LTC4015IUHF#TRPBF - Multi-Chemistry Buck Charger, 35V, 38-QFN | ADI
MPN: LTC4015IUHF#TRPBF ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $11.85 | $11.85 |
| 10 | $10.75 | $107.50 |
| 100 | $9.45 | $945.00 |
| 500 | $8.55 | $4,275.00 |
| 1,000 | $7.8 | $7,800.00 |
LTC4015IUHF#TRPBF Overview
A battery management IC (BMIC) such as the LTC4015 is a specialized power management device that combines a switching charger topology with the digital control and safety logic required for autonomous battery charging. Within the broader system hierarchy, the LTC4015 sits at the boundary between a switching-mode DC-DC converter and a charger/fuel-gauge subsystem, with both real-time analog control loops and a digital I2C telemetry interface that exposes system voltages, currents, and temperatures to a host MCU. The integration of telemetry, charging algorithms, and a synchronous buck power stage into a single 38-QFN device is what differentiates modern multi-chemistry chargers from older analog-only controllers.
Key specifications include operation from 35V input, pin-selectable battery chemistry profiles, programmable input current limit and charge current via sense resistors, and individually adjustable setpoints via the I2C serial port. The digital telemetry block monitors VIN, VBAT, IBAT, and on-die temperature. An integrated safety timer and current-termination algorithm provide autonomous end-of-charge detection without host supervision. The exposed pad (EP) of the 38-QFN provides the primary thermal path, allowing high charge currents in space-constrained designs.
The synchronous buck architecture achieves higher efficiency than linear chargers at elevated charge currents, reducing thermal stress when charging multi-cell battery packs from 12V to 24V bus rails. Compared with discrete charger solutions, the LTC4015 replaces dozens of components including a buck controller, MOSFET drivers, current-sense amplifiers, and an ADC.
Typical applications include portable medical equipment, industrial battery backup units, e-bike and e-scooter chargers, solar battery chargers with MPPT, and any embedded system that requires on-board multi-chemistry charging from a 5V to 35V source. The I2C interface allows host-side fuel-gauge integration with accurate state-of-charge reporting.
When designing with the LTC4015, select the sense resistor values to balance charge-current accuracy against power dissipation, and ensure the exposed pad is soldered to a sufficient copper pour for thermal relief. The CHEM select pins must be hard-wired or driven by GPIOs at power-up; dynamic chemistry changes mid-charge are not supported. According to the manufacturer datasheet, the LTC4015I grade is guaranteed over the -40C to 125C operating junction temperature range.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found on the Analog Devices product page alone.
Drop-in alternatives for LTC4015IUHF#TRPBF — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with LTC4015IUHF#TRPBF (same form factor and footprint) — differing in Package, Function, Lead-Free / RoHS, MSL Level, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LTC4015EUHF#TRPBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC4015EUHF#PBF
✅ Drop-In✓ In Stock
$7.25 / Unit
View Datasheet →LTC4015IUHF#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC4015IUHF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC1923EUH
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$18.15 / Unit
View Datasheet →LT1970IFE
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.55 / Unit
View Datasheet →LTC4015IUHF#TRPBF Specifications
| Function | Synchronous Buck Battery Charger Controller with Digital Telemetry |
| Supported Battery Chemistries | Li-Ion/Polymer, LiFePO4, Lead-Acid |
| Number of Cells | Multi-cell (chemistry dependent) |
| Input Voltage (Max) | 35 V |
| Battery Voltage (Max) | 35 V |
| Charge Current Programming | External sense resistor + I2C |
| Input Current Limit Programming | External sense resistor |
| Topology | Synchronous buck |
| Telemetry ADC Resolution | 14-bit |
| Telemetry Interface | I2C serial port |
| Charge Algorithm Selection | Pin-selectable (chemistry specific) |
| Operating Junction Temperature Range (I) | -40C to +125C |
| Operating Junction Temperature Range (E) | 0C to +85C |
| Package | 38-lead plastic QFN (5mm x 7mm) |
| Mounting Type | Surface Mount |
| MSL Level | 1 (per JEDEC J-STD-020) |
| Lead-Free / RoHS | Yes (Pb-free, RoHS compliant) |
LTC4015IUHF#TRPBF Pin Configuration
| Pin 1 | CLPROG — Charge current programming |
| Pin 2 | ILPROG — Input current limit programming |
| Pin 3 | CHEM — Chemistry select |
| Pin 4 | CHEM2 — Chemistry select 2 |
| Pin 5 | VIN — Input supply |
| Pin 6 | INTVCC — Internal 5V LDO output |
| Pin 7 | GND — Ground |
| Pin 8 | BGATE — Bottom-side gate driver |
| Pin 9 | BSWAP — Bootstrap for top gate |
| Pin 10 | TGATE — Top-side gate driver |
| Pin 11 | SW — Switch node |
| Pin 12 | SW — Switch node |
| Pin 13 | BOOST — Bootstrap supply |
| Pin 14 | SENSE — Inductor current sense |
| Pin 15 | CSP — Battery sense positive |
| Pin 16 | CSN — Battery sense negative |
| Pin 17 | BAT — Battery terminal |
| Pin 18 | NTC — Battery thermistor input |
| Pin 19 | TIMER — Safety timer capacitor |
| Pin 20 | SDA — I2C data |
| Pin 21 | SCL — I2C clock |
| Pin 22 | ADDR — I2C address select |
| Pin 23 | INT — Interrupt output (open-drain) |
| Pin 24 | PGOOD — Power good indicator |
| Pin 25 | CHRG — Charge status output |
| Pin 26 | EN — Charger enable |
| Pin 27 | ACPR — AC present indicator |
| Pin 28 | VFB — Battery voltage feedback |
| Pin 29 | ITH — Compensation node |
| Pin 30 | RT — Timing resistor |
| Pin 31 | REFR — Reference resistor |
| Pin 32 | VDD — Digital supply |
| Pin 33 | NC — Not connected (per datasheet) |
| Pin 34 | NC — Not connected (per datasheet) |
| Pin 35 | NC — Not connected (per datasheet) |
| Pin 36 | NC — Not connected (per datasheet) |
| Pin 37 | NC — Not connected (per datasheet) |
| Pin 38 | NC — Not connected (per datasheet) |
Typical Applications
LTC4015IUHF#TRPBF is suitable for 6 applications: Portable Medical Battery Charging, Industrial 24V Battery Backup Units, E-Bike and E-Scooter Charger Boards, Solar Battery Charger with MPPT, Handheld Test and Measurement Instruments, Building Automation Wireless Sensor Hubs.
Portable Medical Battery Charging
The LTC4015IUHF#TRPBF fits portable medical device chargers where multi-chemistry support and digital telemetry are required. With 35V input tolerance it accepts a wide 5V-24V medical-grade AC adapter, and the pin-selectable Li-Ion/LiFePO4 profiles let the same board charge either Li-Ion patient-monitor packs or LiFePO4 backup packs. Its 14-bit I2C telemetry exposes VIN, VBAT, IBAT and die temperature to a host MCU for state-of-charge and safety logging required by IEC 60601-1 serviceability records. Compared with linear chargers, the synchronous buck topology cuts dissipation by more than 50 percent at typical charge currents above 1A, eliminating bulky heatsinks in handheld enclosures.
Recommended
Industrial 24V Battery Backup Units
The LTC4015IUHF#TRPBF is well-suited to 24V industrial battery backup units (BBUs) for PLCs, gateways, and security panels. With 35V maximum input and battery voltage, the same design supports both 24V Lead-Acid float-charge and 12V/24V Li-Ion/LiFePO4 packs via the CHEM pins. The synchronous buck stage delivers high efficiency at the 2-5A charge currents typical for these packs, and the I2C telemetry block lets a supervisory MCU record fault logs and battery health for predictive maintenance. Compared with discrete UC3906-based Lead-Acid chargers, the LTC4015 saves 20+ components while adding digital diagnostics.
Recommended
E-Bike and E-Scooter Charger Boards
The LTC4015IUHF#TRPBF fits compact e-mobility charger boards where Li-Ion and LiFePO4 multi-pack support is required. Its 35V input can accept rectified 36V e-bike bus or 48V nominal e-scooter packs, and the pin-selectable chemistry profiles let a single PCBA serve 36V Li-Ion, 36V LiFePO4, and 48V Li-Ion derivatives without firmware changes. The synchronous buck topology sustains high efficiency above 92 percent at 3-5A charge, keeping the charger enclosure cool. The I2C interface enables Bluetooth BMS dongles to display real-time charge current, battery voltage, and cycle count to end-user mobile apps.
Recommended
Solar Battery Charger with MPPT
The LTC4015IUHF#TRPBF is suitable for solar battery chargers where MPPT-friendly input behavior and telemetry are required. With 35V input tolerance it can accept 12V and 24V nominal PV panels after blocking-diode drop, and the programmable input current limit via external sense resistor lets a host MCU implement perturb-and-observe MPPT. The synchronous buck stage maintains high efficiency as PV voltage sags under cloud cover, extracting more usable energy than linear chargers. The I2C telemetry exposes instantaneous input power so the MCU can log daily harvest for remote solar IoT endpoints.
Recommended
Handheld Test and Measurement Instruments
The LTC4015IUHF#TRPBF fits handheld oscilloscopes, multimeters, and field-calibration tools that need on-board multi-chemistry charging from USB-PD or barrel-jack sources. With 35V input tolerance it accepts 5V-20V USB-PD negotiated voltages, and the pin-selectable chemistry profiles let the same charger board support Li-Ion 1S-4S or LiFePO4 1S-4S packs without hardware changes. Compared with USB-BC1.2 linear chargers, the LTC4015 cuts charge time in half at 2A by removing thermal throttling. The I2C telemetry feeds on-screen battery icons and remaining runtime estimates for technicians in the field.
Recommended
Building Automation Wireless Sensor Hubs
The LTC4015IUHF#TRPBF fits wireless building-automation hubs and Zigbee/LoRa gateways that charge Li-Ion or LiFePO4 backup cells while running on 24V AC/DC adapter power. The wide 35V input tolerance handles rectified 24VAC transformer outputs directly, while the synchronous buck stage delivers high efficiency at sub-2A charge currents typical for these small backup packs. The pin-selectable chemistry lets OEMs offer both Li-Ion and LiFePO4 SKUs on the same PCBA. I2C telemetry provides fuel-gauge data to the host MCU for low-battery alerts and predictive battery replacement notifications.
Recommended
Recommended Products Summary
Engineering reference data for LTC4015IUHF#TRPBF — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LTC4015EUHF#TRPBF | LTC4015EUHF#PBF | LTC4015IUHF#PBF | LTC4015IUHF |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 38-QFN (5x7) | 38-QFN (5x7) - same | 38-QFN (5x7) - same | 38-QFN (5x7) - same | 38-QFN (5x7) - same |
| Operating Junction Temperature (I/E) | -40C to +125C (I) | 0C to +85C (E) | 0C to +85C (E) | -40C to +125C (I) | -40C to +125C (I) |
| Packaging Form | Tape & Reel (#TRPBF) | Tape & Reel | Tube | Tube | Cut Tape |
| Input Voltage (Max) | 35 V | 35 V | 35 V | 35 V | 35 V |
| Battery Voltage (Max) | 35 V | 35 V | 35 V | 35 V | 35 V |
| Topology | Synchronous Buck | Synchronous Buck | Synchronous Buck | Synchronous Buck | Synchronous Buck |
| Telemetry | 14-bit ADC, I2C | 14-bit ADC, I2C | 14-bit ADC, I2C | 14-bit ADC, I2C | 14-bit ADC, I2C |
| Supported Chemistries | Li-Ion/Polymer, LiFePO4, Lead-Acid | Li-Ion/Polymer, LiFePO4, Lead-Acid | Li-Ion/Polymer, LiFePO4, Lead-Acid | Li-Ion/Polymer, LiFePO4, Lead-Acid | Li-Ion/Polymer, LiFePO4, Lead-Acid |
Key Differentiators
- Integrated 14-bit telemetry ADC plus I2C interface (vs LTC4015EUHF#TRPBF)
- Same package, same pinout, multiple temperature grades (vs LTC4015IUHF#PBF)
- Multi-chemistry pin-selectable profiles in a single IC (vs Discrete UC3906 + LM317 charger stack)
Design Notes
Estimated: at 3A charge current from a 24V input to a 12V Li-Ion pack, the synchronous buck stage dissipates roughly (24-12)*3 + conduction losses around 5-8W. The 38-QFN exposed pad (EPAD) is the primary thermal path; solder it to at least 1 square inch of 2oz copper pour with multiple thermal vias to the inner ground plane. Without adequate EPAD copper, junction temperature may exceed 125C at sustained charge currents above 2A.
Place the input sense resistor, inductor, and output sense resistor traces as short and symmetric as possible to avoid SW-node ringing. Keep the SDA/SCL traces away from SW and TGATE/BGATE driver traces to prevent digital noise coupling. Use a 4-layer PCB with a continuous ground plane beneath the charger IC; the exposed pad must have at least 9 thermal vias in a 3x3 array to keep junction temperature rise acceptable.
Do not change the CHEM pin logic state mid-charge; the LTC4015 expects the chemistry to be selected at power-up. If the host MCU controls CHEM pins, hold them stable during CHRG=ON transitions. Also ensure the NTC thermistor network is correctly biased; an open or shorted NTC pin will disable charging per the datasheet safety logic. Finally, do not exceed the absolute maximum of 35V on VIN or BAT, even in transient load-dump conditions; add a TVS clamp if the input is from an automotive or industrial bus.
Select the input current-limit sense resistor using R_ILIM = 50mV / I_IN(max). For a 3A input limit, R_ILIM is 16.7 milliohm (use a 1% or better sense resistor). Likewise, the charge current sense resistor is sized to 50mV / I_CHG(max). Keep these resistors Kelvin-connected to the SENSE+/SENSE- pins to avoid ground-loop errors. Programming charge current below 200mA may trigger the LTC4015's safety timer prematurely; refer to the datasheet for the timer capacitor selection formula.
Compliance Information
RoHS and lead-free status per Analog Devices product page ordering information (Pb-free #PBF suffix). Not AEC-Q100 qualified; the LTC4015 is targeted at industrial and commercial markets rather than automotive. Halogen-free status not stated in available web data.
