PE3238EK PEREGRINE [Peregrine Semiconductor Corp.], PE3238EK Datasheet - Page 8

• Manufacturer Part Number: PE3238EK
• Manufacturer: PEREGRINE [Peregrine Semiconductor Corp.]

Main Counter Chain
The main counter chain divides the RF input
frequency, F
defined values in the “M” and “A” counters. It is
composed of the 10/11 dual modulus prescaler,
modulus select logic, and 9 bit M counter. Setting
Pre_en “low” enables the 10/11 prescaler. Setting
Pre_en “high” allows F
and powers down the prescaler.
The output from the main counter chain, f
related to the VCO frequency, F
equation:
f
where A
When the loop is locked, F
reference frequency, f
F
where A
A consequence of the upper limit on A is that Fin
must be greater than or equal to 90 x (f
obtain contiguous channels. Programming the M
Counter with the minimum value of “1” will result in
a minimum M Counter divide ratio of “2”.
When the prescaler is bypassed, the equation
becomes:
F
where 1
In Direct Interface Mode, main counter inputs M
and M
Reference Counter
The reference counter chain divides the reference
frequency, f
comparison frequency, f
The output frequency of the 6-bit R Counter is
related to the reference frequency by the following
equation:
f
where 0
Note that programming R equal to “0” will pass the
reference frequency, f
detector.
In Direct Interface Mode, R Counter inputs R
R
©2003-2005 Peregrine Semiconductor Corp. All rights reserved.
Page 8 of 15
p
c
in
in
5
= F
= f
= [10 x (M + 1) + A] x (f
= (M + 1) x (f
are internally forced low (“0”).
r
in
/ (R + 1)
8
/ [10 x (M + 1) + A]
are internally forced low.
M
R
M + 1, 1
M + 1, 1
in
r
, by an integer derived from the user
, down to the phase detector
63
511
r
/ (R+1))
M
M
in
r
, by the following equation:
to bypass the prescaler
511
511
c
r
, directly to the phase
r
.
/ (R+1))
in
is related to the
in
, by the following
r
/ (R+1)) to
p
, is
(1)
(2)
(3)
(4)
4
and
7
Register Programming
Parallel Interface Mode
Parallel Interface Mode is selected by setting the
Bmode input “low” and the Smode input “low”.
Parallel input data, D[7:0], are latched in a
parallel fashion into one of three, 8-bit primary
register sections on the rising edge of M1_WR,
M2_WR, or A_WR per the mapping shown in
Table 7 on page 9. The contents of the primary
register are transferred into a secondary register
on the rising edge of Hop_WR according to the
timing diagram shown in Figure 5. Data are
transferred to the counters as shown in Table 7
on page 9.
The secondary register acts as a buffer to allow
rapid
double buffering for “ping-pong” counter control
is programmed via the FSELP input. When
FSELP is “high”, the primary register contents
set the counter inputs. When FSELP is “low”, the
secondary register contents are utilized.
Parallel input data, D[7:0], are latched into the
enhancement register on the rising edge of
E_WR according to the timing diagram shown in
Figure 5. This data provides control bits as
shown in Table 8 on page 9 with bit functionality
enabled by asserting the Enh input “low”.
Serial Interface Mode
Serial Interface Mode is selected by setting the
Bmode input “low” and the Smode input “high”.
While the E_WR input is “low” and the S_WR
input is “low”, serial input data (Sdata input), B
to B
register on the rising edge of Sclk, MSB (B
first. The contents from the primary register are
transferred into the secondary register on the
rising edge of either S_WR or Hop_WR
according to the timing diagram shown in
Figures 5-6. Data are transferred to the counters
as shown in Table 7 on page 9.
The double buffering provided by the primary
and secondary registers allows for “ping-pong”
counter control using the FSELS input. When
FSELS is “high”, the primary register contents
set the counter inputs. When FSELS is “low”, the
secondary register contents are utilized.
While the E_WR input is “high” and the S_WR
input is “low”, serial input data (Sdata input), B
19
, are clocked serially into the primary
Document No. 70-0031-03 │ UltraCMOS™ RFIC Solutions
changes to the VCO frequency.
Product Specification
PE3238
This
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