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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Battery Chargers

Texas Instruments BQ2057SN

Name: BQ2057SN
Brand: Texas Instruments
SKU: BQ2057SN
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BQ2057SN

Manufacturer:: Texas Instruments

Category:: Battery Chargers

Package:: 8-SOIC (0.154", 3.90mm Width)

Datasheet:: BQ2057SN.pdf

Description:: IC BATT CHG LI-ION 1CELL 8SOIC

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BQ2057SN from Texas Instruments is a fixed 4.1-V, single-cell Li-ion/Li-polymer linear charge management IC with integrated voltage/current regulation, AutoComp™ dynamic impedance compensation, temperature monitoring (via external thermistor), and precharge conditioning. It delivers ±1% voltage regulation accuracy, 0.3-V dropout, and supports high- or low-side current sensing using an external sense resistor. It is used in compact portable electronics requiring safe, cost-effective battery charging.

For engineers reviewing the BQ2057SN datasheet, BQ2057SN pinout, BQ2057SN application, or BQ2057SN equivalent, key selection considerations include its 4.1-V fixed regulation voltage, SOIC-8 package, thermal performance (R_θJA = 157.1°C/W), sleep-mode current (≤6 µA), and compatibility with PNP or P-channel MOSFET pass devices.

Technical Context

The BQ2057SN implements a three-phase linear charging algorithm: preconditioning (at ~10% of regulation current when V_BAT < 3.0 V), constant-current regulation (set by external sense resistor), and constant-voltage regulation (4.1 V ±1%). It uses analog feedback loops for both voltage (BAT pin) and current (SNS pin), with internal reference stability over −20°C to 70°C.

Temperature safety is enforced via dual thresholds (V_TS1 = 30% V_CC, V_TS2 = 60% V_CC) applied to the TS pin, enabling charge suspension outside the valid range. The STAT pin provides 3-state status signaling (High = charging, Low = done, Hi-Z = fault/sleep), and the CC pin drives the external pass transistor as a source-follower.

Key Specifications

Parameter	Value and Actual Design Meaning
Regulation Voltage	4.1 V ±1% - Fixed output for single-cell Li-ion packs; enables precise full-charge termination without external DAC or resistor divider.
Current Regulation Threshold	105 mV (typ.) - Sets charge current I_CHG = 105 mV / R_SNS; supports both high- and low-side sensing configurations.
Precharge Threshold	3.0 V (nom.) - Triggers low-current (~10% of I_CHG) conditioning mode for deeply discharged cells to prevent damage and reduce heat.
Charge Termination Current	−14 mV (typ.) - Detects taper current at SNS pin relative to V_CC (high-side) or V_SS (low-side); ensures reliable end-of-charge detection.
Supply Voltage Range	4.5 V to 15 V - Allows direct connection to common DC adapters or USB-derived rails while maintaining regulation margin over battery voltage.
Thermal Resistance	R_θJA = 157.1°C/W - Defines maximum power dissipation limit (≈190 mW at ΔT = 30°C) in standard SOIC-8 PCB layout without heatsink.
Sleep Current	≤6 µA - Minimizes parasitic drain on battery when input supply (V_CC) is removed, preserving standby time.

Pinout & Package

Package: 8-pin SOIC (SN), body size 4.90 mm × 3.91 mm, surface-mount, RoHS-compliant.

Pin/Terminal	Circuit Role	Design Meaning
SNS	Current sense input	Monitors voltage drop across external sense resistor; determines charge current magnitude and termination threshold.
BAT	Battery voltage sense input	Direct connection to battery positive terminal; provides feedback for 4.1-V regulation and recharge threshold detection.
COMP	AutoComp™ compensation input	Accepts voltage proportional to charge current to dynamically adjust regulation voltage and reduce charge time.
CC	Charge control output	Source-follower driver for external PNP or P-channel MOSFET; regulates pass device conduction to maintain current/voltage.
VSS	Ground reference	Common return for all analog and power circuits; must be low-impedance connection to minimize sensing error.
STAT	Charge status output	3-state open-drain signal: High = charging, Low = done, Hi-Z = temperature fault or sleep mode.
VCC	Supply voltage input	Power source and current reference for high-side sensing; must exceed BAT by ≥0.8 V for proper operation.
TS	Temperature sense input	Accepts voltage from NTC/PTC thermistor divider; disables charge if outside 30%–60% V_CC window.

Key Features

Feature	Design Value
AutoComp™ dynamic compensation	Reduces total charge time by adjusting regulation voltage in real time based on battery internal impedance, without requiring system-level firmware intervention.
Integrated cell conditioning	Applies ~10% of full charge current to batteries below 3.0 V, safely reviving deeply discharged cells while limiting pass-element heating during initial stage.
Programmable high-/low-side current sensing	Eliminates need for level-shifting circuitry: same IC supports either configuration using only resistor value selection and placement-no additional components required.
Three-phase linear charge algorithm	Automatically sequences preconditioning → constant-current → constant-voltage phases with built-in timers and thresholds, reducing host processor overhead.
3-state STAT output	Enables direct LED drive (single or dual-color) or microcontroller interface via simple GPIO read sequence-no external logic or ADC needed.

Applications

Emergency Call Systems	Portable Medical Equipment
Use Scenario: Compact, battery-backed emergency voice/data transceivers deployed in vehicles or field units requiring guaranteed first-charge reliability after long storage. IC Role / Device Role / Timing Role: Linear charge controller managing single-cell Li-ion pack with mandatory temperature qualification and deep-discharge recovery before deployment. Use Value: Preconditioning mode restores functionality of batteries stored at low voltage; AutoComp™ reduces charge time by up to 15% under varying pack impedance conditions.	Use Scenario: Handheld diagnostic tools (e.g., pulse oximeters, glucose meters) needing certified-safe, low-heat charging in clinical environments with strict thermal limits. IC Role / Device Role / Timing Role: Safety-critical battery charger enforcing dual-temperature thresholds (V_TS1/V_TS2) and automatic recharge only after verified voltage decay. Use Value: Hardware-enforced thermal cutoff prevents unsafe charging outside 0°C–45°C operating band; ±1% voltage accuracy ensures consistent cell stress and cycle life.
Gaming Accessories	EPOS Card Readers
Use Scenario: Wireless gaming headsets and controllers with rapid-turnaround recharge requirements and space-constrained PCB layouts. IC Role / Device Role / Timing Role: Compact SOIC-8 charge manager delivering fast, low-thermal-profile charging using P-channel MOSFET pass element. Use Value: 0.3-V dropout minimizes heat generation at high currents; 157.1°C/W thermal resistance allows full 500-mA charging on 2-layer boards without heatsinks.	Use Scenario: Battery-powered electronic point-of-sale terminals used in retail environments where unplanned downtime must be avoided. IC Role / Device Role / Timing Role: Primary charge controller ensuring reliable top-off and automatic recharge after partial discharge during transaction bursts. Use Value: V_RCH = V_REG − 100 mV triggers recharge at 4.0 V, maintaining >95% usable capacity between transactions without user intervention.

Emergency Call Systems

Portable Medical Equipment

Use Scenario: Compact, battery-backed emergency voice/data transceivers deployed in vehicles or field units requiring guaranteed first-charge reliability after long storage.

IC Role / Device Role / Timing Role: Linear charge controller managing single-cell Li-ion pack with mandatory temperature qualification and deep-discharge recovery before deployment.

Use Value: Preconditioning mode restores functionality of batteries stored at low voltage; AutoComp™ reduces charge time by up to 15% under varying pack impedance conditions.

Use Scenario: Handheld diagnostic tools (e.g., pulse oximeters, glucose meters) needing certified-safe, low-heat charging in clinical environments with strict thermal limits.

IC Role / Device Role / Timing Role: Safety-critical battery charger enforcing dual-temperature thresholds (V_TS1/V_TS2) and automatic recharge only after verified voltage decay.

Use Value: Hardware-enforced thermal cutoff prevents unsafe charging outside 0°C–45°C operating band; ±1% voltage accuracy ensures consistent cell stress and cycle life.

Gaming Accessories

EPOS Card Readers

Use Scenario: Wireless gaming headsets and controllers with rapid-turnaround recharge requirements and space-constrained PCB layouts.

IC Role / Device Role / Timing Role: Compact SOIC-8 charge manager delivering fast, low-thermal-profile charging using P-channel MOSFET pass element.

Use Value: 0.3-V dropout minimizes heat generation at high currents; 157.1°C/W thermal resistance allows full 500-mA charging on 2-layer boards without heatsinks.

Use Scenario: Battery-powered electronic point-of-sale terminals used in retail environments where unplanned downtime must be avoided.

IC Role / Device Role / Timing Role: Primary charge controller ensuring reliable top-off and automatic recharge after partial discharge during transaction bursts.

Use Value: V_RCH = V_REG − 100 mV triggers recharge at 4.0 V, maintaining >95% usable capacity between transactions without user intervention.

Equivalent & Alternatives

The following parts are listed as comparable options for similar linear Li-ion charge management applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
BQ2057CSN	Fixed 4.2-V regulation (vs. BQ2057SN's 4.1 V); otherwise identical pinout, features, and SOIC-8 package.	Targeted at higher-capacity single-cell Li-ion chemistries requiring full 4.2-V termination; not suitable for 4.1-V optimized cells.	Select BQ2057CSN only if battery datasheet specifies 4.2-V absolute max charge voltage and tolerance stack-up permits ±1% variation.
BQ2057TSN	Fixed 8.2-V regulation for dual-cell stacks; shares same SOIC-8 footprint and functional architecture but different voltage reference network.	Used in 2S Li-ion packs (e.g., portable scanners, industrial handhelds); incompatible with single-cell systems due to regulation voltage mismatch.	Choose BQ2057TSN when designing for series-connected cells and board layout accommodates identical SOIC-8 placement but requires dual-cell voltage compliance.

Compared with BQ2057CSN and BQ2057TSN, the BQ2057SN offers optimal voltage alignment for legacy or conservative 4.1-V single-cell Li-ion cells, avoiding overvoltage stress while retaining full feature parity-including AutoComp™, temperature qualification, and 3-state STAT signaling-without layout or firmware changes.

Availability

BQ2057SN is available at Aetrix Electronics and suitable for emergency call systems, portable medical equipment, gaming accessories, and EPOS card readers requiring stable component supply across multi-year production cycles.

Supply support for BQ2057SN 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 company specializing in analog, embedded processing, and power management technologies with over 50 years of innovation in precision analog ICs.

The BQ2057SN belongs to TI's BQ2057x family of linear Li-ion charge controllers, designed specifically for cost-sensitive, space-constrained portable electronics needing integrated safety, accuracy, and minimal external component count.

FAQ

What is the exact charge regulation voltage of the BQ2057SN?

The BQ2057SN has a fixed charge regulation voltage of 4.1 V with better than ±1% accuracy over −20°C to 70°C and full supply voltage range. This value is laser-trimmed during manufacturing and does not require external resistors or configuration. The BQ2057SN is distinct from other variants like BQ2057CSN (4.2 V) or BQ2057TSN (8.2 V), and substituting those parts will result in incorrect termination voltage for single-cell 4.1-V Li-ion cells.

Does the BQ2057SN support both high-side and low-side current sensing?

Yes, the BQ2057SN supports both high-side and low-side current sensing configurations without external level shifters or additional components. In high-side mode, the sense resistor connects between VCC and SNS; in low-side mode, it connects between VSS and SNS. The current regulation threshold is 105 mV (typ.) in both cases, though tolerance differs slightly per configuration per datasheet Section 8.5.

How does the BQ2057SN handle deeply discharged batteries?

The BQ2057SN initiates preconditioning (precharge) when the battery voltage falls below 3.0 V (V_min). During this phase, it delivers approximately 10% of the programmed regulation current to safely recover the cell. This reduces thermal stress on the external pass transistor and prevents lithium plating. Preconditioning continues until V_BAT exceeds 3.0 V, after which constant-current charging begins.

What is the function of the COMP pin on the BQ2057SN?

The COMP pin on the BQ2057SN accepts a voltage proportional to charge current to enable AutoComp™ dynamic compensation. This proprietary feature adjusts the regulation voltage in real time to offset voltage drop caused by battery internal impedance, reducing total charge time by up to 15% without compromising safety. The gain is 2.2 V/V (typ.), and the pin must be connected per TI application guidance to realize benefit.

Can the BQ2057SN operate without a thermistor connected to the TS pin?

Yes, the BQ2057SN can operate without a thermistor: connecting the TS pin to a voltage between 30% and 60% of V_CC (e.g., via a resistor divider tied to V_CC/2) disables temperature monitoring and allows uninterrupted charging. However, this removes critical safety protection-TI strongly recommends thermistor use in production designs. Open or shorted TS connections default to charge inhibition.

BQ2057SN Specifications

Product attributes: Attribute value

Manufacturer:: Texas Instruments

Series:: -

Package/Case:: 8-SOIC (0.154", 3.90mm Width)

Packaging:: Bulk

Product Status:: Obsolete

Battery Chemistry:: Lithium Ion/Polymer

Number of Cells:: 1

Current - Charging:: Constant - Programmable

Programmable Features:: Current

Fault Protection:: -

Charge Current - Max:: -

Battery Pack Voltage:: 4.1V

Voltage - Supply (Max):: 15V

Interface:: -

Operating Temperature:: -20°C ~ 70°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC

BQ2057SN FAQ

1.How can I place an order for BQ2057SN through Aetrix?

Please submit a Request for Quotation (RFQ) for BQ2057SN 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 BQ2057SN reliable?

The price and inventory of BQ2057SN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BQ2057SN is usually 5 days.

3.What payment methods are accepted for BQ2057SN?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BQ2057SN transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BQ2057SN?

BQ2057SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BQ2057SN 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 BQ2057SN?

For technical support, including BQ2057SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BQ2057SN requirements.

6.How does Aetrix verify that BQ2057SN is sourced from the original manufacturer or authorized distributors?

All BQ2057SN 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 BQ2057SN meets industry standards.

7.What is the process for return or replacement of BQ2057SN?

All BQ2057SN units undergo pre-shipment inspection (PSI). If there is an issue with BQ2057SN, 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 BQ2057SN part is unused and in its original packaging.

Return procedure for BQ2057SN:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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