TRF2020

SYNTHESIZER FOR GLOBAL SYSTEM

FOR MOBILE (GSM) CELLULAR TELEPHONES

SLWS020B – FEBRUARY 1995 – REVISED JANUARY 1998

7

POST OFFICE BOX 655303

serial interface timing requirements with

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

CI

Input capacitance

10

pF

RI

Input resistance

10 k

Ω

fclock

CLOCK frequency

13

20

MHz

tr, tf

CLOCK input rise and fall time

8

ns

tw(High)

Pulse duration, CLOCK high

20

ns

tw(Low)

Pulse duration, CLOCK low

20

ns

Data before CLOCK high

15

ns

tsu

Under continuous operation

15

ns

tsu

Strobe before CLOCK high

First power on or programmed

from standby mode

10

Cext_coupling 

60 k

Ω

µs

th

Data after CLOCK high

15

ns

th

Strobe after CLOCK high

15

ns

tw(pulse)

Strobe pulse width

2

REF_IN

s

PARAMETER MEASUREMENT INFORMATION

The timing relationship between the TRF2020 Data, Clock, and Strobe registers is shown in Figure 2.

D0

D1

D22

D23

tsu

th

tw(HIGH)

tw(LOW)

tsu

th

tw(PULSE)

Clock Disabled

Store Data

Clock Enabled

Shift in Data

Data

Valid

Data

Change

DATA

CLOCK

STROBE

– VIH

– VIL

– VIH

– VIL

– VIH

– VIL

Figure 2. Serial Data Interface Timing