AK2364 Datasheet, PDF (18/26 Pages) Asahi Kasei Microsystems – Two-way Radio Filterless FM Detector LSI

[AK2364]
Address 0x02 (Control Register 2)
Name
D7(MSB) D6 D5 D4 D3
D2
D1 D0(LSB)
Control
Register 2
Reserved
AGC_TIME[1:0]
AGC0_
STEP
BAND
CAL
Initial Value
0
0
0
0
0
1
0
0
AGC_TIME[1:0] : AGC response time setting
This register set response time for AGC0 gain and AGC1 gain to change by 1step.
AGC_TIME AGC_TIME
[1]
[0]
AGC response time [ms]
AGC0_STEP=0 setting
AGC0_STEP=1 setting
State A State B
State C
State A
State B
State C
0
0
0.56
8.50
8.50
0.38
4.35
4.35
0
1
0.92
8.79
8.79
0.56
4.50
4.50
1
0
1.64
9.37
9.37
0.93
4.79
4.79
1
1
3.08
10.52
10.52
1.66
5.38
5.38
Note: Values above indicate response time during AGC gain changes from maximum to minimum or
from minimum to maximum.
Note: AGC response time differs according to the following states.
State A: AGC0 output level is beyond the upper limit.
State B: AGC0 output level is within the upper limit and AGC1 output level is beyond the upper limit.
State C: AGC1 output level is under the lower limit.
Data
Function
AGC0_
STEP
BAND
CAL
AGC0 gain switching
range setting
Demodulated signal
level setting (Note1)
Discriminator circuit
calibration start
trigger (Note2)
0
±1dB
Operation
1
±2dB
NARROW
WIDE
Invalid
Start
Notes
Note1: When {BAND} register is set to “0”, demodulated signal level at AUDIOOUT pin, when input
signal is Δf=±1.5kHz dev, is 100mVrms typ. When {BAND} register is set to “1”, demodulated signal
level at AUDIOOUT pin, when input signal is Δf=±3.0kHz dev, is 100mVrms typ.
Note2: calibration is performed synchronized with the rising edge of {CAL}. After calibration is
completed, this register is set to “0” automatically. It takes 1.3ms before calibration is completed.
Refer to “calibration procedure” for further information.
Address 0x03 (Software Reset)
Name
D7(MSB) D6
D5
D4
D3
D2
D1 D0(LSB)
Software-reset
SRST[7:0]
Initial Value
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
When data 0x03:10101010 is written to the SRST[7:0] register, software reset is performed.
Refer to System Reset for further information.
MS1431-E-01
- 18 -
2012/10