S-8254A — 3-Series/4-Series Cell Li-Ion Battery Protection IC

Overview

The S-8254A (specifically S-8254AA in a 16-pin TSSOP package) is a high-accuracy protection IC for 3-series or 4-series cell lithium-ion / lithium-polymer rechargeable battery packs, manufactured by ABLIC (formerly Seiko Instruments).

It continuously monitors individual cell voltages ( $V_{C1} \dots V_{C4}$ ) and battery pack charge/discharge currents, controlling external N-channel MOSFET switches to protect against overcharge, overdischarge, discharge overcurrent, and short circuit conditions.

With extremely low operating power consumption ( $30\ \mu\text{A}$ max operating, $0.1\ \mu\text{A}$ max power-down), the S-8254A prevents battery pack degradation and thermal runaway in power tools, E-bikes, robotics, and portable multi-cell battery packs.

Quick reference


Protection Type	3-Series / 4-Series Cell Li-Ion Battery Protection Controller
Package	16-Pin TSSOP
Operating Voltage Range ( $V_{DD}$ )	$2.0\text{ V}$ to $24.0\text{ V}$ DC
Cell Configuration	3 Cells or 4 Cells in Series (Configurable via `SEL` pin)
Overcharge Detection ( $V_{CU}$ )	$4.0\text{ V}$ to $4.4\text{ V}$ ( $\pm 25\text{ mV}$ accuracy)
Overdischarge Detection ( $V_{DL}$ )	$2.0\text{ V}$ to $3.0\text{ V}$ ( $\pm 80\text{ mV}$ accuracy)
Current Consumption	Operating: $30\ \mu\text{A}$ max / Power-down: $0.1\ \mu\text{A}$ max
Gate Drive Outputs	`COP` (Charge Control N-MOS FET), `DOP` (Discharge Control N-MOS FET)

Pinout (16-Pin TSSOP Package)

text

        ┌──────────────┐
   COP ─│ 1         16 │─ NC
   DOP ─│ 2         15 │─ NC
   VMP ─│ 3         14 │─ NC
  DOPD ─│ 4         13 │─ SEL
  COPD ─│ 5         12 │─ VSS
   CTL ─│ 6         11 │─ VC4
   VDD ─│ 7         10 │─ VC3
   VC1 ─│ 8          9 │─ VC2
        └──────────────┘

Pin	Name	Description
1	`COP`	FET gate drive output pin for charge control MOSFET
2	`DOP`	FET gate drive output pin for discharge control MOSFET
3	`VMP`	Voltage monitor input pin (connects to charger / load positive voltage sense)
4	`DOPD`	Capacitor pin for setting overdischarge current detection delay time
5	`COPD`	Capacitor pin for setting overcharge detection delay time
6	`CTL`	Charge/discharge control input pin (Forced shutdown control)
7	`VDD`	Power supply input pin (connects to highest cell potential $V_{C4}$ )
8	`VC1`	Voltage sense input for Cell 1 positive / Cell 2 negative
9	`VC2`	Voltage sense input for Cell 2 positive / Cell 3 negative
10	`VC3`	Voltage sense input for Cell 3 positive / Cell 4 negative
11	`VC4`	Voltage sense input for Cell 4 positive
12	`VSS`	Power supply ground reference pin (connects to Cell 1 negative)
13	`SEL`	Cell select pin: Connect to `VDD` for 4-cell mode; connect to `VSS` for 3-cell mode
14–16	`NC`	No internal connection

Specifications

Parameter	Symbol	Min	Typ	Max	Unit	Conditions
Operating Voltage Range	$V_{DD}$	2.0	—	24.0	V	Power supply voltage
Overcharge Voltage	$V_{CU}$	4.225	4.250	4.275	V	$S-8254AA$ version
Overcharge Release Volts	$V_{CL}$	4.000	4.050	4.100	V	Overcharge hysteresis
Overdischarge Voltage	$V_{DL}$	2.620	2.700	2.780	V	$S-8254AA$ version
Overdischarge Release	$V_{DU}$	2.900	3.000	3.100	V	Overdischarge hysteresis
Discharge Overcurrent 1	$V_{IOV1}$	0.170	0.200	0.230	V	Sense resistor voltage drop threshold
Short Circuit Protection	$V_{SHORT}$	1.000	1.200	1.400	V	Short circuit voltage drop threshold
Operating Current	$I_{OPE}$	—	15.0	30.0	$\mu\text{A}$	Normal operation ( $V_{CELL} = 3.5\text{V}$ )
Power-Down Current	$I_{PDN}$	—	—	0.1	$\mu\text{A}$	Overdischarge state ( $V_{CELL} = 2.0\text{V}$ )

Typical Application Circuit (4-Series Cell BMS)