Component Comparison: Allegro A89505KLPTR vs A89103KETSR-5
Quick verdict
For full-bridge MOSFET gate driving in automotive-grade applications requiring a simple, independent dual-driver IC, the A89505KLPTR is the straightforward choice due to its focused feature set and compact 20-TSSOP package. Conversely, for three-phase motor control or multi-phase power conversion where floating high-side drivers and a wider supply voltage range are needed, the A89103KETSR-5 excels with integrated floating drivers, higher temperature rating, and a more flexible 4.5–85 V supply.
Spec comparison table
| Spec | A89505KLPTR | A89103KETSR-5 | Notes |
|---|---|---|---|
| Channel type | Independent | 3-Phase | 3-phase integration in A89103KETSR-5 simplifies multi-phase designs, reducing components. |
| Current peak output (source/sink) | Not specified | Not specified | No data available; assume similar level; verify in datasheet for high current needs. |
| Driven configuration | Full-Bridge | Floating | Full-bridge driver suits half-bridge and full-bridge topologies; floating drivers enable high-side MOSFET drive in multi-phase setups. |
| Gate type | N-Channel MOSFET | N-Channel MOSFET | Both target N-MOSFETs; no difference here. |
| Grade | Automotive | Automotive | Both AEC-Q100 qualified for automotive reliability. |
| Input type | Non-Inverting | Non-Inverting | Same logic input polarity simplifies control. |
| Logic voltage (V_IL, V_IH) | Not specified | 0.8 V (V_IL), 2 V (V_IH) | Known logic thresholds in A89103KETSR-5 aid in interface design; A89505 unspecified. |
| Mounting type | Surface Mount | Surface Mount | Both SMT packages; no difference. |
| Number of drivers | 2 | 3 | A89103KETSR-5 supports three drivers, fitting three-phase motor control directly. |
| Operating temperature range | -40°C to 135°C (TA) | -40°C to 150°C (TA) | A89103KETSR-5 supports 15°C higher max ambient temperature, better for high-temp designs. |
| Package case | 20-TSSOP (4.40 mm width), Exposed Pad | 28-QFN (5x5 mm), Exposed Pad | QFN package of A89103KETSR-5 offers better thermal dissipation and smaller PCB footprint. |
| Qualification | AEC-Q100 | AEC-Q100 | Both meet automotive qualification standards. |
| Rise/Fall time (typical) | Not specified | 1.2 µs (rise), 150 ns (fall) | Known switching times for A89103KETSR-5 allow precise timing design; unknown for A89505. |
| Supplier device package | 20-TSSOP-EP | 28-QFN (5x5) | Package affects PCB layout and thermal management; QFN generally better for heat. |
| Voltage supply | 50 V | 4.5 V to 85 V | A89103KETSR-5 supports wider supply voltage range, suitable for higher voltage systems. |
Design trade-offs
The A89505KLPTR and A89103KETSR-5 target related but distinct use cases within automotive-grade gate drivers. The A89505KLPTR is a full-bridge driver with two independent channels, optimized for simple half- or full-bridge MOSFET drive applications. Its fixed 50 V supply voltage limits its use to systems within that voltage envelope, but simplifies power supply design. The 20-TSSOP package is common and compact but offers less thermal dissipation than the 28-QFN package of the A89103KETSR-5.
The A89103KETSR-5’s three floating drivers allow direct driving of three high-side N-channel MOSFETs in a 3-phase configuration, eliminating the need for additional bootstrap or floating driver circuitry. This integration reduces component count and board complexity, especially for motor control applications. The wider supply voltage range (4.5 V to 85 V) also supports a broader range of system voltages, including 48 V automotive and industrial applications.
Thermally, the A89103KETSR-5’s 28-QFN package with exposed pad offers superior heat sinking capability, supporting higher ambient temperature operation (up to 150°C) and potentially higher continuous current loads. The A89505KLPTR’s TSSOP package is more limited in thermal performance due to smaller exposed pad area and package size, restricting its use in high-power or high-temperature scenarios.
From a layout perspective, the floating configuration of the A89103KETSR-5 demands careful attention to high-side node switching and PCB isolation. This can complicate layout but reduces external component count. The full-bridge driver A89505KLPTR simplifies layout by driving low-side and high-side MOSFETs referenced to ground or a stable rail.
The lack of detailed rise/fall time and logic voltage information for the A89505KLPTR makes timing and interface design less predictable compared to the A89103KETSR-5, which specifies typical switching times and logic thresholds. This can impact gate drive efficiency and EMI performance.
Cost-wise, the A89103KETSR-5’s larger package and higher integration imply a higher unit price, but savings may be realized in BOM and assembly for multi-phase systems. The A89505KLPTR is likely more cost-effective for simpler two-channel full-bridge designs.
Use-case fit
Choose A89505KLPTR when…
- Designing a 2-channel full-bridge driver for automotive DC-DC converters or motor drive circuits where the system voltage is at or below 50 V.
- You require a compact TSSOP package for tight PCB space constraints but do not need the thermal headroom of a QFN.
- The application involves independent control of two MOSFET channels without floating high-side requirements.
- Cost sensitivity favors a simpler dual-driver IC without the complexity of three-phase floating drivers.
- The ambient temperature will not exceed 135°C, and thermal dissipation requirements are moderate.
Choose A89103KETSR-5 when…
- Implementing a 3-phase motor controller or inverter that requires integrated floating high-side drivers for N-channel MOSFETs.
- Targeting systems with supply voltages above 50 V, up to 85 V, such as 48 V automotive or industrial power systems.
- High ambient temperature operation up to 150°C is needed, or enhanced thermal dissipation is critical.
- PCB layout benefits from reduced external bootstrap components and integrated floating driver channels.
- Precise control over switching times and known logic thresholds simplify firmware timing and signal conditioning.
Drop-in compatibility
No explicit pin or footprint compatibility exists between the A89505KLPTR (20-TSSOP-EP) and the A89103KETSR-5 (28-QFN 5x5). The differences in package type, pin count, and driver configuration (2-channel full-bridge vs 3-phase floating drivers) mean these devices are not drop-in replacements for each other. Substituting one for the other requires redesign of PCB layout, gate drive topology, and likely firmware adjustments. No known pin-to-pin equivalence is documented.
Alternatives to consider
- Texas Instruments UCC37322 – A dual high-speed MOSFET driver with well-documented drive current capability, suitable for full-bridge applications.
- Infineon IRS2005 – Half-bridge driver IC with integrated high- and low-side drivers, a candidate for 2-channel motor or power conversion designs.
- Microchip MCP1407 – Dual MOSFET driver with robust drive current and logic level inputs, useful for gate drive applications requiring fast switching.