LTC4162EUFD-SSTM

Part: LTC4162-S (LTC4162EUFD / LTC4162IUFD variants) — Analog Devices (Linear Technology)

Type: Synchronous Step-Down Lead-Acid Battery Charger with PowerPath and I²C Telemetry

Description: 4.5–35 V input, up to 3.2 A synchronous step-down lead-acid battery charger for 6 V, 12 V, 18 V and 24 V batteries, with a PowerPath manager and 16-bit I²C telemetry.

Operating Conditions:

• Input supply voltage (VIN): 4.5–35 V
• Battery voltage: 2.7–35 V
• Operating junction temperature: -40 to 125 °C (E-grade is guaranteed to meet specifications from 0 to 85 °C junction temperature; -40 to 125 °C is assured by design and characterization. I-grade is guaranteed over the full -40 to 125 °C range)
• DVCC logic reference: 1.8–5.5 V

Absolute Maximum Ratings:

• BATSENS+, VIN, CSP, CSN, CLP, CLN, VOUT, VOUTA: -0.3 to 36 V
• CSP to CSN, CLP to CLN: ±0.3 V
• DVCC: -0.3 to 5.5 V
• ISW: ±3.5 A
• Operating junction temperature: -40 to 125 °C
• Storage temperature: -65 to 150 °C

Key Specs:

• Switching frequency: 1.5 MHz typ (RT = 63.4 kΩ; 1.4–1.6 MHz)
• Maximum duty cycle: 99.5% typ
• Primary switch on-resistance: 90 mΩ typ
• Rectifier switch on-resistance: 90 mΩ typ
• Battery drain current: 0.5 μA typ (1 μA max) when terminated; 2.8 μA typ (5 μA max) in SHIPMODE with VIN = 0
• VIN drain current: 115 μA typ (200 μA max) when terminated
• VIN UVLO rising threshold: 4.4 V typ (4.2–4.6 V)
• VIN OVLO rising threshold: 38.6 V typ (37.6–40 V)
• Charge voltage accuracy: ±0.5 V per 6 V battery
• Telemetry accuracy: span error ±1% of reading for IBAT, IIN, VIN, VBATSENS+ and VOUT
• I²C: up to 400 kHz, address 0b1101000[R/W]

Features:

• Lead-acid charging with absorb and equalize
• 16-bit telemetry of VBAT, IBAT, RBAT, TBAT, TDIE, VIN, IIN and VOUT
• Input undervoltage charge current limit loop
• Input MPPT for solar panel inputs
• Input current limit prioritizes the system load output
• Low-loss PowerPath with instant-on operation with a discharged or missing battery
• Temperature-controlled charging
• Pin compatible with Li-Ion and LiFePO4 versions

Applications:

• Medical instruments
• USB-C Power Delivery
• Industrial handhelds
• Ruggedized notebooks
• Tablet computers

Package:

• 28-pin 4 mm × 5 mm × 0.75 mm QFN (UFD)

• n Medical Instruments
• n USB-C Power Delivery
• n Industrial Handhelds
• n Ruggedized Notebook
• n Tablet Computers

ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full specified operating junction temperature range, otherwise specifications are at T A = 25°C (Note 4). V IN = 18V, DV CC = 3.3V, R SNSI = 10mΩ, RSNSB = 10mΩ unless otherwise noted.

The

l

denotes the specifications which apply over the full specified

operating junction temperature range, otherwise specifications are at T A = 25°C (Note 4). V IN = 18V, DVCC = 3.3V, R SNSI = 10mΩ, RSNSB = 10mΩ unless otherwise noted.

Rev B

When the switching battery charger is enabled at an elevated ambient temperature, LTC4162 self heating may push its junction temperature to an unacceptable level. To prevent overheating the LTC4162 monitors its own die_temp and automatically reduces the icharge_dac to limit power dissipation. The differential servo voltage at CSP to CSN can drop to as low as 1mV giving about 3% (1/32) of the maximum charge current. The thermal regulation algorithm achieves this by enforcing a maximum icharge_dac setting which drops linearly from 31 to 0 as die_temp increases from thermal_reg_start_temp (default 120°C) to thermal_reg_end_temp (default 125°C). When the thermal regulation algorithm is active, charge_status becomes thermal_reg_active. A thermal_reg_active_alert can be set with en_thermal_reg_active_alert and cleared by writing either back to 0. Thermal regulation can be programmed to any temperature within the LTC4162's operating range.

9V to 35V, 3.2A Step-Down Switching Battery Charger with PowerPath

The LTC ® 4162-S is an advanced monolithic synchronous step-down switching battery charger and PowerPath ™ manager that seamlessly manages power distribution between input sources such as wall adapters, backplanes, solar panels, etc., and a lead-acid battery.

A high resolution measurement system provides extensive telemetry information for circuit voltages, currents, battery resistance and temperature which can all be read back over the I 2 C port. The I 2 C port can also be used to configure many charging parameters including charging voltages and currents, termination algorithms and numerous system status alerts.

The LTC4162-S can charge 6V, 12V, 18V and 24V leadacid batteries with as much as 3.2A of charge current.

The power path topology decouples the output voltage from the battery allowing a portable product to start up instantly under very low battery voltage conditions.

The LTC4162-S is available in a thermally enhanced 28pin 4mm × 5mm × 0.75mm QFN surface mount package.

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