AD9552

Rev. C | Page 8 of 32

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

PIN 1

INDICATOR

1

Y4

2

Y5

3

A0

4

A1

5

A2

6

RESET

7

VDD

8

LDO

NOTES

1. EXPOSED DIE PAD MUST BE

CONNECTED TO GND.

24 GND

23 OUT2

22

21 VDD

20 LOCKED

19 LDO

18 VDD

17 LDO

TOP VIEW

(Not to Scale)

AD9552

OUT2

Figure 2. Pin Configuration

Table 8. 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 preset values for the PLL feedback divider and the OUT1

dividers based on the input reference frequency selected via the A[0:2] pins and have

internal 100 kΩ pull-up resistors.

3, 4, 5

A0, A1, A2

I

Control Pins. These pins select the input reference frequency and have internal 100 kΩ pull-

up resistors.

6

RESET

I

Digital Input, Active High. Resets internal logic to default states. This pin has an internal

100 kΩ pull-up resistor, so the default state of the device is reset.

7, 18, 21, 28

VDD

P

Power Supply Connection: 3.3 V Analog Supply.

8, 17, 19

LDO

P/O

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

ground.

9, 10

XTAL

I

Crystal Resonator Input. Connect a crystal resonator across these pins.

11

REF

I

Reference Clock Input. Connect this pin to an active clock input signal, or connect it to VDD

when using a crystal resonator across the XTAL pins.

12

CS

I

Digital Input, Active Low, Chip Select.

13

SCLK

I

Serial Data Clock.

14

SDIO

I/O

Digital Serial Data Input/Output.

15

OUTSEL

I

Logic 0 selects LVDS and Logic 1 selects LVPECL-compatible levels for both OUT1 and OUT2

when the outputs are not under SPI port control. Can be overridden via the programming

registers. This pin has an internal 100 kΩ pull-up resistor.

16

FILTER

I/O

Loop Filter Node for the PLL. Connect an external 12 nF capacitor from this pin to Pin 17 (LDO).

20

LOCKED

O

Active High Locked Status Indicator for the PLL.

26, 22

OUT1, OUT2

O

Complementary Square Wave Clocking Outputs.

27, 23

OUT1, OUT2

O

Square Wave Clocking Outputs.

24, 25

GND

P

Analog Ground.

EP

Exposed Die Pad

The exposed die pad must be connected to GND.