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Voltage Reference – LM285-1.2

Rev 1.0

19/08/25

Pad Layout and Functions

Typical Application

An external series resistor (RS) is connected between supply voltage, VS, and the LM285.

RS determines the current that flows through the load (IL) and the LM285 (IR). Since load current and supply voltage

may vary, RS should be small enough to supply at least the minimum acceptable IR to the LM285 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 LM285 is less than 20mA.

RS is determined by the supply voltage, (VS), the load and operating current, (IL and IR), and the LM285’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

ANODE (-)

-263.5

529.5

2

NO CONNECT

-437

547

3

NO CONNECT

-437

417

4

NO CONNECT

-415

287

5

NO CONNECT

-437

157

6

NO CONNECT

-408

7

7

NO CONNECT

-408

-123

8

NO CONNECT

-408

-253

9

NO CONNECT

-408

-383

10

NO CONNECT

-408

-513

11

NO CONNECT

-251

-513

12

CATHODE (+)

419.5

-529.5

CONNECT CHIP BACK TO ANODE (-)

1060µm (41.73mils)

Schematic

12

11

10

9

8

7

6

5

4

3

2

1

0,0