STMicroelectronics ST890CDR

Overview

ST890CDR from STMicroelectronics is a 1.2 A current-limited, thermally protected high-side P-channel MOSFET power switch in SO8 package, operating from 2.7 V to 5.5 V with 90 mΩ typical R_ON, programmable current limit via external resistor, and active-low open-drain FAULT output. It is used in PCMCIA and access bus slot power control where precise overcurrent and thermal protection are required.

For engineers reviewing the ST890CDR datasheet, ST890CDR pinout, ST890CDR application, or ST890CDR equivalent, key selection criteria include its 1.2 A programmable ILIM, 130 °C thermal shutdown threshold, 25 µA max ICCON quiescent current, and compatibility with 3 V/5 V logic systems in portable and embedded load-switching designs.

Technical Context

The ST890CDR implements a high-side switching architecture using an integrated P-channel MOSFET with internal current-sense and thermal foldback circuitry. Its ON/OFF control is active-low (pin 3), and current limiting is set by an external resistor at the SET pin (pin 5), establishing a precise ILIM between 0.2 A and 1.2 A.

FAULT assertion occurs under three conditions: reaching programmed ILIM, short-circuit detection (V_OUT < 1.6 V), or junction temperature exceeding 130 °C. The FAULT pin is open-drain and requires external pull-up; it remains asserted until fault condition clears and device recovers.

Key Specifications

Pinout & Package

ST890CDR is supplied in SO8 package (ECOPACK® compliant), with exposed pad not internally connected but recommended for PCB ground connection to improve thermal performance. Thermal resistance junction-to-ambient is 160 °C/W under standard PCB 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 AP22653AW5-7, ST890CDR uniquely combines programmable current limiting, thermal shutdown with hysteresis, and a single-resistor configuration - making it optimal for compact, thermally constrained, and variable-load applications requiring deterministic fault coverage.

Availability

ST890CDR is available at Aetrix Electronics and suitable for PCMCIA slot power control, access bus slot switching, and portable diagnostic equipment requiring stable component supply across industrial temperature ranges (0 °C to 70 °C).

Supply support for ST890CDR 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, microcontroller, power, and sensor solutions for automotive, industrial, and consumer markets.

The ST890 belongs to ST's high-side power switch product line, engineered specifically for robust, low-voltage load switching with integrated protection in space-constrained portable and embedded systems.

FAQ

What is the minimum external resistor value for SET pin to achieve 1.2 A current limit?

The ST890CDR uses I_LIM = 1.24 V / R_SET × 1110. To achieve 1.2 A, R_SET = (1.24 V × 1110) / 1.2 A ≈ 1.15 kΩ. Minimum recommended value is 1.1 kΩ to account for tolerance and temperature drift; lower values risk exceeding absolute maximum ratings.

Can the FAULT pin drive an LED directly without a buffer?

No. The FAULT pin is open-drain with VOL ≤ 0.15 V at 1 mA sink, but its absolute maximum sink current is not specified beyond test conditions. Driving an LED risks exceeding safe operating area; a series resistor and optional NPN transistor buffer are required for reliable indication.

Does the ST890CDR support reverse polarity protection on the IN pin?

No. The ST890CDR has no internal reverse-polarity protection. Applying negative voltage to IN (down to −0.5 V absolute maximum) risks latch-up or permanent damage. External Schottky diode or dedicated protection IC is required for reverse-voltage scenarios.

How does thermal shutdown interact with current limiting during sustained overload?

During sustained overload, current limiting activates first (e.g., at 1.2 A), causing power dissipation (I²R_ON). If junction temperature reaches 130 °C, thermal shutdown overrides current limiting and forces the switch OFF. Recovery occurs only after junction cools to ~115 °C, then normal operation resumes if fault is cleared.