Part A
ISL81487LIBZ
Renesas Electronics America Inc.
- Lifecycle
- Active
- Stock
- 3479 PCS
- Package
- SOIC-8
- Series
- Interface - Condutores, Receptores, Transceivers
Replacement verdict
Not a drop-in replacement
The ISL81487LIBZ and ISL8105BCBZ-T are fundamentally different devices and cannot be used interchangeably. The ISL81487LIBZ is an RS-485/RS-422 transceiver, while the ISL8105BCBZ-T is a synchronous buck PWM controller. They differ in function, pinout, package, and electrical characteristics, making cross-replacement impossible without a complete redesign.
Different device function
Different pinout
Different package
Different supply voltage
Parts at a glance
Part B
ISL8105BCBZ-T
Renesas Electronics America Inc.
- Lifecycle
- Active
- Stock
- 6257 PCS
- Package
- SOIC-8
- Series
- PMIC - Reguladores de Voltação - Controladores de Troca DC
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ISL81487LIBZ | ISL8105BCBZ-T | Why it matters |
|---|---|---|---|
| Function | RS-485/RS-422 transceiver | Synchronous buck PWM controller | These devices perform completely different functions, so they are not functionally substitutable in any design. |
| Manufacturer | Renesas Electronics | Renesas Electronics | Same manufacturer, but this does not imply interchangeability between different product families. |
| Package / Mounting Type | 8-SOIC, surface mount | 10-SOIC, surface mount | Different pin counts and footprints prevent direct board-level replacement. |
| Supply Voltage Range | 4.5 V to 5.5 V | 5 V nominal (controller supply) | Operating voltage compatibility is essential for powering the device correctly in a target system. |
| Primary Interface / Control Type | Differential serial data (A/B bus pins) | PWM gate-drive outputs (UGATE/LGATE) | The signal interface determines what external circuitry the device can connect to and control. |
| Typical Application | Industrial data communication buses | DC-DC power conversion / voltage regulation | Application domain mismatch means the parts serve unrelated roles in a system. |
| Data Rate / Switching Frequency | Up to 250 kbps (slew-rate limited) | Fixed switching frequency (controller) | Speed and frequency specifications define the performance envelope and cannot be interchanged. |
| Number of Pins | 8 | 10 | Pin count difference directly affects PCB layout and socket compatibility. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ISL81487LIBZ | ISL8105BCBZ-T |
|---|---|---|
| Supplier | - | Renesas Electronics America Inc |
| Part Status | Active | Obsolete |
| Output Type | - | Transistor Driver |
| Function | - | Step-Down |
| Output Configuration | - | Positive |
| Topology | - | Buck |
| Number of Outputs | - | 1 |
| Output Phases | - | 1 |
| Voltage - Supply (Vcc/Vdd) | - | 6.5V ~ 14.4V |
| Frequency - Switching | - | 300kHz |
| Duty Cycle(Max) | - | 100% |
| Synchronous Rectifier | - | Yes |
| Clock Sync | - | No |
| Control Features | - | Current Limit, Enable |
| Operating Temperature | -40°C ~ 85°C | 0°C ~ 70°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
| Type | Transceiver | - |
| Protocol | RS422, RS485 | - |
| Number of Drivers/Receivers | 1/1 | - |
| Duplex | Half | - |
| Receiver Hysteresis | 70 mV | - |
| Data Rate | 5Mbps | - |
| Voltage - Supply | 4.5V ~ 5.5V | - |
Frequently asked questions
Are the ISL81487LIBZ and ISL8105BCBZ-T interchangeable in a circuit design?
No. The ISL81487LIBZ is a half-duplex RS-485/RS-422 transceiver, while the ISL8105BCBZ-T is a synchronous buck PWM controller. They perform entirely different functions and are not pin-to-pin or functionally interchangeable.
What are the primary functions of the ISL81487LIBZ and ISL8105BCBZ-T?
The ISL81487LIBZ is a 5V-powered, half-duplex RS-485/RS-422 differential transceiver designed for bidirectional data communication over twisted-pair cables. The ISL8105BCBZ-T is a synchronous buck controller intended for DC-DC step-down voltage regulation in power supply designs.
What are the package types for the ISL81487LIBZ and ISL8105BCBZ-T?
The ISL81487LIBZ is offered in an 8-lead SOIC package. The ISL8105BCBZ-T is supplied in an 8-lead SOIC package with a tape-and-reel option (suffix -T). Both use SOIC-8, but their pinouts and functions differ.
Can the ISL81487LIBZ and ISL8105BCBZ-T operate from the same supply voltage?
The ISL81487LIBZ operates from a single 5V supply. The ISL8105BCBZ-T is a controller IC that typically operates from a 5V or 12V bias supply, depending on the application circuit, and is not a direct load-driving transceiver. Their supply requirements and operating conditions are not equivalent.
Do the ISL81487LIBZ and ISL8105BCBZ-T share any common applications?
No. The ISL81487LIBZ is used in industrial automation, data acquisition, and RS-485 networks. The ISL8105BCBZ-T is used in embedded DC-DC power converters, point-of-load regulators, and distributed power systems. Their application domains do not overlap.
Are the ISL81487LIBZ and ISL8105BCBZ-T available in the same temperature grade?
The ISL81487LIBZ is specified for the industrial temperature range of -40°C to +85°C. The ISL8105BCBZ-T is also specified for the industrial temperature range of -40°C to +85°C. However, this similarity does not imply functional compatibility.
Can the ISL81487LIBZ be used as a substitute for the ISL8105BCBZ-T in a power supply design?
No. The ISL81487LIBZ is a transceiver and cannot perform PWM control, gate driving, or voltage regulation. Substituting it for the ISL8105BCBZ-T would result in a non-functional power supply and potential damage to the circuit.