Application of KT148A Voice Chip in Segmented Fields such as Electronic Music Cards, E-Cards and E-Invitations

 I、Introduction

With the explosion of personalized demands in consumer electronics, segmented products such as electronic music cards, e-cards and e-invitations are upgrading from traditional static forms to dynamic interactive experiences. As a cost-effective 32-bit DSP voice chip, KT148A provides an ideal solution for such scenarios with its flexible voice customization capability, low-power design and minimalist hardware interface. This article deeply analyzes the chip characteristics, application scenarios and technical implementations.


II、Core Advantages of KT148A Chip for Interactive Voice Scenarios

KT148A adopts a standard SOP8 package but integrates voice processing capabilities far exceeding similar products: the built-in 420KB storage space can accommodate up to 420 seconds of voice content (up to 400 seconds at 8KHz sampling), and the design of directly driving an 8Ω/0.5W speaker eliminates the need for an external power amplifier circuit, greatly simplifying the hardware layout of card-type products. Its unique technical advantages are particularly prominent in segmented scenarios:

2.1 High Cost-performance Ratio and Reprogrammable Feature

Compared with traditional OTP voice chips, KT148A reduces costs through improved manufacturing processes and supports users to replace voice content by themselves via the serial port. This feature is crucial for small-batch customization scenarios—for example, wedding invitations can quickly update blessing voices according to different couples' needs without re-taping.

2.2 Minimalist Hardware Interface and Low-power Design

The chip adopts a one-wire serial communication protocol, completing voice control with only one data line. Combined with the key triggering function of the PB0 pin (playback by grounding), it realizes the minimalist interaction of sound activation when the card is opened. In terms of power consumption control, the current consumption in standby state is only 25μA, and the ultra-low power mode of 1.7μA entered by the F0 command allows electronic cards to stand by for months under button battery power supply.

2.3 Flexible Voice Management Function

It supports 224 voice segment addresses (expandable to more via the F4 command), meeting the multi-voice segment requirements of complex scenarios. For example, music cards can store multiple pieces of music, triggered for playback by different keys; the F2 loop playback and F3 combined playback commands enable seamless connection between blessing voices and background music.

III、Application Solutions and Innovative Designs in Segmented Scenarios

3.1 Electronic Music Cards: Experience Upgrade from Static to Dynamic

Traditional music cards mostly use pre-recorded voice chips with fixed and unupdatable content. The KT148A solution breaks through this limitation:

• Hardware Implementation: Ground the PB0 pin through a touch switch. When the card is opened, the trigger circuit is turned on, and the chip automatically plays the preset voice; SPK1/SPK2 are directly connected to a miniature speaker without an additional amplifier circuit.

• Voice Customization: Users can convert WAV format audio to F1A format through PC tools and download it to the chip via a CH340G USB-to-TTL module. For example, festival cards can record personalized blessings, and birthday cards can add customized songs.

• Low-power Optimization: After playback, the chip automatically enters a 25μA standby state, achieving a standby time of more than 6 months with a CR2032 battery.

3.2 Interactive E-cards: Multi-segment Voice and Scene Linkage

In high-end greeting card scenarios, the combined playback function of KT148A creates a hierarchical voice experience:

• F3 Command Application: Sending the F3+0x01+0x02+0x03 command plays three segments in sequence: "welcome message → blessing message → background music", with an interval of about 20ms between segments to create a smooth voice narrative chain.

• Dynamic Volume Adjustment: 15-level volume control is realized through the 0xE0-0xEF command. For example, wedding invitations can set medium volume (0xE8) in indoor environments to avoid excessive sound affecting the experience.

• Address Extension Application: For greeting cards needing to store multiple pieces of music, the F4 command can extend the address. For example, sending F4 01 23 (0x123=291) plays the 291st voice.

3.3 E-invitations: Integration of Personalized Voice and Minimalist Hardware

As a high-end etiquette carrier, e-invitations have higher requirements for sound quality and reliability:

• Sound Quality Optimization: It is recommended to convert audio with a 16KHz sampling rate and 6Kbps bit rate. About 200 seconds of high-quality voice can be stored in 420KB space to meet the needs of complete invitation words and background music.

• Anti-interference Design: Series a 1KΩ resistor between the PB1 data pin and the MCU to match the 3.3V TTL level, avoiding signal interference when the card is folded.

• Mass Production Solution: By contacting the customer service, the customized voice can be written into the pre-factory program at one time and burned into the chip along with the program burning, achieving batch customization of voice and solving the efficiency problem of mass production.

IV、Key Points of Technical Implementation and Debugging Guide

4.1 Core Points of Hardware Design

• Power Connection Strategy: Directly connect VBAT (Pin8) when using a 3.7V lithium battery. If using a 2-3V button battery, short Pin7 (VDDIO) and Pin8 to ensure the chip works stably at low voltage.

• Download Mode Activation: When updating the voice, ground SPK1 (Pin5) before power supply, and release it after hearing a "beep" to enter the download mode.

• Speaker Matching: Choose an 8Ω/0.5W miniature speaker first. If the volume is insufficient, replace it with an 8Ω/1W model, and the chip driving capability is compatible with this load.


4.2 Practice of One-wire Communication Protocol

The one-wire communication of KT148A adopts a unique pulse width encoding:

/ One-wire data sending example (play the 5th voice)

void play_voice5() {

    oneline_send_one_data(0x05); // Send voice address 0x05

}

// Loop playback implementation

void loop_play() {

    oneline_send_one_data(0x01); // First send the target voice address

    udelay(20); // Wait for 20ms

    oneline_send_one_data(0xF2); // Send loop command

}

During communication, ensure that the start signal is a 6ms low level, and the data bit uses 200μs high level + 600μs low level to represent "1", and vice versa for "0", with the error controlled within 10%.

4.3 Common Problems and Solutions


V、Industry Trends and Scene Extension of KT148A

With the growth of the personalized gift market, electronic card products are evolving from single voice playback to multimodal interaction. The hardware IIC interface and UART interface of KT148A reserve space for function expansion—such as automatically detecting card opening and closing by connecting a light sensor via IIC; realizing more complex key logic through UART communication with the MCU.

In terms of cost control, the reprogrammable feature of KT148A avoids the trial-error cost of traditional OTP chips, especially suitable for e-commerce customized order scenarios. When more than 223 voice addresses are needed, the address extension scheme of the F4 command solves the massive voice storage demand at an extremely low cost, which is of great value in international business invitations requiring multilingual versions.

From the perspective of technological evolution, KT148A represents the "just right" design philosophy of voice chips in segmented fields—sufficient storage capacity, minimalist hardware interface, and power consumption control as low as 1.7μA, which exactly meets the balance requirements of electronic card products for function, cost and battery life. With subsequent firmware upgrades (such as the F4 command added in version V5), the application boundaries of this chip in segmented scenarios will continue to expand.

VI、Conclusion

With its characteristics of "small package, great capability", the KT148A voice chip provides the optimal solution from technology to cost for segmented fields such as electronic music cards, e-cards and e-invitations. Through the minimalist control of the one-wire serial port, flexible customization of reprogramming and low-power design, this chip is promoting the upgrading of traditional paper cards to intelligent interactive carriers. For hardware developers, mastering its one-wire communication protocol and voice processing process can open up new innovation space in the personalized gift market.

评论

发表评论

此博客中的热门博文

KT148A Voice Chip at Baidu Baike

图片
Voice Chip The KT148A Sound chip is developed by Shenzhen Qingyue Electronics Co., Ltd. and is widely used in security, transportation, and other fields. The KT148A is a 32-bit DSP voice chip in a standard SOP8 package. It features a built-in 420KByte voice storage space, supporting a maximum voice length of 420 seconds, multi-segment voice playback, direct driving of a 0.5W speaker, and user-replaceable voice content. Chinese Name: KT148A Sound Chip Developer: Shenzhen Qingyue Electronics Co., Ltd. Type: Voice Chip Applications: Security, transportation, and related fields 1. Product Overview The KT148A is a 32-bit DSP sound chip in a standard SOP8 package. It has a built-in 420KByte voice storage space, supporting up to 420 seconds of audio, multi-segment playback, direct driving of a 0.5W speaker, and allows users to replace voice content. 2. Product Advantages Cost Reduction & Reprogrammability: Improved manufacturing processes lower costs while allowing repeated firmware upd...
阅读全文

KT148A Voice Chip Issue: Difficult to Play with Code Sending - Normal Playback After Grounding Pin 4, What’s the Reason?

图片
Problem Description: Hello, we’ve encountered an issue and would appreciate your support: With the KT148A chip, after powering on, sending the code rarely triggers playback. However, if we use tweezers to briefly short Pin 4 (PB0) to ground and then send the code again, playback works normally. What could be causing this? Based on the observed behavior, it’s highly likely an issue with the timing of one-wire communication,  particularly with the start signal, which may be too short.  Let’s analyze this in detail and review the KT148A schematic as follows: 1. Pin 4 (PB0) of the Chip: PB0 is a test pin with the default factory function of triggering wake-up and playback when grounded. 2. Customer Description: When the customer uses tweezers to short PB0 (Pin 4) to ground, it follows this principle. The shorting action actually performs two operations: Action 1: The KT148A detects a falling edge signal, wakes up, exits low-power mode, and enters full-speed operation. Action 2: Th...
阅读全文

KT1025A Dual-Mode Bluetooth Audio Chip Layout Description and Design Precautions

图片
  1. Brief Overview 1. First, please refer to the provided BT201 test DEMO module as the standard. 2. If using the chip independently without testing the BT201 module and directly proceeding to layout, background noise is highly likely if experience is limited. Therefore, always compare with the manufacturer’s test board first. 3. The BT201 solution does not include FM functionality. Please note this. The FM circuit should be left floating without hesitation 2. Precautions 1. Background noise or interference is common in Bluetooth audio products. Do not be careless during layout. 2. If you have not worked on audio products before, study online resources thoroughly. Assuming things casually will naturally lead to noise issues. 3. The core principle is to separate analog ground and digital ground. If unclear, consult an experienced engineer. 4. Ensure a clean power supply. Use an LDO whenever possible instead of a DC-DC converter. 5. Bluetooth operates at high-frequency RF and radiat...
阅读全文