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Analog Devices Inc. LTC4012IUF-3#TRPBF
- Part No.:
- LTC4012IUF-3#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Battery Chargers
- Package:
- 20-WFQFN Exposed Pad
- Datasheet:
-
LTC4012IUF-3#TRPBF.pdf
- Description:
- IC BATT CHG MULTI-CHEM 20QFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,934
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Product details
Overview
LTC4012IUF-3#TRPBF from Analog Devices (formerly Linear Technology) is a synchronous buck battery charger controller for multi-chemistry Li-ion, Li-polymer, and lead-acid batteries. It delivers ±0.5% output float voltage accuracy, 4% charge current accuracy, and programmable 6V–28V input/2V–28V output ranges. Designed for notebook computers and portable instruments, it integrates PowerPath™ ideal diode control, AC adapter current limiting, and analog charge current monitoring via the PROG pin.
For engineers reviewing the LTC4012IUF-3#TRPBF datasheet, LTC4012IUF-3#TRPBF pinout, LTC4012IUF-3#TRPBF application, or LTC4012IUF-3#TRPBF equivalent, key selection considerations include its 550kHz quasi-constant-frequency PWM architecture (audible-noise-free with ceramic capacitors), I-grade –40°C to 125°C operation, 20-pin 4mm × 4mm QFN package, and absence of built-in charge termination-requiring external MCU supervision for full algorithm control.
Technical Context
The LTC4012IUF-3#TRPBF implements a current-mode synchronous buck topology with dual-loop control: peak inductor current regulation via ITH and battery voltage regulation via VFB. Its PWM oscillator dynamically adjusts off-time based on (CLP – BAT), maintaining ~550kHz operation across wide input-output differentials while avoiding subharmonic instability.
PowerPath™ control uses INFET to drive an external P-channel MOSFET, regulating forward drop to ~25mV and disabling reverse current within 6µs when DCIN falls below CLP by >25mV. Input current limiting is implemented via CLP/CLN differential sensing with 3% accuracy, and the CHRG pin provides three-state status (strong pull-down, 25µA weak pull-down, high-Z) for C/10 detection and charging mode indication.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage Range | 2V to 28V - fully adjustable via external FBDIV–VFB resistor divider for diverse battery chemistries and cell counts. |
| Charge Current Accuracy | ±4% (I-grade) - enables precise bulk and taper current control without calibration, critical for safe Li-ion charging. |
| Float Voltage Accuracy | ±0.5% - ensures tight regulation of final battery voltage, minimizing overcharge risk and extending cycle life. |
| Switching Frequency | 467–633kHz (typ. 550kHz) - supports compact 6.8µH inductors and ceramic output capacitors without audible noise. |
| Operating Temp Range | –40°C to 125°C - qualified for industrial and extended-temperature portable applications including battery backup systems. |
| Input Current Limit Accuracy | ±3% - allows reliable adapter power budgeting and concurrent system + battery charging without overloading AC sources. |
| Package | 20-pin 4mm × 4mm × 0.75mm QFN - exposes thermal pad (Pin 21) for low-θJA (37°C/W) and stable high-current operation. |
Pinout & Package
20-pin 4mm × 4mm × 0.75mm plastic QFN package with exposed thermal pad (Pin 21 = GND). Requires soldering of exposed pad to PCB ground plane for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CLN (1) | Adapter current limit negative input | Senses voltage 100mV below CLP to trigger input current limiting; must be filtered to reject PWM noise. |
| CLP (2) | Adapter current limit positive input & power rail | Primary input power source (6–28V); supplies internal circuits and sets current limit threshold. |
| INFET (3) | PowerPath ideal diode gate driver | Drives external PMOS to maintain ~25mV forward drop and block reverse current in <6µs. |
| DCIN (4) | DC input sense | Detects presence of adapter; enables charging only when DCIN > BAT + 500mV. |
| GND (5) | Signal and power ground | Internal reference node; electrically tied to exposed thermal pad (Pin 21). |
| SHDN (6) | Active-low shutdown control | Pulled down internally (40kΩ); drives <300mV to force micropower shutdown (<1µA BAT leakage). |
| CHRG (7) | Charge status indicator | Open-drain output with three states: strong pull-down (bulk charge), 25µA weak pull-down (C/10), high-Z (shutdown). |
| ICL (8) | Input current limit indicator | Active-low open-drain flag signaling reduction of charge current due to AC adapter current limiting. |
| VFB (9) | Battery voltage feedback input | High-impedance node (±20nA bias) referenced to 1.2085V internal bandgap; programs output voltage via resistor divider. |
| FBDIV (10) | Feedback divider source | Open-drain PFET connected to BAT during charging; completes resistor divider network for VFB. |
| BAT (11) | Battery pack connection | Direct connection to battery terminal; used for voltage regulation, current sensing reference, and safety monitoring. |
| ITH (12) | PWM error amplifier output | Compensation node setting peak inductor current threshold; external R-C network stabilizes current/voltage loops. |
| PROG (13) | Charge current programming & monitoring | Linearized voltage output proportional to actual charge current; also sets max current via RPROG–GND resistor. |
| CSN (14) | Current sense negative input | Connects to low-side of RSENSE; operates within (BAT – 50mV) to (BAT + 200mV) range. |
| CSP (15) | Current sense positive input | Connects to high-side of RSENSE; same common-mode range as CSN for accurate differential sensing. |
| BGATE (16) | Bottom FET gate driver | Drives synchronous NMOS rectifier; improves efficiency vs. diode-based buck converters. |
| INTVDD (17) | Internal 5V regulator output | Provides 4.85–5.15V (±1%) at up to 20mA; powers gate drivers and internal logic; shuts down in SHDN. |
| SW (18) | Switch node | Connection to external inductor and top/bottom FETs; critical high-dv/dt node requiring careful PCB layout. |
| TGATE (19) | Top FET gate driver | Drives external NMOS switch; bootstrap supply referenced to SW via BOOST pin. |
| BOOST (20) | Bootstrap supply input | Accepts charge from SW–INTVDD network to enable high-side NMOS gate drive above CLP. |
Key Features
| Feature | Design Value |
|---|---|
| No-audible-noise PWM | Quasi-constant 550kHz frequency enables use of ceramic bulk capacitors without piezoelectric whine in portable devices. |
| PowerPath™ ideal diode control | INFET output regulates forward voltage to ~25mV and blocks reverse current in <6µs, eliminating discrete Schottky losses. |
| Programmable input current limit | External RIN sets adapter current limit with ±3% accuracy, enabling simultaneous system load + battery charging. |
| Analog charge current monitor | PROG pin outputs linear voltage proportional to real-time charge current, simplifying MCU-based state-of-charge estimation. |
| Micropower shutdown | <1µA battery leakage in shutdown (SHDN < 300mV), maximizing standby time in battery-backed systems. |
Applications
| Notebook Computers | Portable Instruments |
|---|---|
Use Scenario: Dual-power operation with AC adapter and removable Li-ion battery pack, requiring seamless switchover and thermal-aware charging. IC Role / Device Role / Timing Role: Primary battery charger controller managing constant-current/constant-voltage profiles, input current budgeting, and PowerPath handoff between adapter and battery. Use Value: Enables 95% peak efficiency at 2A charge current (DCIN=20V, BAT=12V), extends runtime via low-quiescent micropower shutdown, and eliminates audible noise in thin-profile chassis. |
Use Scenario: Handheld test equipment with long battery life requirements and need for field-replaceable sealed lead-acid or Li-ion packs. IC Role / Device Role / Timing Role: Flexible chemistry-agnostic charger controller supporting user-selectable battery types via MCU configuration of VFB and PROG networks. Use Value: ±0.5% voltage accuracy prevents overcharge degradation; wide 2V–28V output range accommodates 1–7S Li-ion or 2–12V SLA; I-grade temp range ensures reliability in outdoor environments. |
| Battery Backup Systems | Industrial Portable Terminals |
Use Scenario: Uninterruptible power supply for embedded controllers where clean switchover and predictable recharge time are critical. IC Role / Device Role / Timing Role: High-efficiency buck charger with input current limiting to avoid tripping upstream AC/DC supplies during bulk recharge. Use Value: Programmable AC adapter current limit (via RIN) ensures stable 24V system operation while recharging 24V battery bank at up to 3A without brownouts. |
Use Scenario: Ruggedized warehouse scanners operating in temperature extremes (-20°C to 60°C ambient) with hot-swappable battery modules. IC Role / Device Role / Timing Role: Robust charger IC with –40°C to 125°C junction rating and reverse current protection to survive battery insertion/removal under load. Use Value: INFET-controlled ideal diode prevents backfeed during hot-swap; C/10 detection on CHRG pin enables precise end-of-charge signaling for firmware-controlled termination. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar battery charger controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BQ24725ARSMR | Integrated N-channel MOSFET drivers only (no P-channel INFET); fixed 500kHz switching; no analog PROG monitoring output. | Lacks PowerPath ideal diode control; requires external PMOS and separate reverse-blocking circuitry for adapter input. | Choose BQ24725ARSMR if system already includes discrete ideal diode and prioritizes TI ecosystem support over analog current monitoring. |
| ISL88731IRZ | Asynchronous buck controller (external diode); lower 300kHz max frequency; ±1.5% voltage accuracy; no input current limiting. | Higher conduction losses and audible noise risk with ceramic caps; no AC adapter current budgeting capability. | Choose ISL88731IRZ only for cost-sensitive, non-portable applications where efficiency & noise are secondary to BOM simplicity. |
Compared with LTC4012IUF-3#TRPBF, BQ24725ARSMR requires additional external components for ideal diode functionality and lacks PROG-based current telemetry, while ISL88731IRZ sacrifices efficiency, precision, and input current management-making LTC4012IUF-3#TRPBF the optimal choice for high-performance, noise-sensitive, thermally demanding portable chargers.
Availability
LTC4012IUF-3#TRPBF is available at Aetrix Electronics and suitable for notebook computers, portable instruments, and battery backup systems requiring stable component supply, extended temperature operation, and high-efficiency synchronous charging.
Supply support for LTC4012IUF-3#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 (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors.
The LTC4012IUF-3#TRPBF belongs to Linear's PowerPath™ battery management portfolio, designed specifically for high-efficiency, multi-chemistry, MCU-supervised charging in space-constrained portable and industrial equipment.
FAQ
What battery chemistries does the LTC4012IUF-3#TRPBF support?
The LTC4012IUF-3#TRPBF supports Li-ion, Li-polymer, and lead-acid batteries through fully programmable output voltage (2V–28V) and charge current. It has no built-in termination logic, so external MCU supervision is required to implement chemistry-specific algorithms-including CC/CV, trickle charge, and cutoff conditions-making LTC4012IUF-3#TRPBF adaptable to evolving battery technologies and custom safety protocols.
Does the LTC4012IUF-3#TRPBF include integrated MOSFETs?
No, the LTC4012IUF-3#TRPBF is a controller-only IC and requires external N-channel MOSFETs for the synchronous buck power stage (TGATE and BGATE drive signals provided) and an external P-channel MOSFET for PowerPath™ ideal diode control (driven by INFET). This architecture allows designers to optimize FET selection for voltage, current, and thermal requirements specific to their LTC4012IUF-3#TRPBF application.
How does the LTC4012IUF-3#TRPBF prevent reverse current flow from battery to adapter?
The LTC4012IUF-3#TRPBF uses its INFET output to drive an external P-channel MOSFET, actively turning it off in less than 6µs when DCIN falls below CLP by more than 25mV. This rapid response prevents significant reverse current, protecting both the battery and AC adapter. The LTC4012IUF-3#TRPBF also monitors CLP–CLN differential to enforce input current limiting, further safeguarding upstream power sources.
Can the LTC4012IUF-3#TRPBF operate without an external microcontroller?
The LTC4012IUF-3#TRPBF can perform basic charging (bulk CV/CC) autonomously but lacks built-in charge termination, temperature monitoring, or fault recovery logic. For safe, compliant battery charging, an external MCU is required to interpret CHRG/ICL status pins, read PROG voltage for real-time current, manage VFB setpoint transitions, and execute full charge algorithms-making LTC4012IUF-3#TRPBF a building-block controller rather than a standalone solution.
What is the purpose of the FBDIV pin on the LTC4012IUF-3#TRPBF?
The FBDIV pin on the LTC4012IUF-3#TRPBF serves as the high-side connection point for the external resistor divider that sets battery float voltage via VFB. During charging, FBDIV is actively connected to the BAT pin by an internal PFET, completing the divider network. This design eliminates leakage path errors and ensures accurate voltage regulation independent of divider resistor values-enabling precise LTC4012IUF-3#TRPBF output programming across temperature and load conditions.
LTC4012IUF-3#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- PowerPath™
- Package/Case:
- 20-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Battery Chemistry:
- Multi-Chemistry
- Number of Cells:
- -
- Current - Charging:
- Constant - Programmable
- Programmable Features:
- -
- Fault Protection:
- Over Voltage, Reverse Current
- Charge Current - Max:
- -
- Battery Pack Voltage:
- -
- Voltage - Supply (Max):
- 28V
- Interface:
- -
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-QFN (4x4)
LTC4012IUF-3#TRPBF FAQ
1.How can I place an order for LTC4012IUF-3#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC4012IUF-3#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 LTC4012IUF-3#TRPBF reliable?
The price and inventory of LTC4012IUF-3#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC4012IUF-3#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC4012IUF-3#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC4012IUF-3#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC4012IUF-3#TRPBF?
LTC4012IUF-3#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC4012IUF-3#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 LTC4012IUF-3#TRPBF?
For technical support, including LTC4012IUF-3#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC4012IUF-3#TRPBF requirements.
6.How does Aetrix verify that LTC4012IUF-3#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC4012IUF-3#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 LTC4012IUF-3#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC4012IUF-3#TRPBF?
All LTC4012IUF-3#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC4012IUF-3#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 LTC4012IUF-3#TRPBF part is unused and in its original packaging.
Return procedure for LTC4012IUF-3#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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