Datenblatt-pdf.com


CHT-CG-050 Schematic ( PDF Datasheet ) - ETC

Teilenummer CHT-CG-050
Beschreibung Versatile High Temperature Clock Generator
Hersteller ETC
Logo ETC Logo 




Gesamt 9 Seiten
CHT-CG-050 Datasheet, Funktion
www.DataSheet4U.com
CISSOID The SOI design Specialist
CHT-CG-050
Preliminary datasheet
Version 0.4 (08/2005)
Versatile High Temperature Clock Generator
General Description
The CHT-CG-050 is a versatile High-
Temperature crystal clock generator with
extended functional capabilities. The chip
features a programmable crystal oscillator
driver with an enable/disable control sig-
nal, an external clock input, a programma-
ble divider chain and a programmable
strength three-state output buffer. Using
an external crystal, it is intended to provide
reliable precision performance throughout
the -30 to +225°C temperature range for
supply voltages between 3V and 5V.
The CHT-CG-050 can operate with crys-
tals from 1MHz to 50MHz. The output fre-
quency can be selected by means of a
programmable divider, providing division
factors of one, two, four and eight. The
programmability of the crystal driver allows
working with a wide range of crystals. A
crystal driver enable pin (/XtalEn) is in-
cluded for extremely low power applica-
tions, as well as an output enable pin
(/OE). In applications requiring only a pre-
cision divider chain, where an external
clock source is already present, the crystal
driver may be bypassed by means of in-
puts ExtClkIn and ExtClkEn.
Features
3V to 5V power supply
Qualified from -30 to +225°C (Tj)
Operational up to +250°C (Tj)
Two input sources: crystal (1 to 50
MHz), external clock (DC to 50MHz)
Operation from 32.768kHz crystals
Programmable frequency divider: fin,
fin/2, fin/4 and fin/8
Programmable crystal driver and out-
put driver strength
Available in several standard pack-
ages or as die
Applications
Well logging, Automotive, Aeronautics
& Aerospace
Precision timing
Pin Description
C1_10pF Built-in capacitors with a
C1_20pF common terminal connected
C2_10pF to Vss.
C2_20pF
DIV_0
DIV_1
Inputs to set
factor.
TRUTH TABLE
DIV_1
DIV_0
00
01
10
11
the division
Factor
1
2
4
8
DRI_0
DRI_1
Inputs to set
buffer strength.
TRUTH TABLE
DRI_1
DRI_0
00
01
10
11
the output
Strength
8mA
16mA
24mA
32mA
ExtClkEn When driven HIGH, opera-
tion from the external clock
source is selected.
ExtClkIn Input for an external clock
source.
FOUT
Output signal.
/OE When driven LOW, output is
enabled, When driven
HIGH, output is at high im-
pedance.
R2 Terminal of a 200resistor.
The other terminal of this
resistor is connected to X2.
WWW.CISSOID.COM






CHT-CG-050 Datasheet, Funktion
CHT-CG-050 - Preliminary datasheet - Version 0.4 (08/2005)
6
Circuit functionality
Operating conditions
The CHT-CG-050 has been qualified for
supply voltages ranging from 3V up to
5.5V. The upper limit is imposed by the
technology on which the CHT-CG-050 is
implemented.
The qualification temperature range ex-
tends from -30°C to +225°C, though func-
tionality is above +250°C is achieved with
little increase of the current consumption.
Crystal driver
XtalDR_0 and XtalDR_1 allow the crystal
driver to change its strength to be able to
oscillate with a wide range of crystals, un-
der any supply (3V to 5V) and temperature
(up to 225°C) condition.
The presence of integrated passive com-
ponents offers a great versatility to the
final user. Highly temperature-stable ca-
pacitors allow for a nearly-constant crystal
load along the whole temperature range.
Internal passive components can be by-
passed or tied to ground if needed.
/XtalEn enables or disables the crystal
oscillator to operate, allowing the CHT-
CG-050 to be embedded into power-
optimized high-temperature applications.
Clock source selector
By means of ExtClkEn and ExtClkIn, the
CHT-CG-050 is able to operate either from
its internal crystal oscillator or from an ex-
ternal clock source.
Frequency divider
Four division factors (1, 2, 4 and 8) can be
selected depending on the levels at the
control lines DIV_0 and DIV_1.
Output buffer
A programmable-strength output buffer,
controlled by DRI_0 and DRI_1, enables
the CHT-CG-050 to drive a large range of
output loads, improving the output signal
integrity. The four possible output
strengths are 8mA, 16mA, 24mA and
32mA.
The output buffer has supply terminals
independent from the rest of the circuit,
allowing the system designer to properly
decouple them in noise-sensitive applica-
tion.
Figure 2. Effect of DRI_0 and DRI_1 on the output
signal.
Figure 2 shows the superposition of the out-
put signal when DRI_0, DRI_1 = LOW and
DRI_1 is then set to HIGH, VDD=3V,
T=235°C, Freq = 27MHz. As a result, the
signal integrity is improved.
Packaging options
As mentioned above, the layout of the
CHT-CG-050 allows for a very high level of
flexibility for the system designer. Several
packaging configurations are possible,
from 8-pin to 24-pin standard carriers.
At the packaging stage, many functional
features can be enabled or safely disabled
in order to optimize the form factor accord-
ing to the final user needs.
Typical application
The CHT-CG-050 offers the final user
several possible configurations depending
upon the characteristics of the target ap-
plication.
Figure 3. Full configuration.
WWW.CISSOID.COM

6 Page







SeitenGesamt 9 Seiten
PDF Download[ CHT-CG-050 Schematic.PDF ]

Link teilen




Besondere Datenblatt

TeilenummerBeschreibungHersteller
CHT-CG-050Versatile High Temperature Clock GeneratorETC
ETC

TeilenummerBeschreibungHersteller
CD40175BC

Hex D-Type Flip-Flop / Quad D-Type Flip-Flop.

Fairchild Semiconductor
Fairchild Semiconductor
KTD1146

EPITAXIAL PLANAR NPN TRANSISTOR.

KEC
KEC


www.Datenblatt-PDF.com       |      2020       |      Kontakt     |      Suche