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R5431 Series
3-Cell to 4-Cell Li-ion Battery Protection ICs (Pch High-side Switch Control)

Product Specifications

The R5431 Series are high voltage CMOS-based protection ICs for over-charge/discharge of rechargeable three-cell/four-cell Lithium-ion (Li+) / Lithium polymer, further include a short circuit protection circuit for preventing large external short circuit current and the protection circuits against the excess discharge-current and excess charge current.
Each of these ICs is composed of eleven voltage detectors, a reference unit, a delay circuit, a short circuit protector, an oscillator, a counter, and a logic circuit. When the over-charge voltage threshold or excess-charge current threshold crosses the each detector threshold from a low value to a high value, the output of COUT pin switches to “L” level after internal fixed delay time. To release over-charge detector after detecting over-charge, the detector can be reset and the output of COUT becomes "H" when a kind of load is connected to VDD after a charger is disconnected from the battery pack and the cell voltage becomes lower than over-charge detector threshold. In case that a charger is continuously connected to the battery pack, if the cell voltage becomes lower than the over-charge detector threshold, over-charge state is also released.
The output of DOUT pin, the output of the over-discharge detector and the excess discharge-current detector, switches to “L” level after internally fixed delay time, when discharged voltage crosses the detector threshold from a high value to a value lower than VDET2.
After detecting over-discharge voltage, when the cell voltage becomes higher than the released voltage from over-discharge, over-discharge state is released and the output of DOUT becomes “L”.
By setting DS pin voltage as same as the VDD, the testing time of protection circuit board can be shortened. The delay time of the over-charge detector, over-discharge detector, and excess current detector can be reduced into approximately 1/50. The output type of COUT and DOUT is CMOS.


Operating Input Voltage Range 2.0 V to 20 V (Absolute Maximum Rating: 26 V)
Charger Positive Input Voltage (V+) 30 V (Absolute Maximum Rating)
Supply Current Typ. 12.0 µA
Standby Current Typ. 6.0 µA
Detector Threshold Range 3.6 V to 4.5 V (0.005 V Steps)
Voltage Accuracy ±25 mV
Output Delay Time 1.0 s
Detector Threshold Range 2.0 V to 3.0 V (0.005 V Steps)
Voltage Accuracy ±2.5%
Output Delay Time 1.2 s, 128 ms
Detector Threshold Range VDET3-1: VDD-0.20V
VDET3-2: VDD-0.6V
Voltage Accuracy ±20 mV
Output Delay Time VDET3-1: 1.0 s / 12 ms
VDET3-2: 10 ms / 2 ms
Detector Threshold VDD+0.2V
Voltage Accuracy ±30 mV
Output Delay Time 8 ms
Short Protection Detector Threshold VDD-1.2V
Output Delay Time 300 µs
0V-battery charge Unacceptable: For each cell, charge inhibit voltage is set at Max.=1.1V. (Vnochgn, n=1,2,3,4)
Package SSOP-16

Tap to see the table


for 4-cell protection with CTL function and DS function



SSOP-165.1 mm × 6.4 mm
2 V+
4 NC
5 NC
6 DS
8 NC
9 NC
10 SEL
11 CTL
12 VC4
13 VC3
14 VC2
15 VC1
16 VDD

R5431 Series for Consumer


  • Li+ / Li Polymer protector of over-charge, over-discharge, excess-current for battery pack
  • Over-charge, discharge, and current protectors for notebook-PCs, power tools, and any other gadgets using on board Li+ / Li Polymer battery


In the R5431 Series, input threshold of over-charge, over-discharge, excess charge/discharge current, and output delay time can be designated according to the application.

Product Name   Package Quantity per Reel
R5431Vxxx$A-E2 Consumter SSOP-16 2,000
  • xxx … Serial Number for the R5431 Series designating input threshold for over-charge, over-discharge, excess charge/discharge-current detectors
  • $ … Designation of Output delay option
Code Over-discharge
detector output
delay time
Excess-discharge current
detector threshold
output delay time 1
Excess-discharge current
detector threshold
output delay time 2
A 1200 1000 10
B 128 12 2



Technical Support

Package*1 Reliability*2
SSOP-16 R5431V

*1: The package file includes package dimensions, taping specifications, taping reels dimensions, power dissipations, and land pattern (foot pattern).
*2: Reliability file includes a reliability test report and a reflow profile.

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