UDN2987LW6T - 8-CH Source Driver 350mA SOIC-20 | Allegro
MPN: UDN2987LW6T ✓ Hoạt độngUDN2987LW6T Tóm tắt
An 8-channel source driver is a smart power IC that sits between a microcontroller's logic-level outputs and high-current loads, sourcing current from a positive supply to each load when activated. It is a member of the bipolar high-side switch family within Allegro's broader power management IC portfolio, designed to replace discrete Darlington transistors with built-in protection. The architecture uses eight open-collector Darlington-style outputs with individual overcurrent sensing on every channel.
Key features include 350 mA continuous output current per channel, integrated overcurrent protection with auto-recovery, a 50 V load-dump tolerant output rating, and built-in thermal shutdown. The SOIC-20 package (wide-body, 300-mil) supports surface-mount assembly with adequate thermal performance for the full operating range. Typical quiescent and leakage paths are designed to minimize power dissipation when channels are inactive.
The UDN2987LW6T is built on Allegro's DABIC-5 bipolar process, integrating eight high-side Darlington switches with sense resistors and comparators that throttle each output during a fault. The fault logic latches off the affected channel until the fault clears, preventing destructive thermal runaway. This per-channel protection is an advantage over discrete designs where one transistor failure can damage the whole system.
Typical applications include industrial relay driver boards, automotive dashboard indicator multiplexers, LED matrix displays, and printer hammer or solenoid drivers. The wide output voltage tolerance supports 12 V and 24 V automotive and industrial bus systems directly. Designers appreciate the eight-channel integration when PCB real estate is constrained.
When designing with this part, ensure the supply decoupling capacitor is placed adjacent to the device with low-impedance traces to suppress voltage transients during turn-off of inductive loads. Always use flyback diodes across inductive loads or rely on the internal clamp protection to prevent output overvoltage.
This page synthesizes distributor pricing, drop-in alternatives in the SOIC-20 footprint, and practical design notes not found in the manufacturer datasheet, giving engineers a complete sourcing and integration reference.
Bộ thay thế dễ dàng lắp đặt cho UDN2987LW6T — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với UDN2987LW6T (cùng hình factor và footprint) — khác nhau ở Function, Package, Part Number.
UDN2987LW-6-T
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
UDN2987LWTR-6-T
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →UDN2981LW-6-T
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
UDN2987LW6T Tỷ lệ tối đa & tính chất điện
| Manufacturer | Allegro MicroSystems |
| Part Number | UDN2987LW6T |
| Chức năng | 8-Channel Source Driver |
| Số lượng đầu ra | 8 |
| Configuration | High-Side (Source) |
| Output Current per Channel | 350 mA |
| Kiểu đầu ra | Open-Collector (Darlington Source) |
| Load Voltage (Maximum) | 50 V |
| Input Logic Compatibility | TTL / CMOS |
| Bảo vệ quá dòng | Yes (per-channel) |
| Tắt nhiệt | Yes |
| Process Technology | DABIC-5 Bipolar |
| Hộp | SOIC-20 (Wide-body, 300-mil) |
| Kiểu lắp đặt | Surface Mount |
| Trạng thái RoHS | Compliant |
Cấu hình chân UDN2987LW6T
| Chân 1 | OUT1 — Source output channel 1 |
| Chân 2 | OUT2 — Source output channel 2 |
| Chân 3 | OUT3 — Source output channel 3 |
| Chân 4 | OUT4 — Source output channel 4 |
| Chân 5 | OUT5 — Source output channel 5 |
| Chân 6 | OUT6 — Source output channel 6 |
| Chân 7 | OUT7 — Source output channel 7 |
| Chân 8 | OUT8 — Source output channel 8 |
| Chân 9 | GND — Logic and substrate ground |
| Chân 10 | NC — Not connected |
| Chân 11 | IN1 — Logic input channel 1 |
| Chân 12 | IN2 — Logic input channel 2 |
| Chân 13 | IN3 — Logic input channel 3 |
| Chân 14 | IN4 — Logic input channel 4 |
| Chân 15 | IN5 — Logic input channel 5 |
| Chân 16 | IN6 — Logic input channel 6 |
| Chân 17 | IN7 — Logic input channel 7 |
| Chân 18 | IN8 — Logic input channel 8 |
| Chân 19 | VCC — Logic supply voltage |
| Chân 20 | VS — Load supply voltage (up to 50 V) |
Ứng dụng tiêu biểu
UDN2987LW6T phù hợp cho 6 Áp dụngs: Industrial Relay Driver Board, Automotive Dashboard Indicator Multiplexer, LED Matrix Display Driver, Printer Hammer and Solenoid Driver, Incandescent Lamp Display Driver, Stepper Motor Unipolar Winding Drive.
Industrial Relay Driver Board
The UDN2987LW6T's 350 mA per channel and 50 V load rating make it a direct fit for industrial relay driver boards controlling 24 V coil relays. Each of the eight outputs can independently source current to a relay coil from a 24 V industrial bus, replacing eight discrete Darlington transistors and their base resistors with a single SOIC-20 IC. The integrated overcurrent protection prevents board damage when relay contacts stick or wiring faults occur, while thermal shutdown protects against sustained faults. Designers benefit from the wide-body SOIC package, which provides adequate thermal dissipation at full eight-channel loading.
Được đề xuất
Automotive Dashboard Indicator Multiplexer
Automotive dashboards with many warning lamps and indicator LEDs benefit from the UDN2987LW6T's high-side drive topology and 50 V load-dump tolerance. Eight outputs can directly drive automotive panel lamps at 12 V or 24 V bus levels, sourcing up to 350 mA per lamp without additional transistors. The bipolar DABIC-5 process tolerates the harsh automotive electrical environment including load-dump transients. Per-channel overcurrent protection prevents fire hazards if a lamp shorts, and the wide SOIC-20 package handles the thermal load of multiple simultaneous indicator activations. This matches automotive-grade requirements for warning-light systems.
Được đề xuất
LED Matrix Display Driver
For LED matrix displays using common-anode rows or columns, the UDN2987LW6T's source-driver topology is well matched. Each of the eight outputs can source up to 350 mA to a column, allowing high-brightness LED arrays to be driven directly. TTL/CMOS logic inputs accept standard microcontroller signals with no level shifting required. The integrated overcurrent protection prevents LED chain damage from shorts, while the 50 V tolerance supports longer LED strings. Compared to discrete MOSFET designs, the UDN2987LW6T saves board area and BOM cost across the eight channels while maintaining fault protection.
Được đề xuất
Printer Hammer and Solenoid Driver
Dot-matrix printer hammer mechanisms and industrial solenoid banks require multi-channel high-side drive with precise timing. The UDN2987LW6T delivers 350 mA per channel with TTL-compatible inputs, allowing direct connection to printer controller ASICs or PLC outputs. The eight channels handle multiple solenoids simultaneously while per-channel overcurrent protection limits energy during solenoid stall conditions. The SOIC-20 package fits compact printer controller boards, and the bipolar DABIC-5 process handles the repetitive switching stress of solenoid drive without wear-out concerns seen in some MOSFET drivers.
Được đề xuất
Incandescent Lamp Display Driver
Vintage-style instrumentation and signage often uses incandescent lamps requiring steady DC drive at moderate currents. The UDN2987LW6T drives up to eight incandescent lamps at 12 V or 24 V with 350 mA per channel, well above typical lamp ratings. Cold-filament inrush current is handled by the per-channel overcurrent protection, which limits fault current without nuisance tripping on normal warm-up surges. The bipolar architecture is naturally rugged against the inductive kick seen when lamps are switched, and the wide SOIC-20 thermal pad supports sustained eight-channel operation.
Được đề xuất
Stepper Motor Unipolar Winding Drive
Unipolar stepper motors with center-tapped windings can be driven by the UDN2987LW6T in a half-phase configuration, sourcing current to one winding at a time. The eight outputs allow two stepper motors to be driven simultaneously, with 350 mA per winding suitable for small NEMA 14 or NEMA 17 motors. TTL logic inputs accept standard step-direction pulses from a microcontroller. The integrated fault protection limits winding-short current, and the SOIC-20 wide-body package provides sufficient thermal margin for sustained motor operation. This topology is ideal for low-cost motion-control boards.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho UDN2987LW6T — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | UDN2987LW-6-T | UDN2987LWTR-6-T | UDN2981LW-6-T |
|---|---|---|---|---|
| Package | SOIC-20 (wide-body) | SOIC-20 - same | SOIC-20 - same | SOIC-20 - same |
| Brand | Allegro MicroSystems | Allegro MicroSystems | Allegro MicroSystems | Allegro MicroSystems |
| Number of Channels | 8 | 8 | 8 | 8 |
| Topology | High-Side Source | High-Side Source | High-Side Source | High-Side Source |
| Logic Compatibility | TTL/CMOS | TTL/CMOS | TTL/CMOS | TTL/CMOS |
| Packaging Suffix | -6T (reel) | -6-T (reel) | TR-6-T (reel with leader) | -6-T (reel) |
Bảo phân biệt quan trọng
- Integrated per-channel overcurrent protection (vsDiscrete Darlington array)
- Eight channels in a single SOIC-20 package (vsUDQ2981 (lower current source driver))
- 50 V load tolerance for automotive and industrial buses (vsLower-voltage Darlington drivers (e.g., ULN2803))
Ghi chú thiết kế
Place a low-ESR decoupling capacitor of at least 0.1 uF directly between the VS (pin 20) and GND (pin 9) of the UDN2987LW6T, with traces short and wide. The high-side source driver switches 350 mA per channel, and a poor supply loop creates voltage transients that can exceed the 50 V absolute maximum. Add a bulk electrolytic capacitor (10 uF or larger) on the load supply rail near the IC to absorb turn-off energy from inductive loads.
When driving relays or solenoids from the UDN2987LW6T, always provide a flyback path for inductive kick energy. Although the part has internal clamps, sustained flyback at high current can damage the output stage. Use an external flyback diode across each inductive load, oriented cathode to the output pin. Without flyback protection, the device may enter thermal shutdown during repetitive inductive switching at high currents.
All eight channels of the UDN2987LW6T can source 350 mA continuously, but at full load the SOIC-20 package will dissipate significant power. Estimated: at 24 V supply driving 350 mA on all eight channels, total power dissipation is approximately 67 W (with all loads shorted to GND through a low resistance), making a multi-layer board with thermal vias mandatory. The wide-body SOIC-20 has better thermal performance than narrow-body SOIC; consider adding copper pour on all layers connected to the GND pin.
The UDN2987LW6T accepts TTL/CMOS logic directly on its eight input pins. For long cable runs between the microcontroller and the driver, add 10 kohm pull-up resistors to VCC on each input to prevent floating inputs that could partially turn on the output. In noisy environments such as motor control, place the driver close to the microcontroller with a ground plane to minimize noise coupling into the logic inputs.
Thông tin tuân thủ
RoHS and lead-free compliant per Allegro product page. AEC-Q100 qualification not applicable - this is a bipolar source driver, not an automotive-specific part. Confirm halogen-free status with manufacturer for green-product requirements.
