UDN2987LW - 8-Channel Source Driver, 350mA, 35V | Allegro
MPN: UDN2987LW ✓ فعالUDN2987LW نمای کلی
As a power switch/driver IC, the UDN2987LW functions as a high-side driver that interfaces standard low-level logic (5 V TTL, Schottky TTL, DTL, PMOS, CMOS) with inductive loads such as relays, solenoids, motors, LEDs, and incandescent lamps. Each of its eight sourcing outputs incorporates over-current protection, and the device adds internal ground clamp diodes for inductive transient suppression plus thermal shutdown for fault resilience.
Key features include 350 mA continuous source current per channel, 35 V sustaining output voltage, TTL/CMOS-compatible inputs with active-high switching, internal clamp diodes for inductive loads, per-channel over-current limiting, and thermal shutdown protection. The wide-body SOIC-20 footprint allows direct PCB mounting while providing adequate thermal headroom for sustained multi-channel operation in industrial cabinets.
Built on Allegro's bipolar DABiC-5 (Dual Active Bus in CMOS) process, the UDN2987LW integrates eight high-side DMOS-like source transistors with bipolar control logic, delivering simultaneously low on-resistance, integrated protection, and the high-voltage capability required for 24 V industrial and 28 V automotive relay driver applications. Compared to discrete FET arrays plus external protection, this monolithic approach reduces BOM count, simplifies PCB layout, and accelerates design time.
Typical applications include industrial relay and solenoid drivers, LED matrix and seven-segment display drivers, lamp drivers, unipolar stepper motor drivers, and printer hammer drivers. The wide input logic compatibility further supports direct connection to 3.3 V microcontrollers when paired with a TTL-threshold interface.
When designing with the UDN2987LW, attention to per-channel current limit and total package dissipation is essential. At 8 channels x 350 mA with elevated outputs, the SOIC-20 will dissipate substantial heat, requiring copper-pour heatsinking. Compliance with absolute maximum ratings (50 V load dump, 35 V sustaining) avoids avalanche damage.
جایگزین‌های drop-in برای UDN2987LW — همان پکیج، سازگار پین‌به‌پین. قطعات با پکیج متفاوت که نیاز به تغییر PCB دارند مستثنی هستند.
گونه‌ها در این سری
مدل‌های هم‌سری که جایگزین مستقیم هستند برای UDN2987LW (همان فرم‌فاکتور و فوت‌پرینت) — متفاوت در Package, Topology.
UDN2987LW-6-T
✅ جایگزین مستقیم📋 جایگزین مرجع (خارج از کاتالوگ)
UDN2987LWTR-6-T
✅ جایگزین مستقیمبرای قیمت تماس بگیرید
مشاهده دیتاشیت ←UDN2987LW حداکثر مقادیر مجاز و مشخصات الکتریکی
| Device Type | 8-Channel Source Driver |
| توپولوژی | High-side source driver |
| تعداد خروجی‌ها | 8 |
| Output Current per Channel | 350 mA (continuous) |
| Sustaining Output Voltage | 35 V |
| Logic Input Compatibility | TTL, Schottky TTL, DTL, PMOS, CMOS |
| Input Logic Level | Active high (output ON when input high) |
| Over-Current Protection | Yes, per channel |
| Internal Clamp Diodes | Yes, for inductive loads |
| خاموشی حرارتی | Yes |
| Turn-Off Delay (TPHL) | 200 ns typical (UDN2987LW-6 variant) |
| Supply Voltage Minimum (UDN2987LW-6) | 4.75 V |
| بسته‌بندی | 20-lead wide-body SOIC (SOICW-20) |
| نوع نصب | Surface Mount |
| Process Technology | Bipolar DABiC-5 |
| وضعیت RoHS | Compliant |
پیکربندی پین UDN2987LW
| پین 1 | Input 1 — Logic input channel 1 (TTL/CMOS) |
| پین 2 | Input 2 — Logic input channel 2 |
| پین 3 | Input 3 — Logic input channel 3 |
| پین 4 | Input 4 — Logic input channel 4 |
| پین 5 | Input 5 — Logic input channel 5 |
| پین 6 | Input 6 — Logic input channel 6 |
| پین 7 | Input 7 — Logic input channel 7 |
| پین 8 | Input 8 — Logic input channel 8 |
| پین 9 | GND — Logic ground |
| پین 10 | GND — Logic ground |
| پین 11 | VCC — Logic supply (5 V) |
| پین 12 | VBB — Load supply voltage |
| پین 13 | Output 8 — Sourcing output channel 8 |
| پین 14 | Output 7 — Sourcing output channel 7 |
| پین 15 | Output 6 — Sourcing output channel 6 |
| پین 16 | Output 5 — Sourcing output channel 5 |
| پین 17 | Output 4 — Sourcing output channel 4 |
| پین 18 | Output 3 — Sourcing output channel 3 |
| پین 19 | Output 2 — Sourcing output channel 2 |
| پین 20 | Output 1 — Sourcing output channel 1 |
کاربردهای معمول
UDN2987LW مناسب است برای 6 کاربردs: Industrial Relay and Solenoid Drivers, LED Matrix and Display Drivers, Unipolar Stepper Motor Drivers, Printer Hammer and Solenoid Drivers, Automotive Relay and Lamp Drivers, PLC and Industrial Automation Logic Outputs.
Industrial Relay and Solenoid Drivers
The UDN2987LW drives 24 V industrial relay coils and solenoid valves at up to 350 mA per channel across eight outputs. Internal clamp diodes suppress inductive back-EMF during turn-off, eliminating external flyback components. Per-channel over-current protection guards against shorted coils, and thermal shutdown protects the IC during sustained faults on multiple channels simultaneously.
پیشنهادی
LED Matrix and Display Drivers
Eight sourcing outputs of 350 mA each make the UDN2987LW well-suited for common-anode LED matrix rows, seven-segment displays, and bar-graph indicators. TTL-compatible inputs interface directly with microcontroller GPIO. Active-high switching allows simple bit-banged multiplexing at refresh rates up to a few kHz, while internal current limiting prevents LED burnout from wiring faults.
پیشنهادی
Unipolar Stepper Motor Drivers
For low-current unipolar stepper motors drawing under 350 mA per winding, the UDN2987LW acts as an 8-channel source array, replacing discrete transistor arrays with one integrated part. Each phase winding is driven directly from one output; combined with a complementary sink driver such as UDN2894L, full stepper control is achieved with minimal PCB area.
پیشنهادی
Printer Hammer and Solenoid Drivers
Dot-matrix printers and industrial hammer actuators need fast, repeatable current pulses with back-EMF protection - exactly what the UDN2987LW supplies. Eight channels of 350 mA source drive multiple solenoids in parallel; the device's ~200 ns TPHL on the -6 variant enables sharp, repeatable hammer strikes without coil saturation. Internal clamping protects against solenoid inductive kickback.
پیشنهادی
Automotive Relay and Lamp Drivers
The 35 V sustaining voltage rating comfortably covers 12 V and 24 V automotive and truck electrical systems, including the 50 V load-dump transient when paired with external TVS protection. The UDN2987LW drives relay coils, indicator lamps, and small motors at up to 350 mA per channel, with TTL/CMOS logic inputs that interface cleanly to body-control modules and BCM ASICs.
پیشنهادی
PLC and Industrial Automation Logic Outputs
Programmable logic controllers (PLCs) require 24 V digital outputs to drive field devices. The UDN2987LW translates 5 V CMOS logic from the PLC's microcontroller into 24 V sourcing outputs at 350 mA per channel. Built-in over-current and thermal protection allow operation in cabinets with limited airflow, while internal clamp diodes simplify the BOM by removing external flyback components.
پیشنهادی
خلاصه محصولات پیشنهادی
داده‌های مرجع مهندسی برای UDN2987LW — مقایسه، راهنمای طراحی و اطلاعات انطباق.
راهنمای انتخاب
مقایسه با جایگزین‌ها
| پارامتر | این محصول | UDN2987LW-6-T | UDN2987LWTR-6-T | UDN2987A |
|---|---|---|---|---|
| Package | SOICW-20 | SOICW-20 - same | SOICW-20 - same | DIP-20 - different package |
| Brand | Allegro MicroSystems | Allegro MicroSystems - same | Allegro MicroSystems - same | Allegro MicroSystems - same |
| Output Current per Channel | 350 mA | 350 mA | 350 mA | 350 mA |
| Sustaining Output Voltage | 35 V | 35 V | 35 V | 35 V |
| TPHL (Turn-Off Delay) | Longer (legacy) | 200 ns typical (improved) | 200 ns typical (improved) | Longer (legacy) |
| Over-Current Protection | Yes, per channel | Yes, per channel | Yes, per channel | Yes, per channel |
| Thermal Shutdown | Yes | Yes | Yes | Yes |
| Lifecycle Status | Not for New Design | Active | Active | Active |
تفاوت‌های کلیدی
- Integrated per-channel over-current protection (در مقابلDiscrete transistor arrays (e.g., discrete 2N4401 + fuse))
- Faster TPHL on the -6 variant (در مقابلOriginal UDN2987LW)
- Surface-mount SOICW-20 package (در مقابلUDN2987A in DIP-20 through-hole)
یادداشت‌های طراحی
Estimated: at 8 channels x 350 mA with 24 V load supply and 5 V logic, total dissipation can reach 5-6 W in worst-case full-load scenarios. The SOICW-20 package requires substantial copper-pour heatsinking; a 1 sq-in copper area on a multi-layer PCB is recommended to keep theta_JA within safe limits and avoid triggering thermal shutdown prematurely.
Place VBB bypass capacitors (10 uF to 100 uF electrolytic in parallel with 0.1 uF ceramic) as close to the device pins as possible to suppress load-induced transients. Keep logic input traces short and away from the output traces to prevent cross-talk. Connect the exposed pad (if present on the SOICW variant) to a wide ground pour for optimal thermal performance.
Do not exceed 35 V sustaining voltage on the outputs; for automotive load-dump environments (up to 50 V transient), add an external TVS diode from VBB to ground. Avoid paralleling outputs to exceed the per-channel 350 mA rating - the over-current protection is per channel and does not sum across paralleled channels. The original UDN2987LW (non-6 suffix) is marked 'Not for New Design'; new layouts should use the -6 variant for longevity.
اطلاعات انطباق
RoHS compliant per Allegro product page. Not AEC-Q100 qualified - automotive designs should verify compliance via PPAP documentation with Allegro.
