Protection IC Datasheet

© 2024 Littelfuse, Inc.

Specifications are subject to change without notice.

Revised: JC. 08/12/24

LS0502SCD33

Super Capacitor Protection IC for Backup Power Applications

1

Features and Benefits

RoHS Pb

Description

The LS0502SCD33 is a complete solution for system with backup

storage capacitor or capacitor bank. It integrates input overvoltage,

overcurrent protection circuit, a reverse blocking switch and super

capacitor charging control circuit. It also has built-in cell balance to

provide protection over two cell super capacitor system.

When the main supply is present and above the minimum system

supply voltage, system will draw power from input supply. At the

same time, integrated linear charger charges the storage element

at up to 300 mA current. Once the storage element is charged, the

circuit draws only 2.5 μA of current while it maintains the super

capacitor or other storage element in its ready state. When the

main supply is removed, the integrated reverse blocking switch

will block current flow from system rail to input. The linear charger

will be turned on to provide power to system rail with low

resistance path with up to 2 A current.

Integrated cell balancing circuit will keep monitoring the cell

voltage when charging and keep the two cells voltage at same

level.

The LS0502SCD33 is externally programmable for input current

limit, input overvoltage, charge current limit, and charge voltage

limit. It provides a flag signal when input supply is unplugged so

that main system can taking action.LS0502SCD33 is available in

DFN3X3-10 package.

■ 3.3 V to 5.5 V System Voltage

■ 18 V Input Rating with

Overvoltage Protection

■ Programmable 1.1 V to 5.3 V

Cap Voltage Range

■ Programmable Super

Capacitor Charge Current

■ Programmable Input

Overcurrent Protection

■ Automatic Cell Balancing

■ Automatic Main/Backup

Switchover

■ Up to 2 A Discharge Current

■ Programmable Voltage and

Current Thresholds

■ ±2 % Threshold Accuracy

■ 2.5 μA Ready Quiescent

Current

■ Small Solution Size

■ DFN Package

Applications

■ Handheld Industrial

Equipment

■ Dash Camera

■ IoT

■ SmartMeter

■ Portable Device with

Removable Battery

Functional Block Diagram

VIN

USB 5 V

VSYS

VIN

PFB

ILIMT

GND

VSYS

VCAP

VMID

CFB

ICHG

Super Capacitor

C

IN

Super Capacitor

22 F

C

SYS

22 F

R

LIMT

13 k

R

CHG

12 k

R

PFB_TOP

50 k

R

PFLTB

R

PFB_BOT

R

CFB_TOP

R

CFB_BOT

LS0502SCD33

C

CFB_TOP

22 pF

PFLTB

Super Capacitor Protection IC

for Backup Power Applications

Typical Applications

VIN

VCAP

VSYS

GND

ControlLogic

−

BALEN

+

ICHG

PFLTB

VINFLT

ChargePump

ILIMIT

Charge Current Set

Input OC Set

VCOV

−

CAPOV

+

BAL

VCAP-BAL

−

+

VREF

CFB

CHG

−

+

−

VREF

IOV

IUV

PFB

BodyCtrl

GateCtrl

M1

M2

M3

VMID