4

ATR0809

4792BS–DVD–05/04

Pin Configuration QFN20

Figure 3. Pinning QFN20

I4

RFA

RFB

NER

NE2

20 19 18 17 16

6 7 8 9 10

1

2

3

4

5

15

14

13

12

11

IOUTA

GND

RSA

RSB

IOUTB

Pin Description

Pin

Symbol

Type

Function

1

I4

Analog

Input current, bias voltage approximately GND

2

RFA

Analog

External resistor to GND sets frequency of oscillator A

3

RFB

Analog

External resistor to GND sets frequency of oscillator B

4

NER

Digital

Digital control of channel 1 (read, active low)

5

NE2

Digital

Digital control of channel 2 (active low)

6

NE3

Digital

Digital control of channel 3 (active low)

7

NE4

Digital

Digital control of channel 4 (active low)

8

ENOSC

Digital

Enables RF oscillator (active high)

9

VCC

Supply

5 V power supply

10

SELA

Digital

High: selects IOUTA, RSA, RFA

Low: selects IOUTB, RSB, RFB

11

IOUTB

Analog

Output current source B for laser diode

12

RSB

Analog

External resistor to GND sets swing of oscillator B

13

RSA

Analog

External resistor to GND sets swing of oscillator A

14

GND

Supply

Ground

15

IOUTA

Analog

Output current source A for laser diode

16

ENABLE

Digital

Enables output current (active high)

17

VCC

Supply

5 V power supply

18

IR

Analog

Input current, bias voltage approximately GND

19

I2

Analog

Input current, bias voltage approximately GND

20

I3

Analog

Input current, bias voltage approximately GND