Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 DESCRIPTION PT2256 is an electronic volume controller IC utilizing CMOS Technology specially designed for use on audio equipment. It has 2 built-in channels making it ideally suitable for mono and stereo sound applications. PT2256 provides the Loudness Function, a wide frequency response range and a very low total harmonic distortion, thereby guaranteeing a highly effective and reliable performance. It is housed in 16-pin DIP or SOP package and is functionally compatible with TC9235P. Pin assignments and application circuit are optimized for low cost advantages and easy PCB Layout. FEATURES • • • • • • • • • • CMOS technology Low power consumption Least external components 2 channels in the same chip 0dB to -78dB attenuation can be controlled by up and down pin 20dB tap for loudness circuit Built-in DC output circuit (8 levels) for volume level metering Wide frequency response range Low total harmonic distortion Available in 16 pins DIP or SOP APPLICATION • Audio equipment volume control PT2256 V1.7 -1- August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 BLOCK DIAGRAM VD D VS S OUT1 IN 1 OUT2 IN 2 LT 1 AG N D LT 2 AG N D D e co d e r /U P /D N O SC U p /D o w n C o u n te r C o n tr o l D/A Con ve rte r DCO /I N H /R ST PT2256 V1.7 -2- August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 PIN CONFIGURATION VSS 1 16 VDD OUT1 2 15 OUT2 IN1 3 IN2 LT1 4 14 13 AGND 5 12 LT2 AGND /UP 6 11 DCO /DN 7 10 /INH OSC 8 9 /RST PT2256 PT2256 V1.7 -3- August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 PIN DESCRIPTION Pin Number VSS OUT1 IN1 LT1 AGND I/O O I O - UP I DN I OSC I/O RST I /INH DCO LT2 IN2 OUT2 VDD I O O I O - PT2256 V1.7 Description Negative power supply Volume output pin 1 Volume input pin 1 Tap output pin 1 for loudness function Analog ground pins 1 Volume up control input pin. The 1 step/1 push volume is controlled by pressing the up Key. If the key has been pushed continuously increase. Built-in pull-up resistor. Volume down control input pin. The 1 step/1 push volume is controlled by pressing the down Key. If the key is continuously pressed, the volume control will continuously decrease. Built-in pull-up resistor. Oscillation pin. The oscillation circuit of a resistor and capacitor connection. Oscillator is activated when the key is pressed. Reset pin. This pin sets the initial volume level. The volume level is set to -46dB by “L” Input. Built-in pull-up resistor low active Backup mode input pin DC output pin for volume level meter Tap output pin 2 for loudness function Volume input pin 2 Volume output pin 2 Positive power supply -4- Pin No. 1 2 3 4 5, 12 6 7 8 9 10 11 13 14 15 16 August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 FUNCTION DESCRIPTION ATTENUATION The PT2256 volume control circuit consists of ladder resistors and analog switches. The Tap for loudness function is connected to the Step 10 (-20dB). When the (3.9KΩ) resistor is connected between LT and AGND pins, the attenuation is given in table below. The equivalent circuit is shown below: Step 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Attenuation (dB) 0 -2 -4 -6 -8 -10 -12 -14 -16 -18 -20 -22 -24 -26 -28 -30 Step 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Attenuation (dB) -32 -34 -36 -38 -40 -42 -46 -50 -54 -58 -62 -66 -70 -74 -78 ∞ OUT Step 0 IN Step 1 Step 2 29KΩ Step 9 LT Step 10 Step 11 22KΩ Step 30 AGND Step 31 Note: Step 22 has an initial value of -46dB. PT2256 V1.7 -5- August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 DC OUTPUT FOR VOLUME LEVEL The DC Output for the Volume Level Meter is internally connected to the D/A Converter. PT2256 has 8 stages of output voltage with each stage corresponding to a particular volume level. Please refer to the table below: Step 0-3 4-7 8-11 12-15 16-19 20-23 24-27 28-31 Attenuation (dB) 0-6 8-14 16-22 24-30 32-38 40-50 54-66 70-∞ Output Voltage (V) 7/8 VDD 6/8 VDD 5/8 VDD 4/8 VDD 3/8 VDD 2/8 VDD 1/8 VDD 0 UP/DOWN VOLUME CONTROL PT2256 features two Volume Control Pins, namely: UP and DN. UP is the control pin used to increase volume level while the DN is the control pin used to decrease the volume level. Thus, volume level may regulated using the Up or Down Keys. These keys are operated on a 1 step/1 push volume level control when UP or DN keys are set to “L” Level. If the keys are continuously pressed (input “Low”), then the volume level continuously steps up or down as the case maybe. Please refer to the diagram below for the timing of the key input. /UP, /DN Input Volume Level Control t T a Notes: 1. t= Preventive Time for Chattering (2.2 x 1/fosc ) 2. T= Switching Time to Automatic Mode (10 x 1/fosc) 3. a=Up, Down Speed (2x1/fosc) PT2256 V1.7 -6- August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 INITIALIZATION WHEN POWER ON PT2256 has an auto-initialization function during the Power On period. When Power is turned ON, the volume level is set to the initial value of -46 dB by setting the RST pin to “L” level. Please refer to the diagram below. VDD VDD VIL /RST 0V T ≥1 m s T BACK UP WHEN POWER OFF When the /INH Pin is set at “L” Level, all input and output pins are disabled and the current consumption is reduced to the minimum. Under this condition, the backup becomes possible. Please refer to the diagram below: VDD VDD B ac ku p V D D m in > 4 .5 V 4 . 5V B ac ku p D ata is los t 0V B ac ku p M od e No rm al M ode The backup circuit is given below: No rm al M ode 10 K IN4 001 V DD 51 K 10 K 1 000 µ F /16 V VD D P T 2256 + - /I NH VSS V SS Note: If the VDD drops from 12V to 4.5V, then the backup is possible for a period of 6 days. However, if VDD-Vss drops below 4.5V, the backup becomes impossible. PT2256 V1.7 -7- August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 LOUDNESS FREQUENCY RESPONSE The figure below shows the Loudness Frequency Response Diagram. 0dB -6dB -12dB -42dB -54dB -66dB -78dB ∞ PT2256 V1.7 -8- August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 ABSOLUTE MAXIMUM RATINGS (Unless otherwise stated, Ta=25℃) Parameter Symbol Supply voltage VDD Input voltage VIN Power dissipation PD Operating temperature Topr Storage temperature Tstg PT2256 V1.7 Rating -0.3 to 13 -0.3 to VDD+0.3 300 -40 to +85 -65 ~ +150 -9- Unit V V mW ℃ ℃ August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 ELECTRICAL CHARACTERISTICS (Unless otherwise stated, Ta=25℃, VDD=9V) Parameter Symbol Test Condition Min. Typ. Max. Unit Operating supply VDD 4.5 9.0 12 V voltage Operating supply IDD No load, FOSC=20Hz 0.3 1.0 mA current Stand-by current ISB OSC=0V, /INH=0V 0.1 10 µA Backup voltage VOD 2.0 12 V /INH Pin=0V Backup current IOD 0.1 1.0 µA High level input /UP, /DN, /RST 0.7VDD VDD VIH V voltage /INH 0.8VDD VDD /UP, /DN, /RST 0 0.3VDD Low level input voltage VIL V /INH 0 0.7VDD Between IN~AGND resistor 45 51 75 Voltage resistor RVR KΩ Between IN~LT resistor 26 29 45 Between LT~AGND resistor 19 22 32 High level input IIH /INH input pin. VIL=VDD -1 1 µA current Low level input current IIL /INH input pin, VIN=0V -1 1 µA Pull-up resistor Rup /UP, /DN, /RST input pin 90 110 130 KΩ When 0dB, Between Analog switch on RON IN1~OUT1 and IN2~OUT2 250 400 Ω resistor Resistor △ATT Attenuation error Test attenuation value 0 dB ±2.0 Balance between left Volume resistor error △RVR 0 % ±3.0 and right between left and right Total harmonic FIN=1KHz. THD 0dB 0.01 % distortion VIN=1Vrms, ∞dB Maximum attenuation ATTMAX 80 dB RL=100KΩ, Cross noise CT 0dB 80 dB Rg=600Ω Output noise VN 0dB -90 dB CX=2.2µf, Rx=33KΩ OSC frequency FOSC 18 Hz FIN=1KHz, VIN=1Vrms, Output resistance ROUT 550 650 750 Ω Volume control=0dB FIN=1KHz, VDD=9V 3.5 Maximum input volume VIN Vrms amplitude control=0dB, VDD=12V 4.0 THD<0.08% PT2256 V1.7 - 10 - August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 APPLICATION CIRCUIT SINGLE POWER SUPPLY (NO LOUDNESS AND NO BACKUP CIRCUIT) VDD (4.5 to 12V) 0.1µF 10µF L-Ch Input + + 3.9K UP Key Down Key Rx + VDD VSS OUT1 OUT2 IN1 IN2 LT1 LT2 AGND AGND /UP DCO /INH /DN /RST OSC Cx 10µF 10µF 3.9K + + 10µF L-Ch Output R-Ch Output R-Ch Input 10K 100K 0.1µF PT2256 10K +100µF Note: Modifying the values of Rx and Cx affects the Oscillator Frequency of the IC. If the Fosc value is big, then the volume control change is fast. Likewise, if the Fosc value is small, the volume control change is slow. It is suggested that Rx=33K, Cx=2.2µF. The table for the Rx, Cx and Fosc values are given below: Rx 33K 33K 33K PT2256 V1.7 Cx 1.0µF 2.2µF 10µF Fosc 34.1Hz 17.8Hz 3.4Hz Rx 33K 51K 100K - 11 - Cx 1.0µF 1.0µF 1.0µF Fosc 34.1Hz 22.7Hz 11.8Hz August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 INCLUDING LOUDNESS BUT NO BACKUP CIRCUIT VDD (4.5 to 12V) 0.1µF L-Ch Output 10µF L-Ch Input 0.1µF + + 8.2nF 820Ω 820Ω UP Key Down Key Rx + Cx VDD VSS OUT1 OUT2 IN1 IN2 LT1 LT2 AGND AGND /UP DCO /INH /DN /RST OSC PT2256 10µF 10µF 820Ω 820Ω + + 10µF R-Ch Output R-Ch Input 8.2nF 0.1µF 10K 100K 0.1µF + 10K 100µF Note: Modifying the values of Rx and Cx affects the Oscillator Frequency of the IC. If the Fosc value is big, then the volume control change is fast. Likewise, if the Fosc value is small, the volume control change is slow. It is suggested that Rx=33K, Cx=2.2µF. The table for the Rx, Cx and Fosc values are given below. Rx 33K 33K 33K PT2256 V1.7 Cx 1.0µF 2.2µF 10µF Fosc 34.1Hz 17.8Hz 3.4Hz Rx 33K 51K 100K - 12 - Cx 1.0µF 1.0µF 1.0µF Fosc 34.1Hz 22.7Hz 11.8Hz August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 ORDER INFORMATION Part Number PT2256 PT2256-S PT2256-SN PT2256 (L) PT2256-S (L) PT2256-SN (L) Package 16 Pins, DIP, 300mil 16 Pins, SOP, 300mil 16 Pins, SOP, 150mil 16 Pins, DIP, 300mil 16 Pins, SOP, 300mil 16 Pins, SOP, 150mil Top Code PT2256 PT2256-S PT2256-SN PT2256 PT2256-S PT2256-SN Notes: 1. (L), (C) or (S) = Lead Free. 2. The Lead Free mark is put in front of the date code. PT2256 V1.7 - 13 - August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 PACKAGE INFORMATION 16PINS, DIP, 300MIL PT2256 V1.7 - 14 - August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC Symbol A A1 A2 b b1 b2 b3 c c1 D D1 E E1 e eA eB eC L PT2256 Min. 0.015 0.115 0.014 0.014 0.045 0.030 0.008 0.008 0.780 0.005 0.300 0.240 0.000 0.115 Nom. 0.130 0.018 0.018 0.060 0.039 0.010 0.010 0.790 0.310 0.250 0.100 bsc 0.300 bsc 0.130 Max. 0.210 0.195 0.022 0.020 0.070 0.045 0.014 0.011 0.800 0.325 0.280 0.430 0.060 0.150 Notes: 1. All dimensions are in INCHES. 2. Dimensioning and tolerancing per ANSI Y14.5M-1982. 3. Dimensions “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-. “eB” and “eC” are measured at the lead tips with the loads unconstrained. 6. “N” is the number of terminal positions. (N=16) 7. Pointed or rounded lead tips are preferred to ease insertion. 8. “b2” and “b3” maximum dimensions are not include dambar protrusions. Dambar protrusions shall not exceed 0.010 inch (0.25 mm). 9. Distance between leads including Dambar protrusions to be 0.005 inch minimum. 10. Datum plane -H- coincident with the bottom of lead, where lead exits body. 11. Refer to JEDEC MS-001 Variation AB. JEDEC is the trademark of JEDEC SOLID STATE TECHNOLOGY ASSOCIATION. PT2256 V1.7 - 15 - August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 16PINS, SOPM, 300MIL N H INDEX AREA .25 (.010) M B M E -B- 1 2 3 L -A- h X 45 SEATING PLANE A D -C∞ -e- C A1 .10 (.004) B .25 (.010) M C A M B S Symbol A A1 B C D E e H h L α PT2256 V1.7 Min. Max 2.35 2.65 0.10 0.30 0.33 0.51 0.23 0.32 10.10 10.50 7.40 7.60 1.27 BSC 10.00 10.65 0.25 0.75 0.40 1.27 o 0 8o - 16 - August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 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=16) 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 AA. JEDEC is the trademark of JEDEC SOLID STATE TECHNOLOGY ASSOCIATION. PT2256 V1.7 - 17 - August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 16 PINS, SOP, 150MIL PT2256 V1.7 - 18 - August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 V1.7 PT2256 - 19 - August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC Symbol A A1 A2 b b1 c c1 D E E1 e L L1 L2 R R1 h θ θ1 θ2 PT2256 Min. 1.35 0.10 1.25 0.31 0.28 0.17 0.17 0.40 0.07 0.07 0.25 0° 5° 0° Typ. 9.90 BSC. 6.00 BSC. 3.90 BSC. 1.27 BSC. 1.04 REF. 0.25 BSC. - Max. 1.75 0.25 1.65 0.51 0.48 0.25 0.23 1.27 0.50 8° 15° - Notes: 1. Dimensioning and tolerancing per ANSI Y 14.5M-1994 2. Controlling Dimension: MILLIMETERS. 3. Dimension D does not include mold flash protrusions or gate burrs. Mold flash, protrusions or gate burrs shall not exceed 0.15 mm (0.006 in) per end. Dimension E1 does not include interlead flash or protrusion. Interlead flash or protrusion shall not exceed 0.25mm per side. D and E1 dimensions are determined at datum H. 4. The package top may be smaller than the package bottom. Dimensions D and E1 are determined at the outermost extremes of the plastic body exclusive of mold flash, tie bar burrs, gate burrs and interlead flash, but including any mismatch between the top and bottom of the plastic body. 5. Datums A & B to be determined at datum H. 6. N is the number of terminal positions. (N=16) 7. The dimensions apply to the flat section of the lead between 0.10 to 0.25mm from the lead tip. 8. Dimension “b” does not include dambar protrusion. Allowable dambar protrusion shall be 0.10mm total in excess of the “b” dimension at maximum material condition. The dambar cannot be located on the lower radius of the foot. 9. This chamfer feature is optional. If it is not present, then a pin 1 identifier must be located within the index area indicated. 10. Refer to JEDEC MS-012, Variation AC. JEDEC is the registered trademark of JEDEC SOLID STATE TECHNOLOGY ASSOCIATION. PT2256 V1.7 - 20 - August, 2006 Tel:886-2-66296288 Fax:886-2-29174598 URL:http://www.princeton.com.tw Electronic Volume Controller IC PT2256 REVISION HISTORY Date Revision # Reference # September, 2000 01 PT2256 v1.3 July, 19, 2004 02 PT2256V1.4 August, 13, 2004 03 PT2256 V1.5 March, 24, 2006 04 PT2256 V1.6 August, 15, 2006 05 PT2256 V1.7 PT2256 V1.7 - 21 - Remarks Modification #: 000803 Approval #: 000902 Request #: Request No.: 040708 Approval #: 040705 Modification #: 040705 Request No.: 040811 Approval #: 040806 Modification #: 040805 Approval #: 060316 Modification #: 060315 Approval #: 060811 Modification #: 060806 August, 2006