BU8874 Rohm Semiconductor, BU8874 Datasheet - Page 8

• Manufacturer Part Number: BU8874
• Description: IC DTMF RECEIVER FOR PHONE DIP8
• Manufacturer: Rohm Semiconductor

Specifications of BU8874

• Function: Receiver, DTMF
• Number Of Circuits: 1
• Voltage - Supply: 4.75 V ~ 5.25 V
• Current - Supply: 2.2mA
• Power (watts): 500mW
• Operating Temperature: -10°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: 8-DIP (0.300", 7.62mm)
• Includes: Power Down Mode
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Interface: -

(3) DTMF input
C501 : This is the DC blocking capacitor. Select a ca-
(4) ESt output
The ESt guard time is determined by the CPU of the host
computer, but to reduce the load on the host computer,
the guard time can be set using an external circuit, as
shown in Figure 10.
The relation between a momentary falter in the ESt guard
time (t
(t
shows a timing diagram for guard times.
Communication ICs
GH
), and the time constant is shown below. Figure 12
GL
), a momentary HIGH level in the ESt guard time
pacitor that will pass DTMF signals (greater
than 697Hz) without significantly attenuating
the signals.
JP592 : If DTMF signals are being input directly, both
Q591
R591 X R595
C592, C593
ends should be shorted.
Use these to increase the sensitivity of
the DTMF receiver.
BU8874 / BU8874F
209