nw6005 Integrated Device Technology, nw6005 Datasheet - Page 8

• Manufacturer Part Number: nw6005
• Description: Enhanced Type Ii Caller Id Decoder
• Manufacturer: Integrated Device Technology

OTHER FUNCTIONS
POWER-DOWN MODE
consumption. Power-down can be activated by setting Control Bits 0-2
to ‘100’. Note that momentary transition of CB0-2 into the power-down
code won’t activate power-down but will reset the device.
oscillator are non functional. When the device is in power-down, DATA,
DR/STD, CD are high; EST and ST/GT are low.
the operating current. When FSK is selected, DT-AS detector is
powered down. When DT-AS is selected, FSK demodulator is
powered down. The Tip/Ring and Hybrid input OP amps are not
affected in the intelligent Power-down.
CRYSTAL OSCILLATOR
required for NW6005. The crystal can be directly connected between
OSCIN and OSCOUT pins without any external component. If an
external clock source is used, OSCIN pin should be driven by the
clock source and OSCOUT pin is left floating or is used to drive other
devices. Fig. 8 shows some applications.
NW6005 ENHANCED TYPE II CALLER ID DECODER
The device provides the power-down feature to reduce the power
In this mode, both input OP amps, reference voltage and the
An intelligent Power-down feature is implemented to futher reduce
A 3.579545 MHz crystal oscillator or other external clock source is
(a) Connection of One Device with Crystal Oscillator
(b) Common Crystal Connection of Several Devices
OSCIN
Sharing One Timing Source
3.579545MHz
NW6005
Figure 8. Applicaiton of Clock Driven Circuit
OSCOUT
OSCIN
OSCIN
3.579545MHz
NW6005
NW6005
OSCOUT
OSCOUT
OSCIN
to the next device
NW6005
OSCOUT
8
APPLICATION NOTE
CONTROL BITS PROGRAMMING
as shown in Table 2.
Table 2. Control Bits Programming
HYBRID CONNECTION
connection is recommended. There are two Op Amps in NW6005
which bring convenience for Hybrid connection. When connected to
the Hybrid Op Amp, the Hybrid circuit will attenuate the speech signal
at least 9 dB from the microphone to the speaker, which leads a much
better performance of near-end talkdown and talkoff.
Tip/Ring OP Amp and to detect the CAS signal using the Hybrid OP
Amp. This implementation brings not only optimized talkdown and
talkoff performance, but also the convenience to adjust FSK and CAS
sensitivity separately.
GAIN SETTING
real applications, the gain setting should be determined by industry
standards as well as by customer requirements. The circuit and
calculation method of gain setting is illustrated in Figs. 3 and 4. For
Hybrid connection, the single-ended solution (Fig. 4) is often selected.
sensitivity in order to prevent missing the FSK signal while the CAS
signal is detected. Therefore, it is suggested to set the gain of the Op
Amp for FSK demodulation 3 dB higher than that of the Op Amp for
CAS detection.
THE DIFFERENCE BETWEEN FSK MODE 0 AND MODE1
directly. DCLK and DR pins are unused. The microcontroller reads out
the data by the serial data interface which is implemented by software
programming. The flexibility of using software improves the immunity
to interference.
FSK Demodulation Mode 0
FSK Demodulation Mode 1
Hybrid DT-AS Detection
Tip/Ring DT-AS Detection
Power Down
Factory Test Only
Functionality of the NW6005 can be selected by coding CB0-CB2,
To optimize the device’s talkdown and talkoff performance, Hybrid
It is highly recommended to demodulate the FSK signal using the
Ideally, the gain of the two Op Amps would be set to 0 dB. But in
Typically, the CAS sensitivity should be lower than the FSK
In FSK mode 0, the FSK serial bit stream is output to the DATA pin
Functionality Group
INDUSTRIAL TEMPERATURE RANGE
CB0
1/0
1/0
0
1
1
0
CB1
1
1
1
0
0
0
CB2
1
1
0
1
0
0