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STLC1511

November 2000

This is preliminary information on a new product now in development. Details are subject to change without notice.

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Wide transmit (~80dB) and receive (~69dB)

dynamic range to limit the external filtering

requirements for extended loop reach operation

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Programmable tx gain: 0 ÷ -32dB in 2dB steps

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14-bit D/A converter in transmit path

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Programmable rx gain: 0 ÷40dB in 0.5dB steps

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12-bit A/D converter in receive path

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Integrated phase-locked loop with an externall

LC or crystal oscillator

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Low power: 300mW @ 5.0V

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64-pin TQFP package

1.0 GENERAL DESCRIPTION

The STLC1511 G.lite Analog Front End (AFE) chip

implements the analog transceiver functions required

in both a central office modem and a customer

premise modem. It connects the digital modem chip

with the loop driver and hybrid balance circuits. The

STLC1511 has been designed with excellent dynam-

ic range in order to greatly reduce the external filter-

ing requirements at the front end. The AFE chip and

its companion digital chip along with a loop driver, im-

plement the complete G.992.2 DMT modem solution.

The STLC1511 transmit path consists of a 14-bit

Nyquist rate D/A converter, followed by a program-

mable gain amplifier (TxPGA). The transmit gain is

programmable from 0 to -32dB in 2dB steps.

The STLC1511 receive path contains a buffer ampli-

fier followed by a programmable gain amplifier (RxP-

GA), a low pass anti-aliasing filter, and a 12-bit

Nyquist rate A/D converter. The RxPGA is digitally

programmable from 0 to 40dB in 0.5dB steps.

2.0 PACKAGING AND PIN INFORMATION

2.1 STLC1511 Pin Allocation

The pinout for the STLC1511 is depicted in Figure 1.

TQFP64

ORDERING NUMBER: STLC1511

PRODUCT PREVIEW

NorthenLite™ G.lite BiCMOS

Analog Front-End Circuit

Figure 1. STLC1511 pinout

1

2

3

5

6

4

7

8

9

10

27

11

28 29 30 31 32

59 58 57 56

54

55

53 52 51 50 49

43

42

41

39

38

40

48

47

46

44

45

VSSDIGE1

RXSOUT[1]

RXSOUT[0]

CK35M

VDDDIG1

DIGREF

DIGCLK

DTX

VDDDIG2

VSSDIG2

VDDDIGE1

VCCPLL

VEEPLL

FREQ

OSCNB

OSCPB

OSCNE

QVEEBIAS

VEEBIAS

VCCBIAS

V3P75V

IREF50m

TQFP64

22 23 24 25 26

60

61

62

63

64

17 18 19 20 21

37

36

34

33

35

OSCPE

VCAP

VSSPLL

QVEEPLL

VDDPLL

12

13

14

15

16

QVEEADC

VCCADC

VEEADC

ENB

DRX