📌 Product Overview
The DRV8873 (Texas Instruments) is an integrated H-bridge driver for brushed DC motors, stepper windings, and solenoids, operating from a single 4.5–38V supply and delivering up to 10A peak. It integrates four N-channel MOSFETs with 150mΩ (HS+LS) total RDS(ON) at 25°C.
Engineers evaluating this part should focus on three variables: control interface choice (PH/EN, PWM IN1/IN2, independent half-bridge, or SPI variant DRV8873S), thermal design around the PowerPAD, and the current-mirror-based IPROPI sensing architecture, which eliminates external sense resistors.
🎯 Typical Applications & Design Context
- Factory automation & robotics — wide VM range tolerates 12V/24V bus fluctuation
- ATMs, ePOS, currency counters — built-in OCP and open-load detection support self-diagnostics
- Multi-function and laser printers — dual IPROPI outputs and SPI fault registers ease integration
- Motorized blinds, adjustable desks/beds — 10µA sleep mode suits battery/standby designs
Its suitability comes from integrated protection (UVLO, CPUV, OCP, TSD), configurable control modes, and 1.8V/3.3V/5V logic compatibility—no level shifting needed.
📊 Key Technical Specifications
| Parameter | Value | Notes |
|---|---|---|
| VM operating range | 4.5 – 38 V | Single supply |
| Peak drive current | 10 A | Thermal-limited; verify derating |
| RDS(ON) HS+LS | 150mΩ @ 25°C / 250mΩ @ 150°C | 13.5V, TJ-based |
| Logic input levels | 1.8 / 3.3 / 5 V | No level shifter required |
| Control modes | PH/EN, PWM (IN1/IN2), independent half-bridge | MODE pin |
| Interface options | Hardware (DRV8873H) or SPI (DRV8873S) | Order code matters |
| Sleep current | ~10 µA | nSLEEP low |
| Current sensing | Internal current mirror (IPROPI1/IPROPI2) | No sense resistor |
| Package | 24-pin HTSSOP PowerPAD, 7.70 × 4.40 mm | Thermal pad critical |
💡 The H/S suffix is a real BOM risk: DRV8873H (hardware) and DRV8873S (SPI) differ in pin function (SDI/SDO/SCLK/nSCS vs. nITRIP/nOL). They are not drop-in interchangeable at the firmware level.
⚠️ Absolute Maximum Ratings & Process Limits
| Limit | Boundary | Practical Consequence |
|---|---|---|
| VM absolute max | 38V operating (surge beyond must be reviewed) | Motor back-EMF + supply ripple can exceed 38V during braking; clamp or bulk-cap sizing required (datasheet §9.1) |
| Peak current | 10 A | Sustained current is far lower; rely on OCP thresholds, not peak rating |
| RDS(ON) hot value | 250mΩ @ 150°C | Conduction loss nearly doubles at temperature—thermal budget must use hot RDS(ON), not 25°C |
| Junction temp | TSD shuts down at overtemperature | PowerPAD solder voids cause premature TSD trips in production |
| Charge pump | CPUV fault monitoring | CPH/CPL 47nF X7R capacitor errors cause false faults |
⚠️ Field failure reality: The most common mass-production failure mode is thermal—teams size the PCB copper per the 25°C RDS(ON) figure and hit thermal shutdown (TSD) cycling at 150°C hot values. Second most common: PowerPAD void rate in reflow X-ray inspection exceeding internal spec, degrading junction-to-board heat path.
🧩 Package, Dimensions & Assembly Notes
- Package: 24-pin HTSSOP with PowerPAD, 7.70mm × 4.40mm body
- Thermal pad: Must be soldered to a copper pour with thermal vias; this is the primary heat path, not an option
- External passives: 47nF X7R between CPH/CPL; 1µF/6.3V ceramic on DVDD; bulk capacitance sizing per datasheet §9.1
- Config straps: nITRIP, nOL, and MODE are strap-defined (GND vs. DVDD)—confirm netlists, since mis-strapping silently disables ITRIP or open-load diagnostics
- MSL/reflow: Standard HTSSOP handling; verify soak profile for the exposed pad
🔍 Procurement & Sourcing Insights
- 🔒 Suffix verification: Confirm H vs. S variant on every PO line; mixing them passes electrical continuity checks but fails at firmware bring-up
- 📈 Lifecycle: TI industrial-grade part, generally stable supply—but verify date codes and MSL labeling on reel packaging to avoid reflow defects from aged stock
- ⚡ Channel risk: Huaqiangbei-reclaimed or remarkeds units often show correct marking but failed OCP accuracy; incoming inspection should include IPROPI ratio check
- 🚀 Alternatives: Pin-to-pin substitutes rarely exist across brands due to SPI register and IPROPI scaling differences—budget re-validation time, not just footprint matching
LDeepAI supports sample requests, MOQ-optimized lot sourcing, and datasheet-matched traceability checks for the DRV8873 family.
❓ FAQ
Q: Are DRV8873H and DRV8873S interchangeable?
A: Same package and footprint, but the S variant repurposes four pins for SPI (SDI/SDO/SCLK/nSCS). Hardware designs cannot enable SPI features, and firmware written for the S variant will not run on H boards.
Q: Can I rely on the 10A peak rating for continuous current?
A: No. Continuous capability is thermally limited. At 150°C junction, RDS(ON) rises to 250mΩ, roughly doubling conduction loss. Size continuous current from your thermal resistance and ambient conditions.
Q: Do I need a shunt resistor for current sensing?
A: No. The DRV8873 uses internal current mirrors (IPROPI1/IPROPI2) proportional to high-side FET current. You only need a scaling resistor on IPROPI to set the voltage range for your ADC.
Q: What causes nFAULT to assert at power-up?
A: Common causes: charge pump undervoltage (check the 47nF CPH/CPL cap), open-load diagnostic triggered by nOL strapping, or VM below UVLO threshold during supply ramp.
Q: Is the PowerPAD mandatory to solder?
A: Effectively yes for anything above light loads. Voided or unsoldered pads cause TSD cycling and long-term reliability failures, even if the unit passes functional test at room temperature.
