MITSMI MM1376 Datasheet

MITSUMI

SOP-22

136924587

10 11

22 18 1521 19 17 16 1420 1213

IC for Headphone Stereos MM1376

IC for Headphone Stereos

Monolithic IC MM1376

Outline

This IC was developed for use in 3V headphone stereos, and combines all the basic audio circuitry for
headphone stereos on a single chip.
Recently hearing impairment caused by the high volumes of headphone stereos has become a problem, and
there has been strong demand for functions for limiting loud volumes in the sets themselves. This IC
incorporates an ALC circuit and has functions to hold the output from the headphone to a fixed level; it also
eliminates the ordinary electronic governor circuit in order to accommodate trends toward thinner sets, as
seen in the adoption of BSL motors.

Package

1. Configuration: Pre-and power amps, ALC circuit

2. Internal tape selector: A selector switch allows the user to select between normal and metal tapes.

3. Internal OCL circuit: No need for large-capacitance output capacitor

4. Preamp off function: Preamp alone can be turned off for connection to radio etc.

5. MM1376CF amp gain takes Dolby noise reduction into account

Package

SOP-22

Pin Assignment

1 COM1 12 Power output

2 Preamp non-inverted input 13 V

3 Preamp inverted input 14 Ripple filter

4 Metal switching output 15 Preamp off

5 Preamp output 16 Tape selector

6 Power input 17 Power input

7 Rectifier pin 18 Preamp output

8

9 Power output 20 Preamp inverted input

10 COM2 21 Preamp non-inverted input

11 GND1 22 GND2

ALC control

19 Metal switching output

CC

Absolute Maximum Ratings

Item Symbol Ratings Units

Operating temperature T

Storage temperature T

Power supply current V

Power consumption Pd 350 mW

OPR

STG

CC

-

10~+65

-

40~+125

-

0.3~+7.5 V

°

C

°

C

MITSUMI

Recommended Operating Conditions

Item Symbol Ratings Units

Operating temperature T

OPR

IC for Headphone Stereos MM1376

-

10~65

°

C

Operating voltage V

Electrical Characteristics

(Except where noted otherwise, Ta=25°C, VCC=3V, f=1kHz, R

Item Measurement conditions Min. Typ. Max. Units

Consumption current V

Preamp unit

Open-circuit gain 72 dB

Normal

Closed-circuit gain I

Metal 29.5 32 34.5

Normal

Closed-circuit gain II

Metal 23 25.5 28

Maximum output voltage THD=10% 0.30 0.45 Vrms

Total harmonic distortion ratio V

Normal

Output noise voltage

Metal 20 45 100

Crosstalk between channels Rg=2.2kΩ, V

OPR 2.0~5.0 V

IN=0V 6 14 22 mA

Vo=-10dBm, f=1kHz

-

10dBm, f=5kHz

Vo=

OUT=

-

10dBm 0.05 0.5 %

Rg=2.2k, BPF (400~30kHz)

OUT=

-

10dBm 50 70 dB

L

1=10kΩ, RL2=16Ω)

31 33.5 36

28 30.5 33

30 75 150

dB

dB

µVrms

Ripple rejection

VCC=3V, VR=-20dBm, f

Output voltage with preamp off V

ALC (off) + power amp

Voltage gain P

Voltage gain difference between channels

Maximum output current THD=10%, R

Total harmonic distortion ratio P

Crosstalk between channels P

Output noise voltage Rg=0Ω, BPF (400~30kHz)

V

CC=3V, VR=

Ripple rejection

R=100Hz, Rg=0Ω DF 35 40

f

Input resistance 19 24 29 kΩ

ALC (on) + power amp

Power amp output voltage V

ALC initiation input voltage

R

=100Hz Rg=2.2kΩ

IN=100mVrms, Pre off

45 55 dB

-

80-60 dBm

CF 24 26 28

OUT=5mW

DF 30 32 34

-

20 2dB

L=16Ω 30 50 mW

OUT=5mW 0.5 1.5 %

OUT=5mW 35 45 dB

CF 85 200

DF 135 250

-

20dBm CF 35 45

IN=

-

40dBm

CF

DF

-

34-30-26 dBm

-

56

-

62

dB

µVrms

dB

dBm

ALC width

Input width for output from start of up to +4dB

ALC total harmonic distortion V

Noise of preamp+power amp+ALC

Rg=2.2kΩ (Pre amp), Noise of preamp+power amp

30 40 dB

IN=

-

40dBm 0.5 1.5 %

CF 1.5 6

DF 2.8 6

mVrms