m65845afp Renesas Electronics Corporation., m65845afp Datasheet - Page 9

• Manufacturer Part Number: m65845afp
• Description: Digital Echo With Microphone Mixing Circuit
• Manufacturer: Renesas Electronics Corporation.

M65845AFP
4. Vocal cut
Caution: Inside resistance is changeable one by one which rate is ±30%.
Digital Echo
1. Clock oscillator circuit
Note: The delay time (Td) for echo is determined by the clock frequency (fck).
REJ03F0170-0201 Rev.2.01 Jan 25, 2008
Page 9 of 13
It is a method turned down Lch and Rch input having the same phase and sound.
Low pass cut off frequency fc is determined by a capacitance which connect to pin 36 (vocal cut filter).
It is also having a function which through frequency under vocal level for supplying a lack of low level sound.
at fc = 50 Hz, C34 = 0.15 μF is determined.
This IC incorporates a current control type clock oscillator circuit in it, thus providing circuit configuration just by
connecting an R
Fully internal clock supply prevents occurrence of undesired radiation without affecting any external circuit.
The oscillator frequency fck is following.
fck = 2 MHz (R
Delay time = 1/fck × 24 × N
(N = the number of memory bits = 16384)
fck = 2 MHz (Rc = 51 kΩ): Delay time = 197 ms
fck = 2.6 MHz (Rc = 39 kΩ): Delay time = 150 ms
fck = 3.9 MHz (Rc = 24 kΩ): Delay time = 100 ms
C
for current control pin 32 (CLOCK CONT).
C
= 51 kΩ)
R
C
fc =
DC current
2
R
VC
1
32
R
Clock frequency: fck
VC
C34
36
= 20 k (Typ)
Clock
oscillator
circuit
C34