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SP8714
DS3562
ISSUE 5.1
April 1999
Ordering Information
SP8714 IG MPAS Industrial Temperature Range
Miniature Plastic SOIC Package
SP8714 IG MPAC As above supplied on Tape and Reel
The SP8714 is a switchable divide by 32/33, 64/65
programmable divider which is guaranteed to operate up to
2100MHz. It will operate from a supply of 2.7V to 5.25V and
requires typically 6.8mA (including the output current). It also
features a power down facility for battery economy.
The RF inputs are internally biased and should be
capacitively coupled to the signal source. The output is
designed to interface with CMOS synthesisers.
FEATURES
I Operation to 2100MHz
I Very Low Power
I Single Supply Operation 2.7V to 5.25V
I Power Down Facility for Battery Economy
I Latched Modulus Control Input
I Push Pull Output Drive
I ESD Protection on All Pins
APPLICATIONS
I Cellular Telephones
I Cordless Telephones
ESD precautions must be observed
Fig. 1 Pin connections - top view
MP8
1 8
2 7
3 6
4 5
RF INPUT
POWER DOWN
MODULUS CONTROL
VEE
SP8714
RF INPUT
V
RATIO SELECT
OUTPUT
CC
BIAS
V
CC
2
7
5
250K
NOMINAL
4
CK
D
Q
6
3
V
CC
V
EE
1
8
V
EE
POWER
DOWN
OUTPUT
MC
RS
RF
INPUT
(CLOCK)
DIVIDE BY
4 / 5
DIVIDE BY
8 / 16
CONTROL
LOGIC
D TYPE
Fig. 2 Block diagram
SP8714
2100MHz Very Low Current Multi-Modulus Divider
2
SP8714
ELECTRICAL CHARACTERISTICS
Guaranteed over the following conditions (unless otherwise stated):
V
CC
=+2.7V to +5.25V (with respect to V
EE
), Output load (pin 4) = 10pF, T
amb
= -40
C to +85C (note 2)
Characteristic
Units
Conditions
Supply current
(note 3)
6.8
8.5
mA
Power down input low
Supply current
(note 3)
8
50
A
Power down input high
Power down high
V
CC
-0.5
V
CC
V
Power down low
0
V
CC
-2.0
V
Modulus control high
(note 4)
0.6V
CC
V
CC
V
Divide by 32 or 64
Modulus control low
(note 4)
0
0.4V
CC
V
Divide by 33 or 65
Ratio select high
(note 4, 9)
0.6V
CC
V
CC
V
Divide by 32 or 33
Ratio select low
(note 4, 9)
0
0.4V
CC
V
Divide by 64 or 65
Max. sinewave input frequency
2100
MHz
See Figure 5
Min. sinewave input frequency
200
MHz
See Figure 5
Min. RF input voltage
50
mV RMS RF input 200MHz to
2100MHz. See Figure 5
Max. RF input voltage
200
mV RMS RF input 200MHz to
2100MHz. See Figure 5
Output level (pin 4)
500
600
mV p-p
Modulus set-up time, t
s
(notes 5,6,8)
10
ns
RF input = 1GHz
Modulus hold time, t
h
(notes 6,8)
1
ns
RF input = 1GHz
Power down time, t
pd
(notes 7,8)
10
s
See Figure 9
Power down recovery time, t
pu
(notes 7,8)
8
s
See Figure 9
NOTES
2. All electrical testing is performed at +85
C.
3. Typical values are measured at +25
C and V
CC
= +5V.
4. Modulus Control and Ratio Select are high impedance inputs which can be driven directly by standard CMOS outputs.
5. Modulus control is latched at the end of the previous cycle.
6. See Figure 4.
7. See Figure 8.
8. These parameters are not tested but are guaranteed by design.
9. The ratio select pin is not intended to be switched dynamically.
Value
Min.
Typ.
Max.
ABSOLUTE MAXIMUM RATINGS
Supply voltage (V
EE
=0V)
(note 1)
-0.5V to 7V
Control and RF inputs,
RF output (V
EE
=0V)
(note 1) -0.5V to V
CC
+0.5V
RF input current
(note 1)
10mA
Operating temperature
-40
C to +85C
Storage temperature range
-55
C to +150C
Maximum junction temperature
+150
C
NOTE 1. Duration <2 minutes.
2
SP8714
OPERATING NOTES
The RF inputs are biased internally and are normally coupled to the signal source with suitable capaitors.
The output stage has a novel design and is intended to drive a CMOS synthesiser input. External pull-down resistors or
circuits are not required. The SP8714 is not suitable for driving TTL or similar devices.
The device will operate down to DC frequencies for non-sinusoidal signals provided that the input slew rate is better than
100V/
s.
POWER DOWN (pin 7) is connected internally to a pull-up resistor. If the battery economy facility is not used, pin 7 should
be connected to V
EE
.
Fig. 3 Typical input characteristics
Ratio
Modulus
Division
Select
Control
Ratio
(Pin 3)
(Pin 6)
L
L
65
L
H
64
H
L
33
H
H
32
TYPICAL
SENSITIVITY
TYPICAL
OVERLOAD
1000
800
600
400
200
0
500 1000 1500 2000 2500 3000
* Tested as specified in table of Electrical Characteristics
FREQUENCY (MHz)
RF INPUT VOLTAGE (mV RMS)
GUARANTEED*
OPERATING WINDOW
Table 1 Truth table
Fig. 4 Modulus control timing diagram
RF INPUT
CLOCK
MODULUS
CONTROL
INPUTS
OUTPUT
t s
t h
32 (16)
32 (16) or 33 (17)
DON'T CARE
DON'T CARE
4
SP8714
Fig. 6 Typical S11 parameter for pin 1. V
CC
= +5.0V
Fig. 5 Toggle frequency test circuit
VCC
V CC
RF INPUT
POWER
DOWN
RATIO
SELECT
MC
RF INPUT
OUTPUT
MODULUS
CONTROL 1 INPUT
1n
1n
10n
10n
100n
C L
50
MONITOR
50
SIGNAL
SOURCE
SP8714
OUTPUT
MODULUS
CONTROL 2 INPUT
V EE
S11
PLOT 50 OHM
NORMALISED
f1: 130MHz
f2: 2.49GHz
j0.2
j0.5
j1
j2
-j0.2
-j0.5
-j2
-j1
f1
0.2
0.5
1
2
f2
4
SP8714
Fig. 7 Typical input impedance v. frequency
300
200
100
0
-100
-200
-300
-400
-500
-600
-700
-800
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
INPUT FREQUENCY (MHz)
jx (
)
R(
)
R(
)
jx(
)
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