PT2258

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6-Channel Electronic Volume Controller IC PT2258

DESCRIPTION

PT2258 is a 6-Channel Electronic Volume Controller IC utilizing CMOS Technology specially designed for the new generation of AV Multi-Channel Audio System. PT2258 provides an I2C Control Interface, an attenuation range of 0 to -79dB at 1dB/step, low noise, and high channel separation. Housed in 20 pins, DIP or SOP, PT2258’s pin assignments and application circuit are optimized for easy PCB Layout and cost saving advantages.

FEATURES

• CMOS Technology

• Low Power Consumption • Least External Components

• Attenuation Range: 0 to -79dB at 1dB/step • Operating Voltage: 5 to 9 V

• Low Noise, S/N Ratio>100dB (A-weighting) • High Channel Separation • I2C Bus Control Interface • Selectable Address • 6-Channel Outputs

• Available in 20 pins, DIP or SOP

APPLICATIONS

• AV Surround Audio Equipment • Car Audio • Mini Compo

• Computer Multi-Media Speaker • Other Audio Equipments

PT2258 V1.2 - 1 - July, 2005

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6-Channel Electronic Volume Controller IC PT2258

PIN CONFIGURATION

IN1IN2IN3CODE2DGNDSCLSDAIN4IN5IN6123456710PT225820191817161514131211OUT1OUT2OUT3CODE1VCCREFGNDOUT4OUT5OUT6

PT2258 V1.2 - 2 - July, 2005

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6-Channel Electronic Volume Controller IC PT2258

PIN DESCRIPTION

Pin Name

Description Channel Input No. 1.

IN1 I Connect a Capacitor to Audio Source

Channel Input No. 2

IN2 I Connect a Capacitor to Audio Source

Channel Input No. 3

IN3 I Connect a Capacitor to Audio Source

CODE2 - Refer to Address Code Section DGND - Digital Ground SCL I I2C Clock Input SDA I I2C Data Input

Channel Input No. 4

IN4 I Connect a Capacitor to Audio Source

Channel Input No. 5

IN5 I Connect a Capacitor to Audio Source

Channel Input No. 6

IN6 I Connect a Capacitor to Audio Source

Channel Output No. 6

OUT6 O Connect a Capacitor to the Next Stage

Channel Output No. 5

OUT5 O Connect a Capacitor to the Next Stage

Channel Output No. 4

OUT4 O Connect a Capacitor to the Next Stage

GND - Ground 14

Reference Voltage= 1/2 Vcc

REF - Connect a Capacitor to the Ground

VCC - Power Supply Input 16 CODE1 - Refer to the Address Code Section

Channel Output No. 3

OUT3 O Connect a Capacitor to the Next Stage

Channel Output No. 2

OUT2 O Connect a Capacitor to the Next Stage

Channel Output No. 1

OUT1 O Connect a Capacitor to the Next Stage

I/O

Pin No. 1 2 3

4

5 6 7 8 9 10 11 12 13

14 15 16 17 18 19 20

PT2258 V1.2 - 3 - July, 2005

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6-Channel Electronic Volume Controller IC PT2258

FUNCTIONAL DESCRIPTION

BUS INTERFACE

Data are transmitted to and from the microprocessor to the PT2258 via the SDA and SCL. The SDA and SCL make up the BUS Interface. It should be noted that the pull-up resistors must be connected to the positive supply voltage.

DATA VALIDITY

A data on the SDA Line is considered valid and stable only when the SCL Signal is in HIGH State. The HIGH and LOW States of the SDA Line can only change when the SCL signal is LOW. Please refer to the figure below.

DATACLKData LineStable, DataValidData ChangeAllowed

START AND STOP CONDITIONS

A Start Condition is activated when

1) the SCL is set to HIGH and

2) SDA shifts from HIGH to LOW State. The Stop Condition is activated when

1) SCL is set to HIGH and

2) SDA shifts from LOW to HIGH State. Please refer to the timing diagram below.

BYTE FORMAT

Every byte transmitted to the SDA Line consists of 8 bits. Each byte must be followed by an Acknowledge Bit. The MSB is transmitted first.

PT2258 V1.2 - 4 - July, 2005

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6-Channel Electronic Volume Controller IC PT2258

ACKNOWLEDGE

During the Acknowledge Clock Pulse, the master (µP) puts a resistive HIGH level on the SDA Line. The peripheral (audio processor) that acknowledges has to pull-down (LOW) the SDA line during the Acknowledge Clock Pulse so that the SDA Line is in a Stable Low State during this Clock Pulse.

=Please refer to the diagram below.

The audio processor that has been addressed has to generate an Acknowledge after receiving each byte, otherwise, the SDA Line will remain at the High Level during the ninth (9th) Clock Pulse. In this case, the master transmitter can generate the STOP Information in order to abort the transfer.

TRANSMISSION WITHOUT ACKNOWLEDGE

If you want to avoid the acknowledge detection of the audio processor, a simpler µP transmission may be used. Wait one clock and do not check the slave acknowledge of this same clock then send the new data. If you use this approach, there are greater chances of faulty operation as well as decrease in noise immunity.

INTERFACE PROTOCOL

The interface protocol consists of the following:

• A Start bit

• A Chip Address Byte • ACKAcknowledge bit • A Data byte • A Stop bit

Please refer to the diagram below:

Notes:

1. 2.

ACK = ACKNOWLEDGE

MAX. CLOCK SPEED = 100 BITS/S

PT2258 V1.2

- 5 -

July, 2005

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6-Channel Electronic Volume Controller IC PT2258

PT2258 ADDRESS CODE

PT2258 Address Code depends on the state of CODE1 (Pin No.17) and CODE2 (Pin No.4).

If CODE1 or CODE2 is connected to Vcc, then CODE1 or CODE2 is set to “1”. If CODE1 or CODE2 is connected to the Ground, it is set to “0”. Please refer to the information below:

Condition 1:

CODE1 CODE2 1 1 Then, PT2258 Address Code is 8 CH:

1 0 0 0 1 1 0 0 MSB LSB

Condition 2:

CODE1 CODE2 1 0 Then, PT2258 Address Code is 88 H:

0 0 0 1 0 0 0 1

MSB LSB

Condition 3:

CODE1 CODE2 0 1 Then, PT2258 Address Code is 84 H:

1 MSB

0 0 0 0 1 0 0 LSB

Condition 4:

CODE1 CODE2 0 0 Then, PT2258 Address Code is 80H:

1 MSB

0 0 0 0 0 0 0 LSB

PT2258 V1.2 - 6 - July, 2005

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6-Channel Electronic Volume Controller IC PT2258

I2C BUS INTERFACE START TIME

After Power is turned ON, PT2258 needs to wait for a short time in order to insure stability. The waiting time period for PT2258 to send I2C Bus Signal is at least 200ms. If the waiting time period is less than 200 ms, I2C Control may fail. Please refer to the diagram below.

VPOWER ON90% VDDVDDAt least 200msSDA/SCL PT2258 V1.2 - 7 - July, 2005

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6-Channel Electronic Volume Controller IC PT2258

PT2258 CONTROL SOFTWARE PROCEDURE

1. In order to ensure exact operation under any operating voltage, it is recommended an instruction to clear the register “C0H” must be transmitted first. Please refer to the following diagram:

Start 1 0 0 0 1 0 0 0 Ack11000000Ack Stop 2258 Address Clear Register

2. The PT2258 function register does not have any default settings. After clearing the register, an initial value must send in order to each register. If a register does has not been set, it is possible that no sound will be output.

3. When adjusting the volume of PT2258, it is necessary to send a multiple of 10dB followed by a 1dB code to the attenuator in sequence. If this sequence is not followed, or if only a 10dB or 1dB value is sent, the IC may not operate normally. Please refer to the diagram below:

Volume setting -42dB：

Start 1 0 0 0 1 0 0 0 Ack 11010100ACK111 0 0 0 1 0AckStop PT2258 Address -40dB -2dB

Start 1 0 0 0 1 0 0 0 Ack 11100010Ack1101 0 1 0 0ACKStop PT2258 Address -2dB -40dB The two methods above are both acceptable.

Warning!! The following transmission method is not permitted.

Send only a 10dB attenuation value:

Start 1 0 0 0 1 0 0 0 Ack11010100ACK Stop PT2258 Address -40dB

Send only a 10dB attenuation value:

Start 1 0 0 0 1 0 0 0 Ack11100010ACK Stop PT2258 Address -2dB

Do not send a 10dB code without simultaneously with a 1dB code or in combination with other instruction codes.

Start 1 0 0 0 1 0 0 0 Ack 1 1 1 0 0010Ack11111001ACK1 1 0 1 0 100ACKStop PT2258 Address -2dB All CH mute -40dB

PT2258 V1.2 - 8 - July, 2005

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6-Channel Electronic Volume Controller IC PT2258

DATA BYTES DESCRIPTION

FUNCTION BITS

MSB LSB 1 1 1 0 A3 A2 A1 A0 1 1 0 1 0 B2 B1 B0 0 0 0 1 A3 A2 A1 A0 0 0 0 0 0 B2 B1 B0 0 0 1 1 A3 A2 A1 A0 0 0 1 0 0 B2 B1 B0 0 1 0 1 A3 A2 A1 A0 0 1 0 0 0 B2 B1 B0 0 1 1 1 A3 A2 A1 A0 0 1 1 0 0 B2 B1 B0 1 0 0 1 A3 A2 A1 A0 1 0 0 0 0 B2 B1 B0 1 0 1 1 A3 A2 A1 A0 1 0 1 0 0 B2 B1 B0 FUNCTION

6-Channel, -1dB/step 6-Channel, -10dB/step Channel No. 3, -1dB/step Channel No. 3, -10dB/step Channel No. 4, -1dB/step Channel No. 4, -10dB/step Channel No. 2, -1dB/step Channel No. 2, -10dB/step Channel No. 5, -1dB/step Channel No. 5, -10dB/step Channel No. 1, -1dB/step Channel No. 1, -10dB/step Channel No. 6, -1dB/step Channel No. 6, -10dB/step 6-Channel, Mute

1 1 1 1 1 0 0 M When M= 1, MUTE ON

When M=0, MUTE OFF

ATTENUATION UNIT BIT

A3/--- A2/B2 A1/B1 A0/B0 Attenuation Value(dB)0 0 0 0 0/0 0 0 0 1 -1/-10 0 0 1 0 -2/-20 0 0 1 1 -3/-30 0 1 0 0 -4/-40 0 1 0 1 -5/-50 0 1 1 0 -6/-60 0 1 1 1 -7/-70 1 0 0 0 -8/---- 1 0 0 1 -9/---- Note: Ax=-1dB/step, Bx=-10dB/step

PT2258 V1.2 - 9 - July, 2005

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6-Channel Electronic Volume Controller IC PT2258

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Ratings Vs Supply Voltage 12 Topr Operation Temperature-40～+85 Tstg Storage Temperature

-65～+150

Unit

V ℃ ℃

ELECTRICAL CHARACTERISTICS

(VDD=9V, VI=1Vrms, f=1KHz, Temp=27℃) Symbol Parameter VDD Supply Voltage Is Supply Current RIN

Input Impedance

VCL Max. Input Voltage Sc Channel Separation Crange Volume Control Range Avmax Max. Attenuation Astep Attenuation Step EA Attenuation Error Conditions

FL, FR, CTR, SUB, SL, SR Volume=0dB, THD=1%

Volume=0～-50dB

Min. Typ. Max.Unit5 9 10 V 7 10 12 mA KΩ 22 33 42 2.8 3.0 Vrms

90 100 110 dB 79 dB

-79 dB 1 dB -1.0 0 +1.00.003 0.005

0.01

dB %

90 95 98 dB AMUTE Mute Attenuation A-weighting

Total Harmonic

THD Volume=0dB, input 200mVrms

Distortion Noise Output Noise S/N

Signal-Noise Ratio

Ro Output Impendance A-weighting 0dB=1Vrms, A-weighting

μV 3 5 100

dB

Ω 600 900 105

110

Go Output Gain

FL, FR, CENTER, SUB, SL, SR

Vomax Max. Output Voltage

THD=1%

I2C Section VIL Bus Low Input Level VIH Bus High Input Level

Cref=10μF TINIT Bus Initialization -0.5 0 +0.5dB 2.3 2.5 2.8 Vrms

2.8

2.4 3.0

2.5

V V

250 300 mS PT2258 V1.2 - 10 - July, 2005

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6-Channel Electronic Volume Controller IC PT2258

APPLICATION CIRCUIT INPUT100K100K100K10µF10µF10µF12345IN1IN2IN3CODE2DGNDSCLSDAIN4IN5OUT120OUT219OUT318CODE117VCC16REF15GND14OUT413OUT512OUT611++10µF100K100KVCCOUTPUT+10µF10µF100K+0.1µF10µFICBus2MCU10µF100K100K100K10µ+F10µ+F67++++10µFCref10µF10µF10µF100K100K100K+ 10IN6PT2258Address=88HexDGNDAGND

+++

PT2258 V1.2 - 11 - July, 2005

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6-Channel Electronic Volume Controller IC PT2258

ORDER INFORMATION

Valid Part Number

PT2258 PT2258-S

Package Type 20 Pins, DIP, 300mil 20 Pins, SOP, 300mil

Top Code PT2258 PT2258-S

PT2258 V1.2 - 12 - July, 2005

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6-Channel Electronic Volume Controller IC PT2258

PACKAGE INFORMATION

20 PINS, DIP, 300MIL

PT2258 V1.2

- 13 -

July, 2005

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6-Channel Electronic Volume Controller IC PT2258

Symbol Min. Nom. Max.

A - - 0.210 A1 0.015 - - A2 0.115 0.130 0.195 b 0.014 0.018 0.022 b1 0.014 0.018 0.020 b2 0.045 0.060 0.070 b3 0.030 0.039 0.045 c 0.008 0.010 0.014 c1 0.008 0.010 0.011 D 0.980 1.030 1.060 D1 0.005 - - E 0.300 0.310 0.325 E1 0.240 0.250 0.280 e - 0.100 bsc. - eA - 0.300 bsc. - eB - - 0.430 eC 0.000 - 0.060 L 0.115 0.130 0.150 Notes:

1. All dimensions are in INCHES.

2. Dimensioning and tolerancing per ANSI Y14.5M-1982.

3. Dimension ”A”, ”A1” and ”L” are measured with the package seated in JEDEC Seating Plane Gauge GS-3

4. “D”, ”D1” and “E1” dimensions do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.010 inch.

5. “E” and “eA” measured with the leads constrained to be perpendicular to datum -c- . 6. “eB” and “eC” are measured at the lead tips with the leads unconstrained. 7. N is the number of the terminal positions (N=20)

8. Pointed or rounded lead tips are preferred to ease insertion.

9. “b2” and “b3” maximum dimensions are not include dambar protrusions. Dambar protrusions shall not exceed 0.010 inch (0.25mm)

10. Distance between leads including dambar protrusions to be 0.005 inch minimum. 11. Datum plane -H- coincident with the bottom of lead, where lead exits body. 12. Refer to JEDEC MS-001, Variation AD.

JEDEC is the trademark of JEDEC SOLID STATE TECHNOLOGY ASSOCIATION.

PT2258 V1.2 - 14 - July, 2005

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6-Channel Electronic Volume Controller IC PT2258

20 PINS, SOP, 300MIL

Symbol Min. Nom. Max. A 2.35 - 2.65 A1 0.10 - 0.30 B 0.33 - 0.51 C 0.23 - 0.32 D 12.60 - 13.00 E 7.40 - 7.60 e - 1.27 bsc. - H 10.00 - 10.65 h 0.25 - 0.75 L 0.40 - 1.27 - α 0° 8°

PT2258 V1.2 - 15 - July, 2005

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6-Channel Electronic Volume Controller IC PT2258 Notes:

1. Dimensioning and tolerancing per ANSI Y14.5M-1982.

2. Dimension “D” does not include mold flash, protrusions or gate burrs. Mold Flash, protrusion or gate burrs shall not exceed 0.15 mm (0.006 in) per side.

3. Dimension “E” does not include interlead flash or protrusions. Interlead flash or protrusions shall not exceed 0.25 mm (0.010 in) per side.

4. The chamfer on the body is optional. It is not present, a visual index feature must be located within the crosshatched area.

5. “L” is the length of the terminal for soldering to a substrate. 6. N is the number of the terminal positions (N=20)

7. The lead width “B” as measured 0.36 mm (0.014 in) or greater above the seating plane, shall not exceed a maximum value of 0.61 mm (0.24 in). 8. Controlling dimension: MILLIMETER. 9. Refer to JEDEC MS-013, Variation AC.

JEDEC is the trademark of JEDEC SOLID STATE TECHNOLOGY ASSOCIATION.

PT2258 V1.2 - 16 - July, 2005