Datasheet

8
7
6
5
4
3
2
1
Exposed Pad on Bottom
Connect to Ground
FB
GND
ADJ
PGATE
ISEN
VCC
RT
VIN
1
2
3
4 5
8
7
6
Exposed Pad on Bottom
Connect to Ground
FB
PGATE
ISEN
GND
VCC
ADJ
RT
VIN
1
2
3
4 5
8
7
6
FB
PGATE
ISEN
GND
VCC
ADJ
RT
VIN
LM25085A
SNVS601B –JANUARY 2009–REVISED MARCH 2013 www.ti.com
Connection Diagram
Figure 1. Top View Figure 2. Top View
8-Lead HVSSOP 8-Lead VSSOP
Figure 3. Top View
8-Lead WSON
PIN DESCRIPTIONS
Pin Name Description Application Information
No.
1 ADJ Current Limit Adjust The current limit threshold is set by an external resistor from VIN to ADJ in
conjunction with the external sense resistor or the PFET’s R
DS(ON)
.
2 RT On-time control and shutdown An external resistor from VIN to RT sets the buck switch on-time and switching
frequency. Grounding this pin shuts down the controller.
3 FB Voltage Feedback from the Input to the regulation and over-voltage comparators. The regulation level is 0.9V.
regulated output
4 GND Circuit Ground Ground reference for all internal circuitry
5 ISEN Current sense input for current Connect to the PFET drain when using R
DS(ON)
current sense. Connect to the PFET
limit detection. source and the sense resistor when using a current sense resistor.
6 PGATE Gate Driver Output Connect to the gate of the external PFET.
7 VCC Output of the gate driver bias Output of the negative voltage regulator (relative to VIN) that biases the PFET gate
regulator driver. A low ESR capacitor is required from VIN to VCC, located as close as
possible to the pins.
8 VIN Input supply voltage The operating input range is from 4.5V to 42V. A low ESR bypass capacitor must be
located as close as possible to the VIN and GND pins.
EP Exposed Pad Exposed pad on the underside of the package (HVSSOP-PowerPAD-8 and WSON
only). This pad is to be soldered to the PC board ground plane to aid in heat
dissipation.
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.
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Product Folder Links: LM25085A