Philips Semiconductors

Product specification

SA5217

Postamplifier with link status indicator

2

1998 Oct 07

853-1658 20141

DESCRIPTION

The SA5217 is a 75MHz postamplifier system designed to accept

low level high-speed signals. These signals are converted into a

TTL level at the output. The SA5217 can be DC coupled with the

previous transimpedance stage using SA5210, SA5211 or SA5212A

transimpedance amplifiers. The main difference between the

SA5217 and the SA5214 is that the SA5217 does not make the

output of A1 and input of A2 accessible; instead, it brings out the

output of A2 and the input of A8 thus activating the on-chip Schmitt

trigger function by connecting two external capacitors. The result is

that a much longer string of 1s and 0s, in the bit stream, can be

tolerated. This ”system on a chip” features an auto-zeroed first

stage with noise shaping, a symmetrical limiting second stage, and a

matched rise/fall time TTL output buffer. The system is

user-configurable to provide adjustable input threshold and

hysteresis. The threshold capability allows the user to maximize

signal-to-noise ratio, thereby insuring a low Bit Error Rate (BER).

An auto-zero loop can be used to replace two input coupling

capacitors with a single Auto Zero (AZ) capacitor. A signal absent

flag indicates when signals are below threshold. The low signal

condition forces the TTL output to the last logic state. User

interaction with this ”jamming” system is available. The SA5217 is

packaged in a standard 20-pin surface-mount package and typically

consumes 40mA from a standard 5V supply. The SA5217 is

designed as a companion to the SA5211/5212A and SA5210

transimpedance amplifiers. These differential preamplifiers may be

directly coupled to the postamplifier inputs. The SA5210/5217,

SA5211/5217 or SA5212A/5217 combinations convert nanoamps of

photodetector current into standard digital TTL levels.

APPLICATIONS

with high EMI/RFI

PIN CONFIGURATION

LED

CPKDET

THRESH

GNDA

FLAG

JAM

VCCD

VCCA

GNDD

VOUT

IN1B

IN1A

CAZP

CAZN

OUT2B

IN8B

OUT2A

IN8A

RHYST

RPKDET

NOTE:

1. SOL - Released in large SO package only.

1

2

3

4

5

6

7

8

9

10

20

19

18

17

16

15

14

13

12

11

SD00354

Figure 1. Pin Configuration

FEATURES

ORDERING INFORMATION

DESCRIPTION

TEMPERATURE RANGE

ORDER CODE

DWG #

20-Pin Plastic Small Outline Large (SOL) Package

-40 to +85

°C

SA5217D

SOT163-1

ABSOLUTE MAXIMUM RATINGS

SYMBOL

PARAMETER

SA5214

UNIT

Power supply

+6

V

Power supply

+6

V

Operating ambient temperature range

-40 to +85

°C

Operating junction temperature range

-55 to +150

°C

Storage temperature range

-65 to +150

°C

Power dissipation

1.4

W

Jam input voltage

-0.5 to 5.5

V