ISD17240SYI - 240s Multi-Message Voice Record/Playback IC | Nuvoton
MPN: ISD17240SYI ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.85 | $7.85 |
| 10 | $7.1 | $71.00 |
| 100 | $6.05 | $605.00 |
| 500 | $5.2 | $2,600.00 |
| 1,000 | $4.55 | $4,550.00 |
ISD17240SYI Overview
A multi-message voice record and playback IC (often abbreviated "voice recorder IC" or "ChipCorder") is a self-contained digital audio subsystem that integrates non-volatile storage, an analog microphone preamplifier with Automatic Gain Control, an anti-aliasing filter, a sigma-delta codec, smoothing output filter, and a Class-D-compatible PWM/speaker driver on a single silicon die. In the broader component taxonomy, the ISD1700 family belongs to the audio processor / audio DSP IC category, which itself sits under interface ICs and signal-chain semiconductors used in embedded systems. Because storage is on-chip (no external SPI/I2C EEPROM required), designers eliminate BOM cost and PCB area.
Key features include 2.4 V to 5.5 V single-supply operation, on-chip 160 kΩ microphone bias resistor, pushbutton and SPI control interfaces, selectable sampling rates, and message management that supports up to 8 segments. The device supports both standalone pushbutton operation (no MCU required) and SPI-driven operation for microcontroller-managed playback sequencing. Power-down current is sub-microamp, enabling battery-friendly operation in always-on voice prompt designs.
The ISD17240SYI uses Nuvoton's proprietary zero-power-on multilevel storage technology, which stores audio samples directly in on-chip non-volatile cells rather than converting to a compressed digital stream. This eliminates codec delay and provides instant-on playback in less than 25 ms from trigger, with no software audio stack. The architecture trades bit-depth and noise floor for ultra-low quiescent power and BOM simplification.
Typical applications include industrial voice prompt modules, elevator floor announcers, security alarm voice warnings, medical device audio prompts, vending machine announcements, and consumer appliance voice feedback. The wide 2.4 V to 5.5 V supply range lets the same part serve 3.3 V MCU rails or 5 V industrial buses.
When designing with this device, include a decoupling capacitor of at least 0.1 µF directly across VCC and VSSA pins placed within 5 mm, route the analog ground (VSSA) separately back to the regulator, and ensure speaker traces are short and balanced to minimize click/pop artifacts on playback start.
This page synthesizes distributor pricing, pin-compatible Nuvoton alternatives in the ISD1700 family, and practical design notes not consolidated in the manufacturer datasheet alone.
Drop-in alternatives for ISD17240SYI — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ISD17240SYIR
✅ Drop-In📋 Reference alternative (not in catalog)
ISD17240SY
✅ Drop-In📋 Reference alternative (not in catalog)
ISD17360SYI
✅ Drop-In📋 Reference alternative (not in catalog)
ISD17210SYI
✅ Drop-In📋 Reference alternative (not in catalog)
ISD1790SYI
✅ Drop-In📋 Reference alternative (not in catalog)
ISD17240SYI Specifications
| Product Type | Multi-Message Voice Record/Playback IC |
| Function | Single-chip record and playback |
| Recording Duration | 160 to 480 seconds (sample-rate dependent) |
| Supply Voltage | 2.4 V to 5.5 V |
| Sampling Frequencies | 4 kHz / 5.3 kHz / 6.4 kHz / 8 kHz |
| On-chip Microphone Bias Resistor | 160 kΩ |
| Control Interface | Pushbutton and SPI |
| Package | 28-SOIC |
| Operating Temperature Range | -40 °C to +85 °C (industrial) |
| Number of Messages | Multiple messages, up to 8 segments |
| Output Stage | Differential PWM speaker driver |
| Microphone Input | Analog with on-chip AGC preamplifier |
| Mounting Type | Surface Mount |
| Lead-Free / Pb-Free | Yes |
| RoHS Status | Compliant |
ISD17240SYI Pin Configuration
| Pin 1 | VCC — Power supply, 2.4 V to 5.5 V |
| Pin 2 | VSSD — Digital ground |
| Pin 3 | VSSA — Analog ground |
| Pin 4 | SP+ — Speaker positive output (PWM differential) |
| Pin 5 | SP- — Speaker negative output (PWM differential) |
| Pin 6 | MIC+ — Microphone positive input |
| Pin 7 | MIC- — Microphone reference (or AGND) |
| Pin 8 | AGC — Automatic Gain Control capacitor |
| Pin 9 | REC — Pushbutton record input |
| Pin 10 | PLAYE — Pushbutton edge-triggered playback |
| Pin 11 | PLAYL — Pushbutton level-triggered playback |
| Pin 12 | FT — Feed-through / erase pushbutton |
| Pin 13 | STOP — Stop pushbutton (or run if held low at power-up) |
| Pin 14 | VOL0 — Volume control bit 0 |
| Pin 15 | VOL1 — Volume control bit 1 |
| Pin 16 | VOL2 — Volume control bit 2 |
| Pin 17 | ROSC — Sampling-rate resistor |
| Pin 18 | LED — Record/playback indicator LED driver |
| Pin 19 | MISO — SPI Master-In Slave-Out |
| Pin 20 | MOSI — SPI Master-Out Slave-In |
| Pin 21 | SCLK — SPI serial clock |
| Pin 22 | SSB — SPI active-low chip select |
| Pin 23 | INT — Interrupt output (active low) |
| Pin 24 | RDY — Ready status output |
| Pin 25 | EOM — End-of-message marker output |
| Pin 26 | RESET — Chip reset (active low) |
| Pin 27 | NC — Not connected |
| Pin 28 | NC — Not connected |
Typical Applications
ISD17240SYI is suitable for 6 applications: Industrial Voice Prompt Module, Elevator Floor Announcer, Security Alarm Voice Warnings, Medical Device Audio Prompts, Vending Machine Announcements, Consumer Appliance Voice Feedback.
Industrial Voice Prompt Module
The ISD17240SYI is well suited for industrial voice prompt modules where announcements, status messages, or alarm narrations of 30 to 120 seconds are required. Its 160 to 480 second recording capacity covers most industrial narration scenarios with margin for multi-language prompts or chained segment playback. The 2.4 to 5.5 V supply lets it share the 24 V-to-5 V industrial bus rail, while the -40 to +85 °C industrial temperature grade handles outdoor control cabinets and factory-floor enclosures. Differential PWM outputs directly drive an 8 Ω speaker without an external amplifier, eliminating a stage of analog design. Pushbutton standalone mode means a single IC replaces a microcontroller plus firmware plus audio DAC plus EEPROM, dramatically reducing BOM and BOM-risk.
Recommended
Elevator Floor Announcer
The ISD17240SYI fits elevator floor announcers that play short floor-arrival prompts, ding chimes, and direction announcements on every stop. With 160 seconds minimum at 8 kHz, the part can hold 30 to 40 distinct messages in eight segments without external storage, and instant-on playback in under 25 ms keeps announcements synchronized to door-open events. Its SPI interface allows a small MCU to select messages per floor; pushbutton mode lets simple installations skip the MCU entirely. The 5 V supply range aligns with elevator control-panel rails, and the differential PWM speaker output drives 8 Ω floor-indicating speakers directly. The industrial temperature grade supports unheated machine-room installations.
Recommended
Security Alarm Voice Warnings
The ISD17240SYI delivers pre-recorded warning voice prompts for security alarms, smoke detectors, and intrusion panels where clear human-voice narration is preferred over simple beeps. The 480 second maximum at 4 kHz sample rate is enough for multiple language variants of "Smoke detected, evacuate," "Intruder detected," and instructional messages, and the on-chip AGC amplifier captures consistent audio levels from different microphone placements. Pushbutton-trigger mode allows alarms to fire pre-stored warnings during power-on self-test without any controller; SPI mode allows firmware updates of new messages. The 2.4 to 5.5 V range accepts backup-battery power during mains loss, and the sub-microamp power-down current preserves battery life.
Recommended
Medical Device Audio Prompts
The ISD17240SYI provides safe, low-power voice prompting for medical devices such as blood-pressure monitors, glucometers, nebulizers, and patient-bedside terminals. Its 160 to 480 second capacity covers instructional narration ("Place cuff on upper arm,", "Reading in progress,", "Your reading is...") in multiple languages. The on-chip AGC keeps prompt loudness consistent regardless of microphone positioning during production calibration, and the differential PWM output drives a small speaker without external amplifier stages that could fail safety certification. The industrial temperature grade supports equipment-storage at -20 °C and operating-room conditions; SPI control allows medical firmware to update prompts without factory re-flash. The 2.4 V minimum supply supports lithium-battery operation for portable devices.
Recommended
Vending Machine Announcements
The ISD17240SYI gives vending machines and kiosks human-voice prompts for transactions ("Please insert coin,", "Thank you for your purchase,", "Out of stock") without adding a digital audio codec stack. The 160-second capacity at 8 kHz covers 20 to 30 short prompts in eight segments and supports SPI-driven firmware updates of marketing messages. The on-chip 160 kΩ microphone bias resistor simplifies analog front-end design and reduces BOM count. The differential PWM outputs connect directly to an 8 Ω speaker, eliminating a separate amplifier IC and its associated decoupling. Industrial temperature grading supports outdoor vending enclosures in unheated conditions.
Recommended
Consumer Appliance Voice Feedback
The ISD17240SYI adds voice feedback to consumer appliances such as washing machines, microwave ovens, dishwashers, and air purifiers, replacing beeps with clear spoken status ("Wash cycle complete," "Filter needs replacement"). Its 5 V tolerance aligns with the 5 V standby rails common in white-goods designs, and the SPI interface allows appliance firmware to trigger contextual prompts based on cycle state. The 480-second capacity handles full multi-stage narration across cooking or wash profiles. On-chip non-volatile storage keeps prompts intact across power cycles with zero standby current; industrial temperature rating supports appliance compartment thermal stress and unheated garages.
Recommended
Recommended Products Summary
Engineering reference data for ISD17240SYI — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ISD17240SYIR | ISD17240SY | ISD17360SYI | ISD17210SYI | ISD1790SYI |
|---|---|---|---|---|---|---|
| Package | 28-SOIC | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same |
| Brand | Nuvoton Technology Corporation | Nuvoton Technology Corporation | Nuvoton Technology Corporation | Nuvoton Technology Corporation | Nuvoton Technology Corporation | Nuvoton Technology Corporation |
| Recording Duration | 160 to 480 sec | 160 to 480 sec (same die) | 160 to 480 sec (same die) | 240 to 720 sec (+50%) | 80 to 240 sec (-50%) | 60 to 120 sec (-75%) |
| Supply Voltage | 2.4 V to 5.5 V | 2.4 V to 5.5 V | 2.4 V to 5.5 V | 2.4 V to 5.5 V | 2.4 V to 5.5 V | 2.4 V to 5.5 V |
| Operating Temperature | -40 to +85 C (industrial) | -40 to +85 C (industrial) | 0 to +70 C (commercial) | -40 to +85 C (industrial) | -40 to +85 C (industrial) | -40 to +85 C (industrial) |
| Control Interface | Pushbutton + SPI | Pushbutton + SPI | Pushbutton + SPI | Pushbutton + SPI | Pushbutton + SPI | Pushbutton + SPI |
| Sampling Rates | 4 / 5.3 / 6.4 / 8 kHz | 4 / 5.3 / 6.4 / 8 kHz | 4 / 5.3 / 6.4 / 8 kHz | 4 / 5.3 / 6.4 / 8 kHz | 4 / 5.3 / 6.4 / 8 kHz | 4 / 5.3 / 6.4 / 8 kHz |
| Packaging Format | Tube | Tape and Reel | Tube | Tube | Tube | Tube |
| RoHS / Pb-Free | Compliant / Pb-Free | Compliant / Pb-Free | Compliant / Pb-Free | Compliant / Pb-Free | Compliant / Pb-Free | Compliant / Pb-Free |
Key Differentiators
- Industrial temperature grade in same package as commercial variant (vs ISD17240SY)
- Mid-tier duration fits most industrial prompts with capacity margin (vs ISD17210SYI)
- Pin-compatible capacity expansion path within same family (vs ISD17360SYI)
Design Notes
Place a 0.1 µF ceramic decoupling capacitor within 5 mm of the VCC pin and tie VSSA directly back to the regulator ground with a short trace. The analog and digital grounds (VSSA, VSSD) must connect at a single point near the IC to prevent digital switching noise from coupling into the microphone preamplifier, which would otherwise increase recording background noise. For battery-powered designs, leverage the sub-microamp power-down current by holding STOP low when idle.
Route the SP+ and SP- differential PWM traces as a balanced pair, keeping them short and matched in length to minimize click/pop artifacts at playback start. Keep analog input traces (MIC+, MIC-) away from switching regulators and SPI clock traces to prevent audio-band noise pickup. Place the ROSC resistor within 10 mm of pin 17 to prevent sample-rate jitter. Use a ground pour under the IC and stitch with vias around the package perimeter to provide a low-impedance return path.
Do not exceed 5.5 V on VCC, even transiently; the analog front end will latch and require power cycling to recover. The volume-control pins (VOL0-VOL2) have internal pull-ups and must be tied to GND for default full-volume operation; leaving them floating produces indeterminate output levels. When using SPI mode, ensure SSB is held high during power-up so the device enters the configured SPI mode rather than pushbutton mode. Sampling rate selection via ROSC must match the desired recording duration budget; ROSC value is critical and should be chosen per the Nuvoton datasheet table before laying out the board.
Compliance Information
Pb-Free / RoHS compliant per Mouser product listing and DigiKey catalog. Industrial temperature grade (not AEC-Q100 qualified; this is consumer/industrial voice IC, not automotive). REACH and halogen-free status not stated in the provided distributor data - set to unknown.
