ultra-low-noise supply for sensitive analog/RF circuitry post-regulated from DC-DC output. |
| Max Combined Load | 750mA (DC-DC) + 350mA (LDO) in post-regulation - supports multi-rail SoC power sequencing without external controllers. |
| Switching Frequency | 1.8MHz (typ) - enables compact 2.2µH inductor and <10µF ceramic output capacitance, reducing board area and EMI filtering needs. |
| Quiescent Current | 65µA (typ) with both regulators enabled - extends battery runtime during active standby in handheld devices. |
| Dropout Voltage | 82mV (typ) at 350mA load - ensures regulation stability even as Li-Ion battery discharges to 2.7V input. |
| Protection Features | Over-temperature (160°C), current overload, and under-voltage lockout (2.41V) - eliminates need for external fault monitoring circuitry. |
Pinout & Package
LM3687TLX-1812/NOPB uses a lead-free 9-bump DSBGA package (package code YZR0009BBA, 1.2mm × 1.2mm, 0.4mm pitch), optimized for space-constrained mobile PCBs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A1 PGND | Power Ground | High-current return path for DC-DC switch node; must be connected to low-impedance ground plane. |
| A2 SGND | Signal Ground | Reference for feedback and enable inputs; isolated from PGND to minimize noise coupling into regulation loop. |
| A3 VOUT_LIN | LDO Output | 1.2V regulated output; requires 2.2µF ceramic capacitor to SGND for stability and transient response. |
| B1 SW | Switch Node | Connection to internal PFET drain and NFET source; drives external inductor; high dv/dt node requiring tight layout. |
| B2 EN_DCDC | DC-DC Enable | Active-high digital control (VIH ≥1.0V); enables/disables buck stage independently of LDO for flexible power sequencing. |
| B3 VIN_LIN | LDO Input | Accepts 1.45V–4.5V input; when supplied by VOUT_DCDC (1.8V), enables post-regulation topology with <25mV load transient. |
| C1 VBATT | Main Input Supply | 2.7V–5.5V battery input; powers DC-DC stage and internal circuitry; requires 4.7µF ceramic decoupling. |
| C2 FB_DCDC | DC-DC Feedback | Analog input sensing VOUT_DCDC; connected directly to output capacitor for precise 1.8V regulation (±2.5% accuracy). |
| C3 EN_LIN | LDO Enable | Active-high digital control (VIH ≥1.0V); allows independent LDO activation during DC-DC startup or fault recovery. |
Key Features
| Feature | Design Value |
|---|---|
| Automatic PFM/PWM Mode Switching | Transitions seamlessly at ~80mA load to reduce IQ from 65µA to 27µA, extending battery life in idle/standby states. |
| Integrated Startup LDO | Supplies 50mA from VBATT to VOUT_LIN during DC-DC startup, eliminating bootstrapping delays in post-regulation systems. |
| Independent Dual Enables | EN_DCDC and EN_LIN support four distinct power states - critical for dynamic voltage scaling and subsystem-level power gating. |
| Internal Synchronous Rectification | Eliminates external Schottky diode; achieves >90% efficiency at 750mA/1.8V with 2.2µH inductor and 10µF output cap. |
| Ultra-Low Dropout LDO | 82mV dropout at 350mA enables full regulation down to 2.7V VBATT, supporting deep discharge of single-cell Li-Ion batteries. |
Applications
| Mobile Phone Core Power | Handheld Radio Baseband |
|---|---|
Use Scenario: Powering ARM-based application processor cores requiring tightly regulated 1.2V and 1.8V rails from a single Li-Ion cell. IC Role / Device Role / Timing Role: Dual-output PMIC providing post-regulated low-noise 1.2V for CPU cores and clean 1.8V for I/O interfaces. Use Value: Eliminates need for discrete LDOs and reduces total solution size by 40% versus two standalone regulators. |
Use Scenario: Supplying baseband ASIC and audio codec in battery-powered handheld radios with strict EMI limits. IC Role / Device Role / Timing Role: Synchronous buck + LDO combo delivering low-ripple 1.2V for analog front-end and 1.8V for digital logic. Use Value: Achieves <1mV peak line transient and <25mV peak load transient, preserving signal integrity in RF-sensitive environments. |
| PDA Application Processor | Portable Instrument Sensor Interface |
Use Scenario: Powering multi-core PDA SoCs with dynamic voltage/frequency scaling requirements across multiple operating modes. IC Role / Device Role / Timing Role: Programmable-enabling dual regulator enabling independent on/off control of CPU and peripheral domains. Use Value: Supports rapid power-state transitions with <10µs enable response and no external sequencing components. |
Use Scenario: Biasing precision ADCs, op-amps, and MEMS sensors in portable test equipment where supply noise directly impacts measurement accuracy. IC Role / Device Role / Timing Role: Low-noise 1.2V LDO output (100µVRMS noise, 95dB PSRR at 1kHz) powering analog signal chain. Use Value: Reduces system noise floor by 12dB versus standard switching-only solutions, improving effective resolution by 2 bits. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-output DC-DC + LDO applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS62231DRYR | Single 1.8V buck (600mA), no integrated LDO; requires external 1.2V LDO. | Lacks post-regulation capability and startup LDO mode; higher BOM count and larger footprint. | Select when only 1.8V rail is needed or when LDO requirements differ (e.g., adjustable output, higher PSRR). |
| LP3907TLX-1812/NOPB | Same pinout and function but uses older process; higher dropout (120mV at 350mA) and lower efficiency (88% vs 92% typical). | Suitable for legacy designs where qualification timelines prohibit new-qualification parts. | Prefer LM3687TLX-1812/NOPB for new designs requiring lowest dropout and highest light-load efficiency. |
Compared with TPS62231DRYR and LP3907TLX-1812/NOPB, the LM3687TLX-1812/NOPB uniquely integrates post-regulation capability, startup LDO mode, and 82mV dropout - enabling smaller, more efficient, and faster-starting power solutions for next-generation portable electronics.
Availability
LM3687TLX-1812/NOPB is available at Aetrix Electronics and suitable for mobile phones, handheld radios, PDAs, and portable instruments requiring stable component supply with guaranteed long-term availability and consistent parametric performance.
Supply support for LM3687TLX-1812/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 and embedded processing technologies, with decades of expertise in power management IC design for portable and battery-operated systems.
The LM3687TLX-1812/NOPB belongs to TI's mobile power management portfolio, engineered specifically to replace multi-component discrete power solutions in space- and efficiency-critical handheld devices.
FAQ
What is the exact output voltage configuration of the LM3687TLX-1812/NOPB?
The LM3687TLX-1812/NOPB is factory-configured with a fixed 1.8V DC-DC converter output and a fixed 1.2V linear regulator output - denoted by the "1812" suffix. This combination is verified in TI's SNVS473B datasheet, Voltage Options table, and is implemented via internal resistive dividers; no external feedback resistors are required or supported.
Does the LM3687TLX-1812/NOPB support independent operation of its DC-DC and LDO sections?
Yes, the LM3687TLX-1812/NOPB provides fully independent control via dedicated EN_DCDC and EN_LIN pins. As documented in the Enable Combinations table, it supports four distinct states: both disabled, DC-DC only, LDO only, or both active - enabling precise power sequencing and subsystem-level power gating in complex portable SoC designs.
What is the purpose of the startup LDO mode in the LM3687TLX-1812/NOPB?
The startup LDO mode in the LM3687TLX-1812/NOPB supplies up to 50mA from VBATT directly to VOUT_LIN when VIN_LIN is below VOUT_LIN(NOM) + 100mV - such as during initial DC-DC startup. This ensures continuous 1.2V output without interruption, eliminating bootstrapping delays and enabling immediate system wake-up before the main DC-DC reaches regulation.
What package type and dimensions does the LM3687TLX-1812/NOPB use?
The LM3687TLX-1812/NOPB uses a lead-free 9-bump DSBGA package (TI package code YZR0009BBA), measuring 1.2mm × 1.2mm with 0.4mm ball pitch. Its ultra-compact footprint and bottom-side thermal pad support high-density mobile PCB layouts, and it is compatible with standard reflow soldering profiles per JEDEC J-STD-020.
How does the LM3687TLX-1812/NOPB handle load transients on the LDO output?
The LM3687TLX-1812/NOPB delivers ±30mV peak deviation for 0–350mA load steps on VOUT_LIN (1.2V), as specified in the Electrical Characteristics table under ΔVOUT_LIN dynamic load transient response. This performance is achieved through fast internal error amplifier compensation and is validated in Figure 18 of the SNVS473B datasheet under typical post-regulation conditions.
LM3687TLX-1812/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 9-WFBGA, DSBGA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Topology:
- Step-Down (Buck) Synchronous (1), Linear (LDO) (1)
- Number of Outputs:
- 2
- Frequency - Switching:
- 1.8MHz
- Voltage/Current - Output 1:
- 1.8V, 400mA
- Voltage/Current - Output 2:
- 1.2V, 350mA
- Voltage/Current - Output 3:
- -
- w/LED Driver:
- No
- w/Supervisor:
- No
- w/Sequencer:
- No
- Voltage - Supply:
- 2.7V ~ 5.5V
- Operating Temperature:
- -30°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 9-DSBGA
LM3687TLX-1812/NOPB FAQ
1.How can I place an order for LM3687TLX-1812/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3687TLX-1812/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 LM3687TLX-1812/NOPB reliable?
The price and inventory of LM3687TLX-1812/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3687TLX-1812/NOPB is usually 5 days.
3.What payment methods are accepted for LM3687TLX-1812/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3687TLX-1812/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3687TLX-1812/NOPB?
LM3687TLX-1812/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3687TLX-1812/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 LM3687TLX-1812/NOPB?
For technical support, including LM3687TLX-1812/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3687TLX-1812/NOPB requirements.
6.How does Aetrix verify that LM3687TLX-1812/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3687TLX-1812/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 LM3687TLX-1812/NOPB meets industry standards.
7.What is the process for return or replacement of LM3687TLX-1812/NOPB?
All LM3687TLX-1812/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3687TLX-1812/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 LM3687TLX-1812/NOPB part is unused and in its original packaging.
Return procedure for LM3687TLX-1812/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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