ChipCorders - Which to Choose?

In my last post, I talked about the single message versions of the ChipCorders. All of them are fully self contained devices, just add pushbuttons, microphone and speaker the chip records or plays what ever is in its single memory. There are many applications, however that need multiple messages. There are a lot of ChipCorders to chose from. How do you pick which one to use? Here are a list of questions that will help you zero in on what you need.

1. Does your system already have a speaker driver and a microphone or line input?
Answer: If you already have those parts of your system, you don't need to reproduce them on the ChipCorder. The only "plain" analog memory are the ISD4000 series. These parts have what is essentially a Line-In and Line-out audio interface. They don't have a microphone pre-amp or a speaker driver. They are controlled by an SPI interface with an address resolution of 200 to 400 millseconds. I'll talk more on what that means later. There are 4 different size versions of this part with each having 4 different sample rate offerings. I'll try to explain that later also.

2. Do you have multiple audio inputs you want to mix into and/out of the ChipCorder's analog memory?
Answer: The swiss army knife of ChipCorders is the ISD5100 series. These devices have the same microphone interface as the rest of the ChipCorders but also have 2 other analog inputs, each with 4 different gain settings possible. They also have the standard ChipCorder speaker driver output but additionally have 2 other analog outputs possible. All of the inputs, outputs and analog memory can be configured almost any way, including mixed together. You can even use the on-board anti-aliasing filters in your application for other things beside record and playback.

And if that wasn't enough, all the early mentioned ChipCorders including the afore mentioned ISD4000 series had to be ordered with a fixed sample rate. In the ISD5100 series you can pick your sample rate via software on the fly. Which means you can record some of your messages at one sample rate and others at a different sample rate to maximize the efficiency of the storage area in the part. There are just 4 size versions of the ISD5100 series since you can control the sampe rate via software.

The ISD5100 series is controlled via a two wire I2C interface.

3. Do you need multiple messages but don't want the cost of a micro?
Answer: One of the latest ChipCorders is the ISD1900 series. These parts can be divided into 8 equal length messages where access to each message is controlled by a pin. Or in other words with the correct pin strapping you can build a system with 8 push buttons used to play or record up to 8 individual messages.

Another option is the ISD1700 series which has the best of both worlds (sort of). It has a simple (and a bit crude) multiple message capability. With the chips simple push button interface, you can stack messages in the chip's memory until you run out of space then you can erase the first or last messages and record more. Its sort of a circular memory.

This blog entry is long enough! If you have questions, add a comment to the blog and I'll answer them or get them answered.

Note: ChipCorder is a registered trademark of Nuvoton. This blog is an independent effort and in no way connected to Nuvoton.