STMicroelectronics ST890DTR

Overview

ST890DTR from STMicroelectronics is a 1.2 A programmable current-limited high-side P-channel MOSFET power switch in DFN8L 3×3 package, operating from 2.7 V to 5.5 V with 90 mΩ typical R_ON, active-low FAULT indicator, and thermal shutdown at 130 °C. It enables robust load switching in portable equipment and PCMCIA slots.

For engineers reviewing the ST890DTR datasheet, ST890DTR pinout, ST890DTR application, or ST890DTR equivalent, key selection criteria include programmable current limit (up to 1.2 A), low quiescent current (13 µA ON, 1 µA OFF), SO8/DFN8L package compatibility, thermal protection behavior, and open-drain FAULT signaling for system fault monitoring.

Technical Context

The ST890DTR implements a high-side switching architecture using an integrated P-channel MOSFET with external current-limit programming via a resistor from SET to GND. Its current-limit loop responds within 5 µs (slow mode) and features undervoltage lockout (2.4–2.6 V threshold, 100 mV hysteresis).

Thermal protection activates at 130 °C junction temperature with 15 °C hysteresis, and the FAULT pin asserts low during overcurrent, short-circuit (I_SC ≈ 1.2 × I_LIM), or thermal overload. The device supports both 3 V and 5 V logic-compatible ON control with <0.8 V low-level and >2.4 V high-level thresholds.

Key Specifications

Pinout & Package

The ST890DTR is housed in a thermally enhanced DFN8L 3×3 mm package with exposed pad (unconnected internally but recommended for PCB ground connection to improve thermal performance). Pin numbering follows standard top-view layout.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-side current-limited power switch applications.

Compared with TPS2051BDR and NIS5132MN, the ST890DTR uniquely combines programmable current limiting, DFN8L thermal efficiency (R_thj-amb = 37.6 °C/W), and open-drain FAULT reporting-making it optimal for space-constrained, battery-operated systems requiring configurable protection.

Availability

ST890DTR is available at Aetrix Electronics and suitable for PCMCIA slot power control, portable equipment load switching, and USB peripheral power management requiring stable component supply across industrial and consumer production cycles.

Supply support for ST890DTR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.

The ST890 belongs to ST's high-side power switch product line, engineered specifically for reliable, low-power load switching in portable and interface applications where programmable current limiting and thermal safety are critical.

FAQ

What is the minimum recommended R_SET value for ST890DTR?

The minimum R_SET is determined by the maximum allowable I_LIM of 1.2 A and the SET bias current of ~1.24 V / 1110 ≈ 1.117 mA. Using R_SET = 1.24 V / (I_LIM / 1110), the minimum resistor is ~1.11 kΩ for 1.2 A. Lower values risk exceeding absolute max current rating and invalidating thermal protection margins.

Can ST890DTR drive capacitive loads up to 1000 µF?

Yes - the ST890DTR's current-limiting architecture inherently controls inrush into large capacitive loads. With I_LIM set to ≥1.2 A and proper input/output bypassing (1 µF at IN, 0.1 µF at OUT), it safely charges 1000 µF loads in ~1 ms while staying within SOA limits and avoiding FAULT assertion.

Is the exposed pad on the DFN8L 3x3 package electrically connected?

No - the exposed pad is not internally connected to any die node. Per ST's datasheet (Section 2, Note 1), it is intended solely for thermal conduction to the PCB ground plane. Connecting it to GND improves thermal resistance by ~30% but does not affect electrical functionality or pinout.

Does ST890DTR support reverse-voltage protection?

No - the ST890DTR lacks intrinsic reverse-polarity protection. As a P-channel high-side switch, it conducts only when V_IN > V_OUT and ON is asserted. Reverse voltage applied to OUT (e.g., backfeed) will forward-bias the body diode, potentially causing uncontrolled current flow unless external blocking diodes or MOSFETs are added.