3

ATR0809

4792BS–DVD–05/04

Pin Configuration SSO20

Figure 2. Pinning SSO20

IR

I2

I3

I4

RFA

RFB

NER

NE2

NE3

NE4

VCC

ENABLE

IOUTA

GND

RSA

RSB

IOUTB

SELA

VCC

ENOSC

1

2

3

4

5

6

7

8

9

10

20

19

18

17

16

15

14

13

12

11

Pin Description

Pin

Symbol

Type

Function

1

IR

Analog

Input current, bias voltage approximately GND

2

I2

Analog

Input current, bias voltage approximately GND

3

I3

Analog

Input current, bias voltage approximately GND

4

I4

Analog

Input current, bias voltage approximately GND

5

RFA

Analog

External resistor to GND sets frequency of oscillator A

6

RFB

Analog

External resistor to GND sets frequency of oscillator B

7

NER

Digital

Digital control of channel 1 (read, active low)

8

NE2

Digital

Digital control of channel 2 (active low)

9

NE3

Digital

Digital control of channel 3 (active low)

10

NE4

Digital

Digital control of channel 4 (active low)

11

ENOSC

Digital

Enables RF oscillator (active high)

12

VCC

Supply

5 V power supply

13

SELA

Digital

High: selects IOUTA, RSA, RFA

Low: selects IOUTB, RSB, RFB

14

IOUTB

Analog

Output current source B for laser diode

15

RSB

Analog

External resistor to GND sets swing of oscillator B

16

RSA

Analog

External resistor to GND sets swing of oscillator A

17

GND

Supply

Ground

18

IOUTA

Analog

Output current source A for laser diode

19

ENABLE

Digital

Enables output current (active high)

20

VCC

Supply

5 V power supply