|
|
PDF ML2037 Data sheet ( Hoja de datos )
| Número de pieza | ML2037 | |
| Descripción | 500kHz / Serial Input / Programmable Sine Wave Generator with Digital Gain Control | |
| Fabricantes | Micro Linear | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de ML2037 (archivo pdf) en la parte inferior de esta página. Total 10 Páginas | ||
|
No Preview Available !
October 1998
ML2037*
500kHz, Serial Input, Programmable
Sine Wave Generator with Digital Gain Control
GENERAL DESCRIPTION
The ML2037 is a precision programmable sine wave
generator with a frequency range of DC to 500kHz. The
device is capable of generating a wide frequency range
of low distortion sine waves with no external passive
components. The frequency of the sine wave output is
programmed by a 16-bit word that is loaded through a
serial input. The sine wave output frequency is determined
by the programmed value and the clock frequency. The
clock frequency is derived from either an external crystal
connected to the device or an external clock input to
provide a stable and accurate frequency reference.
The sine wave output of the ML2037 is filtered and has a
programmable amplitude that is digitally programmed in
0.5V steps. The maximum amplitude is 2.0VP-P centered
at a 2.5V level. The device functions from a single 5V
power supply and has a shutdown pin to put the device
into a low power mode that disables the output. A sync
input is provided to allow the synchronization of more
than one device in a system.
FEATURES
s Programmable output frequency:
DC to 400kHz—using a crystal
DC to 500kHz—using an external digital clock
s 3-wire SPI compatible serial interface with double
buffered latch for programming the frequency
s Digital gain control for programming output amplitude
s SYNC input for synchronization of multiple sine waves
s Shutdown pin for sleep mode
s Single 5V power supply operation
* This Part Is End Of Life As Of August 1, 2000
BLOCK DIAGRAM
AGND
9
11
AVCC
12
AVCC
REFERENCE
8 14 15
SHDN G0 G1
DVCC
16
CLK IN
13
CRYSTAL
OSCILLATOR
D GND
1
D GND
5
CLK OUT
3
S ENABLE
7
÷2
S CLK
4
S DATA IN
6
SYNC
2
8-BIT
DAC
8
PHASE
ACCUMULATOR
512 POINT
SINE LOOK-UP
TABLE
16
16-BIT DATA LATCH
16
GAIN
CONTROL &
SMOOTHING
FILTER
16-BIT SHIFT REGISTER
OUT
10
1
1 page  
FUNCTIONAL DESCRIPTION
The ML2037 is composed of a programmable frequency
generator, a sine wave generator, a crystal oscillator, and
a digital interface. The functional block diagram is shown
in Figure 1.
PROGRAMMABLE FREQUENCY GENERATOR
The programmable frequency generator produces a digital
output whose frequency is determined by a 16-bit digital
word.
The frequency generator is composed of a phase
accumulator which is clocked at ½fCLK IN. The value
stored in the data latch is added to the phase accumulator
every two cycles of CLK IN. The frequency of the analog
output is equal to the rate at which the accumulator
overflows and is given by the following equation:
0 5fOUT
= fCLKIN ´
D15 ® D0 DEC
222
(1)
Where (D15–D0) is the decimal value of the
programming word.
The frequency resolution and the minimum frequency are
the same and can be calculated using:
DfMIN
=
fCLKIN
222
(2)
When fCLK IN = 25MHz, DfMIN = 5.96Hz (±2.98Hz).
Lower output frequencies are obtained by using a lower
clock frequency.
The maximum frequency output can be easily calculated
with the following equation:
fOUT(MAX)
=
fCLKIN
26
(3)
When fCLK IN = 25MHz, fOUT(MAX) = 391kHz. Higher
frequencies, up to 500kHz, are obtained by using an
external clock, where 25MHz < fCLK IN < 32MHz.
Due to the phase quantization nature of the frequency
generator, spurious tones can be present in the output in
the range of –50dB relative to fundamental. The energy
from these tones is included in the signal to noise +
distortion specification (SND) given in the electrical
table. The frequency of these tones can be very close to
the fundamental, and it is not practical to filter them out.
SINEWAVE GENERATOR
The sinewave generator is composed of a sine lookup
table, an 8-bit DAC, an output smoothing filter, and an
amplifier. The sine lookup table is addressed by the phase
accumulator. The DAC is driven by the output of the table
and generates a staircase representation of a sine wave.
ML2037
The output filter smooths the analog output by removing
the high frequency sampling components. The resultant
voltage on VOUT is a sinusoid with the second and third
harmonic distortion components at least 40dB below the
fundamental.
The ML2037 has a 2-bit (G1, G0) digital gain control.
With the gain input equal to logic 00, the sine wave
amplitude is equal to 0.5VP-P. Incrementing the gain
control input increases the output amplitude in 0.5V steps
to a maximum of 2.0VP-P. The output amplitude is
accurate to within ±0.5dB over the frequency range.
G1 G0
00
01
10
11
P–P OUTPUT AMPLITUDE
.5V
1.0V
1.5V
2.0V
The analog section is designed to operate over a
frequency range of DC to 500kHz and is capable of
driving 1kW, 50pF loads at the maximum amplitude of
2.0VP-P. The sine wave output is typically centered about
a 2.5V DC level, so for a 2VP-P sine wave, the output will
swing from 1.5V to 3.5V.
CRYSTAL OSCILLATOR
The crystal oscillator generates an accurate reference
clock for the programmable frequency generator. The
internal clock can be generated with a crystal or external
clock.
If a crystal is used, it must be placed between CLK IN and
DGND. An on-chip oscillator will then generate the
internal clock. No other external components are
required. The crystal should be a parallel resonant type
with a frequency between 5MHz to 25.6MHz. It should
be placed physically as close as possible to CLK IN and
DGND, to minimize trace lengths.
The crystal must have the following characteristics:
• Parallel resonant type
• Frequency: 5MHz to 25.6MHz
• Maximum ESR: 120W @ 5 to 10MHz, 80W @10 to
15MHz, and 50W @ 15 to 25.6MHz
• Drive level: 500µW
• Typical load capacitance: 18 - 20pF
• Maximum case capacitance: 7pF
The frequency of oscillation will be a function of the
crystal parameters and board capacitance. In general,
5
5 Page | ||
| Páginas | Total 10 Páginas | |
| PDF Descargar | [ Datasheet ML2037.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| ML2031 | TONE DETECTOR | Micro Linear |
| ML2031CP | TONE DETECTOR | Micro Linear |
| ML2031IP | TONE DETECTOR | Micro Linear |
| ML2032 | Lithium Manganese Dioxide Rechargeable Batteries |  Maxell |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |