ta31275 TOSHIBA Semiconductor CORPORATION, ta31275 Datasheet - Page 8

• Manufacturer Part Number: ta31275
• Description: Am/fm Rf/if Detector Ic For Low Power Wireless System
• Manufacturer: TOSHIBA Semiconductor CORPORATION

12. Control Terminal for Quick Charge Circuit (CHARGE)
13. Bit Rate Filter for FM
14. Bit Rate Filter for AM
charge a given period by time constant of internal resistance and outside capacitance. Enabling the
CHARGE pin requires an external capacitor. In normal operation, connect a capacitor having the same
capacitance as that of the capacitor connected to the REF pin (pin 20).
(the bit rate filter time constant takes into account the internal resistance RSSI (30 kΩ))
CHARGE (15 pin) is control terminal for quick charge circuit. REF (20 pin) control terminal for quick
If the connected external capacitor (C11) is 0.1 µF, the quick charge time is 7 ms (typically).
The current FM bit rate filter is used as a tertiary filter.
If the filter is to be used at a rate other than 1200 bps, please change the filter constant.
The current AM bit rate filter is used as a quadratic filter.
If the filter is to be used at a rate other than 1200 bps, please change the filter constant.
When the filter constants shown below are used, it is not necessary to set the R constant value.
In addition, the current AM bit rate filter can be used as a tertiary filter.
If the filter is to be used at a rate other than 1200 bps, please change the filter constant.
1200 bps
2400 bps
4800 bps
1200 bps
2400 bps
4800 bps
1200 bps
2400 bps
4800 bps
68 kΩ
68 kΩ
68 kΩ
R10
68 kΩ
68 kΩ
68 kΩ
36 kΩ
36 kΩ
36 kΩ
R9



R
R
Quadratic Filter (NRZ)
Quadratic Filter (NRZ)
68 kΩ
68 kΩ
68 kΩ
68 kΩ
68 kΩ
68 kΩ
30 kΩ
30 kΩ
30 kΩ
R10
R10
8
R8
4700 pF
2200 pF
4700 pF
2200 pF
1000 pF
1800 pF
0.01 µF
6800 pF
3300 pF
C20
C20
C20
TA31275FN/ TA31275FNG
1500 pF
2200 pF
1500 pF
560 pF
270 pF
150 pF
680 pF
390 pF
820 pF
C19
C19
C19
3300 pF
1500 pF
680 pF
C18
03-01-23