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Voltage Reference – LM4040D-2.5

Rev 1.1

29/07/22

Pad Layout and Functions

Typical Application

An external series resistor (RS) is connected between the supply voltage, VS, and the

LM4040D.

RS determines the current that flows through the load (IL) and the LM4040D (IR). Since

load current and supply voltage may vary, RS should be small enough to supply at least

the minimum acceptable IR to the LM4040D even when the supply voltage is at its

minimum and the load current is at its maximum value. When the supply voltage is at

its maximum and IL is at its minimum, RS should be large enough so that the current

flowing through the LM4040D is less than 15mA.

RS is determined by the supply voltage, (VS), the load and operating current, (IL and IR),

and the LM4040D’s reverse breakdown voltage, VR.

VS - VR

IL + IR

RS =

VS

RS

VO

IR

IL

IL + IR

VR

COORDINATES (µm)

PAD

FUNCTION

X

Y

1

CATHODE +

120

580

2

ANODE

–

120

135

3

NO CONNECT

530

135

4

NO CONNECT

600

480

5

NO CONNECT

595

610

6

NO CONNECT

430

610

7

NO CONNECT

275

610

CONNECT CHIP BACK TO GND

800µm (31.50 mils)