EL4584

FN7174 Rev 3.00

Page 4 of 15

May 9, 2008

Pin Descriptions

PIN NUMBER

PIN NAME

FUNCTION

1, 2, 16

PROG B,

PROG C, PROG A

Digital inputs to select ÷ N value for internal counter. See Table 2 for values.

3

OSC/VCO OUT

Output of internal inverter/oscillator. Connect to external crystal or LC tank VCO circuit.

4

VDD (A)

Analog positive supply for oscillator, PLL circuits.

5

OSC/VCO IN

Input from external VCO.

6

VSS (A)

Analog ground for oscillator, PLL circuits.

7

CHARGE PUMP

OUT

current is pumped out of the filter capacitor to decrease VCO frequency. During coast mode or when

locked, charge pump goes to a high impedance state.

8

DIV SELECT

Divide select input. When high, the internal divider is enabled and EXT DIV becomes a test pin, outputting

CLK ÷ N. When low, the internal divider is disabled and EXT DIV is an input from an external ÷ N.

9

COAST

10

HSYNC IN

Horizontal sync pulse (CMOS level) input.

11

VDD (D)

Positive supply for digital, I/O circuits.

12

LOCK DETECT

Lock Detect output. Low level when PLL is locked. Pulses high when out of lock.

13

EXT DIVIDER

External Divide input when DIV SEL is low, internal ÷N output when DIV SEL is high.

14

VSS (D)

Ground for digital, I/O circuits.

15

CLK OUT

Buffered output of the VCO.

TABLE 2. VCO DIVISORS

PROG A (PIN 16)

PROG B (PIN 1)

PROG C (PIN 2)

DIV VALUE (N)

000

851

001

864

010

944

011

1135

100

682

101

858

110

780

111

910