Micrel, Inc.

MIC2811/2821

April 2008

3

M9999-042208-A

Pin Configuration

EN1

BIAS

SGND

PGND

VIN1

LDO1

VIN

LDO3

EN1

BIAS

SGND

PGND

VIN1

LDO1

VIN

LDO3

MIC2811

16-Pin 3mm x 3mm MLF

(Top View)

MIC2821

16-Pin 3mm x 3mm MLF

(Top View)

Pin Description

Pin Number

MIC2811

Pin Number

MIC2821

Pin Name

Pin Name

1

1

EN1

Enable Input (LDO 1). Active High Input. Logic High = On; Logic Low = Off;

Do not leave floating.

2

2

BIAS

Internal circuit bias supply. It must be de-coupled to signal ground with a

0.1µF capacitor and should not be loaded.

3

3

SGND

Signal ground.

4

4

PGND

Power ground.

5

5

SW

Switch (Output): Internal power MOSFET output switches.

6

6

DVIN

Power Supply for DC/DC converter. Must be tied to VIN.

7

7

VIN2

Power Supply to LDO2.

8

8

LDO2

Output of LDO2.

9

9

LDO3

Output of LDO3.

10

10

VIN

Supply to bias circuitry and power to LDO3, must be tied to DVIN.

11

11

LDO1

Output of LDO1.

12

12

VIN1

Power Supply to LDO1.

13

13

FB

Feedback input to the error amplifier of the DC/DC converter.

Adjust version: Use external resistor divider from DC/DC output to set VOUT.

Fixed voltage version: Connect directly to VOUT of the DC/DC converter.

14

N/A

BYP

Reference Bypass. Connect external 0.1µF to GND to reduce output noise.

May be left open. Do not connect directly to GND.

N/A

14

EN3

Enable Input (LDO3). Active High Input. Logic High = On; Logic Low = Off;

Do not leave floating.

15

N/A

EN

Enable Input (DC/DC and LDO3). Active High Input. Logic High = On; Logic

Low = Off; Do not leave floating.

N/A

15

EN

Enable Input (DC/DC). Active High Input. Logic High = On; Logic Low = Off;

Do not leave floating.

16

16

EN2

Enable Input (LDO2). Active High Input. Logic High = On; Logic Low = Off;

Do not leave floating.