AD9550

Rev. 0 | Page 7 of 20

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

NOTES

1. NC = NO CONNECT.

2. EXPOSED DIE PAD MUST BE CONNECTED TO GND.

PIN 1

INDICATOR

1

Y4

2

Y5

3

A0

4

A1

5

A2

6

A3

7

REF

8

GND

24 GND

23 OUT2

22

21 VDD

20 LOCKED

19 LDO

18 VDD

17 LDO

TOP VIEW

(Not to Scale)

AD9550

OUT2

Figure 2. Pin Configuration

Table 5. Pin Function Descriptions

Pin No.

Mnemonic

Type1

Description

29, 30, 31,

32, 1, 2

Y0, Y1, Y2, Y3,

Y4, Y5

I

Control Pins. These pins select one of 52 preset output frequency combinations for OUT1 and

OUT2. Each pin has an internal 100 kΩ pull-up resistor.

3, 4, 5, 6

A0, A1, A2, A3

I

Control Pins. These pins select one of 15 preset input reference frequencies. Each pin has an

internal 100 kΩ pull-up resistor.

7

REF

I

Reference Clock Input. Connect this pin to a single-ended active clock input signal.

8, 11, 24, 25

GND

P

Ground.

9, 10

NC

No Connection. Make no external connection to these pins. Do not connect to GND or VDD.

12, 13, 14

OM2, OM1,

OM0

I

Control Pins. These pins select one of eight preset output configurations (see Table 10). Each pin

has an internal 40 kΩ pull-up resistor.

15

RESET

I

Reset Internal Logic. This is a digital input pin. This pin is active low with a 100 kΩ internal pull-up

resistor and resets the internal logic to default states (see the Automatic Power-On Reset section).

16

FILTER

I/O

Loop Filter Node for the PLL. Connect external loop filter components (see Figure 24) from this pin

to Pin 17 (LDO).

17, 19

LDO

P/O

LDO Decoupling Pins. Connect a 0.47 μF decoupling capacitor from each of these pins to ground.

18, 21, 28

VDD

P

Power Supply Connection: 3.3 V Supply. Pin 21 supplies the OUT2 driver and Pin 28 supplies the

OUT1 driver.

20

LOCKED

O

Locked Status Indicator for the PLL. Active high.

26, 22

OUT1, OUT2

O

Complementary Square Wave Clocking Outputs.

27, 23

OUT1, OUT2

O

Square Wave Clocking Outputs.

N/A2

EP

Exposed Die Pad. The exposed die pad must be connected to GND.