[AK4685]
(Pseudo Cap-less /Single-ended input)
The input ATTs are constructed by connecting input resistors (Ri) to LIN1+/- pins and feedback resistors (Rf) between
LAMPO1/ LVCOM1 pin and LIN1-/LIN1+ pin (Figure 11) when using single-ended and pseudo cap-less inputs as well
as when using differential inputs. The input voltage range of the LAMPO1/ LVCOM1 pin is typically +/- 0.33 x AVDD
(Vpp). If the input voltage of the input selector exceeds typ. 5.66Vpp (2Vrms) or 8.48Vpp (3Vrms), the input voltage of
the LAMPO1/ LVCOM1 pins must be attenuated to typ. +/-3.3 x AVDD1/5 (Vpp) ATTs. Table 18 shows Ri and Rf
constant examples.
Rf
LAMPO1
Pr e- Amp
AINL1
LIN1-
-
Ri
Ri
LIN1+
+
LVCOM1
GND
Rf
Figure 11. External Connection Example (single-ended input)
Voltage between LAMPO1
Input Range
ATT Gain [dB]
–2.3
Ri [kΩ]
47
Rf [kΩ]
36
and LVCOM1 pins
8.48Vpp
(3Vrms)
5.66Vpp
(2Vrms)
2.83Vpp
(1Vrms)
+/-3.25Vpp
33
36
+0.7
+/-3.08Vpp
+/-3.18Vpp
16
36
+7.02
Note 32. The input range of the internal ADC is +/-3.3 x AVDD1/5 Vpp typ.
Note 33. The input range is the voltage difference of Ri inputs (AINL1/L2/R1/R2)-GND.
Table 18. Input ATT example (single-end input)
MS1106-E-00
2009/08
- 27 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
