Comparison: MAX17303X+T vs RAJ240057A20DNP#HC1 Battery Fuel Gauge ICs

1. Quick verdict

For single-cell Li-ion/polymer battery packs requiring precise fuel gauging with integrated programmable protections and ultra-low quiescent current, the MAX17303X+T is the better choice, offering advanced ModelGauge m5 algorithm accuracy and comprehensive fault protections. For multi-cell (2–4S) packs where dual interface options (I2C and UART) and integrated fuel gauging with overcurrent and short circuit protection suffice, the RAJ240057A20DNP#HC1 is more suitable, especially when system complexity or communication flexibility is a priority.

2. Spec comparison table

SpecMAX17303X+TRAJ240057A20DNP#HC1Notes
FunctionFuel GaugeFuel GaugeBoth are fuel gauge ICs.
Battery ChemistryLithium Ion/PolymerLithium Ion/PolymerEquivalent.
Number of Cells Supported12–4RAJ240057A20DNP#HC1 supports multi-cell packs (2–4S), MAX17303X+T limited to 1 cell.
Fault ProtectionOver Current, Over Temperature, Over Voltage, Short CircuitOver Current, Short CircuitMAX17303X+T offers more comprehensive protection (temperature, voltage).
InterfaceI2CI2C, UARTRAJ240057A20DNP#HC1 is more flexible with two interfaces.
Operating Temperature Range-40°C to 85°C (TA)-40°C to 85°C (TA)Equivalent.
Mounting TypeSurface MountSurface MountEquivalent.
Package Case15-WLP (1.68 x 2.45 mm)32-HVQFN (4 x 4 mm)MAX17303X+T is smaller, suitable for space-constrained designs.
IC Current (typical active)24 μANot specifiedMAX17303X+T features ultra-low active current, beneficial for battery life.
IC Current (hibernate)18 μANot specifiedMAX17303X+T supports low power hibernate mode.
IC Current (ship mode)5 μANot specifiedMAX17303X+T excels in ultra-low power ship mode.
IC Current (deep ship)0.5 μA / 0.02 μANot specifiedMAX17303X+T supports extremely low current deep ship modes.
Package Pitch0.5 mmNot specifiedSmaller pitch in MAX17303X+T may complicate PCB routing.
Package Size~3 mm x 3 mm4 mm x 4 mmMAX17303X+T is more compact.
Memory Size (nonvolatile)~122 Bytes (User and fuel gauge data)Not specifiedMAX17303X+T offers embedded nonvolatile memory for fuel gauge algorithms and logging.
Absolute Maximum Input Voltage40 VNot specifiedMAX17303X+T supports up to 40 V input, useful for some protection features.
Input Voltage Range2.16 V (min) to 4.9 V (typ)Not specifiedMAX17303X+T specs precise input voltage range.
Output Current Max100 mANot specifiedMAX17303X+T includes internal FET drivers for protection with defined current limits.
Switching Frequency500 kHz to 5 MHz (typ 2 MHz)Not applicableMAX17303X+T includes switching regulator features (not typical for fuel gauges alone).
Operating Voltage (Supply)2.16 V (min) to 4.9 V (typ)Not specifiedMAX17303X+T detailed supply voltage specs.
Battery Capacity Range200 mAh to 1000 mAh (typ)Not specifiedMAX17303X+T targets small to medium single-cell packs.
Temperature MeasurementInternal die temp + external NTC thermistor input (TH pin)Not specifiedMAX17303X+T supports external thermistor temperature sensing; essential for accurate fuel gauging and protection.
Protection FeaturesProgrammable charge/discharge current limits, voltage thresholds, temperature thresholds, short circuit, overcurrentOver Current, Short CircuitMAX17303X+T offers programmable, multi-level protections beyond RAJ240057A20DNP#HC1.
AuthenticationSHA-256 AuthenticationNot specifiedMAX17303X+T supports SHA-256 for secure battery authentication.
Age ReportingCapacity fade, internal resistance, calendar agingNot specifiedMAX17303X+T provides multiple battery health indicators.
Communication ProtocolsI2C standard and SBSI2C and UARTRAJ240057A20DNP#HC1 offers UART, useful for more flexible or legacy system integration.
Package Thermal ResistanceJunction-to-ambient 41°C/W (4-layer PCB)Not specifiedMAX17303X+T data available; insufficient data for RAJ240057A20DNP#HC1.
Package Lead Count15 leads (WLP)32 leads (HVQFN)RAJ240057A20DNP#HC1 larger pin count supports more functions/pins but increases PCB complexity.
Package Footprint1.68 x 2.45 mm (WLP)4 x 4 mm (HVQFN)MAX17303X+T is smaller, better for compact designs.

3. Design trade-offs

The MAX17303X+T is optimized for single-cell lithium-ion/polymer packs, featuring a compact 15-WLP package at 1.68 x 2.45 mm, which is advantageous for space-constrained applications such as wearables or ultra-compact portable devices. Its ultra-low active current consumption (~24 μA) and extremely low ship and deep-ship currents (down to 0.02 μA) make it ideal for maximizing battery life in battery-powered designs that require long shelf life and minimal parasitic drain.

In contrast, the RAJ240057A20DNP#HC1 targets multi-cell battery packs (2–4 cells), which is common in power tools, larger portable equipment, or electric bicycles. Its larger 32-HVQFN package (4x4 mm) supports the additional pins needed for multi-cell voltage sensing and dual communication interfaces (I2C and UART). This flexibility allows system engineers to integrate the fuel gauge into systems with different microcontroller communication requirements or legacy UART interfaces, simplifying firmware adaptation.

MAX17303X+T’s integrated programmable protections extend beyond overcurrent and short-circuit to include overvoltage, undervoltage, and temperature protections with programmable thresholds, enabling more comprehensive battery safety management. The RAJ240057A20DNP#HC1 provides essential overcurrent and short circuit protection but lacks temperature and voltage fault protections, requiring external circuitry for full battery safety compliance.

The MAX17303X+T’s firmware includes the ModelGauge m5 algorithm, which combines coulomb counting and voltage-based fuel gauging with temperature compensation, improving state-of-charge (SOC) accuracy and reducing drift over time. Additionally, it supports SHA-256 authentication to secure battery pack identity, a significant consideration for OEMs concerned with battery counterfeiting or warranty fraud. RAJ240057A20DNP#HC1 does not specify such advanced algorithms or security features.

From a layout standpoint, the WLP package of MAX17303X+T demands more careful PCB design and manufacturing control due to its smaller pitch and less robust mechanical tolerances compared to the more conventional HVQFN package of RAJ240057A20DNP#HC1. However, the smaller footprint can reduce BOM cost and board area, which may justify the increased layout complexity.

Thermally, the MAX17303X+T datasheet provides junction-to-ambient thermal resistance data (41°C/W on a 4-layer board), which suggests moderate thermal dissipation capability. The RAJ240057A20DNP#HC1 lacks specified thermal resistance data, but the larger package and exposed pad design generally aid heat dissipation. For high-current applications, RAJ240057A20DNP#HC1 may handle thermal stresses better, but this depends heavily on system-level thermal design.

Cost-wise, the MAX17303X+T’s advanced features, smaller package, and security capabilities likely position it at a higher unit cost compared to the RAJ240057A20DNP#HC1, which targets multi-cell packs but with more basic protection and communication features. Volume pricing and