Datasheet

LM3485
SNVS178G –JANUARY 2002–REVISED FEBRUARY 2013 www.ti.com
Connection Diagram
Figure 1. Top View
8-Lead Plastic VSSOP-8
Package Number DGK (S-PDSO-G8)
PIN DESCRIPTIONS
Pin Name Pin Description
No.
ISENSE 1 The current sense input pin. This pin should be connected to Drain node of the external PFET.
GND 2 Signal ground.
NC 3 No connection.
FB 4 The feedback input. Connect the FB to a resistor voltage divider between the output and GND for an adjustable
output voltage.
ADJ 5 Current limit threshold adjustment. It connects to an internal 5.5µA current source. A resistor is connected
between this pin and the input Power Supply. The voltage across this resistor is compared with the V
DS
of the
external PFET to determine if an over-current condition has occurred.
PWR GND 6 Power ground.
PGATE 7 Gate Drive output for the external PFET. PGATE swings between V
IN
and V
IN
-5V.
VIN 8 Power supply input pin.
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
Absolute Maximum Ratings
(1)
VIN Voltage −0.3V to 36V
PGATE Voltage −0.3V to 36V
FB Voltage −0.3V to 5V
ISENSE Voltage −1.0V to 36V
ADJ Voltage −0.3V to 36V
Maximum Junction Temperature 150°C
Power Dissipation 417mW at T
A
= 25°C
ESD Susceptibility Human Body Model
(2)
2kV
Lead Temperature Vapor Phase (60 sec.) 215°C
Infrared (15 sec.) 220°C
Storage Temperature −65°C to 150°C
(1) Absolute maximum ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions for which the
device is intended to be functional, but device parameter specifications may not be ensured. For specifications and test conditions, see
the Electrical Characteristics.
(2) The human body model is a 100 pF capacitor discharged through a 1.5kΩ resistor into each pin.
Operating Ratings
(1)
Supply Voltage 4.5V to 35V
Operating Junction Temperature −40°C to +125°C
(1) Absolute maximum ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions for which the
device is intended to be functional, but device parameter specifications may not be ensured. For specifications and test conditions, see
the Electrical Characteristics.
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