SI4779CY Vishay, SI4779CY Datasheet - Page 8

• Manufacturer Part Number: SI4779CY
• Manufacturer: Vishay

Specifications of SI4779CY

• Switch Type: High Side
• Power Switch Family: Si4779CY
• Input Voltage: 3 to 5V
• Power Switch On Resistance: 45mOhm
• Output Current: 2.4A
• Number Of Outputs: Single
• Mounting: Surface Mount
• Supply Current: 70uA
• Package Type: SOIC N
• Operating Temperature (min): 0C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Commercial
• Pin Count: 8
• Power Dissipation: 650mW
• Lead Free Status / Rohs Status: Not Compliant

Si4779CY
Vishay Siliconix
DETAILED DESCRIPTION
The SI4779CY limits the output current to a user-defined
level. When the output current passes through the main
switch a fraction of this current passes through a replica
switch and R
R
of the over current limit; the over current limit should be
set between 0.4 A and 2.4 A (see graph for R
vs. current limit). The circuit shuts down the switch when
the current flowing through the switch exceeds Ilimit.
After a short period of time, the circuit will slowly turn on
the switch again. The length of time off is based on aver-
APPLICATIONS DIAGRAM
Vishay Siliconix maintains worldwide manufacturing capability. Products may be manufactured at one of several qualified locations. Reliability data for Silicon Tech-
nology and Package Reliability represent a composite of all qualified locations. For related documents such as package/tape drawings, part marking, and reliability
data, see
www.vishay.com
8
SET
is an external sense resistor used to set the level
http://www.vishay.com/ppg?71664.
SET
.
Line Input
100 µF
ON
100 kΩ
R
SET
SET
100 kΩ
value
FIGURE 17.
IN
FAULT
ON
SET
Si4779CY
age power consumption, which is designed to be kept
under 500 mW.
If the output is shorted, the circuit will go into an on-off
cycle to protect the switch and to prevent the battery
from draining down.
The fault output (FAULT) goes low when the circuit is in
over current limit or short circuit protection mode. A 100 kΩ
pull-up resistor from FAULT to IN provides a logic-con-
trol signal.
GND
OUT
100 µF
Line Output
11 Ω
S-60423–Rev. B, 20-Mar-06
Document Number: 71664