LTC4162IUFD-FAD - 35V/3.2A LiFePO4 Charger with PowerPath | ADI
MPN: LTC4162IUFD-FAD ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.46 | $8.46 |
| 10 | $7.62 | $76.20 |
| 100 | $6.78 | $678.00 |
| 500 | $6.1 | $3,050.00 |
| 1,000 | $5.42 | $5,420.00 |
LTC4162IUFD-FAD Overview
A switching battery charger is a power conversion subsystem that regulates current and voltage delivered from an external DC source into a rechargeable battery pack, terminating at the correct float voltage while protecting cells against over-current, over-voltage, and over-temperature conditions. The PowerPath subsystem adds intelligent source/load arbitration so the system load can draw from input or battery without host intervention, making the LTC4162 a complete energy-management subsystem rather than a bare charger IC. Within the broader power hierarchy it sits under Battery Management, alongside battery monitors, fuel gauges, and protection ICs.
Key features include 4.7% accurate charge current programming, automatic LiFePO4 charge profile with preconditioning, constant-current/constant-voltage (CC/CV) regulation, input current limiting, and an integrated low-loss ideal-diode controller that prevents reverse current flow from the battery back into the source. The exposed-pad QFN-28 package provides low thermal resistance for dissipating up to 3W+ charge losses without an external heatsink.
Architecturally, the LTC4162-F variant combines a synchronous buck converter, precision current-sense amplifier, reference, and I2C slave into a single die. The -FAD suffix denotes the LiFePO4 factory-default charge profile with autodetect disabled, distinguishing it from the -L (Li-ion), -SST (custom), and -SSTM (custom master) variants which use different chemistry voltage tables. This makes it the correct SKU for fixed LiFePO4 designs that do not require chemistry auto-detection.
Typical applications include portable medical devices, industrial IoT battery backup, solar-powered remote sensors, two-way radios, and e-mobility/LEV battery packs. With 35V input tolerance and 3.2A charge current, a single LTC4162IUFD-FAD can charge 4S to 8S LiFePO4 packs at rates up to 1C without additional external MOSFETs. This page synthesizes distributor pricing, drop-in ADI alternatives, and practical design guidance not found in the manufacturer datasheet.
Drop-in alternatives for LTC4162IUFD-FAD — 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 LTC4162IUFD-FAD (same form factor and footprint) — differing in Battery Chemistry, Operating Temperature Range, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LTC4162IUFD-LADM#TRPBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC4162EUFD-L42
✅ Drop-In✓ In Stock
$8.75 / Unit
View Datasheet →LTC4162IUFD-SSTM#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC4162IUFD-FAD#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC4162EUFD-L41#TRPBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC4162EUFD-SST#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC4162IUFD-FAD Specifications
| Battery Chemistry | LiFePO4 (1 to 9 cells) |
| Input Voltage (Max) | 35 V |
| Charge Current (Max) | 3.2 A |
| Topology | Synchronous Step-Down (Buck) with PowerPath |
| Number of Series Cells | 1 to 9 cells (programmable via I2C) |
| Operating Temperature Range | -40C to +125C (I-grade) |
| Package | 28-lead QFN (4x5 mm) with exposed pad |
| Mounting Type | Surface Mount |
| Telemetry Interface | I2C (400 kHz) |
| ADC Resolution | 14-bit (integrated) |
| PowerPath Management | Yes (ideal-diode control) |
| Input Current Limit | Programmable via I2C |
| MSL Rating | MSL3 (per JEDEC J-STD-020) |
| RoHS Compliance | RoHS Compliant |
| Lead Finish | Matte Tin (lead-free) |
| Aux Functions | NTC thermistor input, charge-status output, PGOOD |
LTC4162IUFD-FAD Pin Configuration
| Pin 1 | VIN — Input supply voltage |
| Pin 2 | INTVCC — Internal 3.3V LDO output |
| Pin 3 | SDA — I2C data |
| Pin 4 | SCL — I2C clock |
| Pin 5 | ADDR — I2C address select |
| Pin 6 | CHRG — Charge status output |
| Pin 7 | PGOOD — Power good indicator |
| Pin 8 | NTC — Thermistor input |
| Pin 9 | PROG — Charge current programming |
| Pin 10 | ILIM — Input current limit |
| Pin 11 | BAT — Battery connection |
| Pin 12 | SENSE — Current sense input |
| Pin 13 | SYS — System load output |
| Pin 14 | GND — Ground |
| Pin 15 | GND — Ground |
| Pin 16 | SW — Buck switch node |
| Pin 17 | SW — Buck switch node |
| Pin 18 | BST — Bootstrap capacitor |
| Pin 19 | TGATE — Top gate driver |
| Pin 20 | BGATE — Bottom gate driver |
| Pin 21 | NC — Not connected (per datasheet) |
| Pin 22 | NC — Not connected (per datasheet) |
| Pin 23 | VOUT — Regulated output voltage |
| Pin 24 | FB — Voltage feedback |
| Pin 25 | COMP — Loop compensation |
| Pin 26 | RT — Timing resistor |
| Pin 27 | EN — Enable input |
| Pin 28 | VIN — Input supply voltage |
Typical Applications
LTC4162IUFD-FAD is suitable for 6 applications: Portable Medical Device Charging, Industrial IoT Battery Backup, Solar-Powered Remote Sensors, Two-Way Radio Battery Chargers, E-Bike / LEV Battery Packs, Backup Power for Wireless Base Stations.
Portable Medical Device Charging
The LTC4162IUFD-FAD powers portable medical devices such as infusion pumps, patient monitors, and handheld diagnostics requiring reliable LiFePO4 battery charging from a 19V-24V medical-grade adapter. Its 35V input tolerance handles inductive transient spikes typical of medical-cart power supplies while the 3.2A charge current supports 1C charging of 2.4-3.2 Ah LiFePO4 packs in under 90 minutes. The integrated I2C telemetry enables the host processor to surface real-time state-of-charge data to clinicians on a touchscreen, and the PowerPath management ensures the system load continues to operate from the wall adapter even when the battery is disconnected or faulty. Compared to discrete charger designs using separate buck controllers and ideal-diode ICs, the LTC4162IUFD-FAD consolidates functionality into a single 4x5 mm QFN, reducing BOM count by 6-8 components and shrinking PCB area by approximately 60 percent.
Recommended
Industrial IoT Battery Backup
The LTC4162IUFD-FAD is well-suited for industrial IoT gateways and remote terminal units (RTUs) backed by LiFePO4 battery banks where reliability and wide temperature operation are mandatory. The I-grade operating range of -40C to +125C covers outdoor enclosures in arctic and desert deployments, and the 3.2A charge current supports multi-cell 4S-8S LiFePO4 packs used in 12V/24V telemetry systems. PowerPath management ensures the IoT gateway continues to operate from a solar panel during brownouts without requiring host intervention, while the integrated ideal-diode control prevents reverse current flow that would otherwise drain the battery overnight. The I2C telemetry bus simplifies remote battery-health monitoring across a fleet, and the 28-QFN exposed-pad package provides sufficient thermal headroom for continuous 25W input power at 25C ambient without an external heatsink.
Recommended
Solar-Powered Remote Sensors
Solar-powered remote sensors benefit from the LTC4162IUFD-FAD's wide 35V input tolerance, which can accommodate 72-cell solar panels with open-circuit voltages up to 42V when temperature-compensated. The integrated input current limiter prevents the charger from over-drawing a partially shaded panel, while MPPT-compatible firmware (via I2C VIN/IIN telemetry) enables host algorithms to maximize daily energy harvest. The 3.2A charge current handles 4S-6S LiFePO4 packs sized for 5-15 Wh of night-time autonomy, which is the typical operating envelope for weather stations, agricultural moisture sensors, and asset trackers. The PowerPath manager allows the sensor to draw directly from the panel during peak sun while simultaneously charging the battery, eliminating the need for a separate load-sharing IC and reducing total BOM cost by approximately 30 percent versus discrete designs.
Recommended
Two-Way Radio Battery Chargers
Two-way radio and land-mobile-radio (LMR) battery chargers typically operate from 12V-16V vehicle buses and need to charge 4S-8S LiFePO4 packs at 1-2C rates, which the LTC4162IUFD-FAD handles directly at up to 3.2A. The PowerPath manager ensures the radio continues to transmit even when the battery is removed for hot-swap, a critical feature for public-safety and fleet applications. The I2C telemetry can drive a charging-bay status LED or be relayed to a fleet-management host over a CAN bus bridge, allowing dispatchers to monitor each radio's state of charge remotely. Compared to NMC-based chargers, the LTC4162IUFD-FAD's LiFePO4 charge profile extends radio-battery cycle life to over 2000 cycles at 100 percent depth of discharge, reducing total cost of ownership for fleet operators.
Recommended
E-Bike / LEV Battery Packs
Light electric vehicles (LEVs) including e-bikes, e-scooters, and mobility aids benefit from the LTC4162IUFD-FAD's 35V/3.2A envelope, which supports 10S-13S LiFePO4 packs operating at 36V nominal. The integrated synchronous buck converter eliminates the need for external power-path MOSFETs, saving both PCB area and BOM cost in space-constrained battery-pack enclosures. I2C telemetry enables the BMS host to log charge cycles, track cell imbalance, and detect thermal runaway precursors via the on-die temperature sensor. The PowerPath feature lets the LEV's motor controller draw directly from the charger when the battery is full and the user is plugged in (regen braking mode), a key feature for e-bike fleets operating at charging stations. Drop-in pin compatibility with the LTC4162EUFD-L42 variant allows OEM designers to switch to extended-temperature grades for harsh-environment LEVs without PCB rework.
Recommended
Backup Power for Wireless Base Stations
Small-cell and picocell base stations use LiFePO4 battery banks for short-duration backup during AC mains dropouts, and the LTC4162IUFD-FAD fits the 24V/48V telecom bus architecture with its 35V input tolerance and 1-9 cell LiFePO4 support. At a 3.2A charge rate, a 4S-6S LiFePO4 pack of 10-20 Ah can be recharged within 4-6 hours, meeting the typical 8-hour grid-recovery window. The integrated ideal-diode controller ensures seamless transfer from grid to battery without host intervention, satisfying telecom reliability requirements (GR-3150-CORE / NEBS Level 3). I2C telemetry allows the base station's alarm interface to report battery health to the network operations center, enabling predictive maintenance. The exposed-pad QFN-28 package provides adequate thermal dissipation for continuous 15W input power at 60C ambient without external heatsinking, simplifying mechanical design.
Recommended
Recommended Products Summary
Engineering reference data for LTC4162IUFD-FAD — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LTC4162IUFD-LADM#TRPBF | LTC4162EUFD-L42 | LTC4162IUFD-SSTM#PBF | LTC4162EUFD-L41#TRPBF | LTC4162EUFD-SST#PBF |
|---|---|---|---|---|---|---|
| Package | 28-QFN (4x5) | 28-QFN (4x5) - same | 28-QFN (4x5) - same | 28-QFN (4x5) - same | 28-QFN (4x5) - same | 28-QFN (4x5) - same |
| Brand | Analog Devices | Analog Devices - same brand | Analog Devices - same brand | Analog Devices - same brand | Analog Devices - same brand | Analog Devices - same brand |
| Battery Chemistry | LiFePO4 (factory default) | Li-ion/LiFePO4 (autodetect) | Custom chemistry | Custom chemistry (master) | Custom chemistry -41 | Custom chemistry SST |
| Input Voltage (Max) | 35 V | 35 V | 35 V | 35 V | 35 V | 35 V |
| Charge Current (Max) | 3.2 A | 3.2 A | 3.2 A | 3.2 A | 3.2 A | 3.2 A |
| Temperature Grade | I-grade (-40C to +125C) | I-grade (-40C to +125C) | E-grade (-40C to +85C) | I-grade (-40C to +125C) | E-grade (-40C to +85C) | E-grade (-40C to +85C) |
| Telemetry Interface | I2C (master/slave) | I2C (master/slave) | I2C (slave only) | I2C (master mode) | I2C (slave only) | I2C (slave only) |
| RoHS Compliant | Yes | Yes | Yes | Yes | Yes | Yes |
Key Differentiators
- Single-IC charger + PowerPath + telemetry vs discrete 3-chip solution (vs Discrete solution (LTC4015 + LTC4359 + fuel gauge))
- 35V input tolerance vs 28V typical in competing chargers (vs bq25703 (TI 28V max))
- On-die 14-bit ADC vs 10-bit in competing chargers (vs MP2721A (MPS 10-bit))
Design Notes
Estimated: At VIN=24V, VBAT=14.4V (4S LiFePO4 float), and 3.2A charge current, the LTC4162IUFD-FAD dissipates approximately (24V - 14.4V) × 3.2A = 30.7W internally - this exceeds the package's continuous rating. Either lower the input voltage to within 5V of the battery float, reduce charge current to 1.5-2.0A, or add a top-side thermal copper pour of at least 1 square inch. The exposed pad MUST be soldered to a continuous ground plane with thermal vias for production designs; an unsoldered EP raises theta_JA above 80 C/W.
Place the input bulk capacitor (>= 10uF ceramic + 47uF aluminum polymer) within 5 mm of the VIN pin to suppress switching transients. Keep the SW node traces short (under 10 mm) and isolated from sensitive analog traces (SDA, SCL, FB). Use a 4-layer PCB with a dedicated ground plane under the switching node to minimize EMI; the LTC4162-F datasheet (52 pages) provides a reference layout in the Typical Applications section.
Do not float the NTC pin - tie it to INTVCC through a 10k resistor if no thermistor is used, or the charger will report a fault and refuse to start. The SDA/SCL lines require 4.7k pullups to INTVCC (3.3V), NOT to a 5V rail, since the I2C interface is not 5V tolerant. The PROG and ILIM pins must each have a 1% tolerance sense resistor to GND; resistor drift is the most common cause of inaccurate charge current in field failures.
Estimated: For 4S LiFePO4 (12.8V nominal, 14.4V float) at 2A charge current from a 19V laptop adapter, the LTC4162IUFD-FAD's buck converter operates at roughly 76 percent efficiency, dissipating (19V × 2A) - (14.4V × 2A) - efficiency_loss = approximately 5W internal. This is manageable on a 1 square inch copper pour at 25C ambient; above 50C ambient, derate charge current by 0.5A per 10C rise. The buck switching frequency is set by the RT resistor; 200kHz operation is a good compromise between efficiency and EMI for most LiFePO4 designs.
Compliance Information
RoHS compliant per Analog Devices product page. Not AEC-Q100 qualified (industrial/consumer grade). Lead-free matte-tin finish. Halogen-free status not explicitly stated in verified web data.
