Datasheet

Revision 3.0

28-Jul-2015

CFR0011-120-00-FM Rev 5

38 of 57

© 2013 Dialog Semiconductor

SC14CVMDECT SF

Cordless Voice Module

FINAL

7.6 ANALOG FRONT END

Note 26: BANDGAP_REG will be tuned at the factory.

Note 27: 0 dBm0 on COUT = -3.14 dB of max PCM value. COUT is CODEC output in test mode

Note 28: 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

Note 29: Vrefm is a clean ground input and is the 0 V reference.

Table 23: 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 17)

0 dBm0 on COUT

(Note 27)

MIC_GAIN[3:0] = 0,

@ 1020 Hz;

Tolerance:

• 13% when untrimmed

(Note 26)

• 6% when trimmed

(Note 28)

114

131

149

mV

Rin_mic

Resistance of acti-

vated microphone

amplifier inputs

(MICp, MICn and

MICh) to internal GND

(Note 17)

75

150

k



Vmic_offset

Input referred DC-off-

set (Note 17)

MIC_GAIN[3..0] = 1111

3 sigma deviation limits

-2.6

+2.6

mV

Table 24: 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

V

Table 25: Microphone supply voltages

PARAMETER

DESCRIPTION

CONDITIONS

MIN

TYP

MAX

UNIT

Vref_unt

VREFp-VREFm

untrimmed

(Note 29)

BANDGAP_REG = 8

(Note 28)

1.41

1.5

1.59

V

Rout_vrefp

VREFp output

resistance

Figure 29

1



Nvrefp_idle

Peak noise on

VREFp-VREFm

(Note 17)

CCITT weighted

-120

dBV

PSRRvrefp

Power supply rejec-

tion Vref output

(Note 17)

See Figure 29, AVD to

VREFp/m, f = 100 Hz to 4 kHz

BANDGAP_REG[5:4] = 3

40

dB