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

2

Pin #

Pin Name

Description

1

VIN

Input Power Supply. Connect to a 5 V system supply rail and bypass with a 10 μF capacitor to GND.

2

PFB

Input voltage sensing input. Connect to the center point of a resistor divider from VIN to GND. It is compared

with internal 1.2 V reference. When PFB is below1.2 V, PFLTB will pull high to indicate input power failure."

3

ILIMT

Input overcurrent protection setting pin. Connect a resistor to ground the set the input overcurrent protection level. If

ILIMT is short to GND, input current limit is set to 3 A. If ILIMT is floating, input current limit is 0 A. The

Limit current is determined by the equation: ILIMT = 30 A*kΩ/RLIMIT

4

ICHG

Charge Current Input. This pin sets the maximum current level for charging super capacitor. The charger current

recommend <350 mA (R

CHG>10 k).

The Charge Current is determined by the equation: ICHG = 3.3 A*kΩ/R

CHG

5

GND

Ground.

6

PFLTB

Open-Drain input power failure indicator. PFLTB goes low when the PFB drop below 1.2 V or (VIN-VSYS) exceed 360

mV. Connect to an external pull up resistor.

7

CFB

VCAP Feedback. Connect to the upper point of a resistor divider from VCAP to GND. Part stops charging super

capacitor when CFB voltage is above 1.1 V.

8

VMID

Super capacitor balance point. Connect to center point of stacked two super capacitors.

9

VCAP

Super Cap. Connect to top point of two super cap stacks.

10

VSYS

Supply rail for internal system. Power is draw from VIN when valid input supply is present. When input power

failed, power will be provided by super capacitor connected to VCAP.

EP

EP

Note: EP use conductive glue and GND PAD has no down bonding.

Pinout Designation

1

3

2

VMID

GND

PFLTB

6

7

8

VIN

ICHG

GND

4

5

CFB

9

10

PFB

Exposed Pad on Backside

ILIMIT

VSYS

VCAP