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SP8714 SP8714
2100MHz Very Low Current Multi-Modulus Divider
DS3562 - 5.1 April 1999
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.
RF INPUT VCC RATIO SELECT OUTPUT
1 2 3 4 SP8714
8 7 6 5
RF INPUT POWER DOWN MODULUS CONTROL VEE
FEATURES s s s s s s s Operation to 2100MHz Very Low Power Single Supply Operation 2.7V to 5.25V Power Down Facility for Battery Economy Latched Modulus Control Input Push Pull Output Drive ESD Protection on All Pins†
MP8
Fig. 1 Pin connections - top view
ORDERING INFORMATION
SP8714 IG MPAS Industrial Temperature Range Miniature Plastic SOIC Package SP8714 IG MPAC As above supplied on Tape and Reel
APPLICATIONS s Cellular Telephones s Cordless Telephones
†
ESD precautions must be observed
V CK 6 MC D
CC 2 250K NOMINAL
D TYPE
Q 7 POWER DOWN
3 RS V CC
BIAS CONTROL LOGIC
5 V EE
RF INPUT (CLOCK)
1
DIVIDE BY 4/5
8 V
DIVIDE BY 8 / 16
4 OUTPUT
EE
Fig. 2 Block diagram
1
SP8714
ABSOLUTE MAXIMUM RATINGS
Supply voltage (VEE=0V) (note 1) -0.5V to 7V Control and RF inputs, (note 1) -0.5V to VCC+0.5V RF output (VEE =0V) RF input current (note 1) 10mA Operating temperature -40°C to +85°C Storage temperature range -55°C to +150°C Maximum junction temperature +150°C NOTE 1. Duration <2 minutes.
ELECTRICAL CHARACTERISTICS
Guaranteed over the following conditions (unless otherwise stated): VCC=+2.7V to +5.25V (with respect to VEE), Output load (pin 4) = 10pF, Tamb = -40°C to +85°C (note 2) Value Characteristic Min. Supply current Supply current Power down high Power down low Modulus control high Modulus control low Ratio select high Ratio select low Max. sinewave input frequency Min. sinewave input frequency Min. RF input voltage Max. RF input voltage Output level (pin 4) Modulus set-up time, ts Modulus hold time, th Power down time, tpd (notes 5,6,8) (notes 6,8) (notes 7,8) 200 500 10 1 10 8 600 (note 4) (note 4) (note 4, 9) (note 4, 9) (note 3) (note 3) VCC-0.5 0 0.6VCC 0 0.6VCC 0 2100 200 50 Typ. 6.8 8 Max. 8.5 50 VCC VCC-2.0 VCC 0.4VCC VCC 0.4VCC mA µA V V V V V V MHz MHz Divide by 32 or 64 Divide by 33 or 65 Divide by 32 or 33 Divide by 64 or 65 See Figure 5 See Figure 5 Power down input low Power down input high Units Conditions
mV RMS RF input 200MHz to 2100MHz. See Figure 5 mV RMS RF input 200MHz to 2100MHz. See Figure 5 mV p-p ns ns µs µs RF input = 1GHz RF input = 1GHz See Figure 9 See Figure 9
Power down recovery time, tpu (notes 7,8)
NOTES 2. All electrical testing is performed at +85°C. 3. Typical values are measured at +25°C and VCC = +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.
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/µs. 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 VEE.
RF INPUT VOLTAGE (mV RMS)
1000
Ratio Select (Pin 3) L L H H
Modulus Control (Pin 6) L H L H
Division Ratio
800 TYPICAL OVERLOAD
600
65 64 33 32
400
TYPICAL SENSITIVITY GUARANTEED* OPERATING WINDOW
200
Table 1 Truth table
0 500 1000 1500 2000 2500 3000
FREQUENCY (MHz)
* Tested as specified in table of Electrical Characteristics
Fig. 3 Typical input characteristics
RF INPUT CLOCK
MODULUS CONTROL INPUTS
DON'T CARE
DON'T CARE
OUTPUT
32 (16)
32 (16) or 33 (17)
ts th
Fig. 4 Modulus control timing diagram
3
SP8714
V CC 100n 50Ω MONITOR 1n 50Ω SIGNAL SOURCE
V CC RF INPUT
V EE POWER DOWN
SP8714
OUTPUT 1n RF INPUT MC RATIO SELECT CL
OUTPUT
10n
10n
MODULUS CONTROL 1 INPUT
MODULUS CONTROL 2 INPUT
Fig. 5 Toggle frequency test circuit
j1 j0.5 j2
S11 PLOT 50 OHM NORMALISED
j0.2
f2
0.2
0.5
1
2
f1
-j0.2
f1: 130MHz f2: 2.49GHz
-j0.5 -j2
-j1
Fig. 6 Typical S11 parameter for pin 1. VCC = +5.0V
4
SP8714
300
200 R( ΩΩ )) R( 100
0
-100
-200
-300 jx jx( (Ω) Ω) -400
-500
-600
-700
-800 100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
2500
.