CF5008A1
NIPPON PRECISION CIRCUITS INC.
VCXO Module IC
OVERVIEW
The CF5008A1 is a VCXO module IC that employs a circuit structure with low parasitic capacitance effects and a wide frequency range. Built-in components mean that few external components are required to construct a VCXO.
FEATURES
s s s s s
s s s
Up to 30 MHz operation Inverter amplifier feedback resistor built-in 8 mA (VDD = 5 V), 4 mA (VDD = 3 V) drive capability 2.7 to 5.5 V supply voltage Circuit structure with low parasitic capacitance effects • Direct connection to varicap diodes and crystal Few external components required to form a VCXO Amplitude limiting resistor Rd built-in Chip form (CF5008A1)
SERIES CONFIGURATION
V ersion CF5008A1 Output frequency fO Input level CMOS Output duty level CMOS S t a n d by output state High impedance
ORDERING INFORMATION
D e vice C F 5 0 0 8 A 1 –2 P ackag e Chip form
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C F5008A1
PAD LAYOUT
(Unit : µm)
UNUSED2 VDD INH XT2 UNUSED1 1 2 3 4 5
(1400,1300)
8
7
6 Q
(0,0) VSS XT
C hip size: 1.40 × 1 .30 mm Chip thickness: 220 ± 30 µm Chip base: V D D l evel
PAD DIMENSIONS
Number 1 2 3 4 5 6 7 8 Name UNUSED1 UNUSED2 XT2 VDD INH Q XT VSS I/O – – O – I O I – Not used. Not used. Oscillator output pin Supply voltage Output-control input pin. Q signal output enabled when HIGH or open. High-impedance output when LOW . Output pin Oscillator input pin Ground Description P ad dimensions [µm] X 153 425 660 865 1202 1245 346 155 Y 1112 1112 1112 1112 1112 152 188 188
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C F5008A1
BLOCK DIAGRAM
Rf CG
XT
VDD
VSS
CD
Rd
Q
CC Rp
XT2
RB2
Control Circuits
INH
OSCILLATOR ELEMENT CONSTANTS (typical values)
R B1 CF5008A1 100k Ω R B2 5 0k Ω Rd 4 50 Ω Rf 1 50k Ω Rp 1 00k Ω CG 20pF CD 10pF CC 70pF
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C F5008A1
SPECIFICATIONS
Absolute Maximum Ratings
VSS = 0 V
P arameter S upply voltage range Input voltage range Output voltage range Operating temperature range Storage temperature range Output current Symbol VDD V IN VOUT T o pr T s tg IO U T Condition Rating −0 .5 to 7.0 −0 .5 to V D D + 0 .5 −0 .5 to V D D + 0 .5 −4 0 to 85 −6 5 to 150 25 Unit V V V °C °C mA
Recommended Operating Conditions
VSS = 0 V, CL ≤ 15 pF, f ≤ 32.5 MHz
Rating P arameter S upply voltage Input voltage Operating temperature Symbol VDD V IN TO P R Condition min 2 .7 VSS −2 0 typ – – – max 5.5 VDD 80 V V °C Unit
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C F5008A1
Electrical Characteristics
VDD = 4.5 to 5.5 V, VSS = 0 V, Ta = −20 to 80 °C unless otherwise noted.
Rating P arameter H IGH-level output voltage L O W -level output voltage Output leakage current HIGH-level input voltage L O W -level input voltage Current consumption I N H p ull-up resistance F eedback resistance Symbol VOH VOL IZ V IH V IL ID D RUP Rf Rd B uilt-in resistance Rc R B1 R B2 CG B uilt-in capacitance CD CC D esign value, determined by the internal wafer pattern M easurement cct 5 M easurement cct 6 Condition min Q : Measurement cct 1, I O H = 8 m A, V D D = 4 .5 V Q : Measurement cct 1, I O L = 8 m A, V D D = 4 .5 V Q : Measurement cct 2, I N H = L O W , V O H = V D D Q: Measurement cct 2, I N H = L O W , V O L = V S S INH INH I N H = o pen, Measurement cct 3, load cct 1, C L = 1 5 p F, f = 30 M H z M easurement cct 4 D esign value, determined by the internal wafer pattern D esign value, determined by the internal wafer pattern – – – – – – 0 100 50 20 10 70 – – – – – – 4.0 – – – 0.8V D D – – 50 – – typ 4.2 0.3 – – – – 28 – 150 450 max – 0.4 10 µA 10 – 0.2V D D 65 150 – – V V mA kΩ kΩ Ω Ω kΩ kΩ pF pF pF V V Unit
Switching Characteristics
VDD = 2.7 to 5.5 V, VSS = 0 V, Ta = −20 to 80 °C unless otherwise noted.
Rating P arameter Symbol Condition min O utput rise time tr 1 M easurement cct 3, load cct 1, 0.1V D D t o 0.9V D D , C L = 1 5 p F M easurement cct 3, load cct 1, 0.9V D D t o 0.1V D D , C L = 1 5 p F Measurement cct 3, load cct 1, Ta = 25 °C , C L = 1 5 p F, f = 3 2 M H z V D D = 2 .7 to 3.6 V V D D = 4 .5 to 5.5 V V D D = 2 .7 to 3.6 V V D D = 4 .5 to 5.5 V V D D = 3 .0 V V D D = 5 .0 V – – – – 42 42 – – typ 3 2.5 3 2.5 – – – – max 8 ns 6 8 ns 6 58 % 58 100 100 ns ns Unit
Output fall time
tf 1
Output duty cycle 1 Output disable delay time Output enable delay time
Duty tP L Z tP Z L
M easurement cct 7, load cct 1, Ta = 25 °C , C L ≤ 1 5 p F
1 . Determined by the lot monitor.
Current consumption and Output waveform with NPC’s standard crystal
Cb
f (MHz) 30
R (Ω) 17.2
L (mH) 4.36
Ca (fF) 6.46
Cb (pF) 2.26
L
Ca
R
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C F5008A1
FUNCTIONAL DESCRIPTION
Standby Function
The oscillator output on Q changes as shown in the following table when INH goes LOW.
INH H IGH (or open) LOW Q fO High impedance Oscillator N or mal operation Nor mal operation
TYPICAL APPLICATION CIRCUIT
Typical circuit structures (CG and CD) that use a varicap device have a reduced frequency range due to the effects of parasitic capacitance. The CF5008A1, however, has built-in components CC and RB2 that are connected in series with the varicap device, increasing the frequency output range.
VCXO Module
Rf
XT
CG
VDD
VCC
X'tal
VSS
GND
CD
Rd
Control Input Q Output
VARI−CAP
CC Rp
XT2
RB2
Control Circuits
INH
Output Enable
CF5008
PARASITIC CAPACITANCE
Parasitic capacitance are unwanted capacitance effects that occur due to the junction capacitance where the protection diodes and transistor drains are connected to the substrate. The following equivalent circuit figure shows the calculated parasitic capacitances. The surface area for each component is calculated from the IC layout pattern, and the capacitance calculated per unit area.
Rf 150k
XT
5.01p
CG 20p
2.4p
Divider (1/1)
VDD
Rd
CD 10p
VSS
CC 70p
Q
XT2
4.7p RB2 50k
Control Circuits
Rp 100k
INHN
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C F5008A1
VARICAP (Variable Capacitance Diodes) SELECTION
The CF5008A1 forms a VCXO with addition of an external varicap (variable capacitance diode) device. This section examines the results using various varicap devices. When the equivalent circuit in figure 1 is used, the load capacitance CL must be changed by a factor of 4 to 5 (10 to 40pF) to affect a ±100ppm frequency change. Varicap devices that can change the capacitance by a factor of 5 require a maximum capacitance in the range approximately 20 to 50pF. Devices matching this criteria are listed in the following table.
L 4.08673mH Ca 7.56439fF R 17.7068 Ω
Cb 2.05389pF
F requency:28.633MHz C L : 20pF
Figure 1. Crystal oscillator element equivalent circuit
Company H ITA C H I HITA C H I HITA C H I HITA C H I HITA C H I P anasonic P anasonic P anasonic TO K O TO K O Product HVU17 HVU359 HVU362 HVC374B HVC375B MA304 MA2S304 MA2ZV05 KV1811E KV1812 Capacitance 1 50.0 to 85.0pF (VR = 1 V) 24.8 to 29.8pF (VR = 1 V) 41.6 to 49.9pF (VR = 1 V) 21.5 to 24.0pF (VR = 1 V) 15.5 to 17.0pF (VR = 1 V) 24.8 to 29.8pF (VR = 1 V) 24.8 to 29.8pF (VR = 1 V) 18.5 to 20.5pF (VR = 1 V) 21.5pF typ (VR = 1 V) 16.0pF typ (VR = 1 V) Capacitance 2 5.23 to 8.84pF (VR = 4 .5V) 6.00 to 8.30pF (VR = 4 V) 10.1 to 14.8pF (VR = 4 V) 12.5 to 14.5pF (VR = 2 V) 4.0pF typ (VR = 4 V) 6.00 to 8.30pF (VR = 4 V) 6.00 to 8.30pF (VR = 4 V) 3.60 to 4.10pF (VR = 4 V) 4.00pF typ (VR = 4 V) 3.00pF typ (VR = 4 V)
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C F5008A1
MEASUREMENT CIRCUITS
Measurement cct 1
When measuring VOL
VDD R3 Q VSS
Measurement cct 4
VDD INH RUP = VSS IRUP VDD IRUP
Signal Generator
R1
C1 XT
When measuring VOH
VDD 0V VDD VOH 0V VDD VOL 0V
R2
A
XT input waveform (10MHz)
Q output
Measurement cct 5
Q output
C1 R1 R2 R3
: 0.001 µF : 50 Ω : 500 Ω : 512.5 Ω
A IRB1
XT1
VDD RB1 = VSS VCNOT VDD IRB1
Measurement cct 2
VDD Q INH VSS
IZ IZ
Measurement cct 6
A
V
A IRB2
XT2
VDD RB2 = VSS VDD IRB2
Measurement cct 3 Measurement cct 7
A
XT X'tal C3 XT2 INH VSS VDD Q
Signal Generator
R1 VDD C1 XT VSS Q INH
IDD
C3 : 15pF C1 : 0.001 µF R1 : 50 Ω
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C F5008A1
Load cct 1
Q output
CL
(Including probe capacity)
C L = 1 5pF : ID D , D UTY, tr1 , tf1
Switching Time Measurement Waveform
Output duty level (CMOS)
Q output
0.9VDD 0.1VDD TW
0.9VDD 0.1VDD
DUTY measuring voltage (0.5V DD)
tr
Output duty cycle (CMOS)
tf
Q output
TW T
DUTY measuring voltage (0.5V DD)
DUTY= TW/ T
100 (%)
Output Enable/Disable Delay
INH
VIL
VIH
tPLZ Q output
INH inputwaveform tr = tf
tPZL
10ns
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CF5008A1
N IPPON PRECISION CIRCUITS INC. reserves the right to make changes to the products described in this data sheet in order to improve the design or performance and to supply the best possible products. Nippon Precision Circuits Inc. assumes no responsibility fo r the use of any circuits shown in this data sheet, conveys no license under any patent or other rights, and makes no claim that the circuits are free from patent infringement. Applications for any devices shown in this data sheet are for illustration only and Nippon Precision Circuits Inc. makes no claim or warranty that such applications will be suitable for the use specified without further testing or modification. The products described in this data sheet are not intended to use for the apparatus which influence human lives due to the failure or malfunction of the products. Customers are requested to comply with applicable laws and regulations in effect now and hereinafter, including compliance with expor t controls on the distribution or dissemination of the products. Customers shall not expor t, directly or indirectly, any products without first obtaining required licenses and approvals from appropriate government agencies. NIPPON PRECISION CIRCUITS INC. 4-3, Fukuzumi 2-chome Koto-ku, Tokyo 135-8430, Japan Telephone: 03-3642-6661 Facsimile: 03-3642-6698 NC9816AE 1999.09
NIPPON PRECISION CIRCUITS INC.
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