LM3485_15 Datasheet, PDF (2/24 Pages) Texas Instruments – Hysteretic PFET Buck Controller

LM3485
SNVS178G – JANUARY 2002 – REVISED FEBRUARY 2013
Connection Diagram
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Figure 1. Top View
8-Lead Plastic VSSOP-8
Package Number DGK (S-PDSO-G8)
Pin Name
ISENSE
GND
NC
FB
ADJ
PWR GND
PGATE
VIN
PIN DESCRIPTIONS
Pin
Description
No.
1 The current sense input pin. This pin should be connected to Drain node of the external PFET.
2 Signal ground.
3 No connection.
4 The feedback input. Connect the FB to a resistor voltage divider between the output and GND for an adjustable
output voltage.
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.
6 Power ground.
7 Gate Drive output for the external PFET. PGATE swings between V_IN and V_IN-5V.
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
PGATE Voltage
FB Voltage
ISENSE Voltage
ADJ Voltage
Maximum Junction Temperature
Power Dissipation
ESD Susceptibility
Lead Temperature
Storage Temperature
Human Body Model⁽²⁾
Vapor Phase (60 sec.)
Infrared (15 sec.)
−0.3V to 36V
−0.3V to 36V
−0.3V to 5V
−1.0V to 36V
−0.3V to 36V
150°C
417mW at T_A = 25°C
2kV
215°C
220°C
−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
Operating Junction Temperature
4.5V to 35V
−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.
2
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