1 - PIN DESCRIPTION (continued)

1.4- Digital, Signal and Control Pins

Pin

Symbol

Description

Polarity

18

DO

Receive Data Output

20

FSH

Data Slicer Time Constant Setting

(Fast/Slow/Hold)

High: slow, tri-state: fast,

low: hold DO goes high on hold (see next table)

9

FN

Forces Data Slicer Reference Time Constant

to fast (STB4395A only)

low: fast (overides FSH)

high: fast, slow or hold (set by FSH)

5

LOCK

VCO lock detect-all 3 PLL

high for LOCK (all three PLL’s)

3

PRGD

Serial Synthesizer Data Input, 16 bits word

high for logic 1. Input sequence:

LO, D14, D13,...,D0. D14 is the MSB.

LO: logic 1 is low transmit power.

1

NPRGEN

Serial Synthesizer Data Enable

low to enable PRGD buffer

2

PRGCLK

Serial Data Clock

held high when no clocking,

clocks in data on positive edge

10

EN

Power Down all functions except Enable Buffer

high for power up, low for standby

4

NTXEN

Receive-Transmit Switch

high for receive, low for transmit

The time constant of the data slicer is set through the pins FSH and FN for the STB4395A and through

FSH only for the STB4395(FN internally connected to High), as listed in the following table :

PIN

FN

High

Low

FSH

High

Slow, DO active

Fast, DO active

TriState

Fast, DO active

Fast, DO active

Low

Hold, DO high

Fast, DO high

1.5 - Power Supply Pins

Pin

Symbol

Description

64

VND

Negative supply for digital regulators, digital input and output buffers

48

VNIF

Negative supply for IF regulators, data output buffer

11

VNOSC

Negative supply for the oscillator regulators + substrate

49

VNRF

Negative supply RF regulators, quadrature input buffers

53

VNPA

Negative supply for PA

62

VPD

Positive supply for digital circuitry

32

VPI

Positive supply for receive oscillator + charge pump

45

VPIF

Positive supply for RX IF + baseband sections

17

VPO

Positive supply for transmit oscillator + charge pump

54, 57

VPRF1 / VPRF2

Positive supplies for RF front end

23, 26

VPS1/ VPS2

Positive supplies for ch. select oscillator + charge pump

63

VRD

Regulated negative supply for digital circuitry

36

VRI

Regulated negative supply for receive oscillator + charge pump

38

VRIF

Regulated negative supply for RX IF + baseband sections

13

VRO

Regulated negative supply for transmit oscillator + charge pump

52

VRRF

Regulated negative supply for RF front end

22

VRS

Regulated negative supply ch. select oscillator + charge pump

STB4395

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