MICRF507 datasheet(14/47 Pages) MICREL

14 / 47 page

Micrel, Inc.

MICRF507

October 2, 2013

Revision 2.2

Control Interface Timing

Figure 4 and Table 2 give the timing specifications for the

control interface.

When in Receive or Transmit mode (but not Power-down

or Standby mode), an additional timing constraint applies:

elapsed time between falling edges of CS must be a

minimum of 2/fc, where fc is the synthesizer’s comparison

frequency (also called phase detector frequency). fc =

fXCO/M,

XCO

time

min

where M = M0 when receiving or transmitting with VCO

modulation, and M = max{M0, M1} when transmitting with

divider modulation.

Symbol

Parameter

Values

Units

Min.

Typ.

Max.

Thigh

Min. high time of

SCLK

Tlow

Min. low time of

SCLK

tfall

Fall time of SCLK

µs

trise

Rise time of SCLK

µs

Tcsr

Time from rising

edge of CS to

falling edge of

SCLK

Tcsf

Min. delay from

rising edge of CS

to rising edge of

SCLK

Twrite

Min. delay from

valid IO to falling

edge of SCLK

during a write

operation

Tread

Min. delay from

rising edge of

SCLK to valid IO

during a read

operation

(assuming load

capacitance of IO

is 25pF)

tPOR

Power on Reset

time

4.6

Table 1. Control Interface Timing

Power-on Reset

The power-on reset time (tPOR), given in Table 2, is defined

as the time from

application of supply voltage to

completion of power on reset.

To determine when the chip has completed its power-on

without waiting for the worst-case time (maximum tPOR), do

the following:

•

Write hex 03 (binary 00000011) to Register 0.

This puts the chip in Standby mode.

•

Read Register 0. If the value read is binary

00000011, then exit; power-on is complete. If not,

go to previous step and repeat.

Because registers are initially in an unknown state after

power-on (exception: Mode[1:0] initializes to 00), always

enter a complete set of register values as the first

transaction, and always enter only nonzero values for N

and M.

Figure 5. Power-On Programming Flowchart

MICRF507 Datasheet(PDF) 14 Page - Micrel Semiconductor

MICRF507 Datasheet(HTML) 14 Page - Micrel Semiconductor

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47

Datasheet Download

Link URL