ST321XS 3~18S Low-Power Battery AFE Protection IC

Name: ST321XS 3~18S Low-Power Battery AFE Protection IC
Brand: STST
SKU: ST321XS

ST321XS

The ST321XS is an ultra-low-power analog front-end protection IC for 3~18S battery packs, covering the ST3210S, ST3214S, ST3214S-T, ST3216S and ST3218S series-count models. It integrates voltage, current and temperature protection, wire-break detection, low-voltage charge inhibition, voltage-differential balancing, discharge inhibition during charge and small-current wake-up, with ±10mV over-voltage accuracy. A 13-bit Σ-Δ ADC, 500-cycle EEPROM and CRC-checked UART interface are built in; Normal current is only 30µA. Available in TSSOP28 / LQFP32L / LQFP48L packages, it is widely used in e-bikes, robot vacuums, power tools and energy storage.

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Specifications

Device Type3~18S low-power battery analog front-end (AFE) protection IC

Cells in Series3~18S

Quiescent CurrentNormal 30µA(typ); Powerdown 2.5µA(typ)

Overcharge Protection Voltage (OVP)2.5~4.5V(config., step5mV); Acc ±10mV

Overcharge Release Voltage2.5~4.5V(OVR config.)

Overdischarge Protection Voltage (UVP)1.0~3.5V(config., step10mV); Acc ±10mV

Overdischarge Release Voltage1.0~3.5V(UVR config.)

Discharge OC Protection 1 (OCD1)12~100mV(config., step4mV), Acc ≤5%

Discharge OC Protection 2 (OCD2)40~200mV(config.)

Short Circuit Protection1.5×/2× OCD2 (SCD_TH config.)

Charge OC Protection (OCC)3~65mV(config., step1mV)

Protection AccuracyOVP/UVP ±10mV (25℃); current 0-pt ≤50µV, acc ≤2%/5%

Temperature ProtectionCharge hi 40~70℃/lo -20~10℃, Discharge hi 45~80℃/lo -40~10℃ (config., step1℃, ±2℃)

Cell BalancingYes (voltage-differential balancing)

Delay TimeOV 0.2~4s; UV 0.5~4s; OCD1 0.5~4s; OCD2 50~500ms; OCC 0.1~8s; SC 50~400µs (reg. config.)

PackageTSSOP28(ST3210S/ST3214S-T)/LQFP32L(ST3214S/ST3216S)/LQFP48L(ST3218S)

Product details

Overview

The ST321XS is an ultra-low-power battery analog front-end protection IC for 3~18S applications: ST3210S for 3-10 series, ST3214S / ST3214S-T for 3-14, ST3216S for 3-16 and ST3218S for 3-18. It integrates voltage, current and temperature protection, wire-break detection, low-voltage charge inhibition, balancing, discharge inhibition during charge and small-current wake-up; a UART interface reads voltage, current and temperature in real time; and a built-in EEPROM allows dynamic configuration of protection thresholds and system parameters.

Features

Over-voltage protection: 2.5~4.5V range, 5mV step, ±10mV accuracy
Under-voltage protection: 1.0~3.5V range, 10mV step, ±10mV accuracy
Discharge over-current protection 1: 12~100mV range, 4mV step
Discharge over-current protection 2: 40~200mV options; short-circuit threshold configurable to 1.5x or 2x OCD2
Charge over-current protection: 3~65mV range, 1mV step
Current protection accuracy: zero-offset ≤50µV, ≤2% within 10mV, ≤5% for 10~100mV
Low-voltage charge inhibition: 0.75~2.25V, ±10mV; balancing start voltage 2.0~4.5V, ±10mV
Charge/discharge high/low temperature protection ±2°C; die over-temperature 115°C±10°C
Small-current wake-up of the MCU during charge/discharge
Built-in 13-bit Σ-Δ ADC and 500-cycle EEPROM; UART communication with CRC check
Voltage-differential balancing, wire-break protection, OCD auto-recovery/lockout and discharge inhibition during charge
Operating voltage 8~80V; operating temperature -40~85°C
Low power: 30µA (typ.) Normal, 2.5µA (typ.) Powerdown
Packages: TSSOP28 (ST3210S, ST3214S-T), LQFP32L (ST3214S, ST3216S), LQFP48L (ST3218S)