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SC14SPNODE SF DECT Module with integrated Antenna and FLASH

3.7 ANALOG FRONT END

Note 16: BANDGAP_REG will be tuned at the factory.

Note 17: 0 dBm0 on COUT = -3.14 dB of max PCM value. COUT is CODEC output in test mode

Note 18: Trimming possibility is foreseen. At system production the bandgap reference voltage can be controlled within 2% accuracy and data can

be stored in Flash. Either AVD or VREF can be trimmed within 2% accuracy. If AVD is trimmed VREF will be within 2% accuracy related to

either AVD. Or vice versa VREF can be trimmed. For Vref trimming measure

VREFp, VREFm) and update BANDGAP_REG[3..0].

Note 19: Vrefm is a clean ground input and is the 0 V reference.

Table 10: Microphone amplifier

PARAMETER DESCRIPTION CONDITIONS MIN TYP MAX UNIT

Vmic_0dB_unt Untrimmed differen-

tial RMS input volt-

age between MICp

and MICn (0 dBm0

reference level)

(Note 8)

0 dBm0 on COUT

(Note 17)

MIC_GAIN[3:0] = 0,

@ 1020 Hz;

Tolerance:

• 13% when untrimmed

(

BANDGAP_REG=8)

(Note 16)

• 6% when trimmed

(Note 18)

114 131 149 mV

Rin_mic Resistance of acti-

vated microphone

amplifier inputs

(MICp, MICn and

MICh) to internal GND

(Note 8)

75 150 k

Vmic_offset Input referred DC-off-

set (Note 8)

MIC_GAIN[3..0] = 1111

3 sigma deviation limits

-2.6 +2.6 mV

Table 11: Microphone amplifier (Operating Condition)

PARAMETER DESCRIPTION CONDITIONS MIN TYP MAX UNIT

Vmic_cm_level MICp and MICn com-

mon mode voltage

MICp and MICn are set to

GND with internal resistors

(Rin_mic). If DC coupled

the input voltage must be

equal to this voltage.

(0.9 V/1.5)*

VREFp

Table 12: Microphone supply voltages

PARAMETER DESCRIPTION CONDITIONS MIN TYP MAX UNIT

Vref_unt VREFp-VREFm

untrimmed

(Note 19)

LOAD

= 0 mA

BANDGAP_REG = 8

(Note 18)

1.41 1.5 1.59 V

Rout_vrefp VREFp output

resistance

Figure 8 1 

Nvrefp_idle Peak noise on

VREFp-VREFm

(Note 8)

CCITT weighted -120 dBV

PSRRvrefp Power supply rejec-

tion Vref output

(Note 8)

See Figure 8, AVD to

VREFp/m, f = 100 Hz to 4 kHz

BANDGAP_REG[5:4] = 3

40 dB