Connection Diagrams

10-Bump micro SMD Package

20098804

Top View

20098805

Bottom View

Ordering Information

Order Number

Output Voltage

Package

NSC Package Marking

Supplied As

LM3661TLX - 1.25

1.05V/1.25V

10Bump Wafer Level

Chip Scale (micro SMD)

SHVB

3000 Units, Tape and Reel

LM3661TL - 1.25

SHVB

250 Units, Tape and Reel

LM3661TLX - 1.35

1.05V/1.35V

SDYB

3000 Units, Tape and Reel

LM3661TL - 1.35

SDYB

250 Units, Tape and Reel

LM3661TLX - 1.40

1.05V/1.40V

SHCB

3000 Units, Tape and Reel

LM3661TL - 1.40

SHCB

250 Units, Tape and Reel

Pin Description

Pin Number

Name

Function

A1

FB

Feedback Analog Input. Connect to the output at the output filter capacitor (see

Typical Application Circuit)

B1

V

SEL

Output Voltage Selection Input. Set this digital input to select the desired output

voltage. Set:

C1

I

SEL

I

I

D1

SYNC/MODE

Synchronization Input. Use this digital input for frequency selection or modulation

control. Set:

external clock in PWM mode.

The LM3661 synchronizes with the rising edge of the external clock.

D2

EN

Enable Input. It has an internal pull down resistor of 1 Mohms. Set this digital input

high for normal operation. For shutdown, set low.

D3

PGND

Power Ground

C3

SW

Switching Node connection to the internal PFET switch and NFET synchronous

rectifier. Connect to an inductor with a saturation current rating that exceeds the peak

current limit.

B3

PV

IN

Power Supply Input to the internal PFET switch. Connect to the input filter capacitor

(See Typical Application Circuit).

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