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
1Y4
2Y5
3A0
4A1
5A2
6A3
7REF
8GND
24 GND
23 OUT2
22
21 VDD
20 LOCKED
19 LDO
18 VDD
17 LDO
9
NC
10
NC
11
GND
12
13
OM1
14
OM0
15
RESET
16
FILTER
32
Y3
31
Y
2
30
Y1
29
Y
0
28
VDD
27
OUT1
26
25
GND
TOP VIEW
(Not to Scale)
AD9550
OUT1
OUT2
OM2
9057-002
Figure 2. Pin Configuration
Table 5. Pin Function Descriptions
Pin No. Mnemonic Type
1
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/A
2
EP Exposed Die Pad. The exposed die pad must be connected to GND.
1
I is input, I/O is input/output, O is output, P is power, and P/O is power/output.
2
N/A means not applicable.
