HT8665 Talking Back with Echo Features • • • • • Single power supply: 4.5V~5.5V ADM algorithm Auto playback with an echo effect DRAM options: – 64K – 256K Sampling rate options: – 32K bps (bits per second) – 16K bps • • • • • • • Recording capacity: 2, 4, 8, 16 seconds A built-in 2 stage microphone amplifier A built-in DRAM refresh circuit A voltage type D/A output A current type D/A output Auto power-off Low power dissipation • Games Applications • • Toys Educations General Description The HT8665 provides a recording capacity of 2 seconds at a 32K bps sampling rate for DRAM of 64K (8 seconds for DRAM of 256K) and 4 seconds at a 16K bps sampling rate (16 seconds for DRAM of 256Kb). A higher sampling rate results in sounds of better quality but sacrifices the recording time, and vice versa. The HT8665 is a single chip CMOS LSI using an ADM algorithm. It is designed for applications on talking back with an echo effect. Functions of the IC consist of recording/playing and auto power off in addition to an echo effect. The IC starts recording when a sound input is detected, and stops to play back when silence lasts 0.5 seconds during recording. The auto power off function is activated once a REC/PLAY cycle has been implemented 64 times or an interval of silence exceeds 2 minutes. 1 21st Dec ’95 HT8665 Pin Assignment Pad Assignment A0 1 40 A2 RASB 2 39 A1 WRB 3 38 A3 DATA 4 37 A4 A8 5 36 A5 NC 6 35 NC CASB 7 34 A6 VDD 8 33 A7 MOTOR 9 32 VSS LEDB 10 31 MS IOUT NC 11 30 DS 12 29 TESTB VOUT 13 28 16KB MIXIN 14 27 START NC 15 26 AIN1 NC 16 25 NC NC 17 24 AIN2 MIXOUT 18 23 AO1 OSC1 19 22 BIAS OSC2 20 21 ADMOUT HT8665 – 40 DIP Chip size: 3260 × 3080 (µm)2 * The IC substrate should be connected to VSS in the PCB layout artwork. Block Diagram 2 21st Dec ’95 HT8665 Unit: µm Pad Coordinates Pad No. X Y Pad No. X Y 1 2 3 4 5 6 7 8 9 10 11 12 13 14 –1447.00 –1434.00 –1447.00 –1447.00 –1429.50 –1447.00 –1450.00 –1106.50 –813.00 –31.00 296.00 626.00 881.50 1143.50 977.75 648.25 354.75 99.25 –178.75 –1004.75 –1300.75 –1300.75 –1300.75 –1300.75 –1300.75 –1300.75 –1300.75 –1300.75 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1447.00 1447.00 1447.00 1442.00 1447.00 1447.00 1346.00 1020.00 741.00 460.00 181.00 –100.00 –393.00 –674.00 –452.75 –189.75 75.25 434.25 718.75 999.75 1300.75 1300.75 1300.75 1300.75 1300.75 1300.75 1300.75 1300.75 15 1447.00 –1305.75 32 –983.50 1300.75 16 17 1447.00 1447.00 –965.25 –717.75 33 –1340.00 1300.75 Pin Description Pin No. Pin Name I/O Internal Connection Description 1 A0 O CMOS DRAM address output 2 RASB O CMOS DRAM row address strobe 3 WRB O CMOS DRAM write enable 4 DATA I/O CMOS DRAM data input/output 5 A8 O CMOS DRAM address output 6 NC — — 7 CASB O CMOS 8 VDD I — 9 MOTOR O CMOS No connection DRAM column address strobe Positive power supply Motor drive output (active high) 10 LEDB O LED indicator: NMOS Idle: LED is turned on; Open Drain Record: LED flashes; Play: LED is turned off. 11 IOUT O PMOS Current type audio output for an external transistor Open Drain 3 21st Dec ’95 HT8665 Pin No. Pin Name I/O Internal Connection Description 12 NC — — No connection 13 VOUT O — Voltage type audio output for an external power AMP 14 MIXIN I — Echo mixer input 15 NC — — No connection 16 NC — — No connection 17 NC — — No connection 18 MIXOUT O — Echo mixer output 19 OSC1 I — Oscillator input 20 OSC2 O — Oscillator output 21 ADMOUT O — ADM D/A output 22 BIAS O — For OP bias de-coupling 23 AO1 O — Internal AMP first stage output 24 AIN2 I — Internal AMP second stage input (inverting) 25 NC — — No connection 26 AIN1 I — Internal AMP first stage input (inverting) 27 START O CMOS 28 16KB I Pull-High Sampling rate selection: Open/high: 32K bps; Low: 16K bps 29 TESTB I Pull-Low For IC test only System start pin 30 DS I Pull-High Echo delay time selection: 1. DRAM of 64K: Open/high: 256ms; Low: 128ms 2. DRAM of 256K: Open/high: 512ms; Low: 256ms 31 MS I Pull-High DRAM size selection: Open/high: 64K; Low: 256K 32 VSS I — 33 A7 O CMOS DRAM address output 34 A6 O CMOS DRAM address output 35 NC — — 36 A5 O CMOS Negative power supply (GND) No connection DRAM address output 4 21st Dec ’95 HT8665 Pin No. Pin Name I/O Internal Connection Description 37 A4 O CMOS DRAM address output 38 A3 O CMOS DRAM address output 39 A1 O CMOS DRAM address output 40 A2 O CMOS DRAM address output Absolute Maximum Ratings Supply Voltage ................................. –0.3V to 6V Storage Temperature................. –50°C to 125°C Input Voltage................. VSS–0.3V to VDD+0.3V Operating Temperature............... –20°C to 70°C (Ta=25°C) Electrical Characteristics Symbol Parameter Test Condition VDD Condition Min. Typ. Max. Unit VDD Operating Voltage — — 4.5 — 5.5 V IOP Operating Current 5V No load, FOSC=1MKHz — 3 6 mA IOH1 IOUT Max. Source Current 5V VOH=0.5V –1.5 –3 — mA IOH2 MOTOR Source Current 5V VOH=4.5 –1 –3.5 — mA IOL LED Sink Current 5V VOH=0.5V 3 –3.5 — mA VIH “H” Input Voltage — — 0.7VDD — VDD V VIL “L” Input Voltage — — 0 — 0.3VDD V VOUT Max. VOUT Output Voltage 5V RL>50K — 1.5 — VP-P FOSC System Frequency 5V ROSC=27K — 1 — MHz 5 21st Dec ’95 HT8665 Functional Description The HT8665 is a single chip LSI with an external DRAM. It is designed for applications on talking back with an echo effect. The recording length of the IC is decided by the data rate along with the size of an external memory. Sounds input from an external microphone are coded through an internal ADM algorithm and saved in an external memory until the memory is full or an interval of silence lasts over 0.5 seconds. Once recording is terminated, the IC will play back the recorded sounds with an echo effect automatically. x DRAM Play function The HT8665 stops to play back the recorded sounds when an interval of silence lasts 0.5 seconds or the memory is full during recording. Its playing rate is the same as the rates of recording and echo effect. The echo delay time is settable by the DS pin as shown. DS 1 0 64Kb 256ms 128ms 256Kb 512ms 256ms DRAM Accumulator Power control Step Size The HT8665 provides a START pin for power control. The START pin is of high impedance and switch Q is turned off at initial. After the START key is triggered, it will output a high level signal and switch Q is turned on. This pin outputs a low level signal and the power of LSI is switched off when a REC/PLAY cycle has been implemented 64 times or an interval of silence lasts over 2 minutes. Estimation D/A + Delay Record function Q The HT8665 provides 2 kinds of sampling rate as well as DRAM interfaces. The sampling rate (S.R.) along with DRAM determine the recording capacity as shown in the following table: (for FOSC=640 KHz) MS (DRAM) 16KB (S.R.) Recording Capacity 1 (64Kb) 1 (32K bps) 2 seconds 1 (64Kb) 0 (16K bps) 4 seconds 0 (256Kb) 1 (32K bps) 8 seconds 0 (256Kb) 0 (16K bps) 16 seconds VDD START VSS Motor The HT8665 provides a motor driving pin. The motor is turned on during playing but off once talking back is terminated. Status display Notes: “1” is connected to VDD or left open. The HT8665 provides an LEDB pin to display its operation status.An external LED is switched on when the IC is in the standby state. It, on the other hand, is switched off when the IC is in the playing state. The LED will flash with the sound volume when the IC is in the recording state, but its intensity will vary inversely with the volume. “0” is connected to VSS. Recording starts whenever a sound input is detected. It then stops once silence is detected or the recording capacity is full. After that, talking back comes into play. 6 21st Dec ’95 HT8665 Flowchart Begin Power Off N START Y Power On Idle State, LED On Voice Input N Y Stay 2 mins N Record State, LED Flash Y Silence or Memory Full N Y Play State, LED Off Silence or Memory Full N Y Increase Recycle Counter N Recycle Counter=64 Y 7 21st Dec ’95 HT8665 Application Circuits LM386 output 8 21st Dec ’95 HT8665 9 21st Dec ’95 HT8665 Two transistor output 10 21st Dec ’95 HT8665 11 21st Dec ’95 HT8665 LM324 output 12 21st Dec ’95 HT8665 100 22µ 10V 8 18 5 A0 7 A1 6 A2 12 A3 11 A4 10 A5 13 A6 9 A7 A8 1 RASB 4 CASB 15 WRB 3 100K DI 2 DO 14 500P MIC 0.1µ 1 39 40 38 37 36 34 33 5 2 7 3 4 29 26 24 23 19 A2 A1 A0 MS START LEDB VDD DS 16KB A5 MOTOR A3 A6 MIXOUT A4 A7 ADMOUT MIXIN A8 RASB CASB WRB DATA IOUT TESTB AIN1 VSS BIAS VOUT AIN2 OSC2 AO1 OSC1 HT8665 27K 8 10 27 28 31 30 9 18 21 14 13 11 22 32 20 100 10K 50K 20K 10K 1K 10K 3 U1A 2 LM324 8050 5.6V 8050 10µ 10V 1K 20K 200K 0.1µ 10µ 10V 8550 START 8050 1K M VCC2 27P VCC 9V 100µ 10V 43K 4 7 10 8 9 LM324 U1C 11 U1B 5 LM324 6 10K 3900P 0.1µ 36K 4001 36K 22µ 10V 1 36K 18K 0.1µ 8050 8550 SPK 8Ω 21st Dec ’95 13 VDD 4.7K 30K 0.1µ VSS 64K/256K DRAM