STMicroelectronics L4987CPT120

Overview

L4987CPT120 from STMicroelectronics is a very low-dropout linear voltage regulator in PPAK package, delivering 5.0 V at up to 200 mA output current with 0.3 V typical dropout (at 200 mA), 70 dB supply voltage rejection at 120 Hz, and logic-controlled shutdown. It features an open-collector dropout flag output and internal thermal/current limiting - used in automotive infotainment power rails and battery-powered portable electronics for regulated local supply.

For engineers reviewing the L4987CPT120 datasheet, L4987CPT120 pinout, L4987CPT120 application, or L4987CPT120 equivalent, key selection criteria include dropout voltage under load, quiescent current in ON/OFF modes, flag output behavior during undervoltage, stability with 2.2 µF ceramic output capacitor, and PPAK thermal performance in constrained PCB layouts.

Technical Context

The L4987CPT120 employs a PNP pass transistor architecture enabling ultra-low dropout (0.3 V typ. at 200 mA) and sub-1 mA quiescent current in active mode. Its control flag is an open-collector NPN output that sinks current when VO drops out of regulation due to input undervoltage, current limit, or thermal shutdown.

Shutdown is TTL-compatible (VIL ≤ 0.8 V, VIH ≥ 2 V), with 10 µA input leakage. The regulator maintains ±2% output voltage accuracy over temperature (–40°C to +125°C) and operates from 5.7 V to 18 V input, supporting automotive load-dump immunity up to 40 V.

Key Specifications

Pinout & Package

Supplied in ST's PPAK (Power Package) - thermally enhanced surface-mount package with exposed drain pad for low-junction-to-case resistance (8 °C/W). Dimensions: 6.0 × 6.6 × 1.1 mm (D × E × A2), 6-pin configuration.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout regulator applications.

Compared with TLV70033DSER and TPS7A2050PDBVR, the L4987CPT120 uniquely combines automotive-grade input robustness (40 V), integrated dropout flag, and PPAK thermal performance - making it irreplaceable in cost-sensitive, safety-aware automotive subsystems requiring hardware-level undervoltage signaling.

Availability

L4987CPT120 is available at Aetrix Electronics and suitable for automotive infotainment systems, portable medical diagnostics, and industrial wireless sensor nodes requiring stable component supply across extended product lifecycles and temperature ranges.

Supply support for L4987CPT120 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 microcontrollers, power management ICs, and automotive-grade analog devices since 1987.

The L4987 series belongs to ST's automotive-qualified linear regulator product line, engineered specifically for robust, low-noise local power in harsh environments - including engine control, body electronics, and infotainment subsystems.

FAQ

What is the maximum input voltage the L4987CPT120 can withstand without damage?

The L4987CPT120 has an absolute maximum DC input voltage rating of 40 V, verified per STMicroelectronics' datasheet Table 2. This enables direct connection to 12 V automotive batteries while surviving ISO 7637-2 load-dump transients without external protection components. Operation above 18 V is not recommended for sustained regulation.

How does the FLAG pin behave during thermal shutdown?

The FLAG pin goes low during thermal shutdown, identical to its behavior during input undervoltage or current limiting - as confirmed in Section 6.1 of the datasheet. It is an open-collector output that actively sinks current when the pass transistor saturates or the internal thermal limiter activates, providing unified fault signaling.

Can the L4987CPT120 be used with a 2.2 µF X7R ceramic capacitor for stability?

Yes - the datasheet explicitly specifies "Only 2.2 µF for stability" with ESR between 0.5 Ω and 10 Ω (Section 1, Features). X7R ceramics meeting this ESR range (e.g., 2.2 µF, 10 V, 0805) are fully qualified and eliminate need for bulk electrolytic capacitors in space-constrained designs.

Is the L4987CPT120 pin-compatible with other ST PPAK LDOs like the L4981?

No - the L4987CPT120 uses a unique 6-pin PPAK footprint with dedicated FLAG and NC pins; the L4981 is a different topology (switching controller) in DIP or SO packages. Pin mapping, function, and package dimensions are not interchangeable - PCB layout must be designed specifically for L4987CPT120's pinout shown in Figure 2.